Onishi A, Mikami H
Jikken Dobutsu. 1985 Oct;34(4):433-7. doi: 10.1538/expanim1978.34.4_433.
The reproductive performance of male aggregation chimeric mice was examined. C57BL/6 in equilibrium BALB/c male chimeras and control animals, C57BL/6, BALB/c, and their reciprocal F1 crosses, were mated with ICR females. Of 45 overt chimeras, 13 produced mixed-genotype progenies and were revealed to be XY/XY chimeras. By karyotype analysis 16 of 32 single-genotype progeny chimeras were determined to be XX/XY chimeras, but the remaining single-genotype progeny chimeras showed only XY metaphase plates, so that their chromosomal sex could not be determined. The mean litter size of C57BL/6 was significantly higher than that of BALB/c. In contrast, the birth rate of C57BL/6 was lower than that of BALB/c. XY/XY chimeras showed almost the same performance as C57BL/6 for litter size and as BALB/c for birth rate. There were no significant differences for both traits between the reciprocal F1 crosses and XY/XY chimeras. The mean litter size of XX/XY chimeras was lower than that of XY/XY chimeras and the differences was statistically significant. Some XX/XY chimeras had very small testes, while XY/XY chimeras had normal testes. Such results indicate that the reproductive performance of XX/XY male chimeras is inferior to that of XY/XY males.
对雄性聚集嵌合小鼠的生殖性能进行了检测。将处于平衡状态的C57BL/6-BALB/c雄性嵌合体以及对照动物C57BL/6、BALB/c及其正反交F1代与ICR雌性小鼠进行交配。在45只明显的嵌合体中，有13只产生了混合基因型后代，经鉴定为XY/XY嵌合体。通过核型分析，32只单基因型后代嵌合体中有16只被确定为XX/XY嵌合体，但其余单基因型后代嵌合体仅显示XY中期板，因此无法确定其染色体性别。C57BL/6的平均窝仔数显著高于BALB/c。相反，C57BL/6的出生率低于BALB/c。XY/XY嵌合体在窝仔数方面表现与C57BL/6几乎相同，在出生率方面表现与BALB/c几乎相同。正反交F1代与XY/XY嵌合体在这两个性状上均无显著差异。XX/XY嵌合体的平均窝仔数低于XY/XY嵌合体，且差异具有统计学意义。一些XX/XY嵌合体的睾丸非常小，而XY/XY嵌合体的睾丸正常。这些结果表明，XX/XY雄性嵌合体的生殖性能低于XY/XY雄性。
