Digital gene expression tag profiling of digit morphologies in bats

As the only truly flying mammals, bats use their unique wing formed from elongated digits connected by membranes to power their flight. The forelimb of bats consists of four elongated digits (digits II-V) and one shorter digit (digit I) that is morphologically similar to the hindlimb digits. Elongation of bat forelimb digits is thought to results from changes in the temporal and spatial expression of a number of developmental genes. As a result, comparing gene expression profiles between short and elongated digit morphologies of the fore- and hindlimbs may elucidate the molecular mechanisms underlying digit elongation in bats. Here, we performed a large-scale analysis of gene expression of forelimb digit I, forelimb digits II-V, and all five hindlimb digits in Myotis ricketti using digital gene expression tag profiling approach. Results of this study not only implicate several developmental genes as robust candidates underlying digit elongation in bats, but also provide a better understanding of the genes involved in autopodial development in general. Overall design: A large-scale analysis of gene expression of 3 different parts of autopods in Myotis ricketti using digital gene expression tag profiling approach.

作为唯一真正具备飞行能力的哺乳动物，蝙蝠依靠由拉长指骨与翼膜连接形成的独特翼结构实现飞行。蝙蝠前肢由四根伸长的指骨（第二至五指骨）以及一根形态与后肢指骨相似的短指骨（第一指骨）构成。学界普遍认为，蝙蝠前肢指骨的伸长源于多个发育基因的时空表达模式改变。因此，对比前肢与后肢中短指骨与伸长指骨的基因表达谱，或可阐明蝙蝠指骨伸长的分子机制。本研究采用数字基因表达标签谱分析（digital gene expression tag profiling）技术，对大足鼠耳蝠（Myotis ricketti）的前肢第一指骨、前肢第二至五指骨以及全部五根后肢指骨开展了大规模基因表达分析。本研究结果不仅揭示出多个参与蝙蝠指骨伸长的核心候选发育基因，同时也为全面理解附肢远端发育相关的各类基因提供了新的认知。实验设计概述：采用数字基因表达标签谱分析技术，对大足鼠耳蝠附肢远端的3个不同部位开展大规模基因表达分析。