Developmental expression of chicken FOXN1 and putative target genes during feather development.
Developmental expression of chicken FOXN1 and putative target genes during feather development.
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DOI：
10.1387/ijdb.130023sy
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发表时间：
2014-02
期刊：
影响因子：
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通讯作者：
D. Darnell;L. S. Zhang;S. Hannenhalli;S. Yaklichkin
中科院分区：
文献类型：
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作者：
D. Darnell;L. S. Zhang;S. Hannenhalli;S. Yaklichkin
FOXN1是叉头盒转录因子家族的一员。FOXN1对哺乳动物的毛发生长和胸腺分化至关重要。与所有羊膜动物都有的胸腺不同，毛发是一种表皮附属物，是在哺乳动物和鸟类最后一个共同祖先出现之后出现的，而且毛发和羽毛在分化和基因表达方面存在显著差异。在这里，我们发现FOXN1在胚胎鸡毛、指甲和胸腺中表达，证明了一种超越明显同源性的进化保守性。在胚胎日（ED） 12时，FOXN1在一些羽芽中表达，而在ED13时，FOXN1的表达沿着羽丝的长度延伸。在ED14， FOXN1 mRNA仅限于近端羽丝，而在远端羽轴中未检测到。在羽毛基部，FOXN1表达于羽鞘上皮和远端倒刺和边缘板，而在中部，FOXN1转录本主要在羽丝的倒刺板中检测到。FOXN1也在爪子中表达；然而，在皮肤或鳞片中未检测到表达。尽管FOXN1在发育中的羽毛中也有表达，但对5个假定的哺乳动物FOXN1靶基因的鸡同源性研究表明，虽然这些基因在羽毛中也有表达，但与FOXN1的表达模式几乎没有相似性，这表明一些基因调控网络可能在表皮附属物的进化过程中出现了分歧。
FOXN1 is a member of the forkhead box family of transcription factors. FOXN1 is crucial for hair outgrowth and thymus differentiation in mammals. Unlike the thymus, which is found in all amniotes, hair is an epidermal appendage that arose after the last shared common ancestor between mammals and birds, and hair and feathers differ markedly in their differentiation and gene expression. Here, we show that FOXN1 is expressed in embryonic chicken feathers, nails and thymus, demonstrating an evolutionary conservation that goes beyond obvious homology. At embryonic day (ED) 12, FOXN1 is expressed in some feather buds and at ED13 expression extends along the length of the feather filament. At ED14 FOXN1 mRNA is restricted to the proximal feather filament and is not detectable in distal feather shafts. At the base of the feather, FOXN1 is expressed in the epithelium of the feather sheath and distal barb and marginal plate, whereas in the midsection FOXN1 transcripts are mainly detected in the barb plates of the feather filament. FOXN1 is also expressed in claws; however, no expression was detected in skin or scales. Despite expression of FOXN1 in developing feathers, examination of chick homologs of five putative mammalian FOXN1 target genes shows that, while these genes are expressed in feathers, there is little similarity to the FOXN1 expression pattern, suggesting that some gene regulatory networks may have diverged during evolution of epidermal appendages.