长爪沙鼠性成熟前后生殖系统的发育情况

Development of Reproductive System of Mongolian Gerbil Before and After Sexual Maturity

目的深入探究长爪沙鼠性成熟过程中生殖系统的发育情况,为其性成熟的确切时间提供直接研究证据。方法本研究选取6~14周龄长爪沙鼠共150只,按6、8、10、12和14周龄分为5组,每组雌雄各15只,称量体质量并采集卵巢、子宫、睾丸、附睾样本,测量各样本组织湿重并计算脏器指数;镜下观察卵巢外观形态;细胞计数仪检测精子数量;每组随机选取6个样本进行HE染色,观察卵巢、睾丸、附睾的组织发育情况。结果雌性沙鼠10周龄时卵巢湿重和卵巢指数均明显增加,且10~14周龄期间无明显变化,子宫湿重和子宫指数均呈阶段性变化;镜下观察外观,10周龄、12周龄、14周龄组黄体发生率分别为46.7%、60%、73.3%;组织切片显示,10周龄起可见明显黄体。雄性沙鼠在6~10周龄阶段睾丸湿重随周龄的增长而逐渐增加,10周龄后无明显变化;睾丸指数在8及12周龄时明显增加,14周龄时明显减小;6~12周龄阶段附睾湿重和附睾指数均随周龄的增长而逐渐增加,14周龄时附睾湿重无明显变化,附睾指数明显减小。细胞计数仪结果显示,6周龄时精子数量为0,10周龄与8周龄相比,附睾内精子数量明显增加,10~14周龄期间无明显变化。组织切片显示,8周龄起,睾丸和附睾内开始出现少量精子,10周龄起可见大量精子。结论随着周龄的增长,雌性沙鼠卵巢在10周龄左右卵泡开始发育成熟并排出卵子,达到性成熟,具备繁殖能力。雄性沙鼠8周龄左右开始产生精子,进入初情期,10周龄左右睾丸发育稳定,精子达最大数量,达到性成熟,此后附睾继续发育,12周龄左右发育稳定。

Objective To investigate in depth the development of the reproductive system during sexual maturation in long-clawed gerbils,and to provide direct research evidence for the exact time of sexual maturation.Method A total of 150 long-clawed gerbils were selected from 6 to 14 weeks of age and divided into 5 groups of 15 males and 15 females according to the ages of 6,8,10,12 and 14 weeks,weighed and collected samples of ovaries,uterus,testes and epididymis,measured the wet weight of the samples and calculated the index of the organisms;the morphology of the ovaries was observed under the microscope,and the spermatozoa were detected by a cytometer;6 samples were randomly selected from each group for HE staining to observe the development of the ovaries,testes and epididymis.Result In female gerbils,ovarian wet weight and ovarian index increased significantly at 10 weeks of age,and there was no significant change between 10 and 14 weeks of age;uterine wet weight and uterine index changed in stages;under microscopic observation,the incidence of corpus luteum in the groups of 10 weeks of age,12 weeks of age and 14 weeks of age was 46.7%,60%and 73.3%,respectively;the tissue sections showed that corpus luteum could be seen clearly from 10 weeks of age.In male gerbils,the wet weight of testes increased gradually with the increase of age from 6 weeks to 10 weeks,but there was no significant change after 10 weeks;the testicular index increased significantly at 8 weeks and 12 weeks of age,and decreased significantly at 14 weeks of age;both epididymal wet weight and epididymal index increased gradually with weekly age from 6 weeks of age to 12 weeks of age,and there was no significant change in epididymal wet weight at 14 weeks of age,and the epididymal index decreased significantly.The result of the cell counter showed that the sperm count was zero at 6 weeks of age,the sperm count in the epididymis increased significantly at 10 weeks of age compared to 8 weeks of age,and there was no significant change between 10 and 14 weeks of age.Tissue sections showed that a small number of spermatozoa began to appear in the testis and epididymis from 8 weeks of age and a large number of spermatozoa were visible from 10 weeks of age.Conclusion As the gerbil’s age increases,the ovaries of female gerbils begin to develop and discharge follicles and eggs at about 10 weeks of age,and the gerbil reaches sexual maturity and the ability to reproduce.Male gerbils began to produce sperm at around 8 weeks of age and entered the first estrus.At around 10 weeks of age,the testes developed stably and the spermatozoa reached the maximum number,reaching sexual maturity,after which the epididymis continued to develop,and its development stabilised at around 12 weeks of age.