Jeffery William R
Department of Biology, University of Maryland, College Park, Maryland 20742, USA.
Annu Rev Genet. 2009;43:25-47. doi: 10.1146/annurev-genet-102108-134216.
A diverse group of animals, including members of most major phyla, have adapted to life in the perpetual darkness of caves. These animals are united by the convergence of two regressive phenotypes, loss of eyes and pigmentation. The mechanisms of regressive evolution are poorly understood. The teleost Astyanax mexicanus is of special significance in studies of regressive evolution in cave animals. This species includes an ancestral surface dwelling form and many con-specific cave-dwelling forms, some of which have evolved their recessive phenotypes independently. Recent advances in Astyanax development and genetics have provided new information about how eyes and pigment are lost during cavefish evolution; namely, they have revealed some of the molecular and cellular mechanisms involved in trait modification, the number and identity of the underlying genes and mutations, the molecular basis of parallel evolution, and the evolutionary forces driving adaptation to the cave environment.
包括大多数主要门类成员在内的各种各样的动物已经适应了洞穴中终年黑暗的生活。这些动物因眼睛退化和色素沉着这两种退化表型的趋同而联系在一起。退化进化的机制尚不清楚。硬骨鱼墨西哥丽脂鲤在洞穴动物退化进化研究中具有特殊意义。该物种包括一种祖先的地表栖息形态和许多同物种的洞穴栖息形态，其中一些是独立进化出其隐性表型的。墨西哥丽脂鲤在发育和遗传学方面的最新进展为洞穴鱼进化过程中眼睛和色素丧失的方式提供了新信息；也就是说，它们揭示了一些与性状改变有关的分子和细胞机制、潜在基因和突变的数量及特性、平行进化的分子基础，以及推动适应洞穴环境的进化力量。
