Articoli di riviste: "Tammar wallaby"

1

Lentle, R. G., I. D. Hume, K. J. Stafford, M. Kennedy, B. P. Springett e S. Haslett. "Observations on fresh forage intake, ingesta particle size and nutrient digestibility in four species of macropod". Australian Journal of Zoology 51, n. 6 (2003): 627. http://dx.doi.org/10.1071/zo02032.

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The particle-size distributions of the ingesta of the sacciform forestomach in free-ranging animals of a grazing macropod species [Macropus eugenii (tammar wallaby)], a grazer/browser [Macropus parma (parma wallaby)], a browser/grazer [Petrogale penicillata (brush-tailed rock-wallaby)] and a browser [Wallabia bicolor (swamp wallaby)] from Kawau Island, New Zealand, were compared with those of captive animals maintained on a standing ryegrass (Lolium perenne) sward. Nutrient digestibility was also measured in tammar and parma wallabies fed ryegrass or browse, i.e. fresh mahoe (Melicytus ramiflora) and this was related to particle-size distributions of the ingesta.There were significant differences in the particle size distributions of digesta from tammar and parma wallabies in the wild but not in captivity. In free-ranging animals the ingesta from both browsing species, the brush-tailed rock-wallaby and the parma wallaby, contained consistently greater proportions of coarse particles and smaller proportions of fine particles than did those of the tammar wallaby. These differences may be correlated with reported differences in their tooth morphologies. However, the presence of significant differences in particle-size distributions of the digesta between brush-tailed rock-wallabies and parma wallabies when constrained to grass, despite reported similarities in their tooth morphology, suggests that factors other than tooth morphology contribute to differences in the oral processing of food by browsing and grazing macropods. There were greater proportions of grass fragments in the coarse than in the finer fractions of ingesta from free-ranging brush-tailed rock-wallabies, indicating that this species is less effective at chewing grass.There were no overall differences between tammar and parma wallabies in the digestibilities of organic matter, neutral-detergent fibre (NDF) or acid-detergent fibre (ADF) but the NDF and ADF digestibilites of both species increased significantly with increase in the proportion of fine ingesta particles and with increase in mass of fermentative digesta.These findings indicate the importance of oral processing to digestive efficiency in macropods and the relationship between oral processing and tooth morphology.

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2

Lentle, R. G., K. J. Stafford, M. A. Potter, B. P. Springett e S. Haslett. "Temporal patterns of drinking in the tammar wallaby (Macropus eugenii Desmarest)". Australian Journal of Zoology 47, n. 1 (1999): 67. http://dx.doi.org/10.1071/zo98035.

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The temporal association between drinking and feeding in four captive tammar wallabies (Macropus eugenii Desmarest) maintained on various foods is examined. Tammars maintained on cubed carrots never drank. In tammars fed pellets food-associated drinking took place and 77.5% (7.4, s.e.) of drinking episodes commenced within 60 s of the beginning or end of a feeding event. Drinking events occurred singly, were of short duration and increased in frequency but not duration, when low-quality pellets were fed. Food- associated drinking in the tammar may result from the induction of drinking episodes of relatively fixed duration by an oropharyngeal reflex.

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3

O'Neill, RJ Waugh, MDB Eldridge, R. Toder, MA Ferguson-Smith, P. C. O'Brien e JAM Graves. "Chromosome evolution in kangaroos (Marsupialia: Macropodidae): Cross species chromosome painting between the tammar wallaby and rock wallaby spp. with the 2n = 22 ancestral macropodid karyotype". Genome 42, n. 3 (1 giugno 1999): 525–30. http://dx.doi.org/10.1139/g98-159.

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Marsupial mammals show extraordinary karyotype stability, with 2n = 14 considered ancestral. However, macropodid marsupials (kangaroos and wallabies) exhibit a considerable variety of karyotypes, with a hypothesised ancestral karyotype of 2n = 22. Speciation and karyotypic diversity in rock wallabies (Petrogale) is exceptional. We used cross species chromosome painting to examine the chromosome evolution between the tammar wallaby (2n = 16) and three 2n = 22 rock wallaby species groups with the putative ancestral karyotype. Hybridization of chromosome paints prepared from flow sorted chromosomes of the tammar wallaby to Petrogale spp., showed that this ancestral karyotype is largely conserved among 2n = 22 rock wallaby species, and confirmed the identity of ancestral chromosomes which fused to produce the bi-armed chromosomes of the 2n = 16 tammar wallaby. These results illustrate the fission-fusion process of karyotype evolution characteristic of the kangaroo group.

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4

Lentle, R. G., I. D. Hume, K. J. Stafford, M. Kennedy, B. P. Springett e S. Haslett. "Differences in renal and alimentary water conservation account for differences in the distribution of tammar and parma wallabies on Kawau Island, New Zealand". Australian Journal of Zoology 51, n. 4 (2003): 371. http://dx.doi.org/10.1071/zo02074.

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Surveys of two wallaby species on Kawau Island, New Zealand, indicated that their distribution was stable so as to permit niche partitioning. Multivariate analysis of environmental factors associated with the relative distribution of tammar and parma wallabies suggested that their distribution may be influenced by the availability of fresh water. Tammar wallabies have greater renal size, mass and relative medullary area than parma wallabies and thus may have greater renal water-conserving capabilities. The tammar colon is significantly longer than that of the parma wallaby and the water content of distal digesta is lower in tammar than in parma wallabies, indicating that the former species may also have greater colonic water-resorption capabilities. A laboratory comparison of the water consumption of tammar and parma wallabies showed that the former drink significantly less than the latter.The superior ability of tammar wallabies to colonise drier areas may have contributed to their survival in the presence of the closely related parma wallaby.

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5

Munn, Adam J., Peter Banks e Ian D. Hume. "Digestive plasticity of the small intestine and the fermentative hindgut in a marsupial herbivore, the tammar wallaby (Macropus eugenii)". Australian Journal of Zoology 54, n. 4 (2006): 287. http://dx.doi.org/10.1071/zo06004.

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We investigated the effects of a ground, pelleted diet versus natural forage on the gross morphology of the gastrointestinal tract of a medium-sized (5–7 kg body mass) macropodid marsupial, the tammar wallaby (Macropus eugenii). The empty wet mass (g) of the small intestine of tammar wallabies maintained on a pelleted diet for 6 weeks was 22% greater than that of animals maintained on natural forage, once body mass was taken into account by ANCOVA. Similarly, the body-mass-adjusted length of the tammar wallaby caecum and proximal colon combined was 25% longer in animals maintained on the pelleted diet compared with those maintained on forage. Our data suggest that food particle size may be directly involved in controlling the size of the post-gastric alimentary tract in tammar wallabies, and thus in their diet choice and nutritional ecology. Notably, this is the first study that links phenotypic plasticity of the gut directly to diet in a marsupial and we conclude that the tammar wallaby is an excellent model for exploring the causes and consequences of digestive plasticity in macropodid marsupials.

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6

Spindler, Rebecca E., Marilyn B. Renfree, Geoffrey Shaw e David K. Gardner. "Reactivating Tammar Wallaby Blastocysts Oxidize Glucose1". Biology of Reproduction 58, n. 6 (1 giugno 1998): 1425–31. http://dx.doi.org/10.1095/biolreprod58.6.1425.

