Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907, USA.
G3 (Bethesda). 2012 Sep;2(9):1113-27. doi: 10.1534/g3.112.003137. Epub 2012 Sep 1.
Although migration plays a critical role in the evolution and diversification of species, relatively little is known of the genetic architecture underlying this life history in any species. Rainbow and steelhead trout (Oncorhynchus mykiss) naturally segregate for both resident and migratory life-history types, respectively, as do other members of the salmonid family of fishes. Using an experimental cross derived from wild resident rainbow and wild migratory steelhead trout from Southeast Alaska and high throughput restriction-site associated DNA (RAD) tag sequencing, we perform a quantitative trait locus (QTL) analysis to identify the number, position, and relative contribution of genetic effects on a suite of 27 physiological and morphological traits associated with the migratory life history in this species. In total, 37 QTL are localized to 19 unique QTL positions, explaining 4-13.63% of the variation for 19 of the 27 migration-related traits measured. Two chromosomal positions, one on chromosome Omy12 and the other on Omy14 each harbor 7 QTL for migration-related traits, suggesting that these regions could harbor master genetic controls for the migratory life-history tactic in this species. Another QTL region on Omy5 has been implicated in several studies of adaptive life histories within this species and could represent another important locus underlying the migratory life history. We also evaluate whether loci identified in this out-crossed QTL study colocalize to genomic positions previously identified for associations with migration-related traits in a doubled haploid mapping family.
尽管迁移在物种的进化和多样化中起着关键作用，但对于任何物种中支持这种生活史的遗传结构，人们知之甚少。虹鳟和钢头鳟（Oncorhynchus mykiss）分别自然分为居留和洄游生活史类型，其他鲑鱼科鱼类也是如此。我们利用来自阿拉斯加东南部野生居留虹鳟和野生洄游钢头鳟的实验杂交，并进行高通量限制位点相关 DNA（RAD）标记测序，进行数量性状位点（QTL）分析，以确定与该物种洄游生活史相关的 27 个生理和形态特征的数量、位置和遗传效应的相对贡献。总共定位到 37 个 QTL 到 19 个独特的 QTL 位置，解释了 27 个与洄游相关的 27 个特征中的 19 个的 4-13.63%的变异。两个染色体位置，一个在 Omy12 染色体上，另一个在 Omy14 染色体上，各自为与洄游相关的特征携带 7 个 QTL，表明这些区域可能在该物种的洄游生活史策略中拥有主要的遗传控制。另一个位于 Omy5 上的 QTL 区域已经在该物种的适应性生活史的几项研究中被涉及，并且可能代表了迁移生活史的另一个重要基础。我们还评估了在这个杂交 QTL 研究中鉴定的基因座是否与在双倍单倍体作图家族中与与洄游相关的特征相关的基因组位置重合。
