Journal articles: 'Elevational cline'

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Jin, Yuanting, and Pinghu Liao. "An elevational trend of body size variation in a cold-climate agamid lizard, Phrynocephalus theobaldi." Current Zoology 61, no. 3 (June 1, 2015): 444–53. http://dx.doi.org/10.1093/czoolo/61.3.444.

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Abstract The pattern that many ectotherms have smaller body sizes in cold environments follows the converse to Bergmann’s rule and is most frequently found in lizards. Allen’s rule predicts animals from warm climates usually have longer tails and limbs, while these traits tend to be shorter in individuals from cold climates. We examined body size variation in an endemic Chinese lizard Phrynocephalus theobaldi along a broad elevational gradient (3,600–5,000 m on the Qinghai-Tibetan Plateau). Female body size showed a U-shaped cline, decreasing with increased elevation within the range 3,600–4,200 m, but increasing at elevations > 4200 m. Male body size continued to increase with increasing elevations. Both sexes showed an increased pattern of extremity length with elevation that does not conform to Allen’s rule. Limb length and tail length increased along the elevational gradients. In terms of color pattern, an abdominal black speckled area appears at elevations >4,200 m. This trait increases in size with increased elevation. Unlike most studies, our results indicated that annual sunshine hours corresponding to the activity period of the lizards could play an important role on the positive body size cline in environments at very high elevations > 4200 m.

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Calfee, Erin, Daniel Gates, Anne Lorant, M. Taylor Perkins, Graham Coop, and Jeffrey Ross-Ibarra. "Selective sorting of ancestral introgression in maize and teosinte along an elevational cline." PLOS Genetics 17, no. 10 (October 11, 2021): e1009810. http://dx.doi.org/10.1371/journal.pgen.1009810.

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While often deleterious, hybridization can also be a key source of genetic variation and pre-adapted haplotypes, enabling rapid evolution and niche expansion. Here we evaluate these opposing selection forces on introgressed ancestry between maize (Zea mays ssp. mays) and its wild teosinte relative, mexicana (Zea mays ssp. mexicana). Introgression from ecologically diverse teosinte may have facilitated maize’s global range expansion, in particular to challenging high elevation regions (> 1500 m). We generated low-coverage genome sequencing data for 348 maize and mexicana individuals to evaluate patterns of introgression in 14 sympatric population pairs, spanning the elevational range of mexicana, a teosinte endemic to the mountains of Mexico. While recent hybrids are commonly observed in sympatric populations and mexicana demonstrates fine-scale local adaptation, we find that the majority of mexicana ancestry tracts introgressed into maize over 1000 generations ago. This mexicana ancestry seems to have maintained much of its diversity and likely came from a common ancestral source, rather than contemporary sympatric populations, resulting in relatively low FST between mexicana ancestry tracts sampled from geographically distant maize populations. Introgressed mexicana ancestry in maize is reduced in lower-recombination rate quintiles of the genome and around domestication genes, consistent with pervasive selection against introgression. However, we also find mexicana ancestry increases across the sampled elevational gradient and that high introgression peaks are most commonly shared among high-elevation maize populations, consistent with introgression from mexicana facilitating adaptation to the highland environment. In the other direction, we find patterns consistent with adaptive and clinal introgression of maize ancestry into sympatric mexicana at many loci across the genome, suggesting that maize also contributes to adaptation in mexicana, especially at the lower end of its elevational range. In sympatric maize, in addition to high introgression regions we find many genomic regions where selection for local adaptation maintains steep gradients in introgressed mexicana ancestry across elevation, including at least two inversions: the well-characterized 14 Mb Inv4m on chromosome 4 and a novel 3 Mb inversion Inv9f surrounding the macrohairless1 locus on chromosome 9. Most outlier loci with high mexicana introgression show no signals of sweeps or local sourcing from sympatric populations and so likely represent ancestral introgression sorted by selection, resulting in correlated but distinct outcomes of introgression in different contemporary maize populations.

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Anderson, Rodolfo O., Lesley A. Alton, Craig R. White, and David G. Chapple. "Ecophysiology of a small ectotherm tracks environmental variation along an elevational cline." Journal of Biogeography 49, no. 2 (January 23, 2022): 405–15. http://dx.doi.org/10.1111/jbi.14311.

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Brandt, Erin E., Kevin T. Roberts, Caroline M. Williams, and Damian O. Elias. "Low temperatures impact species distributions of jumping spiders across a desert elevational cline." Journal of Insect Physiology 122 (April 2020): 104037. http://dx.doi.org/10.1016/j.jinsphys.2020.104037.

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Lu, Xin, Lina Tong, and Xiaoyan Ma. "Variation of body size, age structure and growth of a temperate frog, Rana chensinensis, over an elevational gradient in Northern China." Amphibia-Reptilia 30, no. 1 (2009): 111–17. http://dx.doi.org/10.1163/156853809787392685.

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AbstractIdentifying the patterns of body size, age and growth in relation to environments may help us to understand the evolution of life history of organisms. This study compared the variability in these demographic traits of a temperate frog, Rana chensinensis, among populations from Northern China located at three elevations (567, 1470 and 1700 m) with distinct mean annual temperature (12.1, 5.8 and 3.9°C). Overall, frogs from higher elevations tended to be larger in body size, partially because despite shorter growing seasons, they lived longer as a result of delayed maturity. However, discordance with the expected cline was detected between neighboring populations and the variation was sex specific. Adult females became significantly older and larger as elevation varied from 567 m to 1470 m, but the two traits no longer increased with an elevational shift from 1470 m to 1700 m. Adult males at 1470 m were similar in age and size to animals at 567 m but significantly younger and smaller than those at 1700 m. This suggested that sexes could be exposed to different pressures along elevation gradients with females being stronger than males in life history responses to the elevation-induced environmental change. We also showed that factors other than age also contributed to size differences both among populations and between the sexes.

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Wagg, Cameron, Brian C. Husband, D. Scott Green, Hugues B. Massicotte, and R. Larry Peterson. "Soil microbial communities from an elevational cline differ in their effect on conifer seedling growth." Plant and Soil 340, no. 1-2 (November 3, 2010): 491–504. http://dx.doi.org/10.1007/s11104-010-0621-x.

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Nelson, Annika S., Cole T. Symanski, Matthew J. Hecking, and Kailen A. Mooney. "Elevational cline in herbivore abundance driven by a monotonic increase in trophic‐level sensitivity to aridity." Journal of Animal Ecology 88, no. 9 (June 19, 2019): 1406–16. http://dx.doi.org/10.1111/1365-2656.13034.

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Wang, Guo-Dong, Bao-Lin Zhang, Wei-Wei Zhou, Yong-Xin Li, Jie-Qiong Jin, Yong Shao, He-chuan Yang, et al. "Selection and environmental adaptation along a path to speciation in the Tibetan frog Nanorana parkeri." Proceedings of the National Academy of Sciences 115, no. 22 (May 14, 2018): E5056—E5065. http://dx.doi.org/10.1073/pnas.1716257115.

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Tibetan frogs, Nanorana parkeri, are differentiated genetically but not morphologically along geographical and elevational gradients in a challenging environment, presenting a unique opportunity to investigate processes leading to speciation. Analyses of whole genomes of 63 frogs reveal population structuring and historical demography, characterized by highly restricted gene flow in a narrow geographic zone lying between matrilines West (W) and East (E). A population found only along a single tributary of the Yalu Zangbu River has the mitogenome only of E, whereas nuclear genes of W comprise 89–95% of the nuclear genome. Selection accounts for 579 broadly scattered, highly divergent regions (HDRs) of the genome, which involve 365 genes. These genes fall into 51 gene ontology (GO) functional classes, 14 of which are likely to be important in driving reproductive isolation. GO enrichment analyses of E reveal many overrepresented functional categories associated with adaptation to high elevations, including blood circulation, response to hypoxia, and UV radiation. Four genes, including DNAJC8 in the brain, TNNC1 and ADORA1 in the heart, and LAMB3 in the lung, differ in levels of expression between low- and high-elevation populations. High-altitude adaptation plays an important role in maintaining and driving continuing divergence and reproductive isolation. Use of total genomes enabled recognition of selection and adaptation in and between populations, as well as documentation of evolution along a stepped cline toward speciation.

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Meier, Joana I., Patricio A. Salazar, Marek Kučka, Robert William Davies, Andreea Dréau, Ismael Aldás, Olivia Box Power, et al. "Haplotype tagging reveals parallel formation of hybrid races in two butterfly species." Proceedings of the National Academy of Sciences 118, no. 25 (June 21, 2021): e2015005118. http://dx.doi.org/10.1073/pnas.2015005118.

