Drickamer L C
Biol Reprod. 1983 May;28(4):843-8. doi: 10.1095/biolreprod28.4.843.
Previous investigations have hypothesized a link between regulation of population size in various rodent species and changes in allele frequencies for certain loci that exert their effects on particular behaviors or processes related to reproduction. Drickamer (1981a) has shown that age of first vaginal estrus can be shifted by artificial selection and that there is a relatively high heritability for this trait in laboratory Mus. This paper reports on two related experiments, one a test of reverse selection on strains of mice previously selected for early and late first vaginal estrus, and the other a compilation of data for a variety of traits related to reproduction for the original base stock and four artificially selected stocks. The original selection for early and late onset of puberty did not result in fixation of the trait-enough residual variation remained so that in eight generations of selection it was possible to significantly reverse the timing of first estrus. Traits related to reproduction including litter size, pup weight, survival of pups to 21 days, weight at 21 days, fertility and birth intervals all were not affected by the selection process across all five stocks tested. These results are discussed with regard to changes in puberty and generation time in Mus as a factor in population regulation.
以往的研究推测，在各种啮齿动物物种中，种群数量的调节与某些基因座等位基因频率的变化之间存在联系，这些基因座对与繁殖相关的特定行为或过程产生影响。德里卡默（1981a）表明，首次阴道发情的年龄可以通过人工选择来改变，并且在实验室小鼠中，这一性状具有相对较高的遗传力。本文报道了两项相关实验，一项是对先前因首次阴道发情早和晚而被选择的小鼠品系进行反向选择的测试，另一项是对原始基础种群和四个人工选择种群的各种繁殖相关性状的数据汇编。最初对青春期早晚的选择并未导致该性状的固定——仍存在足够的残余变异，以至于在八代选择中，有可能显著逆转首次发情的时间。在所测试的所有五个种群中，与繁殖相关的性状，包括产仔数、幼仔体重、幼仔存活到21天的情况、21天时的体重、生育力和出生间隔，均未受到选择过程的影响。本文就小鼠青春期和世代时间的变化作为种群调节的一个因素对这些结果进行了讨论。