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7

Kay, D. J., e A. L. Kitchener. "Immune response of the tammar wallaby (Macropus eugenii) to sperm antigens". Reproduction, Fertility and Development 15, n. 8 (2003): 429. http://dx.doi.org/10.1071/rd03009.

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In the present study, male and female tammar wallabies were immunised with whole tammar wallaby sperm in adjuvant. An assay for sperm antibodies using a live sperm ELISA has been developed to detect sperm surface antigens and used to validate an assay using a 3-[(3-cholamidopropyl) dimethylammonio]-1 propanesulfonate (CHAPS) membrane extract of whole tammar wallaby sperm. The tests were used to monitor the immune response to whole sperm in both male and female tammar wallabies. Antisera with a limited array of specificities were generated, with those locating to the midpiece region of the sperm appearing the most likely candidates for targets for fertility perturbation based on immunofluorescence of fixed and non-fixed sperm. These systemically generated antibodies were demonstrated to have access to both the female and male tammar reproductive tracts and were found on ejaculated sperm and antibodies from female sera and follicular fluid-labelled fresh ejaculated sperm from non-immunised males. Preliminary sequencing of these proteins has identified some possibilities for further investigation.

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8

Sankovic, Natasha, Wayne Bawden, John Martyn, Jennifer A. M. Graves e Kurt Zuelke. "Construction of a marsupial bacterial artificial chromosome library from the model Australian marsupial, the tammar wallaby (Macropus eugenii)". Australian Journal of Zoology 53, n. 6 (2005): 389. http://dx.doi.org/10.1071/zo05033.

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With the accelerating recognition of the power of comparative genomics, there is now enormous interest in sequencing the genomes of a broad range of species. Marsupials diverged at an important evolutionary time. The model Australian marsupial, the tammar wallaby (Macropus eugenii), has long been a resource for biological and genetic studies of marsupials, and the availability of a bacterial artificial chromosome (BAC) library will be a valuable resource in these studies. A tammar wallaby BAC library was constructed using pRazorBAC vector. It contains 55 296 clones with an average insert size of 108 kb, representing 2.2 times coverage of the wallaby genome (based on an estimated 2.7 × 109 bp haploid genome size). The library was arrayed in 384-well plates, and spotted in duplicate onto nylon membranes. Screening these membranes has yielded clones containing 34 single-copy genes distributed over the genome, while it failed for only one gene. Each probe isolated 1–12 BAC clones and, to date, no chimeric clones have been found. This BAC library will constitute an invaluable resource for creating physical maps, positional cloning of genes and other sequences in the tammar wallaby, as well as comparative mapping studies in mammals.

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9

Lentle, R. G., K. J. Stafford, Y. Hemar, P. Aseruvujanon, D. J. Mellor e P. J. Moughan. "Changes in the physical properties of stomach digesta during fasting in tammar wallabies (Macropus eugenii eugenii)". Australian Journal of Zoology 55, n. 6 (2007): 383. http://dx.doi.org/10.1071/zo07055.

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We compared changes in the particle size profiles, permeability and elastic shear modulus of digesta in the forestomach and rumen of fasting tammar wallabies (Macropus eugenii eugenii) and fistulated sheep respectively that had been fed chopped lucerne hay. The wet mass of digesta in the tammar wallaby stomach declined curvilinearly over 24 h. The relative proportion of particles >2 mm in size in tammar wallaby digesta increased significantly and that of particles <2 mm in size decreased significantly after 12 h of fasting. This contrasted with the sheep rumen digesta, in which the relative proportions of coarse and fine particles did not change significantly over time. The permeability of wallaby digesta increased significantly after 24 h whilst that of sheep declined. All samples of tammar digesta had a significant elastic component (G′) that was preserved throughout the period of fasting. Interaction between component particles was significant at all times, digesta behaving as a weak gel. The ratio of energy lost to energy stored during flow of digesta tended to decrease during the period of fasting, indicating an increase in behaviour as an elastic solid. The relationship between G′ and dry matter content and mean particle size indicated that these phenomena resulted from progressive loss of finer digesta particles and that digestion in the wallaby stomach, via permeation of the particulate by the fluid phase, was possible for up to 33 h after eating.

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10

Gamat, M., M. B. Renfree, A. J. Pask e G. Shaw. "230. Megalin, RAP and Nkx3.1 expression in the developing reproductive tract of a marsupial, the tammar wallaby". Reproduction, Fertility and Development 20, n. 9 (2008): 30. http://dx.doi.org/10.1071/srb08abs230.

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Androgens induce the differentiation of the urogenital sinus (UGS) to form a prostate. An early marker of this response is upregulation of the transcription factor Nkx3.1 in the urogenital epithelium in the precursors of prostatic buds. In tammars, prostate differentiation begins ~3 weeks after birth and after the time the testis starts to secrete androgens, and 2 weeks after androgen stimulated Wolffian duct differentiation. The reason for this delay in prostate differentiation is unexplained. Androgen receptors are present in the UGS, and the potent androgen, androstanediol, induces prostatic development in females. Whilst androgens may diffuse into cells by across the cell membrane, there is increasing evidence that steroids are also internalised actively via the cell-surface transport molecule Megalin. We are exploring the possibility that the delay may be related to the establishment of a Megalin-mediated pathway. Megalin is a cell surface receptor expressed on epithelia and mediates the endocytosis of a wide range of ligands, including SHBG-bound sex steroids. Megalin action is regulated by Receptor Associated Protein (RAP), which acts as an antagonist to Megalin action. This study cloned partial sequences of Megalin, RAP and Nkx3.1 and examined their expression in the developing urogenital sinus of the tammar wallaby using RT–PCR. The cellular distribution of Megalin protein in the developing UGS was examined using immunohistochemistry. Megalin, RAP and Nkx3.1 in the tammar were all highly conserved with eutherian orthologueues. Megalin and Nkx3.1 transcripts were detected in the liver, kidney, ovary, testis and developing urogenital sinus of male and female tammars. In the developing UGS of the tammar, there was strong staining for Megalin protein in the urogenital epithelium with some diffuse staining in the surrounding mesenchyme. Together, these results suggest that Megalin could be a key gene in the mediation of androgen action in prostatic development in the tammar wallaby.

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11

Magarey, Genevieve M., e Karen E. Mate. "Timing and ultrastructure of events following intracytoplasmic sperm injection in a marsupial, the tammar wallaby (Macropus eugenii)". Reproduction, Fertility and Development 15, n. 7 (2003): 397. http://dx.doi.org/10.1071/rd03033.

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The aim of the present study was to determine the timing of oocyte activation, sperm decondensation and pronucleus formation after intracytoplasmic sperm injection (ICSI) in the tammar wallaby and to determine the fate of sperm structures at an ultrastructural level. Metaphase II-stage tammar wallaby oocytes were injected with spermatozoa and cultured for 1 (n = 15), 2 (n = 24), 4 (n = 30), 6 (n = 14), 8 (n = 32), 10 (n = 25), 12 (n = 29) or 19 h (n = 12). Oocytes were assessed using light, fluorescence and electron microscopy. The timing of oocyte activation and sperm decondensation after ICSI in the tammar wallaby is relatively similar to that of some eutherian species. Resumption of meiosis II was observed from 1 h and the first female pronucleus was seen 6 h after ICSI. Most oocytes (88%) possessed a female pronucleus by 10 h. Intact acrosomes persisted with intact sperm heads up to 2 h after ICSI. At 10 h, 80% of oocytes possessed a male pronucleus. The sperm tail had undergone considerable degeneration by 10 h after ICSI, including breakdown of the fibrous sheath dense fibres. The identification of sperm tail and midpiece remnants adjacent to pronuclei confirms that the events observed in wallaby oocytes after ICSI are not due to parthenogenetic activation.

