Bitner-Mathé B C, Klaczko L B
Departamento de Biologia, Instituto de Biociências, USP, São Paulo, Brazil.
Hereditas. 1998;128(1):67-71. doi: 10.1111/j.1601-5223.1998.00067.x.
We studied the major sources influencing the variation of the number of aristal branches in a natural population of Drosophila mediopunctata. Flies were collected on six occasions at different altitudes in Parque Nacional do Itatiaia (Brazil). The progenies of these flies were reared in the laboratory at 16.5 degrees C. The number of aristal branches ranges from 11 to 15 and is influenced by sex. Estimates of the natural heritability showed that at least 20% of the total phenotypic variation is due to additive genetic variation. Although the heritability of this trait estimate in the laboratory was larger (42%), the difference between the two estimates is not statistically significant. Thus, for the number of aristal branches, laboratory estimates of heritability provide reasonable estimations of both the magnitude and significance of heritabilities in nature. The mean numbers of aristal branches in the wild-caught flies from different altitudes or months are homogeneous. The same was observed for the means of its progeny kept in the laboratory under controlled conditions. On the other hand, wild-caught females have significantly fewer aristal branches than their laboratory-raised daughters, which suggests that an environmental factor or factors may have an important influence on this trait.
我们研究了影响拟果蝇自然种群中触角芒分支数量变异的主要来源。在巴西伊塔蒂亚伊国家公园的不同海拔高度分六次采集果蝇。这些果蝇的后代在实验室中于16.5摄氏度下饲养。触角芒分支数量在11至15之间，且受性别影响。自然遗传力估计表明，至少20%的总表型变异是由加性遗传变异引起的。尽管该性状在实验室中的遗传力估计值更大（42%），但这两个估计值之间的差异无统计学意义。因此，对于触角芒分支数量，实验室遗传力估计为自然条件下遗传力的大小和显著性提供了合理估计。来自不同海拔或月份的野生捕获果蝇的触角芒分支平均数量是相同的。在实验室控制条件下饲养的其后代的平均值也观察到同样情况。另一方面，野生捕获的雌性果蝇的触角芒分支明显少于在实验室饲养的女儿，这表明一个或多个环境因素可能对该性状有重要影响。
