Study On Molecular Mechanism Of Increasingcashmere By Light-controlling

This study was to explore the effect of light-controlling on cashmere growth and fiber quality of Shaanbei White Cashmere goats,meanwhile,the hair follicle density,related hormone concentration,and the relative expression of hormone receptor and hair follicle development related genes was detected to elucidate the molecular mechanism of increasing cashmere by light-controlling,further to provide a theoretical basis for improving cashmere yield and elucidating the molecular mechanism of cashmere growth.Exp.1 Effects of light-controlling on cashmere growth,cashmere fiber quality and hair follicle density of Shaanbei White Cashmere goatsA total of one hundred and thirty non-pregnant ewes were randomly divided into treatment group and control group with sixty-five goats in each group.At the same levels of nutrition,the control group was fed freely,but the treatment group was treated with light-controlling from 16:30 pm to 9:30 am.The entire trial period from May 15,2015 to May 15,2016,in which light-controlling processing period from May 15,2015 to October 15,2015.A total of ten goats were randomly selected and collected with five goats in each group.The cashmere length was measured accurately,while the bodyside skin tissue was collected to measure the hair follicle density monthly.At the end of trial,all of goats were sheared and the cashmere fiber quality was analyzed.The results showed that:(1)Treatment group cashmere was early germination than control group,the length and rate of growth cashmere were increased by light-controlling in June and July(P<0.05);(2)The cashmere length increased significantly by 1.25 cm(P<0.05),and the cashmere yield increased by 99.34 g;(3)Light-controlling treatment significantly reduced the primary follicle density in September(P<0.05),significantly increased the secondary follicle density in June and July(P<0.05),and significantly increased the values of S/P in July and September(P<0.05).Exp.2 Effects of light-controlling on related hormone concentrations and hormone receptor expression of Shaanbei White Cashmere goatsExperiment design was consistent with Exp.1,the jugular vein blood and bodyside skin tissue were collected to measure the serum levels of related hormone and the expression of hormone receptor genes.The results showed that:(1)The MT concentration was significantly increased in June,July and September,the PRL concentration was significantly reduced in June,July and December(P<0.05),the T4 concentration was significantly increased in July(P<0.05),and the E2 concentration was significantly increased in June,August,January,February and March(P<0.05)by light-controlling treatment;(2)The relative expression of ROR alpha was up-regulated significantly in June,October,December and February(P<0.05),but down-regulated significantly in July,November,January,March and April(P<0.05)by light-controlling treatment.Light-controlling treatment had no significant influence on the relative expression of PRLR and TR alpha,however,the peak expression of TR beta in advance to February.The relative expression of ER alpha was down-regulated significantly in July,August,January,March and April(P<0.05),but up-regulated significantly in September and October(P<0.05),and the peak expression of ER alpha was delayed to October by light-controlling treatment.The relative expression of ER beta was up-regulated significantly in June,August,October and March(P<0.05),but down-regulated significantly in July,February and April(P<0.05)by light-controlling.Exp.3 Effects of light-controlling on the hair follicle development related gene expression of Shaanbei White Cashmere goatsExperiment design was consistent with Exp.1,the bodyside skin tissue was collected monthly to measure the expression of hair follicle development related genes.The results showed that: The relative expression of β-catenin was up-regulated significantly in May,June and July(P<0.05),the relative expression of PDGFA was up-regulated significantly from May to July(P<0.05),and the first peak expression was advanced to August by light-controlling treatment.The relative expression of BMP2 was up-regulated significantly from June to August(P<0.05),however,the relative expression of BMP4 was down-regulated significantly in July(P<0.05).The relative expression of FGF5 was up-regulated significantly in all experiment period except in March by light-controlling treatment(P<0.05),meanwhile,the peak expression of FGF5 was delayed to January.The above results showed that increasing the serum MT concentration,reducing the serum PRL concentration,up-regulating the relative expression of ER beta,while down-regulating the relative expression ofERalpha,then up-regulating the relative expression ofβ-catenin,PDGFA,BMP2 and FGF5,but down-regulated BMP4 expression by light-controlling,thus accelerating the reconstruction of secondary hair follicle,increasing secondary follicle density and S/P ratio,and thus inducing early growth of cashmere,then increasing cashmere yield.