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12

D Patterson, S., K. Bell e WE Poole. "Tammar Wallaby Plasma Protease Inhibitory (Pi) Proteins". Australian Journal of Biological Sciences 40, n. 4 (1987): 355. http://dx.doi.org/10.1071/bi9870355.

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Electrophoretic examination (isoelectric focusing and polyacrylamide gel electrophoresis) of 157 plasmas from a Kangaroo Island population of tammar wallabies (Macropus eugenii) resulted in the identification of five putative condominant protease inhibitor alleles, F, I, M, P and S, which exhibited microheterogeneity due to variable terminal sialic acid content. The frequencies of the five alleles in this popUlation were 0.041(F), 0.682(1), 0.194(M), 0.073(P) and O.OIO(S). The proteins had isoelectric points in the pH range 3.94-4.38, Mr of 60 500 to 66 000 and were identified as protease inhibitors by their abilities to inhibit both trypsin and chymotrypsin. Protein blotting of the denatured proteins demonstrated cross reaction with antiserum to human ai-protease inhibitor.

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13

Schneider, Nanette Y., Terence P. Fletcher, Geoff Shaw e Marilyn B. Renfree. "The vomeronasal organ of the tammar wallaby". Journal of Anatomy 213, n. 2 (agosto 2008): 93–105. http://dx.doi.org/10.1111/j.1469-7580.2008.00933.x.

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14

Young, L. J., e E. M. Deane. "Culture and Stimulation of Tammar Wallaby Lymphocytes". Veterinary Research Communications 31, n. 6 (23 gennaio 2007): 685–701. http://dx.doi.org/10.1007/s11259-007-0057-9.

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15

McFarlane, James R., Carl D. Rudd, Lynda M. Foulds, Terry P. Fletcher e Marilyn B. Renfree. "Isolation and partial characterization of tammar wallaby luteinizing hormone and development of a radioimmunoassay". Reproduction, Fertility and Development 9, n. 4 (1997): 475. http://dx.doi.org/10.1071/r96089.

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Tammar wallaby (Macropus eugenii) luteinizing hormone (LH) was purified from pituitaries collected from wild and captive populations by salt sequential precipitation, ion exchange chromatography and gel filtration. Pituitary tissue (5 g) yielded 1·8 mg of purified wallaby luteinizing hormone (ME-14B), as verified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). A heterologous radioimmunoassay has been developed for measurement of LH in plasma of marsupials using a monoclonal antibody raised against bovine LH (518B7). This assay system was able to measure basal LH concentrations in male and female tammars and detected a significant rise in plasma LH in response to oestradiol benzoate in female tammars and luteinizing hormone-releasing hormone (LHRH) in males. Parallel dose–response curves were also obtained from pituitary extracts from four other species of marsupial (brushtail possum, Trichosurus vulpecula; brown antechinus,Antechinus stuartii; kowari, Dasyuroides byrnei; and Eastern pygmy possum,Cercartetus nanus) in this assay, which suggests its usefulness in the measurement of LH in other marsupial species.

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16

Collet, C., R. Joseph e K. Nicholas. "Molecular characterization and in-vitro hormonal requirements for expression of two casein genes from a marsupial". Journal of Molecular Endocrinology 8, n. 1 (febbraio 1992): 13–20. http://dx.doi.org/10.1677/jme.0.0080013.

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ABSTRACT Two marsupial casein genes have been isolated from a tammar wallaby (Macropus eugenii) mammary gland cDNA library. Comparisons of the tammar α- and β-casein genes with their eutherian homologues reveal extensive divergence at the levels of nucleotide and amino acid sequences. Regions of similarity between the tammar and eutherian Ca2+-sensitive caseins are restricted to the major phosphorylation sites and the signal peptides. Quantification of casein mRNA levels in hormone-stimulated mammary gland explants from tammars in late pregnancy suggests that maximal induction of the β-casein gene is dependent upon prolactin and insulin, while maximal induction of the α-casein gene is dependent upon prolactin, insulin and cortisol. These results are in contrast to earlier studies which show that the maximal induction of a putative 19 kDa casein, α-lactalbumin and β-lactoglobulin in the tammar mammary gland is dependent upon prolactin alone. The expression of the latter three genes is not modulated by other hormones known to play a role in the in-vitro initiation of lactation in eutherians.

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17

Lentle, R. G., I. D. Hume, K. J. Stafford, M. Kennedy, S. Haslett e B. P. Springett. "Comparisons of indices of molar progression and dental function of brush-tailed rock-wallabies (Petrogale penicillata) with tammar (Macropus eugenii) and parma (Macropus parma) wallabies". Australian Journal of Zoology 51, n. 3 (2003): 259. http://dx.doi.org/10.1071/zo02007.

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We measured parameters of molar progression and dental function in the brush-tailed rock-wallaby (Petrogale pencilliata) (a browser/grazer) and compared them with data from the tammar wallaby (Macropus eugenii) (a grazer) and the parma wallaby (Macropus parma) (a grazer/browser).Although the mean value of the molar index (MI) was higher in rock-wallabies than in parma and tammar wallabies the mean rate of increase of log(MI) with log(body mass) was similar in the three species. Reported differences between these species in their rates of molar progression with age may therefore result from differences in their rates of bodily growth. The findings indicate that molar progression in the rock-wallaby is governed by the growth of the bones of the viscerocranium (mesial shift), rather than by diet-induced movement of the teeth within the bones of the viscerocranium (mesial drift), and was not influenced by the persistence of P4 premolars. It is therefore unlikely that differences in the rate of molar progression are directly linked to differences in diet.The relationship between functional dental parameters and body mass differed between brush-tailed rock-wallabies and tammar wallabies, species of differing dietary habit, but did not differ between brush-tailed rock-wallabies and parma wallabies, species of more similar dietary habit. Thus the total length of upper transverse lophine ridges and the interlophine distances of the M1 to M3 upper molars of brush-tailed rock-wallabies were not different from those of parma wallabies but were significantly greater than those of tammar wallabies. These differences can be interpreted in terms of greater emphasis on crushing/grinding of browse in the rock-wallabies and parma wallabies.

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18

Jungnickel, M. K., e L. A. Hinds. "Hormonal profiles in the tammar wallaby, Macropus eugenii, following FSH/LH superovulation". Reproduction, Fertility and Development 12, n. 8 (2000): 457. http://dx.doi.org/10.1071/rd99037.

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This study investigated the effect of superovulation with exogenous porcine FSH/LH on the normal hormonal milieu of the tammar wallaby (Macropus eugenii). During seasonal and lactational quiescence, groups of 6 females were treated with either multiple doses of porcine follicle-stimulating hormone (FSH) (8 6 mg i.m., 12 h apart) followed by a single subcutaneous injection of 4 mg porcine luteinizing hormone (LH) on Day 5 or saline. Blood samples were collected throughout each 10-day experimental period and each female was examined twice daily for signs of a recent copulation. On Day 9, females were killed and their reproductive tracts removed for examination and flushed for eggs. During both seasonal and lactational quiescence, treatment with porcine FSH/LH induced circulating concentrations of progesterone, porcine FSH and porcine LH that were within the normal range of the natural tammar oestrous cycle. However, higher plasma oestradiol concentrations (30–50 g mL–1) than would be expected in a natural tammar preovulatory rise and the presence of ‘highly stimulated’ ovaries in several of the treated animals suggests that some degree of over-stimulation was occurring. During both seasonal sampling periods, behavioural oestrus was detected in treated tammars in the absence of a withdrawal of progesterone. This data suggests that plasma progesterone is not the critical factor inducing behavioural oestrus.

