小柯机器人

美国哈佛医学院Matthew P. Harris研究组取得最新进展。他们揭示斑马鱼中形成肢体状骨骼结构的发展潜力。2021年2月5日出版的《细胞》杂志发表这一成果。

他们确定斑马鱼突变体的胸鳍中形成多余的长骨。这些新的骨骼整合到肌肉组织中，形成关节，并与相邻元素进行关节运动。这种表型是由激活先前未识别的附属结构调节因子vav2和waslb的突变引起的，这些突变以共同的途径起作用。该途径是整个脊椎动物的附属结构发育所必需的，并且小鼠中Wasl的缺失导致与鼠类Hox突变体相似的缺陷。

相应地，多余骨骼的形成需要Hox11功能，并且vav2 / wasl途径中的突变驱动hoxa11b的表达增强，表明与前臂的发育同源。他们的发现揭示了鳍中潜在的、类似于肢体的模式能力，该能力由简单的遗传扰动激活。

据了解，附属结构的变化是脊椎动物进化过程中关键过渡基础。沿近端-远端轴添加骨骼元素有助于进行关键转换，包括从鳍到肢的转换，从而可以产生多种运动模式。

附：英文原文

Title: Latent developmental potential to form limb-like skeletal structures in zebrafish

Author: M. Brent Hawkins, Katrin Henke, Matthew P. Harris

Issue&Volume: 2021-02-04

Abstract: Changes in appendage structure underlie key transitions in vertebrate evolution. Addition of skeletal elements along the proximal-distal axis facilitated critical transformations, including the fin-to-limb transition that permitted generation of diverse modes of locomotion. Here, we identify zebrafish mutants that form supernumerary long bones in their pectoral fins. These new bones integrate into musculature, form joints, and articulate with neighboring elements. This phenotype is caused by activating mutations in previously unrecognized regulators of appendage patterning, vav2 and waslb, that function in a common pathway. This pathway is required for appendage development across vertebrates, and loss of Wasl in mice causes defects similar to those seen in murine Hox mutants. Concordantly, formation of supernumerary bones requires Hox11 function, and mutations in the vav2/wasl pathway drive enhanced expression of hoxa11b, indicating developmental homology with the forearm. Our findings reveal a latent, limb-like pattern ability in fins that is activated by simple genetic perturbation.

DOI: 10.1016/j.cell.2021.01.003

Source: https://www.cell.com/cell/fulltext/S0092-8674(21)00003-9