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Averof, Michalis. "HOM/Hox genes of a crustacean : evolutionary implications". Thesis, University of Cambridge, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.319512.
Pełny tekst źródłaZhou, Bo. "Structural studies of geminin-hox and smad-hox complexes /". View abstract or full-text, 2007. http://library.ust.hk/cgi/db/thesis.pl?BICH%202007%20ZHOU.
Pełny tekst źródłaSvingen, Terje, i n/a. "Hox Transcription Factors: Their Involvement in Human Cancer Cells and In Vitro Functional Specificity". Griffith University. School of Biomolecular and Biomedical Science, 2005. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20050830.135356.
Pełny tekst źródłaSvingen, Terje. "Hox Transcription Factors: Their Involvement in Human Cancer Cells and In Vitro Functional Specificity". Thesis, Griffith University, 2005. http://hdl.handle.net/10072/365774.
Pełny tekst źródłaThesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Biomolecular and Physical Sciences
Full Text
Ackema, K. B. "Hox genes and mesenchymal stem cells". [S.l.] : Rotterdam : [The Author] ; Erasmus University [Host], 2008.
Znajdź pełny tekst źródłaSmith, Margaret Louise. "An analysis of Hox genes in Myriapods". Thesis, University of Cambridge, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.624853.
Pełny tekst źródłaPlaça, Jessica Rodrigues. "Avaliação do perfil genômico dos genes da família HOX em tumores a partir de dados de bancos públicos". Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/17/17154/tde-17042018-161612/.
Pełny tekst źródłaThe HOX gene family comprises a set of evolutionarily highly conserved transcription factors. In mammals, HOX genes are subdivided into four clusters: HOXA, HOXB, HOXC and HOXD, acting on the embryonic development with regulation of biological processes such as proliferation, differentiation, migration, angiogenesis and apoptosis that are reactivated during carcinogenesis. Recent studies indicate that HOX genes may play a relevant role in the formation of several solid tumors, but it has not been possible to systematically characterize the expression of HOX genes in tumors as well as to determine their targets in tumors. Thus, the general aim of this project was to characterize the in vivo model of HOX genes in carcinogenesis. To accomplish this goal the differential profile of HOX genes was identified between normal and tumor samples. HOX gene targets were identified and, when differentially expressed, were associated with HOX genes regardless of methylation and CNA indices. Finally, the final associations between the HOX genes and their targets were enriched with the KEGG and GO databases. Different signatures of HOX gene expression were identified in different tumors, associated with the anteroposterior axis of the human body, as well as the embryonic leaflets originating from the tumor tissues, compatible with the expression pattern in the embryonic development. A considerable number of HOX genes preferentially act via enhancers in the regulation of their targets. As an example, the HOXB7 and HOXC11 genes, which function as pro-tumor modulators. Finally, the study shows that in view of the growing number of public genomic data, it is possible to make feasible projects of great scientific value.
Pearce, Jonathan J. H. "Murine chromobox genes and the maintenance of Hox gene expression patterns". Thesis, University of Cambridge, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282013.
Pełny tekst źródłaLincoln, Joy. "Developmental studies of the murine homeobox gene, Hoxa-9". Thesis, Durham University, 2002. http://etheses.dur.ac.uk/4145/.
Pełny tekst źródłaCaronia, Giuliana. "A 147L substitution in the HOXD13 homeodomain causes a novel human limb malformation by producing a selective loss of function". Thesis, Open University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.275109.
Pełny tekst źródłaNagui, Refki Khalil Peter. "Hox genes and the evolution of adaptive phenotypes". Thesis, Lyon 1, 2014. http://www.theses.fr/2014LYO10288/document.