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Genetic variation segregates as linked sets of variants or haplotypes. Haplotypes and linkage are central to genetics and underpin virtually all genetic and selection analysis. Yet, genomic data often omit haplotype information due to constraints in sequencing technologies. Here, we present “haplotagging,” a simple, low-cost linked-read sequencing technique that allows sequencing of hundreds of individuals while retaining linkage information. We apply haplotagging to construct megabase-size haplotypes for over 600 individual butterflies (Heliconius erato and H. melpomene), which form overlapping hybrid zones across an elevational gradient in Ecuador. Haplotagging identifies loci controlling distinctive high- and lowland wing color patterns. Divergent haplotypes are found at the same major loci in both species, while chromosome rearrangements show no parallelism. Remarkably, in both species, the geographic clines for the major wing-pattern loci are displaced by 18 km, leading to the rise of a novel hybrid morph in the center of the hybrid zone. We propose that shared warning signaling (Müllerian mimicry) may couple the cline shifts seen in both species and facilitate the parallel coemergence of a novel hybrid morph in both comimetic species. Our results show the power of efficient haplotyping methods when combined with large-scale sequencing data from natural populations.

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Baranovská, E., and M. Knapp. "Steep converse Bergmann's cline in a carrion beetle: between- and within-population variation in body size along an elevational gradient." Journal of Zoology 304, no. 4 (December 6, 2017): 243–51. http://dx.doi.org/10.1111/jzo.12527.

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Amari, Hichem, Rabah Zebsa, Amel Lazli, Soufyane Bensouilah, Mohamed Khalil Mellal, Hayat Mahdjoub, Moussa Houhamdi, and Rassim Khelifa. "Differential elevational cline in the phenology and demography of two temporally isolated populations of a damselfly: Not two but one taxon?" Ecological Entomology 44, no. 1 (October 8, 2018): 93–104. http://dx.doi.org/10.1111/een.12680.

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Ishizuka, W., K. Ono, T. Hara, and S. Goto. "Use of intraspecific variation in thermal responses for estimating an elevational cline in the timing of cold hardening in a sub-boreal conifer." Plant Biology 17, no. 1 (July 2, 2014): 177–85. http://dx.doi.org/10.1111/plb.12214.

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Bensouilah, Soufyane, Zinette Bensakhri, Rabah Zebsa, Hichem Amari, Abdeldjalil Youcefi, Abdelheq Zouaimia, Hayet Mahdjoub, et al. "Reproductive phenology of the spider Micrommata ligurina (C.L. Koch, 1845) (Araneae; Sparassidae) across an elevational gradient in Northeast Algeria." Ekológia (Bratislava) 41, no. 3 (September 1, 2022): 254–61. http://dx.doi.org/10.2478/eko-2022-0026.

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Abstract Decreased ambient temperature and shorter reproductive seasons are the two main obstacles that ectotherms face at higher elevations. Studies have shown that some life history traits such as phenological windows of activity, duration, and fitness components vary as elevation increases. However, studies on the elevational gradient at the southern range limit of species are lacking. In this study, we aim at assessing some aspects of the life history of a spider species, the sprassid Micrommata ligurina (C.L. Koch, 1845), across an elevational gradient from 30 to 1030 m in Northeast Algeria. There was strong evidence of an elevational shift in the phenology of reproduction with a delay rate of 2.2 days per 100 m of elevation, and the three quantiles of the phenology (10, 50, and 90%) shifted with the same magnitude across elevation. In all sites from low to high elevation, the species showed a decrease in number of individuals. The mean number of eggs was 200 ± 35 eggs, and the mean number of hatching eggs was 110.9 ± 23.5 eggs. The clutch size at high elevation sites was higher than that of low-elevation sites, but in contrast, the hatching success was higher at lower elevation sites. Overall, the species exhibited clear elevational clines in life history traits and abundance, suggesting a high potential of plasticity. This work constitutes the first study carried out on spider species ecology in the region.

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Chukir, Tariq, Yi Liu, Katherine Hoffman, John P. Bilezikian, and Azeez Farooki. "Calcitriol Elevation Is Associated with a Higher Risk of Refractory Hypercalcemia of Malignancy in Solid Tumors." Journal of Clinical Endocrinology & Metabolism 105, no. 4 (December 16, 2019): e1115-e1123. http://dx.doi.org/10.1210/clinem/dgz278.

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Abstract Background Hypercalcemia of malignancy (HCM) is a common complication of advanced cancer. PTH-independent HCM may be mediated through different mechanisms: (1) humoral HCM, caused by the secretion of PTH-related peptide (PTHrP), (2) local osteolysis resulting from metastatic lesions, and (3) calcitriol-mediated hypercalcemia. Calcitriol-mediated HCM in patients with nonlymphomatous solid tumors is thought to be rare. Methods We performed a retrospective chart review from 2008 to 2017 to characterize further patients at our institution with solid tumors who had HCM with concomitant elevations in calcitriol. Patients with PTH-dependent hypercalcemia and patients with evidence of granulomatous disease were excluded, as were patients with hematologic malignancies. We hypothesized that patients with HCM and elevated calcitriol levels would respond less favorably to treatment with antiresorptive therapy compared with patients with HCM but without calcitriol elevation. We also aimed to assess mortality and determine if PTHrP and phosphorus levels correlate with calcitriol because both factors may alter calcitriol levels. Results Of 101 eligible patients, calcitriol was elevated in 45 (45%). PTHrP was elevated in 76% of patients with elevated calcitriol compared with 52% of patients without calcitriol elevation. The mean PTHrP value did not differ between patients with HCM and elevated calcitriol (36.3 ± 22 pg/mL) and those without calcitriol elevation (37.4 ± 19 pg/mL). Those with elevated calcitriol levels generally did not respond completely to antiresorptive treatment (80% incomplete response rate), whereas most patients without an elevation in calcitriol responded well to antiresorptive treatment (78% response rate: P < .001). There was no significant difference in the percentage of patients with metastatic bone disease among the 2 groups (49% vs. 55%, respectively). There was no difference in mortality between the 2 groups (P = .14). A weak but significant negative correlation was found between phosphorus and calcitriol (Pearson r = -0.261, P = .016). This correlation was only significant in patients without calcitriol elevation (Pearson r = -0.4, P = .0082). Also, a significant negative correlation was found between PTHrP and phosphorus, again only in patients without calcitriol elevation. Discussion In the setting of HCM, patients with calcitriol elevation are much less likely to respond to antiresorptive therapy than patients without calcitriol elevation. Because calcitriol elevation did not appear to be correlated with hypophosphatemia or elevated PTHrP, it would appear that calcitriol production under these conditions is autonomous, and not subject to normal physiological controls. These observations indicate that calcitriol elevations in patients with HCM have clinical significance.

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Lim, Marisa C. W., Ke Bi, Christopher C. Witt, Catherine H. Graham, and Liliana M. Dávalos. "Pervasive Genomic Signatures of Local Adaptation to Altitude Across Highland Specialist Andean Hummingbird Populations." Journal of Heredity 112, no. 3 (February 25, 2021): 229–40. http://dx.doi.org/10.1093/jhered/esab008.

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Abstract Populations along steep environmental gradients are subject to differentiating selection that can result in local adaptation, despite countervailing gene flow, and genetic drift. In montane systems, where species are often restricted to narrow ranges of elevation, it is unclear whether the selection is strong enough to influence functional differentiation of subpopulations differing by a few hundred meters in elevation. We used targeted capture of 12 501 exons from across the genome, including 271 genes previously implicated in altitude adaptation, to test for adaptation to local elevations for 2 highland hummingbird species, Coeligena violifer (n = 62) and Colibri coruscans (n = 101). For each species, we described population genetic structure across the complex geography of the Peruvian Andes and, while accounting for this structure, we tested whether elevational allele frequency clines in single nucleotide polymorphisms (SNPs) showed evidence for local adaptation to elevation. Although the 2 species exhibited contrasting population genetic structures, we found signatures of clinal genetic variation with shifts in elevation in both. The genes with SNP-elevation associations included candidate genes previously discovered for high-elevation adaptation as well as others not previously identified, with cellular functions related to hypoxia response, energy metabolism, and immune function, among others. Despite the homogenizing effects of gene flow and genetic drift, natural selection on parts of the genome evidently optimizes elevation-specific cellular function even within elevation range-restricted montane populations. Consequently, our results suggest local adaptation occurring in narrow elevation bands in tropical mountains, such as the Andes, may effectively make them “taller” biogeographic barriers.

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Carlson, Jane E., and Kent E. Holsinger. "Extrapolating from local ecological processes to genus-wide patterns in colour polymorphism in South African Protea." Proceedings of the Royal Society B: Biological Sciences 282, no. 1806 (May 7, 2015): 20150583. http://dx.doi.org/10.1098/rspb.2015.0583.

