Leamy L
Department of Biology, University of North Carolina, Charlotte 28223.
Growth Dev Aging. 1992 Spring;56(1):35-43.
Litter size, brain size, and body size were examined in inbred and hybrid house mice of three different ages in order to test whether litter size exhibits a positive genetic, but negative environmental association with both brain and body size. As estimated from among-line covariation, litter size showed a positive, but non-significant genetical association with brain and body size. It also showed a significant, negative environmental association with brain and body size, as hypothesized. Over all inbreds and hybrids, litter size explained 8% and 14%, respectively, of the within-strain (environmental) variation in brain and body size. It was concluded that the negative phenotypic association of litter size with brain size and especially body size is the reflection of a well-known negative maternal environmental effect whereby mice with large body sizes tend to produce larger litters of mice with smaller body sizes.
为了检验窝仔数是否与脑容量和身体大小呈现正遗传但负环境的关联，研究人员对三种不同年龄的近交系和杂交家鼠的窝仔数、脑容量和身体大小进行了检测。根据品系间协方差估计，窝仔数与脑容量和身体大小呈现正的但不显著的遗传关联。正如所假设的那样，它还与脑容量和身体大小呈现显著的负环境关联。在所有近交系和杂交系中，窝仔数分别解释了脑容量和身体大小的品系内（环境）变异的8%和14%。研究得出结论，窝仔数与脑容量尤其是身体大小的负表型关联是一种众所周知的负母体环境效应的反映，即体型大的小鼠往往会生出体型较小的较多窝仔。