Pełny tekst źródłaPopulations are faced with selective pressures that act on certain traits resulting in phenotypic divergence. The evolution of adaptive morphological traits is often associated with changes in pre-Existing structures. In semiaquatic insects, a dramatic growth of thoracic appendages is associated with their adaptation and efficient locomotion on the water surface. This particular leg allometry facilitated the exploitation of aquatic habitats, a restricted niche for their terrestrial relatives; and hence opens a new array of ecological opportunities. Additionally, the derived group of water striders has undergone further appendage modification, such that T2-Legs are longer than T3-Legs, a ground plan associated with the specialization to open water. Water striders have evolved a derived mode of locomotion through rowing on water. They move their mid-Legs in simultaneous sweeping strokes for propulsion, and move their hind-Legs in fine movements for orientation. Leg specification and elongation in semiaquatic insects happens during early embryogenesis as the newly hatching nymphs emerge with functional legs. The Hox transcription factor Ubx was found to be implicated in the reversal in leg ground plan. Nonetheless, the genetic mechanisms underlying these leg adaptive changes are still poorly understood. The presented thesis investigates these questions through two main goals: first, to uncover the genes and pathways implicated in the development and dramatic elongation of the legs; second, to examine the dynamics of Hox control responsible for the reversal in leg ground plan characteristic of water striders
Basford, Joshua E. "Colinear Expression of the Mouse HoxB Cluster: Potential Regulatory Role of Histone H4 Acetylation". University of Cincinnati / OhioLINK, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=ucin997988435.
Pełny tekst źródłaTümpel, Stefan Wolfgang. "Transcriptional regulation of Hox genes during hindbrain development". Thesis, Open University, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.424272.
Pełny tekst źródłaSundaramoorthi, Hemalatha. "Identification of Hox Genes Controlling Thrombopoiesis in Zebrafish". Thesis, University of North Texas, 2015. https://digital.library.unt.edu/ark:/67531/metadc822768/.
Pełny tekst źródłaGray, Sophie. "The role of HOX genes in pancreatic cancer". Thesis, University of Surrey, 2015. http://epubs.surrey.ac.uk/807615/.
Pełny tekst źródłaDe, Kumar Bony. "Induction of Hox genes and genome wide identification of Hox binding sites in mice". Thesis, Open University, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.607467.
Pełny tekst źródłaZhang, Yunzhe. "Role of linker histone H1 in epigenetic regulation of pluripotency genes and Hox genes". Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/54829.
Pełny tekst źródłaPetrey, Maria Elaine. "CONSTRUCTION OF THE pC5C9LZAP VECTOR FOR ANALYSIS OF ELEMENTS RESPONSIBLE FOR SHARED AND SEPARATE REGULATION OF HOXC-8 AND HOXC-6". University of Cincinnati / OhioLINK, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=ucin997731452.
Pełny tekst źródłaAbdel, Samad Omar. "Hox genes and the specification of neuronal phenotype in the vertebrate hindbrain : transcriptional regulation of the Hox target gene Phox2b". Université Louis Pasteur (Strasbourg) (1971-2008), 2004. http://www.theses.fr/2004STR13027.
Pełny tekst źródłaElstob, Philip Ronald. "Hox gene function and cell identity in Drosphila". Thesis, University College London (University of London), 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.272353.
Pełny tekst źródłaMoreno, González Eduardo. "Characterization of the Hox patterning genes in acoel flatworms". Doctoral thesis, Universitat de Barcelona, 2010. http://hdl.handle.net/10803/1909.
Pełny tekst źródłaFinding the extant bilateral organism closest to the bilaterian ancestor is the first and necessary step to open new ways of analysis. Recent molecular phylogenies have convincingly shown that the acoel flatworms, traditionally classified within the turbellarian Platyhelminthes, are the sister group of the remaining Bilateria, branching out before the common ancestor of protostomes, and deuterostomes.
Hox and ParaHox genes encode for transcriptional regulators involved in the control the AP body axis in all bilateral animals. Hox genes are usually organized in clusters in Bilateria, which have been originated by means of several gene tandem duplications from an original ProtoHox gene. In addition, Hox genes show a collinear correspondence between gene order within the cluster and the body levels at which these genes are expressed.
On the contrary, in the phylogenetic sister group of Bilateria, the Cnidaria, Hox genes are not linked in a single cluster and do not seem to play a similar role for patterning the OA axis.