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Polymorphic traits are central to many fundamental discoveries in evolution, yet why they are found in some species and not others remains poorly understood. We use the African genus Protea— within which more than 40% of species have co-occurring pink and white floral colour morphs — to ask whether convergent evolution and ecological similarity could explain the genus-wide pattern of polymorphism. First, we identified environmental correlates of pink morph frequency across 28 populations of four species. Second, we determined whether the same correlates could predict species-level polymorphism and monomorphism across 31 species. We found that pink morph frequency increased with elevation in Protea repens and three section Exsertae species, increased eastward in P. repens , and increased with seed predation intensity in section Exsertae . For cross-species comparisons, populations of monomorphic pink species occurred at higher elevations than populations of monomorphic white species, and 18 polymorphic species spanned broader elevational gradients than 13 monomorphic species. These results suggest that divergent selection along elevational clines has repeatedly favoured polymorphism, and that more uniform selection in altitudinally restricted species may promote colour monomorphism. Our findings are, to our knowledge, the first to link selection acting within species to the presence and absence of colour polymorphism at broader phylogenetic scales.

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Rehfeldt, G. E. "Ecological Adaptations in Douglas-fir (Pseudotsuga menziesii var. glauca). IV. Montana and Idaho Near the Continental Divide." Western Journal of Applied Forestry 3, no. 4 (October 1, 1988): 101–5. http://dx.doi.org/10.1093/wjaf/3.4.101.

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Abstract Seventy-seven seedling populations of Douglas-fir (Pseudotsuga menziesii var. glauca) sampled from near the Continental Divide in Idaho and Montana exhibited pronounced genetic differences when compared in three common environments. Differentiation involved several traits that are components of an annual developmental cycle that must be completed within a growing season of finite length. Consequently, the elevational and geographic dines of genetic variation tend to parallel variation in the length of the growing season at the seed source. Such clines suggest that maladaptation in artificial reforestation can be controlled by limiting the transfer of seeds. While geographic transfers can be relatively liberal, elevational transfers should be limited to ±90 m (300 ft) from the seed source at elevations below 1,400 m (4,600 ft), to ±125 m (410 ft) for elevations between 1,400 and 2,000 m (4,600 and 6,550 ft), and ±200 m (560 ft) for elevations above 2,000 m (6,550 ft). West. J. Appl. For. 3(4):101-105, October 1988.

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Beckers, Hein, Anneser, Vanselow, and Löffler. "Differences in Mobility and Dispersal Capacity Determine Body Size Clines in Two Common Alpine-Tundra Arthropods." Insects 11, no. 2 (January 22, 2020): 74. http://dx.doi.org/10.3390/insects11020074.

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The Arctic is projected to be severely impacted by changes in temperature and precipitation. Species react to these changes by shifts in ranges, phenology, and body size. In ectotherms, the patterns of body size clines and their underlying mechanisms are often hard to untangle. Mountains provide a space-for-time substitute to study these shifts along multiple spatial gradients. As such, mobility and dispersal capacity might conceal reactions with elevation. We test this influence on body size clines by comparing two common arthropods of the alpine tundra. We find that high mobility in the lycosid spider Pardosa palustris blurs elevational effects. Partially low mobility at least during development makes the carabid beetle Amara alpina more susceptible to elevational effects. Specific life-history mechanisms, such as brood care in lycosid spiders and holometabolic development in carabid beetles, are the possible cause.

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Dunlap, J. M., P. E. Heilman, and R. F. Stettler. "Genetic variation and productivity of Populustrichocarpa and its hybrids. VII. Two-year survival and growth of native black cottonwood clones from four river valleys in Washington." Canadian Journal of Forest Research 24, no. 8 (August 1, 1994): 1539–49. http://dx.doi.org/10.1139/x94-201.

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A common-garden study of Populustrichocarpa Torr. & Gray was initiated in 1985 when clonal material from 128 trees was collected from sites distributed along two mesic (Hoh and Nisqually) and two xeric (Dungeness and Yakima) river valleys. This material was grown for 1 year at Puyallup, Wash. In spring 1986, cuttings from this material were used to establish two replicate plantations, one at Puyallup and one at Wenatchee, Wash. Over the 2 year period, trees were assessed for survival, damage, and growth. Two-year survival was 86% at Puyallup and 59% at Wenatchee; survival was higher for mesic-origin trees at both sites. At Wenatchee, mortality was mainly due to a droughty soil and hot, dry climate in the first year, and damage was due to the tarnished plant bug (Lygus spp.), field voles (Microtus spp.), and grasshoppers (Family Acrididae). At both locations, Melampsoraoccidentalis Jacks. leaf rust was found mainly on trees originating from Yakima. Mean 2-year height and diameter at Puyallup were 457 cm and 40 mm, respectively; corresponding values at Wenatchee were 320 cm and 29 mm. At Puyallup, 2-year stem volume (diameter2 × height) decreased significantly in this order: Nisqually (13 500 cm3) = Hoh > Dungeness > Yakima (4700 cm3). Within the Nisqually trees, clones from lower, milder climate elevations grew more than those from the upper elevations. The reverse was true for the Yakima trees, presumably because the lower elevation trees are adapted to an arid climate and are very susceptible to Melampsora rust. At Wenatchee, high microsite heterogeneity masked much of the genetic variation. The genetic variance component (among rivers, sites, and clones) for stem volume at Puyallup increased from 27 to 51% over the second year. In analyses of each river valley, genetic components (elevational group and clone) were also high at 27–63%; however, for the Yakima trees, the elevational group variance (40%) was much larger than for the other valleys (0–7%) and suggests a steep selection gradient midway along the river transect.

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Rehfeldt, G. E. "A model of genetic variation for Pinus ponderosa in the Inland Northwest (U.S.A.): applications in gene resource management." Canadian Journal of Forest Research 21, no. 10 (October 1, 1991): 1491–500. http://dx.doi.org/10.1139/x91-209.

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Models were developed to describe genetic variation among 201 seedling populations ofPinusponderosa var. ponderosa in the Inland Northwest of the United States. Common-garden studies provided three variables that reflected growth and development in field environments and three principal components of six variables that reflected patterns of shoot elongation. Regression models were developed for describing genetic variation across the landscape. Using functions of latitude, longitude, and elevation as descriptors, these models produced values of R2 that were as large as 0.66, while averaging 0.39. The models described genetic variation as occurring along relatively steep elevational clines and gentle geographic (i.e., latitudinal and longitudinal) clines. An exercise at validating the models with independent data supported their veracity. Predictions made by the models are applied to limiting seed transfer, designing breeding zones, planning gene conservation programs, interpreting phenotypic variation, and predicting the effects of environmental change on the adaptedness of populations.

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Jin, Yuan-Ting, and Nai-Fa Liu. "Altitudinal variation in reproductive strategy of the toad-headed lizard, Phrynocephalus vlangalii in North Tibet Plateau (Qinghai)." Amphibia-Reptilia 28, no. 4 (2007): 509–15. http://dx.doi.org/10.1163/156853807782152507.

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Abstract Phrynocephalus vlangalii, a toad-headed viviparous sand lizard, is endemic in the Northern Tibet (Qinghai) Plateau in China. Lizards were collected from 14 localities along the large altitudinal gradient (2289-4565 m a.s.l) to analyze the variation of reproductive traits among localities. Both litter size and mean offspring (scaled embryo) mass were positively correlated with female snout-vent length (SVL). Females produced fewer and larger offspring with increasing elevation when the effect of body size (SVL) was removed. This strategy may possibly be correlated with early survival and growth of offspring. The decreased litter size cline along altitudinal gradient might be correlated with more anatomical constraints at higher altitudes. The lizard has lower coefficient of variation (CV) of litter size at higher environments. Moreover, females from higher elevations had less reproductive investment (relative litter mass, RLM). Study concluded that P. vlangalii fit into the common pattern of higher elevation animals that have smaller clutches of larger offspring and lower reproductive effort.

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Leinonen, Päivi H., Matti J. Salmela, Kathleen Greenham, C. Robertson McClung, and John H. Willis. "Populations Are Differentiated in Biological Rhythms without Explicit Elevational Clines in the Plant Mimulus laciniatus." Journal of Biological Rhythms 35, no. 5 (July 6, 2020): 452–64. http://dx.doi.org/10.1177/0748730420936408.

