关键词: 卷羽鸡, 毛囊发育, KRT75, SNP, 表达

Abstract: 【Objective】The Objective of this study is to analyzes the features and curve process of frizzled feather, the development of frizzled feather follice, sequence features and expression rules of candidate gene KRT75 in frizzled feather follicle development. 【Method】 The frizzled feathers of 360 frizzled chicks from 1 to 300 days were observedto know the curve process, and the microstructure of rachis, barbules, anf hooks between frizzled and contour feather were compared. The development of feather follicle between frizzled feather and contour feather at 8th in embryonic period was compared by Microscopic section technology. The total RNA from the embryonic 13 day skin of frizzled feather and contour feather was extracted, respectively, reverse transcripted cDNA，connected with the PMD-18T vector，the products were transformed into DH5α competent cells, coated plates, monoclonal colony was selected for PCR, and the positive plasmid was chosen for sequencing. In addition, 15 frizzled and contour feather chicks at 300 days were randomly selected to collect vein blood under the wing, blood genome pillar extraction kit was used to extract DNA, the PCR products were also sequenced after purification, and the DNAMAN software was used to analyze genetic characteristics of KRT75 gene. The total RNA was also extracted from embryonic 8 to 17 day skin of frizzled feather and contour feather; respectively, reverse transcripted cDNA, and the SYBR kit was used to analyze KRT75 gene expression during the formation of feather follicle. 【Result】 The down feather appeared disorder and curved in newborn frizzle chicks, the largest curvature of feather was observed at 6 weeks. The frizzled feather rachis curved outward, barbules could not hooked together to form a closed feather; the development of frizzled feather follicle and contour feather follicle was both from E8 to E16, there were some differences in the medulla and barb ridge between frizzled feather and normal one from E12 to E15, in the E12 to E14 day, the medulla of frizzled feather were bigger than contour feather, but the barbule plates were smaller than contour feather. The CDS of KRT75 gene was 1 569 bp both in frizzled feather and contour feather chickens, no 69 bp deletion mutation was detected in CDS region of frizzled chicken KRT75 gene. Three SNPs ( 954bp: T>C; 967bp: T>C; 978bp: C>T) were found compared frizzled chicken with Princess chicken. The expression of KRT75 was significantly different between frizzled feather and contour feather, KRT75 was low expression in contour feather follice but was highly expressed in frizzled feather follicle from E9 to E17, especially in E9,E10 and E12 to E15, the KRT75 of frizzled feather was highly significant than contour feather(P<0.01). 【Conclusion】 Frizzled feather of KiRin Chicken was not caused by 69 bp detection mutation of KRT75 gene. The three SNPs (955bp: T>C; 967bp: T>C; 978bp: C>T) could be used as molecular markers in distinguishing frizzled and contour feathers.