Expression And Analysis Of Keratin Family Genes In Liaoning New-breeding Cashmere Goat

Keratin family genes main contain two kinds of genes including Keratins and Keratinassociated proteins, they are the major structural proteins of cashmere and are closely relatedto cashmere-fiber quality. According to some correlational studies, BMP signaling pathwaywas one of the signaling pathway associated with the growth of hair follicles, it could controlthe growth of hair follicles indirectly, thereby affected the hair type and cashmere fiberdiameter.In order to further study the relationship between keratin family genes and cashmerefiber fineness, and whether there is some connections between the keratin family genes andBMP-mediated signaling pathway, quantitative real-time PCR is used to detect expression ofK26, KAP26.1, KAP6.2, KAP7.1and KAP8.2in hair follicles during anagen, catagen andtelogen. Using RT-PCR to detect expressions of these five genes in goat skin, ear tissuesduring catagen and skin cells during telogen. Constructing BMP signaling pathwayinhibitor-Noggin gene lentivirus vector by using RNAi technology, knocked down Noggingene in goat skin cells effectively, detect expression of keratin family genes using quantitativereal-time PCR.The results were as follow:(1)The results of quantitative real-time PCR showed:KAP7.1, KAP8.2, KAP26.1and K26expression levels were higher in secondary folliclesthan in primary follicles during anagen (P <0.01), but higher in primary follicles duringcatagen. The differences between the two follicle types in terms of KAP8.2expression, andK26and KAP26.1expression were significant (P <0.05and P <0.01, respectively), but thelevels of KAP6.2expression in primary and secondary follicles showed opposite tendenciesto the above four genes. The relative telogen expression levels of K26and KAP26.1in skinwere much lower than that in catagen, the levels of other genes were similar to those incatagen.(2) The results of semi-quantitative RT-PCR demonstrated: the expression levels ofall five genes varied in skin and ear tissues during catagen, and in skin cells during anagen.KAP6.2, KAP7.1, KAP8.2and KAP26.1were all expressed in the above tissues, but K26wasonly slightly expressed in skin cells in anagen.(3)The results of RNAi as follows: LentiviralRNAi vectors specific interfere with Noggin gene was constructed by RNAi technology;BMP signaling pathway was activated successful through knockout Noggin gene, the relativeexpression levels of KAP6.2, KAP7.1, K26and KAP11.1showed a downward trend exceptKAP8.2gene. By the above results, we can draw the following conclusions:1) Expressions of KAP6.2,KAP7.1, KAP8.2, K26and KAP26.1were different in primary and secondary follicles anddifferent tissues during different periods of cashmere fiber formation, It could be inferred thatthese genes had a potentially important role in regulating cashmere-fiber fineness and periodicvariation of hair follicles.2) The RNAi of Noggin gene repressed expressions of relatedkeratin family genes. These findings provided a theoretical basis for researching thelinkages between BMP signaling pathway and keratin family genes in the future, it also laid agood foundation of improving cashmere quality and breeding in the future.