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Mate, Karen E., e Janine M. Buist. "Timing and regulatory aspects of oocyte maturation in vitro in the tammar wallaby (Macropus eugenii)". Reproduction, Fertility and Development 11, n. 5 (1999): 247. http://dx.doi.org/10.1071/rd99069.

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Oocytes from a marsupial, the tammar wallaby (Macropus eugenii), resemble those of eutherian mammals in their ability to resume meiosis in vitro when cultured under suitable conditions. Culture for 42–48 h in Eagle’s minimum essential medium (EMEM) supplemented with 10% fetal calf serum, and 10 g mL –1 porcine luteinizing hormone (pLH) was required in order for oocytes, collected from the large antral follicles (> 2 mm diameter) of tammar wallabies (primed with 6 mg of porcine follicle stimulating hormone twice daily for four days), to proceed to metaphase II (MII) of meiosis. Under these conditions, chromatin condensation was observed within 4–8 h of culture in 61% of oocytes; metaphase I (MI) chromosomes were observed from 18–30 h of culture (66%); and most oocytes (76%) progressed to MII by 42 h in vitro. The addition of cycloheximide, a protein synthesis inhibitor, at concentrations of 1–100 g mL –1 , prevented maturation of tammar wallaby oocytes in vitro. This effect was reversible, as oocytes washed free of cycloheximide after 4 h of incubation were able to progress to MII. The addition of cycloheximide to wallaby oocytes at MI of meiosis prevented normal progression to MII suggesting that proteins critical for nuclear maturation are synthesized throughout the maturation process. Genistein, a protein kinase inhibitor decreased maturation of wallaby oocytes in a dose dependent manner. However, the concentration required to significantly inhibit maturation of wallaby oocytes (60 g mL –1 ) was greater than that required for eutherian species. Most wallaby oocytes were able to undergo germinal vesicle breakdown (GVBD) in the presence of high concentrations of genistein but produced abnormal chromatin configurations and were unable to progress to MII. Future studies will examine whether cytoplasmic changes occur in marsupial oocytes in vitro and their temporal relationship to nuclear maturation.

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Ishihara, Teruhito, Oliver W. Griffith, Gerard A. Tarulli e Marilyn B. Renfree. "Male germline development in the tammar wallaby, Macropus eugenii". Reproduction 161, n. 3 (marzo 2021): 333–41. http://dx.doi.org/10.1530/rep-20-0634.

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Male germ cells undergo two consecutive processes – pre-spermatogenesis and spermatogenesis – to generate mature sperm. In eutherian mammals, epigenetic information such as DNA methylation is dynamically reprogrammed during pre-spermatogenesis, before and during mitotic arrest. In mice, by the time germ cells resume mitosis, the majority of DNA methylation is reprogrammed. The tammar wallaby has a similar pattern of germ cell global DNA methylation reprogramming to that of the mouse during early pre-spermatogenesis. However, early male germline development in the tammar or in any marsupial has not been described previously, so it is unknown whether this is a general feature regulating male germline development or a more recent phenomenon in mammalian evolutionary history. To answer this, we examined germ cell nuclear morphology and mitotic arrest during male germline development in the tammar wallaby (Macropus eugenii), a marsupial that diverged from mice and humans around 160 million years ago. Tammar pro-spermatogonia proliferated after birth and entered mitotic arrest after day 30 postpartum (pp). At this time, they began moving towards the periphery of the testis cords and their nuclear size increased. Germ cells increased in number after day 100 pp which is the time that DNA methylation is known to be re-established in the tammar. This is similar to the pattern observed in the mouse, suggesting that resumption of germ cell mitosis and the timing of DNA methylation reprogramming are correlated and conserved across mammals and over long evolutionary timescales.

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Young, Lauren J., Jessica Gurr, Katrina Morris, Sabine Flenady e Katherine Belov. "Molecular characterisation of Interleukin-2 in two Australian marsupials (the tammar wallaby, Notamacropus eugenii, and the Tasmanian devil, Sarcophilus harrisii) facilitates the development of marsupial-specific immunological reagents". Australian Mammalogy 41, n. 1 (2019): 39. http://dx.doi.org/10.1071/am17027.

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Interleukin-2 (IL-2) is an important regulator of cellular immunity in mammals. For many years, our inability to identify the expression of this cytokine in marsupials hindered our capacity to progress studies in metatherian immunology. Here, we report the use of molecular techniques to characterise the IL-2 gene for the tammar wallaby (Notamacropus eugenii) and the Tasmanian devil (Sarcophilus harrisii), which allowed the prediction of the structure and probable functions of the IL-2 proteins of these species. Deduced marsupial IL-2 proteins show considerable sequence identity to each other and to common brushtail possum (Trichosurus vulpecula) IL-2 (≥65%) but shared only 35% (tammar wallaby) and 32% (Tasmanian devil) identity with human IL-2. This difference means that reagents used to study IL-2 in human and other eutherians are unlikely to cross-react with marsupials. As a key step in furthering our ability to study cellular immune responses in marsupials and, more specifically, the susceptibility of macropodoid marsupials to intracellular pathogens, a polyclonal antibody was designed for the detection and future investigation of tammar wallaby IL-2 protein expression. The molecular data and polyclonal antibody described herein will support our development of gene probes and immunological reagents that will aid studies of infection and disease in marsupials.

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Rose, R. W., J. A. A. Horak, A. D. Shetewi e S. M. Jones. "Pregnancy in a marsupial, the Tasmanian pademelon (Thylogale billardierii)". Reproduction, Fertility and Development 11, n. 3 (1999): 175. http://dx.doi.org/10.1071/rd99058.

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The Tasmanian pademelon, Thylogale billardierii, is a medium-sized wallaby that adapts well to captivity and, unlike the well-studied tammar wallaby, is capable of breeding all year round. It may, there-fore, be a useful model species for research into the reproductive biology of macropod marsupials. This paper presents necessary background data on histological changes in the reproductive organs and the rate of embryonic growth during gestation in T. billardierii. After Day 4 RPY (removal of young from the pouch) the gravid and non-gravid uteri differ significantly in some histological parameters. The corpus luteum becomes active by Day 6 RPY and is fully developed by Day 14 RPY; it begins to degenerate from Day 19 RPY. Plasma progesterone concentrations through gestation follow a pattern similar to that in the tammar wallaby. There is an early, smaller, peak at Day 5 RPY, with plasma concentrations of progesterone then falling until the larger pre-partum peak occurs several days before birth.

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23

Lentle, R. G., I. D. Hume, K. J. Stafford, M. Kennedy, S. Haslett e B. P. Springett. "Molar progression and tooth wear in tammar (Macropus eugenii) and parma (Macropus parma) wallabies". Australian Journal of Zoology 51, n. 2 (2003): 137. http://dx.doi.org/10.1071/zo02008.