Since it is still unclear when in the evolutionary history of bilaterians the Hox system first conferred positional identity along the AP-axis, the comparative study of the patterning genes Hox and ParaHox in acoel flatworms, could be crucial to understand the origin of the Hox-ParaHox axial patterning system and how the morphological transition from radial to bilateral animals took place.
In this Thesis, we report on the cloning, genomic arrangement, and expression domains of Hox genes in the acoel species Symsagittifera roscoffensis. Three Hox genes were detected: one from each of the major groups of Hox genes, which are anterior, central, and posterior, named SrHox1, SrHox5 and SrHoxPost respectively. All acoel species studied to date contain the same minimal complement of three Hox genes and one Cdx ParaHox gene, suggesting that the last common bilaterian ancestor (or Urbilateria) had a simple Hox gene complement, composed of only 3 or 4 genes.
In bacterial artificial chromosome cloning, sequencing, and chromosomal fluorescence in situ hybridization, Hox genes were not observed as being clustered in a unique genomic region in S. roscoffensis. Nevertheless, despite its dispersion within the genome, Hox genes are expressed in nested domains along the AP axis in the juvenile worm. The basic set of Hox genes in acoels and their coarse nested spatial deployment might be the first indicators of the role of Hox genes in the evolution of bilateral symmetry and AP positional identity from a hypothetical radial ancestor.
In order to understand how the AP axis has been established over evolutionary time, the execution of functional analyses is essential. With this purpose, we have performed the knockdown of the posterior Hox, IpHoxPost, during the postembryonic development, regeneration and adulthood of the acoel species Isodiametra pulchra, using RNA interference technologies.
The analysis has been done for the first time in acoels, and we demonstrate that the functions of this gene are restricted to the posterior region of the animal, within the muscular and neural tissues. We conclude, therefore, that the posterior Hox genes were used to specify and maintain defined anatomical regions within the AP axis of animals since the beginning of bilaterian evolution.
"Caracterización de los genes Hox en el acelo Symsagittifera roscoffensis"
TEXTO:
Los genes Hox codifican factores de transcripción que regionalizan el eje antero-posterior durante el desarrollo embrionario en todos los animales bilaterales estudiados.
Los animales radiales (cnidarios y ctenóforos) poseen genes Hox, pero estos no desempeñan un rol similar al de sus homólogos en Bilateria, por lo que el sistema de regionalización Hox puede ser considerado una innovación de los Bilateria.
Recientes análisis filogenéticos han demostrado que Acoelomorpha (acelos y nemertodermátidos), un grupo de gusanos clasificados tradicionalmente como platelmintos, divergieron antes del último antecesor común de protóstomos y deuteróstomos.
En consecuencia, representan el grupo de organismos bilaterales idóneo para estudiar la evolución del sistema Hox entre cnidarios y bilaterales. Por este motivo, el objetivo principal de esta tesis ha sido analizar el sistema Hox en acelos.
Encontramos un complemento simple de 3 genes Hox en las 2 especies de acelos estudiadas: Symsagittifera roscoffensis e Isodiametra pulchra. Estos genes no están ligados en el genoma de S. roscoffensis pero se expresan de forma colinear durante el desarrollo postembrionario, lo que representa el primer ejemplo de expresión colinear de genes Hox en Bilateria, indicando que la colinearidad estuvo presente en el ancestro de todos los Bilateria.
Las funciones del Hox posterior fueron analizadas mediante RNA de interferencia en I. pulcra. El fenotipo knockdown indica que IpHoxPost está implicado en la regulación del establecimiento de las estructuras morfológicas en la parte posterior, especialmente de los músculos bucales y los situados alrededor de los aparatos copuladores; así como en el proceso de maduración de los huevos y la proliferación celular. Esto indica que el rol del Hox posterior en la regulación del desarrollo y diversificación del mesodermo postembrionario y la musculatura ha surgido tempranamente durante la evolución de los Bilateria.