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Environmental variation along an elevational gradient can yield phenotypic differentiation resulting from varying selection pressures on plant traits related to seasonal responses. Thus, genetic clines can evolve in a suite of traits, including the circadian clock, that drives daily cycling in varied traits and that shares its genetic background with adaptation to seasonality. We used populations of annual Mimulus laciniatus from different elevations in the Sierra Nevada in California to explore among-population differentiation in the circadian clock, flowering responses to photoperiod, and phenological traits (days to cotyledon emergence, days to flowering, and days to seed ripening) in controlled common-garden conditions. Further, we examined correlations of these traits with environmental variables related to temperature and precipitation. We observed that the circadian period in leaf movement was differentiated among populations sampled within about 100 km, with population means varying by 1.6 h. Significant local genetic variation occurred within 2 populations in which circadian period among families varied by up to 1.8 h. Replicated treatments with variable ecologically relevant photoperiods revealed marked population differentiation in critical day length for flowering that ranged from 11.0 to 14.1 h, corresponding to the time period between late February and mid-May in the wild. Flowering time varied among populations in a 14-h photoperiod. Regardless of this substantial population-level diversity, obvious linear clinality in trait variability across elevations could not be determined based on our genotypic sample; it is possible that more complex spatial patterns of variation arise in complex terrains such as those in the Sierra Nevada. Moreover, we did not find statistically significant bivariate correlations between population means of different traits. Our research contributes to the understanding of genetic variation in the circadian clock and in seasonal responses in natural populations, highlighting the need for more comprehensive investigations on the association between the clock and other adaptive traits in plants.

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Xing, Shuang, Wenda Cheng, Akihiro Nakamura, Chin Cheung Tang, Shuyin Huang, Erica Odell, Eben Goodale, Uromi M. Goodale, and Timothy C. Bonebrake. "Elevational clines in morphological traits of subtropical and tropical butterfly assemblages." Biological Journal of the Linnean Society 123, no. 3 (January 27, 2018): 506–17. http://dx.doi.org/10.1093/biolinnean/blx159.

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Pitteloud, Camille, Patrice Descombes, Sara Sànchez-Moreno, Alan Kergunteuil, Sébastien Ibanez, Sergio Rasmann, and Loïc Pellissier. "Contrasting responses of above- and below-ground herbivore communities along elevation." Oecologia 194, no. 3 (October 19, 2020): 515–28. http://dx.doi.org/10.1007/s00442-020-04778-7.

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Abstract Above- and below-ground herbivory are key ecosystem processes that can be substantially altered by environmental changes. However, direct comparisons of the coupled variations of above- and below-ground herbivore communities along elevation gradients remain sparse. Here, we studied the variation in assemblages of two dominant groups of herbivores, namely, aboveground orthoptera and belowground nematodes, in grasslands along six elevation gradients in the Swiss Alps. By examining variations of community properties of herbivores and their food plants along montane clines, we sought to determine whether the structure and functional properties of these taxonomic groups change with elevation. We found that orthoptera decreased in both species richness and abundance with elevation. In contrast with aboveground herbivores, the taxonomic richness and the total abundance of nematode did not covary with elevation. We further found a stronger shift in above- than below-ground functional properties along elevation, where the mandibular strength of orthoptera matched a shift in leaf toughness. Nematodes showed a weaker pattern of declined sedentary behavior and increased mobility with elevation. In contrast to the direct exposal of aboveground organisms to the surface climate, conditions may be buffered belowground, which together with the influence of edaphic factors on the biodiversity of soil biota, may explain the differences between elevational patterns of above- and below-ground communities. Our study emphasizes the necessity to consider both the above- and below-ground compartments to understand the impact of current and future climatic variation on ecosystems, from a functional perspective of species interactions.

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Wang, Mengying, Qiaochu Xue, Xiang Li, Knut Krohn, Stefanie Ziesche, Uta Ceglarek, Matthias Blüher, et al. "Circulating Levels of microRNA-122 and Hepatic Fat Change in Response to Weight-Loss Interventions: CENTRAL Trial." Journal of Clinical Endocrinology & Metabolism 107, no. 5 (January 17, 2022): e1899-e1906. http://dx.doi.org/10.1210/clinem/dgac023.

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Abstract Purpose Little is known about the relations between changes in circulating microRNA-122 (miR-122) and liver fat in response to weight-loss interventions. We aimed to investigate the association between miR-122 and changes of hepatic fat content during 18-month diet and physical activity interventions. Methods The CENTRAL trial is an 18-month randomized, controlled trial among adults with abdominal obesity or dyslipidemia. Subjects were randomly assigned to a low-fat diet or a Mediterranean/low-carbohydrate diet. After 6 months of dietary intervention, each diet group was further randomized into added physical activity groups or no added physical activity groups for the following 12 months of intervention. The current study included 220 participants at baseline and 134 participants with repeated measurements on serum miR-122 and hepatic fat content over 18 months. Results Serum miR-122 significantly increased from baseline to 18 months, while no difference was observed across the 4 intervention groups. We found a significant association between miR-122 and hepatic fat content at baseline, as per unit increment in log-transformed miR-122 was associated with 3.79 higher hepatic fat content (P < 0.001). Furthermore, we found that higher elevations in miR-122 were associated with less reductions in hepatic fat percentage during 18-month interventions (β = 1.56, P = 0.002). We also found a significant interaction between changes in miR-122 and baseline fasting plasma glucose with hepatic fat content changes in 18 months (P interaction = 0.02). Conclusions Our data indicate that participants with higher elevation in serum miR-122 may benefit less in reduction of hepatic fat content in response to diet and physical activity interventions.

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Zhang, Nana, Stephen J. Tonsor, and M. Brian Traw. "A geographic cline in leaf salicylic acid with increasing elevation inArabidopsis thaliana." Plant Signaling & Behavior 10, no. 3 (March 4, 2015): e992741. http://dx.doi.org/10.4161/15592324.2014.992741.

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Xing, Shuang, Wenda Cheng, Akihiro Nakamura, Chin Cheung Tang, Evan J. Pickett, Shuyin Huang, Erica Odell, Eben Goodale, Uromi M. Goodale, and Timothy C. Bonebrake. "Corrigendum: Elevational clines in morphological traits of subtropical and tropical butterfly assemblages." Biological Journal of the Linnean Society 123, no. 3 (February 17, 2018): 694. http://dx.doi.org/10.1093/biolinnean/bly016.

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Rehfeldt, Gerald E. "Adaptation of Picea engelmannii populations to the heterogeneous environments of the Intermountain West." Canadian Journal of Botany 72, no. 8 (August 1, 1994): 1197–208. http://dx.doi.org/10.1139/b94-146.

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Seedlings from 104 natural populations of Engelmann spruce (Picea engelmannii) and 10 blue spruce (Picea pungens) populations from the Intermountain West, U.S.A., were compared in common gardens. Comparisons involved 16 characters that described growth, development, and cold hardiness plus nine monoterpenes. Canonical discriminant analyses detected one population of blue spruce that had been misidentified, readily separated populations of blue and Engelmann spruce, suggested that three Southwest populations differed markedly from Intermountain populations of Engelmann spruce, but identified no Intermountain populations that reflected introgression with blue spruce. Genetic differences were detected among populations of Engelmann spruce for 16 of the morphometric characters, and multiple regression models accounted for as much as 70% of the variance among populations. The regressions described genetic variation occurring along clines that were dominated by elevational and latitudinal effects. The slope of the clines, however, was relatively gentle; populations located within the same physiographic province must be separated by at least 420 m in elevation before genetic differentiation becomes a reasonable possibility. By providing a means for assessing the degree by which similar genotypes recur across the landscape, the regression models have direct practical application in programs ranging from land management to conservation biology. Key words: population differentiation, genetic variation, ecological genetics.

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West, Rachel, Joyce Hong, José G. B. Derraik, Dianne Webster, Natasha L. Heather, and Paul L. Hofman. "Newborn Screening TSH Values Less Than 15 mIU/L Are Not Associated With Long-term Hypothyroidism or Cognitive Impairment." Journal of Clinical Endocrinology & Metabolism 105, no. 9 (June 29, 2020): e3329-e3338. http://dx.doi.org/10.1210/clinem/dgaa415.

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Abstract Background It is unclear whether newborns with mild thyrotropin elevation (mTSHe) are at risk of neurocognitive impairment. We assessed whether mTSHe at birth persists during childhood and compared neurocognitive functioning to siblings. Methods This study encompassed children born in the Auckland region (New Zealand) with a newborn screen TSH level of 8 to 14 mIU/L blood, age 6.9 to 12.6 years at assessment, and their siblings. Thyroid function tests (serum TSH and free thyroxine) and neurocognitive assessments were performed, including IQ via the Wechsler Intelligence Scale for Children, fourth edition. Results Ninety-six mTSHe individuals were studied, including 67 children recruited with 75 sibling controls. Mean mTSHe newborn TSH level was 10.1 mIU/L blood and 2.4 mIU/L at assessment (range, 0.8-7.0 mIU/L, serum). Although higher newborn TSH levels in the mTSHe group correlated with lower full-scale IQ scores (r = 0.25; P = .040), they were not associated with the magnitude of the IQ difference within sibling pairs (P = .56). Cognitive scores were similar for mTSHe and controls (full-scale IQ 107 vs 109; P = .36), with a minor isolated difference in motor coordination scores. Conclusions Our data do not suggest long-term negative effects of neonatal mild TSH elevation. TSH elevation below the screen threshold appears largely transient, and midchildhood neurocognitive performance of these children was similar to their siblings. We propose that associations between neonatal mild TSH elevation and IQ are due to familial confounders. We caution against the practice of reducing screening CH cutoffs to levels at which the diagnosis may not offer long-term benefit for those detected.

