Genetic and developmental basis of evolutionary pelvic reduction in threespine sticklebacks
Genetic and developmental basis of evolutionary pelvic reduction in threespine sticklebacks
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DOI：
10.1038/nature02415
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发表时间：
2004-04-15
期刊：
影响因子：
64.8
通讯作者：
Kingsley, DM
中科院分区：
文献类型：
--
作者：
Shapiro, MD;Marks, ME;Kingsley, DM
后肢缺失在许多不同的动物身上反复进化，其分子机制尚不清楚。为了确定在自然种群中骨盆缩小的遗传变化的数量和类型，我们对骨盆结构完整或缺失的三条刺鱼进行了遗传杂交。全基因组连锁图谱显示骨盆缩小是由一个主染色体区域和四个小染色体区域控制的。Pitx1定位于控制骨盆大小大部分变异的主要染色体区域。骨盆缩小的鱼表现出与Pitx1基因敲除小鼠相同的左右不对称，但没有显示出Pitx1蛋白序列的变化。相反，盆腔缩小的刺鱼表现出部位特异性的Pitx1表达的调节变化，在盆骨和尾鳍前体中表达减少或缺失。主要发育控制基因的调节性突变可能提供了一种在自然群体中产生快速骨骼变化的机制，同时保留了这些基因在其他过程中的基本作用。
Hindlimb loss has evolved repeatedly in many different animals by means of molecular mechanisms that are still unknown. To determine the number and type of genetic changes underlying pelvic reduction in natural populations, we carried out genetic crosses between threespine stickleback fish with complete or missing pelvic structures. Genome-wide linkage mapping shows that pelvic reduction is controlled by one major and four minor chromosome regions. Pitx1 maps to the major chromosome region controlling most of the variation in pelvic size. Pelvic-reduced fish show the same left-right asymmetry seen in Pitx1 knockout mice, but do not show changes in Pitx1 protein sequence. Instead, pelvic-reduced sticklebacks show site-specific regulatory changes in Pitx1 expression, with reduced or absent expression in pelvic and caudal fin precursors. Regulatory mutations in major developmental control genes may provide a mechanism for generating rapid skeletal changes in natural populations, while preserving the essential roles of these genes in other processes.