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Abstract (sommario):

We investigated the functional significance of molar progression and the influence of diet on the usefulness of molar progression as an index of age in two macropodid marsupials, the tammar wallaby (Macropus eugenii), a grazing species, and the parma wallaby (Macropus parma), a browser/grazer, by exploring the relationships between the index of molar progression and several skull and tooth parameters. We also tested allometric models that related molar progression and aspects of tooth morphology to body mass. Results support the notion that molar progression in these closely related macropods results from 'mesial shift'(forward movement resulting from growth of the bones of the skull bearing the dentary, the anterior viscerocranium) rather than from 'mesial drift' (forward movement of molars relative to the anterior viscerocranium).There were no significant differences between the two species in the rate of molar progression despite differences in diet. Instead, the greater reliance of tammar wallabies on grasses was reflected in differences in their tooth morphology from that of parma wallabies. The sum of the breadths of erupted molariform teeth of tammars increased significantly faster with body mass and with length of the anterior viscerocranium than in parma wallabies and approximated a theoretical model for compensation with metabolic body mass more closely than models based on other morphological parameters.The total mesiodistal length of dentition, the mesiodistal lengths of the component teeth of the proximal molar row, and the distance between the mesial and distal lophs were all significantly lower in tammar wallabies than in parma wallabies. These differences result in tammar wallabies having greater numbers of transverse cutting edges per unit of molar tooth length, which maximises the efficiency of comminution of long grass fibres.

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24

Molinia, FC, e JC Rodger. "Pellet-freezing spermatozoa of two marsupials: the tammar wallaby, Macropus eugenii, and the brushtail possum, Trichosurus vulpecula". Reproduction, Fertility and Development 8, n. 4 (1996): 681. http://dx.doi.org/10.1071/rd9960681.

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Abstract (sommario):

A protocol was developed for pellet-freezing spermatozoa of the tammar wallaby and the brushtail possum. Seren was collected by electro-ejaculation and wallaby spermatozoa were washed by 'swim-up' into phosphate-buffered saline (PBS), whereas possum spermatozoa were not washed. Wallaby spermatozoa were screened for toxicity in diluents containing a range of cryoprotectants (0-10%): dimethyl sulfoxide (DMSO), ethylene glycol and propanediol. Possum spermatozoa were tolerant of diluents containing 17.5% glycerol. Wallaby and possum spermatozoa were diluted 1:1 with the most promising cryoprotective diluents (final concentrations in PBS: possum, 17.5% glycerol; wallaby, 7.5% glycerol + 10% DMSO) and, after 5 min equilibration at room temperature, were pellet-frozen. Pellets were thawed (35 degrees C) and wallaby spermatozoa were washed by centrifugation (200 g for 5 min) and resuspended in PBS to minimize cryoprotectant toxicity. A high proportion of possum spermatozoa was recovered after freezing (67.5%), having good progressive motility (3.6 on a 0-5 scale). The progressive motility of frozen-thawed wallaby spermatozoa was also high (3.0), but only 10% of motile spermatozoa were recovered. The pellet-freezing method in conjunction with the post-thaw washing procedure (wallaby) may produce a viable population of cryopreserved marsupial spermatozoa suitable for use in assisted-breeding techniques such as in vitro fertilization and artificial insemination.

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25

Baudinette, R. V., G. K. Snyder e P. B. Frappell. "Energetic cost of locomotion in the tammar wallaby". American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 262, n. 5 (1 maggio 1992): R771—R778. http://dx.doi.org/10.1152/ajpregu.1992.262.5.r771.

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Abstract (sommario):

Rates of oxygen consumption and blood lactate levels were measured in tammar wallabies (Macropus eugenii) trained to hop on a treadmill. In addition, the work required to overcome wind resistance during forward locomotion was measured in a wind tunnel. Up to approximately 2.0 m/s, rates of oxygen consumption increased linearly with speed and were not significantly different from rates of oxygen consumption for a quadruped of similar body mass. Between 2.0 and 9.4 m/s, rates of oxygen consumption were independent of hopping speed, and between 3.9 and 7.9 m/s, the range over which samples were obtained, blood lactate levels were low (0.83 +/- 0.13 mmol.min-1.kg-1) and did not increase with hopping speed. The work necessary to overcome drag increased exponentially with speed but increased the energy cost of locomotion by only 10% at the average speed attained by our fast hoppers. Thus, during hopping, the energy cost of locomotion is effectively independent of speed. At rates of travel observed in the field, the estimated energy cost of transport in large macropods is less than one-third the cost for a quadruped of equivalent body mass. The energetic savings associated with this unique form of locomotion may have been an important physiological adaptation, enabling large macropods to efficiently cover the distances necessary to forage in the semiarid landscapes of Australia.

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26

Blumstein, Daniel T., Janice C. Daniel, Jodie G. Ardron e Christopher S. Evans. "Does Feeding Competition Influence Tammar Wallaby Time Allocation?" Ethology 108, n. 11 (novembre 2002): 937–45. http://dx.doi.org/10.1046/j.1439-0310.2002.00823.x.

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27

DEANE, E. M., K. BASDEN, L. BURNETT, A. PROOS e D. W. COOPER. "Serum analytes in the Tammar wallaby, Macropus eugenii". Australian Veterinary Journal 75, n. 2 (febbraio 1997): 141–42. http://dx.doi.org/10.1111/j.1751-0813.1997.tb14177.x.

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28

Cone-Wesson, Barbara K., Kenneth G. Hill e Guang-Bin Liu. "Auditory brainstem response in tammar wallaby (Macropus eugenii)". Hearing Research 105, n. 1-2 (marzo 1997): 119–29. http://dx.doi.org/10.1016/s0378-5955(96)00199-2.

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29

Hickford, D., S. Frankenberg e M. B. Renfree. "Performing Surgery on Tammar Wallaby (Macropus eugenii) Adults". Cold Spring Harbor Protocols 2009, n. 12 (1 dicembre 2009): pdb.prot5333. http://dx.doi.org/10.1101/pdb.prot5333.

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30

Hickford, D., S. Frankenberg e M. B. Renfree. "Surgery on Tammar Wallaby (Macropus eugenii) Pouch Young". Cold Spring Harbor Protocols 2009, n. 12 (1 dicembre 2009): pdb.prot5334. http://dx.doi.org/10.1101/pdb.prot5334.

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31

Hickford, D., S. Frankenberg e M. B. Renfree. "Culturing Tammar Wallaby (Macropus eugenii) Pouch Young Gonads". Cold Spring Harbor Protocols 2009, n. 12 (1 dicembre 2009): pdb.prot5336. http://dx.doi.org/10.1101/pdb.prot5336.

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32

Nicholas, K. R., e C. H. Tyndale-Biscoe. "Prolactin-dependent accumulation of α-lactalbumin in mammary gland explants from the pregnant tammar wallaby (Macropus eugenii)". Journal of Endocrinology 106, n. 3 (settembre 1985): 337–42. http://dx.doi.org/10.1677/joe.0.1060337.

