不同肤色山羊皮肤组织形态学及黑色素生成相关基因的表达分析

The Characteristic Histomorphology of Various Skin Colors and Expression of Genes Involved in Melanogenesis in Goats

旨在阐明酉州乌羊皮肤发育的组织形态学特点以及黑色素高度沉积的可能分子机制,本研究选取渝东白山羊(白色皮肤)为对照,对100日龄酉州乌羊和渝东白山羊胎儿皮肤组织进行了组织形态学分析;并检测了成年酉州乌羊和渝东白山羊皮肤组织以及B16黑色素细胞增殖、分化阶段Pax3、Mitf与Tyr的表达变化。结果表明,在山羊胎儿皮肤快速发育阶段,两品种间皮肤黑色素沉积差异明显;Pax3与Tyr在酉州乌羊皮肤中表达量显著高于渝东白山羊(P<0.001),而Mitf则无明显差异(P>0.05);相对于细胞增殖阶段,B16细胞在分化时Pax3表达显著下调(P<0.001),Tyr的表达显著上调(P<0.01),而Mitf无明显差异(P>0.05)。研究结果提示,在皮肤发育分化的早期阶段,酉州乌羊与渝东白山羊黑色素细胞的迁移路线可能不同;Pax3下调与Tyr上调是色素细胞分化并生成黑色素的必要条件;酉州乌羊皮肤黑色素高度沉积与Pax3、Tyr的大量表达有关。

The objective of this study was to elucidate the characteristics in histomorphology and the potential molecular mechanisms underlying the dermal hyperpigmentation in Youzhou Darkskin goat.First,we analyzed the characteristics of histomorphology in 100d-fetal skin in Youzhou Dark-skin goat(dark skin)and Yudong White goat(normal skin).Then we examined the mRNA expression of Pax3,Mitfand Tyrin skin and B16 cells in the 2breeds.The results showed that:1)There were significant differences in the skin pigmentation between breeds at fetus skin rapid development stage;2)The skin mRNA levels of Pax3 and Tyr were significantly higher in Youzhou Dark-skin goat than that in Yudong White goat(P<0.001),whereas no significant difference was observed in Mitfexpression between the 2breeds(P>0.05);3)The expression of Pax3 was decreased(P<0.001),Tyr was increased(P<0.01)during the B16 cell differentia-tion,as compared with the proliferating B16 cells.The results indicate that:1)There might be diversity in migration pathway of the dermal melanocytes between the dark-skin and normal skin goats during the early stage of skin development differentiation;2)Downregulation of Pax3 and upregulation of Tyr are indispensible for melanogenesis in melanocytes;3)The high expression of Pax3 and Tyr are associated with the dermal hyperpigmentation in Youzhou Dark-skin goat.