Thorsteinsdottir, Unnur. "Functional analysis of selected Hox homeobox genes in hematopoiesis". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq25175.pdf.
Pełny tekst źródłaCwajna, Mark. "The sequential function of Hox genes in limb development". Thesis, McGill University, 2011. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=96918.
Pełny tekst źródłaDes expériences de perte de fonction ont démontré que la mise en place de l'architecture du squelette des membres requière la fonction des gènes HoxA et HoxD. Cependant, le rôle de ces gènes au cours de l'osteochondrogenèse est inconnu. Le but de mon projet de recherche était de définir ce rôle.En absence des gènes HoxA/D, le développement des membres est compromis dès les stades précoces, bien avant le début de l'osteochondrogenèse. Par conséquent, j'ai généré et analysé des inactivations conditionnelles des gènes HoxA/D dans le lignage osteochondrogenic afin d'établir le rôle de ces gènes au cours du développement osseux. Mes résultats montrent que la croissance des os en développement requiert la fonction des gènes HoxA/D dans le lignage osteochodrogénique. De plus, la comparaison entre l'inactivation ubiquitaire et conditionnelle permet de mieux comprendre la contribution précoce et tardif des gènes HoxA/D dans la formation du squelette des membres.
Vinagre, Tânia. "Hox genes control the specification of global vertebral domains". Doctoral thesis, Universidade Nova de Lisboa, Instituto de Tecnologia Química e Biológica, 2011. http://hdl.handle.net/10362/5250.
Pełny tekst źródłaThe development of an animal from embryo to adult is an actively regulated process, largely controlled through differential gene expression. Hox genes are key modulators of embryonic development. Among other functions, they are essential for patterning the body plan by conferring identity to segments along the anterior-posterior axis. In vertebrates, Hox genes can specify the identity of both individual vertebrae and global vertebral domains in the axial skeleton. Hox group 10 is responsible for the layout of the lumbar region by inhibiting rib formation, while Hox group 11 defines the sacral domain of the skeleton. It was previously thought that ribs were set out by default. Hence, it was suggested that another Hox gene would have to inhibit rib formation in the cervical domain, similarly to Hox group 10 in the caudal part of the skeleton. We produced mice bearing ribs in every vertebrae by overexpressing Hoxb6 in the PSM under the control of the Dll1 promoter, showing that the thoracic area is formed through the activity of Hox group 6 genes that specifically induce rib formation, and that the cervical domain is defined as the area that precedes Hox group 6 expression. In this study, we used our two Hox over-expression mouse models with complementary rib phenotypes to study the molecular mechanisms of rib development.(...)
Hogvall, Mattias. "Analysis of Wnt ligands and Fz receptors in Ecdysozoa : Investigating the evolution of segmentation". Licentiate thesis, Uppsala universitet, Paleobiologi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-266019.
Pełny tekst źródłaGoodman, Frances Rebecca. "Human malformations caused by mutations in the 5' HOX genes". Thesis, University College London (University of London), 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312045.
Pełny tekst źródłaKaschula, Richard. "The regulation of Hox genes by microRNAs during Drosophila development". Thesis, University of Sussex, 2014. http://sro.sussex.ac.uk/id/eprint/48805/.
Pełny tekst źródłaBel-Vialar, Sophie. "Fonction des genes du groupe polycomb dans la regulation des genes hox chez la souris". Aix-Marseille 2, 1998. http://www.theses.fr/1998AIX22019.
Pełny tekst źródłaGhosh, Priyanjali. "Investigating the Gene Regulatory Network Underlying Caudal Hindbrain Specification in Embryonic Zebrafish". eScholarship@UMMS, 2018. https://escholarship.umassmed.edu/gsbs_diss/979.
Pełny tekst źródłaChan, Chun-leung Sherwin, i 陳俊良. "Expression profiling and epigenetic regulation of Hox genes in cellular models of chondrogenesis". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B44515534.
Pełny tekst źródłaKan, Shih-hsin. "Molecular genetics of human limb malformations : hox genes and FGF pathways". Thesis, University of Oxford, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.275273.