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Kouser, Yasmeen. "A Comparative Diversity Analysis of Soil Nematodes of Rajouri, Jammu and Kashmir, India." Bioscience Biotechnology Research Communications 14, no. 4 (December 25, 2021): 1687–700. http://dx.doi.org/10.21786/bbrc/14.4.47.

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Diversity of Nematode communities in Pir Panjal range of Jammu and Kashmir along with nematodes’ driven indices were studied. Himalayan mountainous areas of district Rajouri were selected. Community composition and trophic structure (feeding types) were assessed and were analyzed at various altitudes and across varied habitats, which differ signiﬁcantly on moving from low elevation to high elevation areas. A total of 47 genera were recorded across mountain clines. In terms of taxonomic groups, in higher elevations, the order Dorylaimids represent 55.18%, followed by Tylenchida 28.85%, Mononchida 2.38%, Rhabditida 2.18%, and Aphelenchida 2.05%, whereas in the lower reaches, the order Rhabditida represent 30.18%, followed by Dorylaimids 28.75%, Tylenchida 15.85%, Mononchida 10.05% and Aphelenchida 1.05%. In terms of trophic groups, in the upper reaches, omnivores (56.6%) predominate, representing highest number, followed by plant parasitic (33.4%), bacterivore (4.2%), predatory (3.2%) and fungivore (2.60%). In the lower reaches, Bacterivores (38.08%) predominates, followed by omnivores (29.85%), plant parasitic (18.5%), predatory (12.5%) and fungivores (1.07%). The total nematode abundance and diversity were found increasing with elevation This pattern applied to most genera and feeding types. Across the regions, nematode diversity and community composition increases positively with elevations and richer habitats as given by Simpson index and Shannon-Weaver index. We conclude that nematode assemblages are potentially good bioindicators of climate change. They reacted sensitively and predictably to the changing environment. Thus, nematodes have suitability for long-term monitoring of biodiversity and community changes. Sampling techniques are well standardized and inexpensive. Furthermore, feeding types of nematodes can be determined with minimal taxonomic skills.

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Tsaban, Gal, Anat Yaskolka Meir, Hila Zelicha, Ehud Rinott, Alon Kaplan, Aryeh Shalev, Amos Katz, et al. "Diet-induced Fasting Ghrelin Elevation Reflects the Recovery of Insulin Sensitivity and Visceral Adiposity Regression." Journal of Clinical Endocrinology & Metabolism 107, no. 2 (October 6, 2021): 336–45. http://dx.doi.org/10.1210/clinem/dgab681.

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Abstract Context Lower fasting ghrelin levels (FGL) are associated with obesity and metabolic syndrome. Objective We aimed to explore the dynamics of FGL during weight loss and its metabolic and adiposity-related manifestations beyond weight loss. Methods This was a secondary analysis of a clinical trial that randomized participants with abdominal obesity/dyslipidemia to 1 of 3 diets: healthy dietary guidelines (HDG), Mediterranean diet (MED), or green-MED diet, all combined with physical activity (PA). Both MED diets were similarly hypocaloric and included 28 g/day walnuts. The green-MED group further consumed green tea (3-4 cups/day) and a Wolffia globosa (Mankai) plant green shake. We measured FGL and quantified body fat depots by magnetic resonance imaging at baseline and after 18 months. Results Among 294 participants (body mass index = 31.3 kg/m2; FGL = 504 ± 208 pg/mL; retention rate = 89.8%), lower FGL was associated with unfavorable cardiometabolic parameters such as higher visceral adipose tissue (VAT), intrahepatic fat, leptin, and blood pressure (P < 0.05 for all; multivariate models). The ∆FGL18-month differed between men (+7.3 ± 26.6%) and women (−9.2% ± 21.3%; P = 0.001). After 18 months of moderate and similar weight loss among the MED groups, FGL increased by 1.3%, 5.4%, and 10.5% in HDG, MED, and green-MED groups, respectively (P = 0.03 for green-MED vs HDG); sex-stratified analysis revealed similar changes in men only. Among men, FGL18-month elevation was associated with favorable changes in insulin resistance profile and VAT regression, after adjusting for relative weight loss (HbA1c: r = −0.216; homeostatic model of insulin resistance: r = −0.154; HDL-c: r = 0.147; VAT: r = −0.221; P < 0.05 for all). Insulin resistance and VAT remained inversely related with FGL elevation beyond that explained by weight loss (residual regression analyses; P < 0.05). Conclusion Diet-induced FGL elevation may reflect insulin sensitivity recovery and VAT regression beyond weight loss, specifically among men. Green-MED diet is associated with greater FGL elevation.

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Lee, Jennifer E., Michael J. Somers, and Steven L. Chown. "Density, body size and sex ratio of an indigenous spider along an altitudinal gradient in the sub-Antarctic." Antarctic Science 24, no. 1 (September 23, 2011): 15–22. http://dx.doi.org/10.1017/s0954102011000629.

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AbstractAlthough spiders are a diverse and ecologically important group of predators across the sub-Antarctic islands, relatively little is known about their biology. Here we provide data on the abundance, body size variation and sex ratio of an indigenous spider,Myro kerguelenensis, across an altitudinal gradient on Marion Island. In so doing we test explicitly the hypotheses that density will decline with declining resource availability at higher elevations, and that a converse Bergmann body size cline will be found in this species. Density ofM. kerguelenensisdecreased with altitude and ranged from a mean density of 5.3 (SD 3.42) individuals per m2at 50 m a.s.l. to a mean density of 0.83 (SD 1.15) individuals per m2at 600 m a.s.l. Mean female sternum width was 1.39 mm (SD 0.44) and mean male sternum width was 1.40 mm (SD 0.22). No evidence for Bergmann or converse Bergmann clines was found. At increasing altitudes, sex ratios became increasingly female-biased with populations at 600 m a.s.l. comprising 0.87 (SD 0.28) females, on a proportional basis, possibly as a result of resource limitation and an increase in the prevalence of sexual cannibalism. The food web implications of this study are highlighted.

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LeBlanc, John W., Janine K. Hasey, Richard B. Standiford, Mike Connor, and Roy M. Sachs. "Eucalyptus for Low Elevation Foothill Plantations in California." Western Journal of Applied Forestry 12, no. 4 (October 1, 1997): 104–7. http://dx.doi.org/10.1093/wjaf/12.4.104.

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Abstract In March 1984 we established a test plantation of selected Eucalyptus and poplar seedlings species and clones on a range site in the Sierra Nevada foothills. The main objectives were to evaluate survival and growth of the various species and clones and to determine a rotation age for intensively managed hardwood trees grown under low elevation foothill conditions. Seedlings and clones of six species of Eucalyptus and one hybrid poplar were grown with short rotation intensive culture techniques for 7 yr. Rotation age, defined as the culmination of mean annual increment, varied from 3 to 6 yr. The best producing clone produced 8 cords of fuelwood per acre per year. The potential for damage from freezing and snow at these elevations is also discussed. West. J. Appl. For. 12(4):104-107.

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Kubota, Sodai, and Daisuke Yabe. "Elevation of Fasting GLP-1 Levels in Child and Adolescent Obesity: Friend or Foe?" Journal of Clinical Endocrinology & Metabolism 106, no. 9 (May 5, 2021): e3778-e3780. http://dx.doi.org/10.1210/clinem/dgab301.

