Natural selection on a major armor gene in threespine stickleback
Natural selection on a major armor gene in threespine stickleback
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DOI：
10.1126/science.1159978
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发表时间：
2008-10-10
期刊：
影响因子：
56.9
通讯作者：
Schluter, Dolph
中科院分区：
文献类型：
--
作者：
Barrett, Rowan D. H.;Rogers, Sean M.;Schluter, Dolph
选择对决定适应性性状的基因的影响的实验估计增加了我们对进化机制的理解。我们测量了外胞质异常基因座的基因型选择，这是三刺棘鱼侧板差异的基础。一个衍生的等位基因（低）导致板数减少，在海洋棘鱼从海洋中定居淡水后反复固定，其中祖先等位基因（完整）占主导地位。我们将携带这两种等位基因的海棘鱼移植到淡水池塘中，并追踪了一代的基因型频率。一旦侧板发育，低等位基因的频率就会增加，这很可能是由于生长优势。幼虫阶段的逆向选择和一生中为适应而改变的优势表明，要么该基因影响了正在进行选择的其他性状，要么相关的位点也影响了适应。
Experimental estimates of the effects of selection on genes determining adaptive traits add to our understanding of the mechanisms of evolution. We measured selection on genotypes of the Ectodysplasin locus, which underlie differences in lateral plates in threespine stickleback fish. A derived allele (low) causing reduced plate number has been fixed repeatedly after marine stickleback colonized freshwater from the sea, where the ancestral allele (complete) predominates. We transplanted marine sticklebacks carrying both alleles to freshwater ponds and tracked genotype frequencies over a generation. The low allele increased in frequency once lateral plates developed, most likely via a growth advantage. Opposing selection at the larval stage and changing dominance for fitness throughout life suggest either that the gene affects additional traits undergoing selection or that linked loci also are affecting fitness.