Bult A, Lynch C B
Biology Department, Wesleyan University, Middletown, Connecticut 06459-0170, USA.
Behav Genet. 1996 Jul;26(4):439-46. doi: 10.1007/BF02359488.
Replicate high-selected, control, and low-selected lines were crossed at generation 46 of bidirectional selection for thermoregulatory nest-building behavior. Previous analysis of the lines at their limits had revealed multiple responses to uniform selection, where each of the four selected lines responded differently to reverse selection (Laffan, 1989). The reciprocal F1 crosses showed significant heterosis for nest-building behavior compared to the contemporaneous generations of the parental lines. This pattern of heterosis in all three crosses is consistent with the finding that nest-building behavior in each of the four replicate lines had a different genetic basis, in spite of the phenotypic similarity between the two replicate lines in the high and low direction of nesting. This heterosis effect and the larger number of young weaned in all three crosses compared to their respective contemporaneous generation of the parental lines also support earlier findings that larger nests are closely related to fitness.
在对体温调节筑巢行为进行双向选择的第46代时，对高选择品系、对照品系和低选择品系进行了杂交。之前对处于极限状态的品系的分析揭示了对统一选择的多种反应，其中四个选择品系中的每一个对反向选择的反应都不同（拉方，1989年）。与亲本品系的同期世代相比，正反交F1杂交在筑巢行为上表现出显著的杂种优势。所有三个杂交组合中的这种杂种优势模式与以下发现一致：尽管在筑巢行为的高、低两个方向上的两个重复品系之间存在表型相似性，但四个重复品系中的每一个的筑巢行为都有不同的遗传基础。这种杂种优势效应以及与亲本品系各自同期世代相比，所有三个杂交组合中断奶幼崽数量更多，也支持了早期的研究结果，即更大的巢穴与适应性密切相关。
