Heritability and genetic correlation of abdominal and caudal vertebral numbers in latitudinal populations of the medaka Oryzias latipes

作者：Kiso Shinya; Miyake Takashi; Yamahira Kazunori^*

来源：Environmental Biology of Fishes, 2012, 93(2): 185-192.

DOI：10.1007/s10641-011-9904-1

• Adaptation
• Additive genetic variation
• Developmental module
• Full-sib
• Latitude

Body axes of fishes consist of two anatomically distinct types of vertebrae: abdominal and caudal. In the medaka Oryzias latipes, the number of abdominal vertebrae increases with increasing latitudes, whereas caudal vertebrae do not vary systematically across latitudes, suggesting local adaptation in abdominal vertebral numbers. However, because heritable variation in abdominal and caudal vertebral numbers has not been examined within each latitudinal population, it is not clear whether abdominal and caudal vertebrae can evolve independently. Offspring-midparent regression demonstrated substantial heritability of abdominal vertebral numbers in each of two latitudinal populations whereas the heritability of caudal vertebral numbers was not significant. Full-sib analyses revealed that intra-family variation was larger in caudal vertebrae than in abdominal vertebrae, indicating larger non-additive genetic variation and/or larger errors of development in the former. Moreover, the genetic correlation between abdominal and caudal vertebral numbers was very weak. These results suggest that abdominal and caudal vertebrae are controlled by separate developmental modules, which supports their independent evolution with local adaptation of abdominal vertebral numbers in this fish. On the other hand, the weak heritability of caudal vertebrae suggests that the evolution of caudal vertebrae may be restricted, causing unequal evolutionary lability between abdominal and caudal regions.

• 出版日期2012-2