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Abstract (sommario):

ABSTRACT The minimal hormonal requirements for the in-vitro accumulation of α-lactalbumin have been investigated in a marsupial, the tammar (Macropus eugenii). Mammary gland explants from 24-day pregnant tammars cultured in medium containing bovine insulin, cortisol and ovine prolactin showed a progressive increase in accumulation of α-lactalbumin during 4 days of incubation. No increment was observed if prolactin was omitted from the medium. However, a similar rate of increase was observed after 3 days of culture in medium containing prolactin alone. This induction of α-lactalbumin was maximal at a prolactin concentration of approximately 0·02 mg/l, which corresponds to physiological levels during pregnancy and early lactation. The absence of an effect of bovine insulin on tammar explants is not due to a general unresponsiveness to this hormone since insulin-stimulated DNA synthesis and amino acid uptake was evident after 3 days of culture. The inclusion of tri-iodothyronine and raised concentrations of cortisol in culture media have been shown to modulate α-lactalbumin synthesis in eutherian mammals but were without effect in the tammar. In addition, increased levels of progesterone did not inhibit the induction of α-lactalbumin, confirming an earlier invivo study suggesting that progesterone withdrawal may not be the lactogenic trigger in this species. Thus the pregnant tammar is the only species yet described in which α-lactalbumin is induced maximally in vitro in response to a single hormone. J. Endocr. (1985) 106, 337–342

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33

Lentle, R. G., I. D. Hume, K. J. Stafford, M. Kennedy, S. Haslett e B. P. Springett. "Comparison of tooth morphology and wear patterns in four species of wallabies". Australian Journal of Zoology 51, n. 1 (2003): 61. http://dx.doi.org/10.1071/zo01078.

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Abstract (sommario):

Tooth morphology of two browsing macropods (brush-tailed rock-wallabies and swamp wallabies), one grazing species (tammar wallaby) and one mixed feeder (parma wallaby) are compared. The dental action of a single tammar wallaby was studied by cinefluoroscopy. Cinefluoroscopy showed independent rotation of each hemi-jaw on occlusion in the tammar, and the disposition of molar striae suggest a similar pattern of jaw movement in all four species. There was a close relationship between incisor and molar action in both grazing and browsing species. Initial occlusion of the anterior facets of the incisors brought about a grasping action in browsing species and a fine cutting action in grazing species. In both grazing and browsing species these incisor actions were coincident with a cutting action by the transverse lophs during molar occlusion. Subsequent independent rotation of each hemi-jaw results in fine cutting by the lateral facets of the incisors, in both grazers and browsers, at the same time as the molar arrays perform a crushing action in browsers and a secondary cutting action in grazing species. Thus the teeth of the four species showed a number of similarities (independent rotation of each hemi-jaw) along with some differences (incisor and molar actions) that appear to represent adaptations for efficient aquisition and oral processing of browse or graze.

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34

Frankenberg, S., A. J. Pask e M. B. Renfree. "259. Pluripotency genes in a marsupial, the tammar wallaby". Reproduction, Fertility and Development 20, n. 9 (2008): 59. http://dx.doi.org/10.1071/srb08abs259.

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Abstract (sommario):

Markers of pluripotency and early differentiation in the early embryo have been extensively characterised in eutherian species, most notably the mouse. By comparison, mechanisms controlling pluripotency and early lineage specification have received surprisingly little attention in marsupials, which represent the second major infraclass of mammals. Early marsupial embryogenesis exhibits overt morphological differences to that of eutherians, however the underlying developmental mechanisms may be conserved. In order to characterise early marsupial development at the molecular level, we have identified, cloned and analysed expression of orthologueues of several eutherian genes encoding transcription factors and signalling molecules involved in regulating pluripotency and early lineage specification. These genes include POU5F1 (OCT4), SOX2, NANOG, FGF4, FGFR2, CDX2, EOMES, TEAD4, GATA6 and KITL and are all expressed at early stages of development in the tammar. In addition, we have identified and cloned tammar POU2, which has orthologueues in non-mammalian vertebrates. POU2 is a paralogue of POU5F1 – a master regulator of pluripotency in eutherians. Genomic analysis indicates that POU5F1 arose via gene duplication of POU2 before the monotreme-therian divergence. Both genes have persisted in marsupials and monotremes, while POU2 was lost early during eutherian evolution. Similar expression profiles of tammar POU5F1 and POU2 in early embryos and gonadal tissues suggest possible overlapping roles in the maintenance of pluripotency.

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35

Hendry, KA, KJ Simpson, KR Nicholas e CJ Wilde. "Autocrine inhibition of milk secretion in the lactating tammar wallaby (Macropus eugenii)". Journal of Molecular Endocrinology 21, n. 2 (1 ottobre 1998): 169–77. http://dx.doi.org/10.1677/jme.0.0210169.

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Abstract (sommario):

The lactating tammar wallaby progressively alters the rate of secretion and composition of its milk to provide appropriate nutrition for the developing offspring, whose needs are signalled by changes in the pattern and efficiency of its sucking. Tammars are also capable of asynchronous concurrent lactation, when the mother provides a dilute milk for a newborn young permanently attached to the teat (phase 2A of lactation), and a concentrated milk from an adjacent mammary gland for a young-at-heel (phase 3). The relationship between suckling behaviour and milk secretion, and the ability of adjacent glands to function independently, suggests that milk secretion is controlled locally, within each mammary gland, by a mechanism sensitive to frequency and completeness of milk removal. To determine if tammar milk contains a factor able to control milk secretion, milk fractions have been screened in tissue and cell culture bioassays. A 6-30 kDa fraction of phase 3 whey was found to inhibit milk constituent synthesis and secretion in vitro, and inhibitory activity was associated with two discrete fractions obtained by anion exchange chromatography, which contained protein bands migrating anomalously at 66 kDa and 63 kDa in SDS-PAGE. These bands were recognised in Western blotting by antiserum raised against a bovine autocrine inhibitor of milk secretion. By the same criteria, milk secreted in phase 2B of tammar lactation, when milk secretion is low and suckling intermittent but less vigorous than phase 3, also contained a feedback inhibitor of milk secretion. The results indicate that, as in dairy animals, marsupial milk secretion is under local control through feedback inhibition by a milk protein, and raise the possibility that autocrine feedback may influence the transition from phases of low milk secretion (phase 2A, 2B) to a high rate in the final third phase of lactation.

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36

Hickford, D., A. Pask, G. Shaw e M. B. Renfree. "264. Primordial germ cell specification in a marsupial, the tammar wallaby". Reproduction, Fertility and Development 20, n. 9 (2008): 64. http://dx.doi.org/10.1071/srb08abs264.

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Abstract (sommario):

Primordial germ cells (PGCs) are the precursors of the gametes. In the mouse, PGCs are specified within the proximal epiblast in response to signals from the extraembryonic membranes during early gastrulation. Epiblast cells competent to form PGCs express Ifitm3. A subset of these cells then express Blimp1, a marker of PGC precursors. Once lineage-restricted, PGCs express Stella. Germ cells entering the gonads express VASA protein, which is a component of the germ plasm in animals in which germ cells are specified by the inheritance of maternal determinatives. Almost all of the research on mammalian PGC specification has used the mouse as a model and it is tacitly assumed that findings in the mouse will apply to mammals in general. We are using the tammar wallaby as a marsupial model for PGC specification. Eutherians and marsupials diverged 125–148 million years ago, so comparisons between the two will provide insights into the evolution of the control of mammalian PGC specification. There are IFITM clusters in both the human (chromosome 11) and mouse (chromosome 7). In the mouse, IFITM1, 2 and 3 are expressed in PGCs, whereas IFITM4 and 5 are not (1). Only one IFITM member, IFITM5, is annotated in the opossum Ensemble database. We have cloned one tammar IFITM member and identified at least one other putative member in the tammar trace archive database. We have also cloned tammar BLIMP1 and VASA, both of which show high sequence conservation with other mammals. RT–PCR profiles for both genes during tammar gastrulation are similar to those for the mouse. In contrast, no marsupial STELLA orthologueue has been identified in either the opossum or tammar genomes. These findings suggest that some but not all of the signals and mechanisms involved in eutherian PGC specification are also applicable to marsupials. (1) Lange UC, Saitou M, Western P, Barton SC and Surani MA (2003) BMC Dev. Biol. Epub 2003 Mar 19

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37

Lentle, R. G., I. D. Hume, K. J. Stafford, M. Kennedy, B. P. Springett, R. Browne e S. Haslett. "Temporal aspects of feeding events in tammar (Macropus eugenii) and parma (Macropus parma) wallabies. I. Food acquisition and oral processing". Australian Journal of Zoology 52, n. 1 (2004): 81. http://dx.doi.org/10.1071/zo02043.

