Wu W, Xu R F, Xiao L, Xu H, Gao G
Laboratory of Animal Genetics and Breeding, College of Animal Science and Technology, Jilin Agricultural University, Changchun, PR China.
Poult Sci. 2008 Jan;87(1):204-11. doi: 10.3382/ps.2007-00197.
beta-Catenin signaling has been reported to initiate feather bud development. In the present study, beta-catenin gene was isolated and identified from a cDNA library constructed using embryonic goose skin. Expression patterns of beta-catenin gene in the dorsal skin of goose embryos were investigated using the methods of semi-quantitative reverse transcription PCR, Northern blot analysis, and in situ hybridization. The sequence of beta-catenin was found highly conserved at the amino acid level, sharing 100, 99, and 99% identity with chicken, Chinese soft-shell turtle, and human sequences, respectively. Relatively high levels (62.51 +/- 7.11% to 101.74 +/- 7.29%) of beta-catenin mRNA were detected in the dorsal skin samples. The levels of beta-catenin expression were most prominent at the early stage from embryo day (E)10 to E20 and then significantly declined with the embryonic development. In situ hybridization demonstrated that at E10, beta-catenin expression was mainly observed at the surface periderm cells and the localized region of the epidermal layer. Because feather bud forms with an anterior-posterior orientation, strong staining was observed in the periderm layer and in the ectoderm and epidermis with a diffuse distribution within the internal area of the buds. The stronger staining was seen in the barb ridges than in the center pulp of the feather follicles at E18 and E20. In this study, expression of Shh as a marker gene for the bud development was examined paralleling with expression patterns of beta-catenin. It was found that the expression pattern of beta-catenin was almost similar spatially and temporally to that of Shh mRNA at the later stages of bud development. The differential beta-catenin mRNA expression in the goose dorsal skin may be essential for promoting the normal development of embryonic feather bud.
据报道，β-连环蛋白信号传导可启动羽毛芽的发育。在本研究中，从使用鹅胚胎皮肤构建的cDNA文库中分离并鉴定了β-连环蛋白基因。采用半定量逆转录PCR、Northern印迹分析和原位杂交方法，研究了β-连环蛋白基因在鹅胚胎背部皮肤中的表达模式。发现β-连环蛋白的序列在氨基酸水平上高度保守，与鸡、中华鳖和人类序列的同一性分别为100%、99%和99%。在背部皮肤样本中检测到相对较高水平（62.51±7.11%至101.74±7.29%）的β-连环蛋白mRNA。β-连环蛋白的表达水平在胚胎第10天（E）至E20的早期最为突出，然后随着胚胎发育而显著下降。原位杂交表明，在E10时，β-连环蛋白的表达主要在表面的周皮细胞和表皮层的局部区域观察到。由于羽毛芽以前后方向形成，在周皮层以及外胚层和表皮中观察到强烈染色，在芽的内部区域呈弥漫分布。在E18和E20时，羽枝嵴中的染色比毛囊中心髓质中的染色更强。在本研究中，平行于β-连环蛋白的表达模式，检测了作为芽发育标记基因的Shh的表达。发现在芽发育的后期，β-连环蛋白的表达模式在空间和时间上与Shh mRNA的表达模式几乎相似。鹅背部皮肤中β-连环蛋白mRNA的差异表达可能对促进胚胎羽毛芽的正常发育至关重要。
