Department of Developmental Biology, Stanford University School of Medicine, California, United States.
Department of Genetics, Stanford University School of Medicine, California, United States.
Elife. 2018 Nov 30;7:e38555. doi: 10.7554/eLife.38555.
Vertebrate pelvic reduction is a classic example of repeated evolution. Recurrent loss of pelvic appendages in sticklebacks has previously been linked to natural mutations in a pelvic enhancer that maps upstream of . The sequence of this upstream enhancer is not conserved to mammals, so we have surveyed a large region surrounding the mouse gene for other possible hind limb control sequences. Here we identify a new pelvic enhancer, , that maps downstream rather than upstream of drives expression in the posterior portion of the developing hind limb, and deleting the sequence from mice alters the size of several hind limb structures. sequences are broadly conserved from fish to mammals. A wild stickleback population lacking the pelvis has an insertion/deletion mutation that disrupts the structure and function of , suggesting that changes in this ancient enhancer contribute to evolutionary modification of pelvic appendages in nature.
脊椎动物骨盆缩小是一个典型的重复进化的例子。棘鱼中反复失去骨盆附肢的现象此前已被证实与位于上游的骨盆增强子中的自然突变有关。这个上游增强子的序列与哺乳动物并不保守，因此我们在小鼠基因周围的一个大片段区域内对其他可能的后肢控制序列进行了调查。在这里，我们鉴定出一个新的骨盆增强子 ，它位于 下游而非上游，驱动着发育中的后肢后段的表达，并且从小鼠中删除该序列会改变几个后肢结构的大小。从鱼类到哺乳动物， 序列广泛保守。一个缺少骨盆的野生棘鱼种群存在一个插入/缺失突变，破坏了 的结构和功能，这表明这个古老的增强子的变化有助于自然状态下骨盆附肢的进化修饰。