Pełny tekst źródłaBrooke, Nina Michelle. "The origin and evolution of hox-like genes : insights from amphioxus". Thesis, University of Reading, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.287648.
Pełny tekst źródłaAparicio, Samuel Alves Jana. "Studies on the Hox genes of the Japanese pufferfish, Fugu rubripes". Thesis, University of Cambridge, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363343.
Pełny tekst źródłaPatraquim, Pedro Miguel Queirós do Patrocínio. "Molecular and developmental impact of RNA processing on mammalian Hox genes". Thesis, University of Sussex, 2016. http://sro.sussex.ac.uk/id/eprint/61484/.
Pełny tekst źródłaPettini, Tom. "The role of novel long non-coding RNAs in Hox gene regulation". Thesis, University of Manchester, 2013. https://www.research.manchester.ac.uk/portal/en/theses/the-role-of-novel-long-noncoding-rnas-in-hox-gene-regulation(c8e44900-3ac0-40be-8ec6-b50179381d17).html.
Pełny tekst źródłaWeicksel, Steven E. "hox Gene Regulation and Function During Zebrafish Embryogenesis: A Dissertation". eScholarship@UMMS, 2013. https://escholarship.umassmed.edu/gsbs_diss/692.
Pełny tekst źródłaWeicksel, Steven E. "hox Gene Regulation and Function During Zebrafish Embryogenesis: A Dissertation". eScholarship@UMMS, 2010. http://escholarship.umassmed.edu/gsbs_diss/692.
Pełny tekst źródłaNegre, de Bofarull Bárbara. "Caracterización Genómica y Funcional de las Reorganizaciones del Complejo de Genes Hox en Drosophila". Doctoral thesis, Universitat Autònoma de Barcelona, 2005. http://hdl.handle.net/10803/3883.
Pełny tekst źródłaHomeotic (Hox) genes code for transcription factors involved in the specification of segmental identity in the anteroposterior axis of the early metazoan embryo. These genes are usually clustered and arranged in the same order as they are expressed along the anteroposterior body axis. The conservation of this Hox gene organization along the phylogeny has suggested the existence of functional constraints. However, the partial disassembly of the Caenorhabditis elegans complex and the three splits observed in the Drosophila genus question whether this organization is an absolute necessity for proper function in some lineages. In this work, I analysed the genomic and functional consequences of the two splits present in Drosophila buzzatii, a member of the repleta species group. In the first part, the coding regions of the labial (lab) gene were cloned in D. buzzatii and D. virilis. The sequences of these two species were compared with that of D. melanogaster to test whether the change in position of lab in de D. buzzatii lineage produced any change in gene structure or sequence evolution. The results show that the substitution rate is heterogeneous along the gene but homogeneous along the phylogeny. The nucleotide substitution rate of lab has been constant in spite of the positional change. In the second part, two regions of the D. buzzatii genome have been sequenced, one including the lab y abdominal A (abdA) genes and the other containing the proboscipedia (pb) gene, and compared with the genic organization of D. melanogaster and D. pseudoobscura to precisely locate the breakpoints. The noncoding sequences of these regions have also been compared, and a high presence of conserved blocks has been observed in the introns and surrounding regions of Hox genes. The comparison of these conserved blocks with the known regulatory regions of the Hox genes (lab, pb and abdA) in D. melanogaster shows that the position and order of the regulatory regions is conserved between the three species, with minor exceptions. Finally the expression pattern of the three Hox genes has been analysed in embryos and imaginal discs of D. buzzatii, D. repleta, D. virilis, and D. melanogaster, four species with different Hox gene arrangements. The two splits took place through two paracentric inversions, with their breakpoints between the regulatory regions of adjacent genes. So that the regulatory regions and expression patterns of these Hox genes have been conserved in spite of the reorganizations. In Drosophila the Hox gene complex seems to be composed by independent modules (including the gene and its regulatory regions), whose association is not required for proper function. The organization of these genes is modular and their clustering seems de result of phylogenetic inertia more than of functional necessity. The discovery of more rearrangements in other lineages and the significance of temporal colinearity in some organisms suggest that the functional cause of the conservation of this genomic organization would be temporal colinearity. Rearrangements would be the consequence of the loss of temporal colinearity in organisms with a very rapid mode of embriogenesis.
