Shifts in pigeon limb identity reveal conserved genetic networks
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ABSTRACT:
ORGANISM(S): Columba livia Gallus gallus
PROVIDER: GSE127775 | GEO | 2020/02/28
REPOSITORIES: GEO
Similar Datasets
Project description:The genetic and developmental mechanisms that control the decision between scale and feather growth â two profoundly different epidermal appendages, and an important developmental shift in the evolution of birds from their dinosaurian ancestors â remain poorly understood. Domestic pigeons display dramatic variation in foot epidermal appendages within a single species, and classical studies suggest that a small number of genes control much of this variation; thus pigeons provide a tractable model to understand skin appendage specification and variation. Here we show that feathered feet in pigeons are the consequence of a partial transformation of limb-type identity mediated by cis-regulatory changes in the hindlimb-specific transcription factor Pitx1 and forelimb-specific transcription factor Tbx5. We also demonstrate that ectopic hindlimb expression of Tbx5 is associated with the development of foot feathers in domestic chickens, suggesting that similar developmental mechanisms underlie phenotypic convergence in avian lineages that diverged over 100 MYA. These results show how qualitative and quantitative changes in expression of regional patterning genes can generate localized changes in organ fate and morphology, and provide a viable molecular mechanism for the evolution of hindlimb scale and feather distribution in dromaeosaurs. Examination of H3K27ac status in embryonic limb buds from two domestic pigeon breeds, racing homer and Indian fantail
2016-04-03 | E-GEOD-67875 | biostudies-arrayexpress
Project description:The genetic and developmental mechanisms that control the decision between scale and feather growth – two profoundly different epidermal appendages, and an important developmental shift in the evolution of birds from their dinosaurian ancestors – remain poorly understood. Domestic pigeons display dramatic variation in foot epidermal appendages within a single species, and classical studies suggest that a small number of genes control much of this variation; thus pigeons provide a tractable model to understand skin appendage specification and variation. Here we show that feathered feet in pigeons are the consequence of a partial transformation of limb-type identity mediated by cis-regulatory changes in the hindlimb-specific transcription factor Pitx1 and forelimb-specific transcription factor Tbx5. We also demonstrate that ectopic hindlimb expression of Tbx5 is associated with the development of foot feathers in domestic chickens, suggesting that similar developmental mechanisms underlie phenotypic convergence in avian lineages that diverged over 100 MYA. These results show how qualitative and quantitative changes in expression of regional patterning genes can generate localized changes in organ fate and morphology, and provide a viable molecular mechanism for the evolution of hindlimb scale and feather distribution in dromaeosaurs.
2016-04-03 | GSE67875 | GEO
Project description:Extensive functional analyses have demonstrated that the pituitary homeodomain transcription factor Pitx1 plays a critical role in specifying hindlimb morphology in vertebrates. However, much less is known regarding the target genes and cis-regulatory elements through which Pitx1 acts. Earlier studies suggested that the hindlimb transcription factors Tbx4, HoxC10, and HoxC11 might be transcriptional targets of Pitx1, but definitive evidence for direct regulatory interactions has been lacking. Using ChIP-Seq on embryonic mouse hindlimbs, we have pinpointed the genome-wide location of Pitx1 binding sites during mouse hindlimb development and identified potential gene targets for Pitx1. We determined that Pitx1 binding is significantly enriched near genes involved in limb morphogenesis, including Tbx4, HoxC10, and HoxC11. Notably, Pitx1 is bound to the previously identified HLEA and HLEB hindlimb enhancers of the Tbx4 gene and to a newly identified Tbx2 hindlimb enhancer. Moreover, Pitx1 binding is significantly enriched on hindlimb relative to forelimb-specific cis-regulatory features that are differentially marked by H3K27ac. However, our analysis revealed that Pitx1 also strongly associates with many functionally verified limb enhancers that exhibit similar levels of activity in the embryonic mesenchyme of forelimbs and hindlimbs. We speculate that Pitx1 influences hindlimb morphology both through the activation of hindlimb specific enhancers as well as through the hindlimb-specific modulation of enhancers that are active in both sets of limbs. Embryonic hindlimb buds from 4 ICR mouse samples were used.
2012-12-01 | E-GEOD-41591 | biostudies-arrayexpress
Project description:Hindlimb and Forelimb-specific Tbox factors integrates their mode of action with distinct Hox factors resulting in different transcriptional outcomes. In addition, hindlimb-specific Tbx4, Hoxc10 and Pitx1 act on the same platform to target common putative downstream genes for hindlimb development
2018-03-08 | GSE104398 | GEO
Project description:Extensive functional analyses have demonstrated that the pituitary homeodomain transcription factor Pitx1 plays a critical role in specifying hindlimb morphology in vertebrates. However, much less is known regarding the target genes and cis-regulatory elements through which Pitx1 acts. Earlier studies suggested that the hindlimb transcription factors Tbx4, HoxC10, and HoxC11 might be transcriptional targets of Pitx1, but definitive evidence for direct regulatory interactions has been lacking. Using ChIP-Seq on embryonic mouse hindlimbs, we have pinpointed the genome-wide location of Pitx1 binding sites during mouse hindlimb development and identified potential gene targets for Pitx1. We determined that Pitx1 binding is significantly enriched near genes involved in limb morphogenesis, including Tbx4, HoxC10, and HoxC11. Notably, Pitx1 is bound to the previously identified HLEA and HLEB hindlimb enhancers of the Tbx4 gene and to a newly identified Tbx2 hindlimb enhancer. Moreover, Pitx1 binding is significantly enriched on hindlimb relative to forelimb-specific cis-regulatory features that are differentially marked by H3K27ac. However, our analysis revealed that Pitx1 also strongly associates with many functionally verified limb enhancers that exhibit similar levels of activity in the embryonic mesenchyme of forelimbs and hindlimbs. We speculate that Pitx1 influences hindlimb morphology both through the activation of hindlimb specific enhancers as well as through the hindlimb-specific modulation of enhancers that are active in both sets of limbs.
