沙鼠母鼠的胎儿在子宫内的位置会影响其所孕育窝仔的性别比例。

A gerbil dam's fetal intrauterine position affects the sex ratios of litters she gestates.

作者信息

Clark M M, Galef B G

机构信息

Department of Psychology, McMaster University, Hamilton, Ontario, Canada.

出版信息

Physiol Behav. 1995 Feb;57(2):297-9. doi: 10.1016/0031-9384(94)00239-2.

DOI:10.1016/0031-9384(94)00239-2

PMID:7716206

Abstract

The vaginally delivered litters of gerbil dams that, in utero, occupied intrauterine positions between two males fetuses (2M females) contain a greater proportion of sons than do the vaginally delivered litters of gerbil dams that were gestated between two female fetuses (2F females). This difference in the sex ratios of litters delivered vaginally by 2M and 2F gerbils might reflect sex-biased differences in perinatal mortality in the litters of 2M and 2F dams. However, the results of the present experiment, in which gerbil litters were delivered by caesarian section from females that developed in 2M and 2F intrauterine positions, demonstrated unequivocally that 2M female gerbils gestate male-biased litters, whereas 2F female gerbils gestate female-biased litters.

摘要

在子宫内处于两个雄性胎儿之间子宫位置的沙鼠母鼠经阴道分娩的窝仔（2M雌性）中，雄性所占比例高于在两个雌性胎儿之间孕育的沙鼠母鼠经阴道分娩的窝仔（2F雌性）。2M和2F沙鼠经阴道分娩的窝仔性别比例差异可能反映了2M和2F母鼠窝仔围产期死亡率的性别差异。然而，在本实验中，从处于2M和2F子宫位置发育的雌性沙鼠通过剖腹产分娩窝仔的结果明确表明，2M雌性沙鼠孕育雄性偏多的窝仔，而2F雌性沙鼠孕育雌性偏多的窝仔。