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Abstract Glucagon-like peptide-1 (GLP-1) receptor agonists have been gaining much attention as a therapeutic approach to type 2 diabetes and obesity. Stinson et al recently reported that fasting GLP-1 is higher in children and adolescents with overweight/obesity and that it associates with cardiometabolic risk factors in a cross-sectional study comprising more than 4000 subjects. Obvious questions include why fasting GLP-1 is significantly increased in children and adolescents with overweight/obesity and why this is correlated with cardiometabolic risks. It has been shown that the inflammatory cytokine interleukin-6 (IL-6) stimulates GLP-1 secretion from pancreatic α-cells. IL-6-induced GLP-1 secretion could therefore play a role in expanding the β-cell reservoir in compensation for increased insulin needs due to exacerbation of insulin resistance. On the other hand, augmented GLP-1 secretion leads to increased insulin secretion, thereby enhancing hepatic lipogenesis and stimulating adipogenesis, which might underlie the associations of fasting GLP-1 with % body fat, triglycerides, and alanine aminotransferase. It is also possible that GLP-1 levels are naturally increased to oppose body weight gain to maintain body weight. However, it is important to note the differing biological effects of GLP-1 at physiological and pharmacological levels, which are evident in body weight reduction by GLP-1 receptor agonists and DPP-4 inhibitors. The Stinson study clearly demonstrated that fasting GLP-1 associates with overweight/obesity and cardiometabolic risk factors in children and adolescents. However, additional experiments need to be carried out to fully understand the relevance of these observations to human disease and health.

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Cui, Jifa, Bingxin Wang, Shengnan Ji, Huawei Su, and Youbing Zhou. "Revisiting classic ecogeographical rules, using a widely distributed mouse species (Apodemus draco)." Animal Biology 70, no. 4 (September 15, 2020): 359–72. http://dx.doi.org/10.1163/15707563-bja10012.

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Abstract Ecogeographical rules predict an association between specific adaptive morphological/physiological traits and latitude, elevation or cooler climates. Such ecogeographical effects are often expressed most clearly in widely distributed species due to continuous selective adaptation occurring over their geographic range. Based on 40 population sampling sites of 116 adult individuals (female, ; male, ) across an elevational range of 191–2573 m, we tested whether morphological traits accorded with predictions of Bergmann’s rule, Allen’s rule and Hesse’s rule for the South China field mouse (Apodemus draco). The effects of elevation on body size, appendage length and heart size were tested by fitting Linear Mixed-Effects Models. None conformed to Bergmann’s, Allen’s or Hesse’s rule. Clines in body size opposed Bergmann’s rule, and foot and snout length ratios opposed Allen’s rule. We conclude that South China field mice, a widely distributed species, exhibit an acute thermoregulation mechanism in which in colder conditions body sizes decrease – as opposed to altering heart sizes or surface area to volume ratios – requiring less energy to regulate body temperatures. Also, there was a stronger selective pressure to increase partial appendage lengths (i.e., foot and snout) to adapt to the specific environment (e.g. longer period of snow cover, up to 2573 m) rather than on a general shortening of appendages to cope with colder conditions.

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Mikitová, Barbora, Martina Šemeláková, and Ľubomir Panigaj. "Wing morphology and eyespot pattern of Erebia medusa (Lepidoptera, Nymphalidae) vary along an elevation gradient in the Carpathian Mountains." Nota Lepidopterologica 45 (July 5, 2022): 233–50. http://dx.doi.org/10.3897/nl.45.68624.

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Butterfly wings play a crucial role during flight, but also in thermoregulation, intraspecific signalling and interaction with predators, all of which vary across different habitat types and may be reflected in wing morphology or colour pattern. We focused on the morphological variability of Erebia medusa in order to examine patterns and variations in the colouration and morphology of wings from areas representing different habitat types with different environmental characteristics. The barrier (larger fragments of forest) between populations of Erebia medusa along the elevation gradient of Kojšovská hoľa might be the aspect that hinders the movement of the population. The wing characteristics (shape, size, spotting) of males representing populations of Carpathian mountain habitats (Volovské vrchy, Ondavská vrchovina) located at different elevations were measured. The forewing shape analysis, using geometric morphometry based on 16 landmarks, showed significant differences between populations from different elevation levels. The pattern of the forewings also varied between populations. Morphological changes among individuals of Erebia medusa populations along the elevation gradient in the Carpathian Mountains showed that in the cold, highland habitats we observed smaller, narrower and elongated forewings with a reduced number of spots, while males from warmer habitats at low elevations had rounder, larger and more spotted forewings. Introduction The ecological role of individual butterfly species is largely reflected in the wings, whose shape, size and colour pattern often have adaptive value and provide information about important differences, even at the population level (Altizer and Davis 2010; Mega 2014). The variability of butterfly wing shape or size, which reflects flight performance (Cespedes et al. 2015; Le Roy et al. 2019a, b), can even provide insight into the suitability of the habitat (Pellegroms et al. 2009; Chazot et al. 2016) and the dispersal rate (Wells et al. 2018; Taylor-Cox et al. 2020). The final wing shape and size of adults depends on conditions of larval development, which can be affected by aggregation behaviour (Allen 2010; Montejo‐Kovacevich et al. 2019; Palmer et al. 2019) but also by environmental conditions (Karl and Fischer 2008; Gibbs et al. 2011; Van Dyck et al. 2016; Palmer et al. 2019). Phenotypic clines along environmental gradients can sometimes be explained by ecological rules, whose use on insects can be debatable (Blanckenhorn and Demont 2004). Bergmann’s rule is the classic ecogeographic principle that relates the body size of endotherms with environmental temperature (or latitude) (Shelomi 2012). The converse of Bergmann’s rule (Park 1949; Mousseau 1997), based on the season length effect, predicts a decrease of body size with elevation. Various clines in body size can also be explained by a combination of several other theories or hypotheses, such as the north-south cline theory (Nylin and Svärd 1991) or the “temperature – size rule” (Angilletta and Dunham 2003). The wing eyespot pattern, which may serve different functions, can also play an irreplaceable role. While the pattern on the dorsal side is usually used for intraspecific communication (Oliver et al. 2009; Westerman et al. 2012; Tokita et al. 2013), the eyespots on the ventral side are rather used to deceive predators by intimidation or deflection by distracting predators from the vital, vulnerable body parts (Lyytinen et al. 2003; Stevens 2005; Stevens et al. 2007; Kodandaramaiah 2011; Prudic et al. 2015; Ho et al. 2016). Moreover, in several butterfly species, wing colour modifications are related to thermoregulation (Dennis and Shreeve 1989; Taylor-Cox et al. 2020). Previous studies (Nice et al. 2005; Jugovic et al. 2018) have demonstrated that populations separated by time, space or geographical barrier may undergo changes in the shape, size and colouration of external traits (Tatarinov and Kulakova 2013). Restrictions of the movement and migration of butterfly species have an impact on the intensity and direction of gene flow between populations (Andrews 2010; Slatkin and Excoffier 2012). Characterisation of the morphological traits of E. medusa, a species inhabiting a wide range of environments, can provide insight into the selection pressures that affect adaptive responses (Cespedes et al. 2015; Taylor-Cox et al. 2020). For the sedentary butterfly Erebia medusa, high intraspecific variability (numerous subspecies) and mosaic distribution throughout most of its Euro-Siberian region is characteristic (Warren 1936; Schmitt et al. 2000; Polic et al. 2014). Our study focused especially on the influence of elevation differences in the Carpathian region on intraspecific variation. For this species, large fragments of forests (Schmitt et al. 2000) may be a serious obstacle for movement. According to the study by Kleckova and Klecka (2016), E. medusa prefers a warm environment, so the adaptations to high elevation habitats needed for the activity of this species can be expected. Lower activity due to low temperature can cause a decrease of chances of escape; therefore, selection will act against some individuals (large sized or with large eyespots) (Dennis et al. 1986). A higher number of eyespots, which are important especially in escape mechanisms, may reflect increased rates of predation with rising temperature (Hillebrand et al. 2009; Vucic-Pestic et al. 2011) but also by sexual selection (Tokita et al. 2013). Based on morphological features (wing size, shape, colour pattern) examined by traditional and geometric morphometry, we focused on the morphological differences between populations from habitats differing in elevation and separated by forest areas. We predicted that the morphological diversity between E. medusa populations would show changes that correlate with the average annual temperature, which varies within the elevation gradient. Our study is based on the hypothesis that i) morphological traits of males (size, shape and pattern of forewings) vary in response to various environmental conditions within an elevation gradient. We also focused on examining whether ii) the forewing size of individuals from higher elevations is smaller than the forewing size of individuals from lower and warmer regions, which induce longer feeding periods during larval development (Juhász et al. 2016). Further, iii) males from higher elevation habitats with lower temperatures were expected to have aerodynamically (narrower, angular) shaped wings that reduce energy costs (Dudley 2002; Lentink et al. 2007; Kovac et al. 2012). Finally, iv) a reduction in the eyespot number with elevation, involving various selection pressures, was expected (Slabý 1950; Tatarinov and Kulakova 2013).

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Tamura, T., J. Mizuguchi, and H. Nariuchi. "Regulatory role of CD4/L3T4 molecules in IL-2 production by affecting intracellular Ca2+ concentration of T cell clone stimulated with soluble anti-CD3." Journal of Immunology 145, no. 1 (July 1, 1990): 78–84. http://dx.doi.org/10.4049/jimmunol.145.1.78.

