自发雄性不育近交系MIJ大鼠形态学特征观察

目的:了解本实验室培育的自发雄性不育近交系MIJ大鼠的形态学特征。方法:分别取1月龄、2月龄、3月龄不育大鼠(不育组,A组)、近交系内正常大鼠(系内正常组,B组)、正常雄性Wistar大鼠(正常对照组,C组),观察生长发育情况,常规方法制备病理切片,观察睾丸、附睾等器官组织学变化;取骨髓,常规方法染色体制片,G显带,进行染色体分析。结果:不育组大鼠体重增长速度稍慢,生殖器官发育迟缓;1月龄时腹腔内隐睾;睾丸下降时间、精索长度、睾丸引带长度、睾丸系数、附睾系数均明显落后于其他二组;且睾丸生精上皮发育不全,附睾内精子数量明显减少;但染色体形态及数目均正常,未观察到畸变。结论:自发雄性不育近交系MIJ大鼠呈睾丸下降延迟、睾丸发育不全、少精等特征,可以作为人类男性不育研究的良好动物模型。

Morphological Characteristic in the Spontaneous Infertile Male Inbred MIJ Rats

Objective: To investigate the morphological characteristics in the spontaneous infertile male inbred MIJ rats bred in our lab. Methods: The infertility male Wister rats (infertility group, group A), normal Wister male rats from the inbred (control group from the inbred, group B), and growth states of normal male Wister rats(control group, group C) of postnatal 1 month, postnatal 2 months, and postnatal 3 months were observed. The histological changes of testicle and epididymis were observed. Chromosome's G banding was disposed and the types of chromosome were analyzed. Results: Compared with other groups, the weight growth rate was a little slower, and reproductive organs were developmental retardation in group A. The group A of 1st postnatal month had intra-abdominal testes. Compared with other groups, the time of testicular descent, the length of varicosity and gubernaculum testis, the index of testicle and epididymis were significantly decreased in group A, P<0.01. The histopathological examination suggested that the seminiferous epithelium became atrophy, and sperm amount in lumens of seminiferous tubules was decreased in group A, but chromosome number and morphology were normal. Conclusion: The spontaneous infertile male MIJ rats showed the characteristics of the delayed testicular descent, testis hypoplasia, and oligozoospermia, and could serve as the better model for the study of male infertility.