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Abstract (sommario):

We studied parameters that influence the efficiency of food acquisition and oral processing in the tammar wallaby (a grazer) and the parma wallaby (a grazer/browser), both in captivity and under free range on Kawau Island, New Zealand.In captivity, both species spent less time feeding per gram of dry matter intake when browsing than when grazing, and there were no significant differences between the species with respect to the rates of feeding per gram of dry matter intake of a given food. However, under free-ranging conditions, tammar wallabies spent longer feeding than did parma wallabies, so it was likely that tammar wallabies spent more time grazing than browsing. Differences in the relationships between feeding event and inter-feed interval duration in captive and free-ranging wallabies indicated that feeding behaviour was influenced by different factors in the two situations.Microtemporal analysis of the chewing sounds of free-ranging tammar and parma wallabies showed that the interval between the first and second sounds in a 'run' of chewing sounds was longer than that between subsequent intervals, indicating that there was a time cost associated with food aquisition. However, as there were no significant differences between the two wallaby species, either in the mean duration of 'runs' of chewing sounds within feeding events or in the mean duration of whole feeding events, this cost was similar for grazing and browsing. Chewing characteristics differed from those of larger (eutherian) herbivores in that the numbers of chews in a run were not randomly distributed, both species having a preponderance of runs with seven chews. Whilst, the intervals between the second and subsequent chewing sounds in a run did not vary in a periodic manner, such as would occur in batch processing of food, they were more prolonged in runs with more chewing sounds and were significantly longer in tammar wallabies than in parma wallabies. Thus, the slower rate of oral processing of grass was likely due to a generally slower rate of chewing when grazing than when browsing.

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38

Hinds, LA, TP Fletcher e JC Rodger. "Hormones of oestrus and ovulation and their manipulation in marsupials". Reproduction, Fertility and Development 8, n. 4 (1996): 661. http://dx.doi.org/10.1071/rd9960661.

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Abstract (sommario):

Oestrus and ovulation occur spontaneously in the majority of marsupials, with behavioural oestrus usually occurring 1-2 days before ovulation. The hormone changes that occur at this time have been described in the most detail for the monovular tammar wallaby Macropus eugenii. The respective roles of the Graafian follicle, corpus luteum and the pituitary in the events leading up to oestrus and ovulation in this species are also reviewed. Recently, various protocols have been developed for superovulation of marsupials, including Australian species, such as the brush-tailed possum, fat-tailed dunnart, brush-tailed bettong and tammar wallaby, and the American laboratory opossum, Monodelphis domestica. These protocols provide an opportunity for studying the regulation of ovarian activity and for the collection of larger quantities of material for the study of gamete maturation, in vitro fertilization and embryonic development.

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39

Collet, C., R. Joseph e K. Nicholas. "Cloning, cDNA analysis and prolactin-dependent expression of a marsupial alpha-lactalbumin". Reproduction, Fertility and Development 2, n. 6 (1990): 693. http://dx.doi.org/10.1071/rd9900693.

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Abstract (sommario):

The gene for alpha-lactalbumin has been cloned from a tammar wallaby (Macropus eugenii) mammary gland cDNA library. Tammar alpha-lactalbumin has approximately 50 and 30% homology to the alpha-lactalbumins of eutherians at the levels of nucleotide and protein sequence respectively. Comparison of the inferred tammar polypeptide sequence with the sequence of the eutherian proteins reveals extensive divergence at almost all of the non-essential amino acid residues. However, the hydropathy plots of the tammar protein are almost identical to those of eutherian alpha-lactalbumins, suggesting that protein conformation is conserved. The tammar gene encodes a transcript of approximately 975 bases. Northern blot analysis of hormone-stimulated mammary gland explants shows that maximal induction of alpha-lactalbumin mRNA is dependent on prolactin and that expression is not modulated by other hormones that play a role in the initiation of lactation in eutherians.

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40

Lentle, R. G., K. J. Stafford, M. A. Potter, B. P. Springett e S. Haslett. "Ingesta particle size, food handling and ingestion in the tammar wallaby (Macropus eugenii Desmarest)". Australian Journal of Zoology 47, n. 1 (1999): 75. http://dx.doi.org/10.1071/zo98038.

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Abstract (sommario):

The particle size distribution of stomach contents from 25 tammar wallabies (Macropus eugenii Desmarest) shot in the Okataina State Forest and adjoining farmland near Rotorua, New Zealand, were determined. There was a greater percentage of finer, and a smaller percentage of larger, particles than reported in the stomach contents of larger macropods. The chewing and biting activities of four free-ranging tammars fitted with radio-microphone collars were monitored. Chewing rates (chews per minute) were similar to those of other small herbivorous vertebrates. There were significantly lower rates of chewing and higher chew-to- bite ratios when browsing than when grazing. Observations of browsing by three captive tammars showed inefficient handling by mutually opposed palms and digitopalmar grip, resulting in low rates of ingestion. We suggest that tammars lower the time necessary for fermentation of food by reducing the size of food particles, and that their choice between graze and browse is influenced by food handling and chewing investment.

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41

Arthur, H., K. Bell e D. W. Cooper. "Plasma protein polymorphisms in the tammar wallaby, Macropus eugenii". Australian Journal of Zoology 46, n. 2 (1998): 193. http://dx.doi.org/10.1071/zo97047.

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Abstract (sommario):

Five populations of the Australian tammar wallaby, Macropus eugenii, from Kangaroo Island, South Australia, and Garden, Abrolhos and Middle Islands and Perup, Western Australia, were examined for plasma protein polymorphisms. Select Kangaroo/Garden Island hybrids and backcross progeny were also included in the study. Vitamin D binding protein (GC), albumin (ALB), transferrin (TF), protease inhibitor (PI), haemopexin (HX), haptoglobin (HP) and immunoglobulin G (IgG) were identified by polyacrylamide gel electrophoresis, pH 7.9, isoelectric focusing, pH 4.2–4.9, and immunoblotting with rabbit antisera to human proteins. Five GC (A, B, C, D, E), two ALB (A, B), two TF (A, B) and five PI (I, J, L, M, P) variants were detected, and limited family studies demonstrated a codominant allelic inheritance for each of the systems.

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42

Whitworth, D. J., Geoffrey Shaw e M. B. Renfree. "Müllerian duct regression in a marsupial, the tammar wallaby". Anatomy and Embryology 196, n. 1 (26 giugno 1997): 39–46. http://dx.doi.org/10.1007/s004290050078.

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43

Borchers, Clare, Geoff Shaw, Doug Eckery, Marilyn Renfree e David Robertson. "67. Inhibin in the male tammar wallaby, Macropus eugenii". Reproduction, Fertility and Development 15, n. 9 (2003): 67. http://dx.doi.org/10.1071/srb03ab67.