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Abstract To elucidate the role of CD4 molecule in T cell activation, the effect of anti-CD4 on T cell IL-2 production was examined by using an alloreactive Th clone. The alloreactive T cell used in the present experiments produced IL-2 in response to soluble anti-CD3 epsilon-chain (anti-CD3) without accessory cell or insoluble antibody carrier. The IL-2 production was suppressed by the addition of anti-CD4 in cultures. An intracellular free Ca2+ concentration ([Ca2+]i) of the T cell clone was elevated by anti-CD3 stimulation, but the elevation was suppressed in the presence of anti-CD4. When the clone was stimulated in Ca2(+)-free medium, the elevation of [Ca2+]i was not observed. When Ca2+ influx was induced by calcium ionophore A23187 or ionomycin, the clone produced IL-2 in response to anti-CD3 in the presence of anti-CD4. When polyclonal T cell line or several other alloreactive T cell clones were examined for their anti-CD3 response, essentially the same results as mentioned above were obtained. Taken together, these results suggest that the slow and sustained elevation of [Ca2+]i is an essential signal for IL-2 production of T cells, and that anti-CD4 suppresses the IL-2 production by interfering the [Ca2+]i elevation. The significance of CD4 molecules in murine T cell activation was discussed.

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Freeman, Benjamin G. "Little evidence for Bergmann's rule body size clines in passerines along tropical elevational gradients." Journal of Biogeography 44, no. 3 (July 4, 2016): 502–10. http://dx.doi.org/10.1111/jbi.12812.

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Levy, Richard A., and César R. Nufio. "Dispersal potential impacts size clines of grasshoppers across an elevation gradient." Oikos 124, no. 5 (October 24, 2014): 610–19. http://dx.doi.org/10.1111/oik.01615.

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Hirohata, Shunsei, Kiyoaki Tanimoto, and Koji Ito. "Elevation of Cerebrospinal Fluid Interleukin-6 Activity in Patients with Vasculitides and Central Nervous System Involvement." Clinical Immunology and Immunopathology 66, no. 3 (March 1993): 225–29. http://dx.doi.org/10.1006/clin.1993.1029.

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Zhang, Yang, Weijie Sun, Sainan Zhu, Youyuan Huang, Yu Huang, Ying Gao, Junqing Zhang, Huixia Yang, and Xiaohui Guo. "The Impact of Thyroid Function and TPOAb in the First Trimester on Pregnancy Outcomes: A Retrospective Study in Peking." Journal of Clinical Endocrinology & Metabolism 105, no. 3 (November 2, 2019): e368-e380. http://dx.doi.org/10.1210/clinem/dgz167.

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Abstract Context The impact of mild TSH elevation (2.5–4.08 mIU/L) on pregnancy outcomes is unclear. The treatment strategy for mild TSH elevation is dependent on thyroid peroxidase antibody (TPOAb) status according to the guidelines. Objective To assess the effects of mild thyroid dysfunction combined with TPOAb status in the first trimester on pregnancy outcomes and the impact of levothyroxine (L-T4) treatment on pregnancy outcomes. Design The study retrospectively evaluated 3562 pregnant women. A total of 3296 untreated women were divided into 4 subgroups: group A: 4.08 < TSH <10 mIU/L, TPOAb+/-; group B: 2.5 < TSH ≤ 4.08 mIU/L, TPOAb+; group C: 2.5 < TSH ≤ 4.08 mIU/L, TPOAb–; and group D: 0.23 ≤ TSH ≤ 2.5 mIU/L, TPOAb+/-. The other 266 women with L-T4 treatment were divided into TSH 4.08 to 10 mIU/L and 2.5 to 4.08 mIU/L subgroups. Setting The study was conducted at Peking University First Hospital in China. Patients A total of 3562 pregnant women were evaluated. Main Outcome Measures The incidence of pregnancy outcomes in the untreated subgroups (groups A-D) and treated subgroups were measured. Results Miscarriage and maternal composite outcome risks were 3.53 (1.85–6.75) and 2.19 (1.26–3.81) times greater in group A; 1.58 (1.17–2.13) and 1.27 (1.04–1.54) times greater in group C than in group D. L-T4 improved the miscarriage risk in the TSH 4.08 to 10 and 2.5 to 4.08 mIU/L groups but doubled the risk of gestational diabetes mellitus in the TSH 2.5 to 4.08 mIU/L treated group compared with the untreated group. Conclusions TSH 2.5 to 4.08 mIU/L combined with TPOAb– during early pregnancy was associated with miscarriages and maternal composite outcomes. The advantages and disadvantages of L-T4 administration in TSH 2.5 to 4.08 mIU/L pregnant women remain uncertain.

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Sandoval-Arango, S., H. Cárdenas Henao, and J. Montoya-Lerma. "Divergence in Bergmann’s clines: elevational variation and heritability of body size in a leaf-cutting ant." Insectes Sociaux 67, no. 3 (June 24, 2020): 355–66. http://dx.doi.org/10.1007/s00040-020-00771-8.

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Buckley, L. B., and C. R. Nufio. "Elevational clines in the temperature dependence of insect performance and implications for ecological responses to climate change." Conservation Physiology 2, no. 1 (August 25, 2014): cou035. http://dx.doi.org/10.1093/conphys/cou035.

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Wu, Harry X., Cheng C. Ying, and John A. Muir. "Effect of geographic variation and jack pine introgression on disease and insect resistance in lodgepole pine." Canadian Journal of Forest Research 26, no. 5 (May 1, 1996): 711–26. http://dx.doi.org/10.1139/x26-081.

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Incidence of western gall rust (Endocronartiumharknessii (J.P. Moore) Y. Hiratsuka), stalactiform blister rust (Cronartiumcoleosporioides Arth.), needle cast (Lophodermellaconcolor (Dearn.) Darker), and sequoia pitch moth (Synanthedonsequoiae (Hy. Edwards) (Lepidoptera: Sesiidae)) attacks were investigated in a lodgepole pine (Pinuscontorta Dougl. ex Loud, van latifolia Engelm.) provenance–family test plantation located at Red Rock Tree Improvement Station, Prince George, British Columbia. This plantation contains 778 wind-pollinated families from 53 provenances in British Columbia, Alberta, and the Yukon Territory. Pest incidence was assessed in 1993 when the plantation was 21 years old. Provenance had a significant effect on resistance to the four disease and insect attacks. Regression models using latitude, longitude, and elevation as predictors accounted for 38% to 80% of the provenance variation in pest incidence. Geographic patterns of genetic variation in pest resistance essentially followed longitudinal and elevational clines. The most interesting finding is the strong relationship between pest incidence and provenance distance to the western limit of the natural range of jack pine (Pinusbanksiana Lamb,): the closer a lodgepole pine provenance is to the edge of jack pine distribution, the higher is its resistance to the pests. We hypothesize that jack pine introgression may have played a significant role in the evolution of pest defense in lodgepole pine. Effective selection and breeding for pest resistance in lodgepole pine may have to look beyond the intraspecific gene pool.

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Shi, Mingjian, Ali M. Manouchehri, Christian M. Shaffer, Nataraja Sarma Vaitinadin, Jacklyn N. Hellwege, Joe-Elie Salem, Lea K. Davis, et al. "Genetic Thyrotropin Regulation of Atrial Fibrillation Risk Is Mediated Through an Effect on Height." Journal of Clinical Endocrinology & Metabolism 106, no. 7 (April 25, 2021): 2124–32. http://dx.doi.org/10.1210/clinem/dgab272.

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Abstract Context A genetic predisposition to lower thyrotropin (TSH) levels is associated with increased atrial fibrillation (AF) risk through undefined mechanisms. Objective Defining the genetic mediating mechanisms could lead to improved targeted therapies to mitigate AF risk. Methods We used 2-sample mendelian randomization (MR) to test associations between TSH-associated single-nucleotide variations and 16 candidate mediators. We then performed multivariable mendelian randomization (MVMR) to test for a significant attenuation of the genetic association between TSH and AF, after adjusting for each mediator significantly associated with TSH. Results Four candidate mediators (free thyroxine, systolic blood pressure, heart rate, and height) were significantly inversely associated with genetically predicted TSH after adjusting for multiple testing. In MVMR analyses, adjusting for height significantly decreased the magnitude of the association between TSH and AF from –0.12 (SE 0.02) occurrences of AF per SD change in height to –0.06 (0.02) (P = .005). Adjusting for the other candidate mediators did not significantly attenuate the association. Conclusion The genetic association between TSH and increased AF risk is mediated, in part, by taller stature. Thus, some genetic mechanisms underlying TSH variability may contribute to AF risk through mechanisms determining height occurring early in life that differ from those driven by thyroid hormone–level elevations in later life.

