Abstract: The aim of our work is to discover molecular biology mechanisms underlying testis regression in mink. To this end, HE staining technique was used to examine the histological morphology of mink testis at different stages during regression. In addition, real-time PCR (RT-PCR) was applied to determining the expression levels of the members of transforming growth factor beta (TGFB) family and their receptors at different stages in mink testes. Our results showed that the diameters and the weights of the mink testis were gradually reduced after April, being only half of the diameter and 1/8 of the weight in July. In parallel, histological assessment demonstrated that mink testis experienced severe regression, i.e. the lumen of the seminiferous tubules was progressively absent, while the diameter of the seminiferous tubules was reduced to 1/3 of its largest size during the same time. The RT- PCR data indicated that the expression levels of the members of TGFB, such as TGFb3, INHBA; and their receptors, like TGFBR1, ACVR2A, ACVR2B, SMAD2 and SMAD4, decreased in the mink testis from April to July. Our study suggests that the signaling pathways of the TGFB superfamily may play a key role in preventing degeneration in the mink.

Key words: Mink, Testicular regression, Seasonal breeding, TGFB superfamily signaling pathways

摘要： 为了探究水貂季节性睾丸退化的分子机制，本研究利用HE染色技术对不同退化时期的水貂睾丸组织进行了组织学研究，同时利用荧光定量PCR技术对不同退化时期的水貂睾丸组织中TGFB家族生长因子及其受体基因表达量变化进行了研究。结果发现在水貂睾丸退化期间，其直径逐渐缩短到原来的1/2，重量逐渐降低到原来的1/8。HE染色结果发现，4~7月水貂睾丸经历了严重退化，而且曲细精管的管腔逐渐消失，同时曲细精管的直径减小到其最大尺寸的1/3。荧光定量PCR结果发现TGFb3、INHBA、TGFBR1、ACVR2A、ACVR2B、SMAD2、SMAD4基因相对表达量在水貂睾丸退化期间都呈下降趋势。本研究表明TGFB信号通路可能在水貂睾丸退化期间发挥了重要功能。

关键词: 水貂, 睾丸退化, 季节性繁殖, TGFB超家族信号通路