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44

Leihy, M. W., G. Shaw, J. D. Wilson e M. B. Renfree. "Development of the Penile Urethra in the Tammar Wallaby". Sexual Development 5, n. 5 (2011): 241–49. http://dx.doi.org/10.1159/000334053.

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45

Hickford, D., S. Frankenberg e M. B. Renfree. "Culturing Tammar Wallaby (Macropus eugenii) Peri-gastrulation Stage Embryos". Cold Spring Harbor Protocols 2009, n. 12 (1 dicembre 2009): pdb.prot5337. http://dx.doi.org/10.1101/pdb.prot5337.

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46

Hickford, D., S. Frankenberg e M. B. Renfree. "Immunohistochemical Staining of Sectioned Tammar Wallaby (Macropus eugenii) Tissue". Cold Spring Harbor Protocols 2009, n. 12 (1 dicembre 2009): pdb.prot5338. http://dx.doi.org/10.1101/pdb.prot5338.

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47

Herbert, C. A., T. E. Trigg, M. B. Renfree, G. Shaw, D. C. Eckery e D. W. Cooper. "Long-term effects of deslorelin implants on reproduction in the female tammar wallaby (Macropus eugenii)". Reproduction 129, n. 3 (marzo 2005): 361–69. http://dx.doi.org/10.1530/rep.1.00432.

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Abstract (sommario):

The contraceptive and endocrine effects of long-term treatment with implants containing the GnRH agonist deslorelin were investigated in female tammar wallabies (Macropus eugenii). Fertility was successfully inhibited for 515 ± 87 days after treatment with a 5 mg deslorelin implant (n= 7), while control animals gave birth to their first young 159 ± 47 days after placebo implant administration (n= 8). The duration of contraception was highly variable, ranging from 344 to 761 days. The strict reproductive seasonality in the tammar wallaby was maintained once the implant had expired. This inhibition of reproduction was associated with a significant reduction in basal LH concentrations and a cessation of oestrous cycles, as evidenced by low progesterone concentrations. There was evidence to suggest that some aspect of either blastocyst survival, luteal reactivation, pregnancy or birth may be affected by deslorelin treatment in some animals. These results show that long-term inhibition of fertility in the female tammar wallaby is possible using slow-release deslorelin implants. The effects of deslorelin treatment were fully reversible and there was no evidence of negative side effects. Slow-release GnRH agonist implants may represent a practicable method for reproductive management of captive and semi-wild populations of marsupials.

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48

Basden, K., D. W. Cooper e E. M. Deane. "Development of the lymphoid tissues of the tammar wallaby Macropus eugenii". Reproduction, Fertility and Development 9, n. 2 (1997): 243. http://dx.doi.org/10.1071/r96032.

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Abstract (sommario):

A study has been made of the development of four lymphoid tissues from birth to maturity in the tammar wallaby Macropus eugenii —the cervical and thoracic thymus, lymph nodes and gut-associated lymphoid tissue (GALT). The development of these tissues in the tammar wallaby is similar to that in two other marsupials, the quokka Setonix brachyurus and the Virginian opossum Didelphis virginiana. Lymphocytes were first detected in the cervical thymus of the tammar at Day 2 post partum and in the thoracic thymus at Day 6. They were subsequently detected in lymph nodes at Day 4 and in the spleen by Day 12 but were not apparent in the GALT until around Day 90 post partum. By Day 21, the cervical thymus had developed distinct areas of cortex and medulla and Hassall’s corpuscles were apparent. The maturation of other tissues followed with Hassall’s corpuscles in the thoracic thymus by Day 30 and nodules and germinal centres in the lymph nodes by Day 90. Measurement of immunoglobulin G concentrations in the serum of young animals indicated a rise in titre around Day 90 post partum, correlating with the apparent maturation of the lymphoid tissues.

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49

Saunders, Norman R., Katarzyna M. Dziegielewska, Sophie C. Whish, Lyn A. Hinds, Benjamin J. Wheaton, Yifan Huang, Steve Henry e Mark D. Habgood. "A bipedal mammalian model for spinal cord injury research: The tammar wallaby". F1000Research 6 (15 giugno 2017): 921. http://dx.doi.org/10.12688/f1000research.11712.1.

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Background: Most animal studies of spinal cord injury are conducted in quadrupeds, usually rodents. It is unclear to what extent functional results from such studies can be translated to bipedal species such as humans because bipedal and quadrupedal locomotion involve very different patterns of spinal control of muscle coordination. Bipedalism requires upright trunk stability and coordinated postural muscle control; it has been suggested that peripheral sensory input is less important in humans than quadrupeds for recovery of locomotion following spinal injury. Methods: We used an Australian macropod marsupial, the tammar wallaby (Macropus eugenii), because tammars exhibit an upright trunk posture, human-like alternating hindlimb movement when swimming and bipedal over-ground locomotion. Regulation of their muscle movements is more similar to humans than quadrupeds. At different postnatal (P) days (P7–60) tammars received a complete mid-thoracic spinal cord transection. Morphological repair, as well as functional use of hind limbs, was studied up to the time of their pouch exit. Results: Growth of axons across the lesion restored supraspinal innervation in animals injured up to 3 weeks of age but not in animals injured after 6 weeks of age. At initial pouch exit (P180), the young injured at P7-21 were able to hop on their hind limbs similar to age-matched controls and to swim albeit with a different stroke. Those animals injured at P40-45 appeared to be incapable of normal use of hind limbs even while still in the pouch. Conclusions: Data indicate that the characteristic over-ground locomotion of tammars provides a model in which regrowth of supraspinal connections across the site of injury can be studied in a bipedal animal. Forelimb weight-bearing motion and peripheral sensory input appear not to compensate for lack of hindlimb control, as occurs in quadrupeds. Tammars may be a more appropriate model for studies of therapeutic interventions relevant to humans.

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Cheung, Timothy C., e John P. Hearn. "Molecular cloning and tissue expression of the gonadotrophin-releasing hormone receptor in the tammar wallaby (Macropus eugenii)". Reproduction, Fertility and Development 14, n. 3 (2002): 157. http://dx.doi.org/10.1071/rd01124.

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Gonadotrophin-releasing hormone (GnRH) plays a pivotal role in the endocrine control of both reproduction and embryonic development. This first study of the marsupial GnRH receptor (GnRH-R) gene in the tammar wallaby provides information on the complex molecular events that regulate hypothalamic-pituitary- gonadal function in marsupials, and allows a comparison with eutherian mammals. Two identical wallaby GnRH-R cDNA clones were obtained, one isolated from cDNA generated from the testis of a 79-day-old pouch young and the other from the pituitary of an adult. Wallaby GnRH-R is composed of 328 amino acid residues. Sequence analysis showed that wallaby GnRH-R contains 7 transmembrane domains and is a member of the G protein- coupled receptor family. A putative protein kinase A phosphorylation site and a putative protein kinase C (PKC) phosphorylation site were found in the first intracellular loop, and an additional PKC phosphorylation site was located in the third intracellular loop. Comparisons with the eutherian GnRH-Rs show a greater diversity in the N-terminal extracellular domain. Wallaby GnRH-R has approximately 80% amino acid sequence homology with eutherian GnRH-Rs and 93% homology with the brush-tail possum, another member of the Diprotodontia semiorder.

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