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Krams, Sheri M., Sean Cao, Michihiro Hayashi, Janeth C. Villanueva, and Olivia M. Martinez. "Elevations in IFN-γ, IL-5, and IL-10 in Patients with the Autoimmune Disease Primary Biliary Cirrhosis: Association with Autoantibodies and Soluble CD30." Clinical Immunology and Immunopathology 80, no. 3 (September 1996): 311–20. http://dx.doi.org/10.1006/clin.1996.0129.

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van der Boom, Trynke, Congzhuo Jia, Joop D. Lefrandt, Margery A. Connelly, Thera P. Links, Uwe J. F. Tietge, and Robin P. F. Dullaart. "HDL Cholesterol Efflux Capacity is Impaired in Severe Short-Term Hypothyroidism Despite Increased HDL Cholesterol." Journal of Clinical Endocrinology & Metabolism 105, no. 9 (August 6, 2020): e3355-e3362. http://dx.doi.org/10.1210/clinem/dgaa411.

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Abstract Context Severe hypothyroidism has profound effects on lipoprotein metabolism including high-density lipoprotein (HDL) cholesterol elevations but effects on HDL function metrics are unknown. Objective To determine the impact of severe short-term hypothyroidism on HDL particle characteristics, HDL cholesterol efflux capacity (CEC), and HDL antioxidative capacity. Design Observational study with variables measured during severe short-term hypothyroidism (median TSH 81 mU/L) and after 20 weeks of thyroid hormone supplementation (median TSH 0.03 mU/L) (Netherlands Trial Registry ID 7228). Setting University hospital setting in The Netherlands. Patients Seventeen patients who had undergone a total thyroidectomy for differentiated thyroid carcinoma. Main outcome measures HDL particle characteristics (nuclear magnetic resonance spectrometry), CEC (human THP-1-derived macrophage foam cells and apolipoprotein B-depleted plasma), and HDL anti-oxidative capacity (inhibition of low-density lipoprotein oxidation). Results During hypothyroidism plasma total cholesterol, HDL cholesterol and apolipoprotein A-I were increased (P ≤ 0.001). HDL particle concentration was unchanged, but there was a shift in HDL subclasses toward larger HDL particles (P < 0.001). CEC was decreased (P = 0.035), also when corrected for HDL cholesterol (P < 0.001) or HDL particle concentration (P = 0.011). HDL antioxidative capacity did not change. Conclusion During severe short-term hypothyroidism CEC, an important antiatherogenic metric of HDL function, is impaired. HDL cholesterol and larger HDL particles are increased but HDL particle concentration is unchanged. Combined, these findings suggest that HDL quality and quantity are not improved, reflecting dysfunctional HDL in hypothyroidism.

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Dunlap, J. M., R. F. Stettler, and P. E. Heilman. "Genetic variation and productivity of Populustrichocarpa and its hybrids. VIII. Leaf and crown morphology of native P. trichocarpa clones from four river valleys in Washington." Canadian Journal of Forest Research 25, no. 10 (October 1, 1995): 1710–24. http://dx.doi.org/10.1139/x95-185.

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A common-garden study of Populustrichocarpa Torr. & Gray was initiated in 1985, when clonal material from 128 trees was collected from sites distributed along two mesic (Hoh, Nisqually) and two xeric (Dungeness, Yakima) river valleys. This material was grown for 1 year at Puyallup, Wash. In spring 1986, cuttings from this material were used to establish two replicate plantations, one at Puyallup and the other at Wenatchee, Wash. Data were collected from a subset of 80 clones on 8 single-leaf and 14 crown traits after two growing seasons. Analyses of variance revealed significant (p ≤ 0.10) differences among rivers in nearly all single-leaf traits by the second year at both plantations. Two-year leaf sizes at Puyallup significantly declined in this order: Hoh (388 cm2) > Nisqually > Dungeness > Yakima (194 cm2). At Wenatchee, a similar mesic > xeric pattern was found among river sources, but leaves were smaller there. When grown at Puyallup, leaves of clones from lower elevations in the Yakima valley were significantly (p ≤ 0.10) smaller, lighter, thinner, and weighed less per unit area than upper elevation clones. Chi-square tests showed that abaxial leaf surfaces were greener in Yakima trees than in trees from other locations, especially in those from the the lower Yakima valley. In the crown traits of trees grown in Puyallup, river and clone-within-site-within-river effects were significant for all traits, whereas site-within-river effects were significant for only 8 traits. Mesic-origin trees were significantly larger in size traits, e.g., branch length, than xeric-origin trees. Trees from the Yakima drainage system were leafier and branchier (p ≤ 0.10) than both Nisqually and Hoh trees. Values for most crown traits were greater (p ≤ 0.10) in the xeric, lower Yakima clones than in the mesic, upper Yakima clones. These mesic-xeric differences were similar for Dungeness trees, although there were few significant differences between the lower and upper elevational groups. Single-leaf and crown traits of trees from the four river valleys seem to be adapted to the respective mesic and xeric conditions of the source environments. Within the Yakima river valley, a sharp change in leaf and crown traits and in atmospheric moisture levels coincide midway along the transect, suggesting the presence of a steep selection gradient in the Bristol Canyon area.

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Miller, Bradley S., Eric Velazquez, and Kevin C. J. Yuen. "Long-Acting Growth Hormone Preparations – Current Status and Future Considerations." Journal of Clinical Endocrinology & Metabolism 105, no. 6 (November 2, 2019): e2121-e2133. http://dx.doi.org/10.1210/clinem/dgz149.

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Abstract Context Long-acting GH (LAGH) preparations are currently being developed in an attempt to improve adherence. The profile of GH action following administration of LAGH raises practical questions about clinical monitoring and long-term safety and efficacy of these new therapeutic agents. Methods Recent literature and meeting proceedings regarding LAGH preparations are reviewed. Results Multiple LAGH preparations are currently at various stages of development, allowing for decreased GH injection frequency from daily to weekly, biweekly, or monthly. Following administration of LAGH, the serum peak and trough GH and IGF-I levels vary depending upon the mechanism used to prolong GH action. Randomized, controlled clinical trials of some LAGH preparations have reported non-inferiority compared with daily recombinant human GH (rhGH) for improved growth velocity and body composition in children and adults with GH deficiency (GHD), respectively. No significant LAGH-related adverse events have been reported during short-term therapy. Conclusion Multiple LAGH preparations are proceeding through clinical development with some showing promising evidence of short-term clinical efficacy and safety in children and adults with GHD. The relationship of transient elevations of GH and IGF-I following administration of LAGH to efficacy and safety remain to be elucidated. For LAGH to replace daily rhGH in the treatment of individuals with GHD, a number of practical questions need to be addressed including methods of dose adjustment, timing of monitoring of IGF-I, safety, efficacy, and cost-effectiveness. Long-term surveillance of efficacy and safety of LAGH preparations will be needed to answer these clinically relevant questions.

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Miyauchi, A., V. Dobre, M. Rickmeyer, J. Cole, L. Forte, and K. A. Hruska. "Stimulation of transient elevations in cytosolic Ca2+ is related to inhibition of Pi transport in OK cells." American Journal of Physiology-Renal Physiology 259, no. 3 (September 1, 1990): F485—F493. http://dx.doi.org/10.1152/ajprenal.1990.259.3.f485.

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Stimulation of changes in cytosolic free calcium by parathyroid hormone was determined in three opossum kidney (OK) cell types, OK wild-type, OKP clone, and OKH clone. All three types of OK cells express parathyroid hormone (PTH)-sensitive adenylate cyclase and adenosine 3',5'-cyclic monophosphate (cAMP) production. However, only the OK wild-type and the OKP clone respond to PTH with inhibition of sodium-dependent Pi transport and transient increase in cytosolic calcium. Characterization of the increases in cytosolic calcium in the wild-type and OKP clones revealed they were due in part to stimulation of Ca2+ release from intracellular stores, probably by inositol 1,4,5-trisphosphate (IP3), which was stimulated by PTH. PTH-stimulated Ca2+ transients were also inhibited by protein kinase C activation. These data are compatible with PTH receptor-mediated phospholipase C activation and its feedback inhibition by protein kinase C. The OKH cells demonstrated a slow increase in cytosolic calcium when stimulated by cyclic nucleotides but no evidence for PTH stimulation of Ca2+ release from intracellular stores. Thus the absence of an inhibitory response of sodium-dependent Pi transport to PTH in the OKH cells is associated with the absence of the rapid transient elevations of cytosolic Ca2+ such as those produced by IP3 production. These data suggest an important cooperative role for cAMP and the phospholipase C-stimulated Ca2(+)-protein kinase C message system in the regulation of Pi transport.

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Journal articles on the topic 'Elevational cline'

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