Mapping a cave fish genome: Polygenic systems and regressive evolution
Mapping a cave fish genome: Polygenic systems and regressive evolution
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DOI：
10.1093/jhered/93.1.19
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发表时间：
2002-01-01
影响因子：
3.1
通讯作者：
Wilkens, H
中科院分区：
文献类型：
--
作者：
Borowsky, R;Wilkens, H
我们使用随机扩增多态性 DNA (RAPD) 指纹技术在 Astyanax mexicanus 鱼（一种在地表和洞穴中都有种群）中生成匿名 DNA 标记。地表个体有眼睛和色素；穴居球虫形式是盲目的并且色素脱失。我们将表层鱼和 Pachon 种群洞穴鱼杂交，生成了长度为 1064 cM（约是基因组总长度的一半）的 RAPD 基因组图谱，用于筛选穴形性状的数量性状基因座 (QTL)。绘制了三个与眼睛尺寸减小相关的 QTL、两个与黑色素细胞数量减少相关的 QTL、两个与条件因子相关的 QTL，以及单因子性状（白化病）的基因座。这些因素平均占回交中这些性状变异的 46%。结果首次直接证明该种群的穴形变化是多因素的。发现了两对紧密连锁的QTL。每个都包含一个回归性状和一个建设性性状 QTL。这些密切的联系不太可能是偶然发生的（每个 P < .05），表明多效性或遗传搭便车可能促进了穴形进化。
We used random amplified polymorphic DNA (RAPD) fingerprinting to generate anonymous DNA markers in the fish Astyanax mexicanus, a species with both surface and cave populations. Surface individuals are eyed and pigmented; troglobitic forms are blind and depigmented. We hybridized surface fish and Pachon population cave fish and produced a RAPD genomic map 1064 cM in length (about half the total length of the genome) that was used to screen for quantitative trait loci (QTL) for troglomorphic traits. Three QTL for reduced eye size, two for decreased numbers of melanophores, two for condition factor, and the locus for the unifactorial trait, albinism, were mapped. These factors account for an average of 46% of the variance in these traits in the backcross. The results are the first direct demonstration that troglomorphic changes in this population are multifactorial. Two closely linked pairs of QTL were found. Each consisted of a regressive and a constructive trait QTL. These close linkages are unlikely to have occurred by chance (P < .05 for each) and suggest that troglomorphic evolution might be facilitated by pleiotropy or by genetic hitchhiking.