Institute of Reproductive Biology, Leibniz Institute for Farm Animal Biology (FBN), Dummerstorf, Germany.
Institute of Genetics and Biometry, Leibniz Institute for Farm Animal Biology (FBN), Dummerstorf, Germany.
Andrology. 2020 Sep;8(5):1419-1427. doi: 10.1111/andr.12802. Epub 2020 May 16.
Recently we described two outbred mouse lines which have been selected for high fertility. These mouse models doubled the number of offspring per litter.
Although selected for a primarily female-trait of high fertility (increased litter size), we were interested whether also males of the fertility lines show differences within their reproductive organs.
We investigated males from two outbred mouse lines which have been selected for the phenotype "high fertility" for more than 170 generations. In the present study, we analysed the testicular cell type composition by flow cytometry. We further investigated the weights of reproductive organs, histomorphometry of testis as well as studied sperm motility parameters using a thermal stress assay as well as a sperm hyperactivation assay.
Here, we describe that males of the fertility line (FL) 1 show an increased percentage of diploid cells within the testis. Flow cytometric analysis identified this enlarged cell population as Leydig cells. Testis weights were unaffected whereas the weights of seminal vesicles of FL1 and FL2 were increased compared to Ctrl bucks. FL2 males show decreased diameter of tubulus seminiferi and an enhanced spermatid/Sertoli cell index. Sperm motility parameters of FL1 and Ctrl males are initially indistinguishable but FL1 spermatozoa show a better performance in a thermal stress experiment over a 5 hours observation period.
These data indicate that although selected for a primarily female-trait of high fertility also males from the fertility lines are effected by defined alterations in their reproductive organs.
Some of these alterations are FL1-specific others are FL2-associated, indicating that different molecular strategies warrant the high-fertility phenotype on the female as well as on the male side.
最近，我们描述了两个经过选择的具有高繁殖力的近交系小鼠品系。这两个小鼠模型使每窝后代的数量增加了一倍。
尽管这些小鼠模型是通过选择具有高繁殖力的主要雌性特征（增加窝仔数）而选育出来的，但我们还想知道繁殖力品系的雄性动物在其生殖器官中是否也存在差异。
我们研究了经过 170 多代选择具有“高繁殖力”表型的两个近交系小鼠品系的雄性动物。在本研究中，我们通过流式细胞术分析睾丸细胞类型组成。我们进一步研究了生殖器官的重量、睾丸组织形态计量学以及使用热应激试验和精子超激活试验研究精子运动参数。
我们描述了繁殖力品系 1（FL1）的雄性动物睾丸中存在更多的二倍体细胞。流式细胞术分析鉴定出这个增大的细胞群体为莱迪希细胞。睾丸重量不受影响，而 FL1 和 FL2 的精囊重量增加。FL2 雄性动物的曲细精管直径减小，精子/支持细胞指数增加。FL1 和对照雄性动物的精子运动参数最初无法区分，但 FL1 精子在 5 小时观察期的热应激试验中表现更好。
这些数据表明，尽管选择的是高繁殖力的主要雌性特征，但繁殖力品系的雄性动物的生殖器官也受到了明确的改变。
其中一些改变是 FL1 特异性的，另一些是 FL2 相关的，这表明不同的分子策略在雌性和雄性方面都保证了高繁殖力表型。