Natarajan, Dipa. "Design and use of Hox-2 gene targeting constructs in murine embryonic stem cells". Thesis, University of Cambridge, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240072.
Pełny tekst źródłaWang, Xing'an, i 王兴安. "Cross talk between Hox genes and sonic hedgehog signaling during mousehindbrain neurogenesis". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B45901041.
Pełny tekst źródłaKolm, Peggy J. (Peggy Jeannette). "Patterning of the posterior neurectoderm by labial-like Hox genes and retinoids". Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/43468.
Pełny tekst źródłaQuigley, Hailey. "The Role of 5’ hox13 Genes in Danio rerio (Zebrafish) Caudal Fin Ray/Joint Development and Regeneration". Thesis, Université d'Ottawa / University of Ottawa, 2021. http://hdl.handle.net/10393/42027.
Pełny tekst źródłaReid, Alasdair Ian. "Expression and mis-expression of hox genes during morphogenesis of the chick skin". Thesis, University of Cambridge, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.620553.
Pełny tekst źródłaStower, Hannah Mary. "Dynamic histone modifications at the promoters of Hox genes in embryonic stem cells". Thesis, University of Birmingham, 2009. http://etheses.bham.ac.uk//id/eprint/483/.
Pełny tekst źródłade, Almeida Osório João Guilherme Patrício Picão. "Post-transcriptional regulation of Hox genes during Drosophila neural development : mechanisms and biological roles". Thesis, University of Sussex, 2015. http://sro.sussex.ac.uk/id/eprint/51613/.
Pełny tekst źródłaChauvet, Sophie. "Fonctions des proteines hox : determinants intrinseques de specificite et genes effecteurs chez drosophila melanogaster". Aix-Marseille 2, 1999. http://www.theses.fr/1999AIX22052.
Pełny tekst źródłaBomtorin, Ana Durvalina. "Expressão de Ultrabithorax e o Desenvolvimento Casta-Específico de Apêndices Torácicos de Apis mellifera". Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/17/17135/tde-29082013-105415/.
Pełny tekst źródłaAlong with differences in physiological and behavioral characteristics, workers and queens of Apis mellifera also differ in appendage morphology. Some appendage specializations in the hind legs of honeybee workers, which are highly specialized pollinators, deserve special attention. The hind tibia of the worker has an expanded bristle-free region used for carrying pollen and propolis, the corbicula. In queens, this structure is absent. Although these morphological differences have been well characterized, the genetic inputs triggering the development of this alternative morphology have remained unknown. Through microarray analysis, we detected 1,952 genes that are differentially expressed during worker versus queen hind leg development. The gene expression signatures of the two castes have similar patterns of genes controlling development. At the beginning of the last larval instar, Ultrabithorax (Ubx) activators are more strongly expressed than in prepupae and early pupae; at this time Ubx expression is approximately 25 times higher. Within the gene expression signature, we identified a cluster formed by genes in which Ubx, Twist and Zeste binding sites are over-represented. This cluster includes genes for which Drosophila orthologs are known to be bound by Ubx, as in the case of lola. We also tested the extent of Ubx mRNA processing during wing and leg development. Unexpectedly, we found Ubx alternative splicing in both workers and queens; there were two microexons (m1 and m2) encoding 42 nt and 53 nt, respectively, arguing against the hypothesis that alternative splicing occurs exclusively within the Diptera. Inclusion of the m2 exon inserts a stop codon upstream from the exon containing the homeodomain, producing a truncated protein. Moreover, these bee microexons conserve the nucleotides known to be important for alternative splicing in Drosophila. During bee wing development, Ubx mRNA isoforms are transcribed in similar amounts in both castes; however, during leg development, queens produce 60% of the Ubx levels transcribed by workers. Analysis of 3UTR usage during bee development revealed a microsatellite region transcribed within the Ubx 3UTR. The predicted secondary structure locations separated the coding region into three branches and the proximal and the distal 3UTR regions. Deep-sequencing analysis revealed that eight out of 51 miRNAs predicted to target the Ubx mRNA are more highly expressed in worker forewings and two are more expressed in the hindwings. Therefore, we conclude that Ubx differential expression is activated by transcription factors that bind to its promoter, by control of alternative splicing, and moreover by microRNAs differentially expressed according to tissue and caste, resulting in differential morphogenesis of the hind leg in honeybee females.
