褪黑激素对PDGFA基因在绒山羊皮肤毛囊中表达模式的影响

【目的】探讨血小板衍生生长因子A（platelet-derived growth factor A，PDGFA）在内蒙古阿尔巴斯绒山羊皮肤毛囊上的表达规律和褪黑激素对其的影响。【方法】选择体重和产绒量相当的阿尔巴斯绒山羊成年母羊，分为4组，即从不埋植的对照组和3组不同时间埋植褪黑激素的试验组。试验组在埋植期间每隔一个月按照2 mg?kg-1 BW的剂量在绒山羊耳后皮下埋植褪黑激素。采集12个月（从2009年8月至2010年7月）的受试羊体侧部皮肤样品，用定量逆转录PCR （qRT-PCR）检测皮肤中PDGFA基因的表达量。【结果】各组间PDGFA基因的表达模式不同。对照组在11月时其表达量为全年最低，在12月，随着毛囊周期性生长缓慢进入退行期，其PDGFA基因的表达量也缓慢上升，并在休止期（1-4月）高度表达。而开始埋植褪黑激素后，仅第二年埋植组在翌年1月时表达量显著提高（P<0.05）；在2月与连续两年埋植组一样，随着绒毛开始脱落，PDGFA基因的表达量也有下降趋势；到5月，其表达量显著低于1月（P<0.05），此时新一轮的绒毛已长出体表。停止埋植褪黑激素后，仅第一年埋植组翌年PDGFA基因的表达模式和毛囊生长周期与对照组基本一致。【结论】绒山羊皮肤组织当中PDGFA基因在毛囊生长期低表达，退行期和休止期高表达。埋植褪黑激素可缩短毛囊生长周期。PDGFA基因是一个控制毛囊从兴盛期向退行期和休止期转化的因子。

Influence of Melatonin Implanting on PDGFA Gene Expression in Skin Hair Follicle

【Objective】The expression regulation of PDGFA gene in skin follicles of Inner Mongolia Cashmere goat and the influence of melatonin on it were studied.【Method】Eight Cashmere mature femal goats with similar live weight were selected,and devided into four groups: never implanted as the control group and three groups of implanted melatonin in different times.The melatonin at a dose of 2 mg kg-1 was implanted behind ears per 2 months during the implanting period.The body skin was collected in 12 months(from August 2009 to July 2010),and PDGFA gene expression was detected by using qRT-PCR.【Result】The implanting MT into Cashmere goat influenced its hair growth cycle.The expression model of PDGFA gene in the skin and the hair growth cycle was different among groups.The lowest expression of PDGFA gene was noticed in November in control group.However,in December,the expression of PDGFA gene improved slowly with the hair growth went into catagen,and during telogen(from January to April),it kept higher level expression.After starting implanting MT into Cashmere goat,for the group just implanted melatonin in the second year,the expression of PDGFA gene was significantly improved(P<0.05) in next January.Similar results were found in implanted group for two years,it was lower with wool shedding in February,it was significantly lower in May than in January(P<0.05),and some new wool appeared on the skin at the same time.After stopping implanting MT for Cashmere goat,the PDGFA gene expression model of the group just implanted melatonin in the first year was similar with the control group.【Conclusion】 PDGFA gene had low expression in the Cashmere goat hair growth phase,and high expression in catagen and telogen.Melatonin implanted into Cashmere goat shortened hair growth cycle.PDGFA gene is a factor controlling the trarsformation of Cashmere goat hair from growth phase to catagen and telogen.