2012-12-01 | GSE41591 | GEO
Project description:Transcriptomes of mouse embryonic autopods were generated detecting expression of approximately 26179 transcripts in the developing forelimb or hindlimb autopods, representing about 58 % of the probe sets on MOE-430 A/B GeneChip. Three biological replicate array experiments were finished for each condition and MAS5.0 signal were used to do data analysis. Forty-four transcripts with expression differences higher than 2-fold were detected(T test, P<0.05), including Tbx4, Tbx5, Hoxc10 and Pitx1 which were previously shown to be differentially expressed in developing forelimb and hindlimb bud by in situ hybridization and SAGE study (Margulies 2001). RTPCR and in situ experiments confirmed several top differentially expressed genes which were newly discovered by our experiments. Vast amount of transcripts and its family members such as Bmp, Fgf, Epha, Wnt, T-box and Hox families detected to be highly expressed or differentially expressed in developing autopods, suggesting that the complexity of transcriptomes of developing autopods and dynamic differential expression and differential combinations of gene expression signals in the developing limb tissue contributes to differences in forelimb versus hindlimb patterning. The differentially expressed genes are the essential factors for morphological diversification of developing limb structures.
2007-08-09 | E-GEOD-2560 | biostudies-arrayexpress
Project description:Transcriptomes of mouse embryonic autopods were generated detecting expression of approximately 26179 transcripts in the developing forelimb or hindlimb autopods, representing about 58 % of the probe sets on MOE-430 A/B GeneChip. Three biological replicate array experiments were finished for each condition and MAS5.0 signal were used to do data analysis. Forty-four transcripts with expression differences higher than 2-fold were detected(T test, P<0.05), including Tbx4, Tbx5, Hoxc10 and Pitx1 which were previously shown to be differentially expressed in developing forelimb and hindlimb bud by in situ hybridization and SAGE study (Margulies 2001). RTPCR and in situ experiments confirmed several top differentially expressed genes which were newly discovered by our experiments. Vast amount of transcripts and its family members such as Bmp, Fgf, Epha, Wnt, T-box and Hox families detected to be highly expressed or differentially expressed in developing autopods, suggesting that the complexity of transcriptomes of developing autopods and dynamic differential expression and differential combinations of gene expression signals in the developing limb tissue contributes to differences in forelimb versus hindlimb patterning. The differentially expressed genes are the essential factors for morphological diversification of developing limb structures. Keywords = microarray Keywords = mouse Keywords = autopod Keywords = limb Keywords = development Keywords = gene expression Keywords = transcriptome Keywords: repeat sample
2005-06-01 | GSE2560 | GEO
Project description:Pitx1, critical regulator of a limited hindlimb-specific gene network, targets the limb development program common to both fore- and hindlimbs in order to implement hindlimb-specific limb morphology.
2017-09-19 | GSE100728 | GEO
Project description:Pitx1, critical regulator of a limited hindlimb-specific gene network, targets the limb development program common to both fore- and hindlimbs in order to implement hindlimb-specific limb morphology.
2017-09-19 | GSE100727 | GEO
Project description:Development of the complex structure of the vertebrate limb requires carefully orchestrated interactions between multiple regulatory pathways and proteins. Among these, precise regulation of 5’ Hox transcription factor expression is essential for proper limb bud patterning and development. Here, we identified Geminin (Gmnn) as a novel regulator of this process. A conditional model of Gmnn deficiency resulted in loss or severe reduction of forelimb skeletal elements, while both the forelimb autopod and hindlimb were unaffected. 5’ Hox gene expression expanded into more proximal and anterior regions of embryonic forelimb buds in this Gmnn-deficient model. A second conditional model of Gmnn deficiency instead caused a similar but less severe reduction of hindlimb skeletal elements and hindlimb polydactyly, while not affecting the forelimb. An ectopic posterior Shh signaling center was evident in the anterior hindlimb bud of Gmnn-deficient embryos in this model. This center ectopically expressed Hoxd13, the Hoxd13 target Shh, and the Shh target Ptch1, while these mutant hindlimb buds also had reduced levels of the cleaved, repressor form of Gli3, a Shh pathway antagonist. Together, this work delineates a new role for Gmnn in modulating Hox expression to pattern the vertebrate limb.
2020-06-05 | GSE143211 | GEO