Campo-Paysaa, Florent. "Evolution du développement chez les Chordés : une histoire d'acide rétinoïque, de gènes hox et de microARNs". Thesis, Lyon, École normale supérieure, 2011. http://www.theses.fr/2011ENSL0653.
Pełny tekst źródłaThe aim of the evolutionary developmental biology is to study the developmental mechanisms at the base of morphological diversification. In this context, I decided to focus my attention on the emergence of vertebrates during evolution by carrying out comparative analyses in several deuterostome models. The work carried out during of my thesis can be subdivided into three major projects: (i) I addressed the link between brain evolution and modifications in retinoic acid (RA) signaling during chordate development. In particular, I investigated the roles of RA signaling in brain development in a jawless vertebrate, the lamprey Lampetra fluviatilis, and compared the results with developmental mechanisms in the invertebrate chordate amphioxus and classical developmental model systems in jawed vertebrates. Data obtained from these comparative studies provided insights into the evolution of brain patterning in vertebrate evolution. (ii) I investigated the evolution of the regulatory landscape of hox gene clusters that are known to be fundamental for the patterning of the chordate central nervous system. The identification of conserved non-coding elements and putative RA response elements (RAREs) in hox clusters of different chordate species combined with the in vivo characterization of functional RAREs in mouse F9 cells provided an integrated view of the evolution of RA-dependent hox cluster regulation in chordates. (iii) I studied the roles of microRNAs (miRNAs) in chordate evolution by comparing the miRNA complements of different deuterostome species. This analysis provided novel insights about the general mechanisms of miRNA emergence in animals and highlighted species-specific miRNA complement amplifications in different deuterostome lineages. In sum, these studies have tackled different aspects of chordate evolution from an evo-devo perspective, aiming at an integrated view of the molecular mechanisms underlying vertebrate diversification
Moreau, Chloé. "From lateral plate mesoderm formation to limb position - Linking hox collinear activation and forelimb position in birds". Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066492/document.
Pełny tekst źródłaLimb position along the main body axis is highly consistent within one species but very variable among tetrapods. Despite major advances in our understanding of limb patterning in three dimensions, how limbs reproducibly form along the anteroposterior axis remains largely unknown. Hox genes have long been suspected to play a role in this process, however supporting evidences are mostly correlative and a direct role has yet to be demonstrated. Here, using bird embryos, I show that limb position is established very early during development, during the process of gastrulation. I find that the formation of the Lateral Plate Mesoderm (i.e. the embryonic compartment from which limbs will form) is a progressive process and that co-linear activation of Hox genes sequentially patterns it along the antero-posterior axis. Subsequent combinatorial activation and repression activities of Hox genes on limb initiation are particularly critical to pattern the LPM into limb- and non-limb-forming domains. Finally, by analyzing chicken, zebra finch and ostrich embryos which exhibit variation in their forelimb position, I show that relative changes in the timing of co-linear Hox gene activation during gastrulation underlie variation in limb position. Altogether these result shed light on the cellular and molecular mechanism that regulate limb position by showing a direct and early role for Hox genes in this process during gastrulation and provide a mechanism for variation in body plan organization observed in tetrapods
Rottkamp, Catherine Anne-Marie. "The Role of Hox Cofactors in Vertebrate Spinal Cord Development". Case Western Reserve University School of Graduate Studies / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=case1194575822.
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