水禽是具有游泳能力、适应水中捕食的鸟类统称。水禽的最大特征之一是具有适于游泳的脚蹼，而脚蹼对水禽的生存起到了重要作用，进而促进了水禽的物种多样性。然而，水禽脚蹼发育与进化的分子机制尚不十分明确。1951年，Hamburger和Hamilton建立了被广泛使用的鸡胚发育时段系统，但鸭胚胎发育时段系统始终没有被建立。水禽的趾间膜和蝙蝠的指间膜属于趋同进化，根据前期对蝙蝠翼手指间膜的研究和文献证据，我们推测水禽脚蹼的形成很可能是由多基因特殊表达模式调控的。因此，我们将比较鸡和鸭胚胎发育的形态变化特征，找到鸡和鸭胚胎发育的对应时段，建立鸭胚发育时段系统，为水禽的发育与进化研究奠定基础。我们还将应用转录组测序、原位杂交和基因过表达等方法，发现和验证调控趾间膜发育的关键基因，揭示水禽脚蹼发育与进化的分子机制，并与蝙蝠指间膜发育与进化的分子机制进行比较，揭示趋同进化现象分子机制的异同。

The waterfowl is a clade of birds, which have the ability to swim and prey in the water. One of the most important features of waterfowls is they have webbed feet, which are useful for swimming and play an important role for living and therefore promoting species diversity of waterfowls. However, the molecular mechanism of development and evolution of waterfowl webbed feet is still uncertain. In 1951, Hamburger and Hamilton established a widely used embryonic staging system for the chicken, but the embryonic staging system of the duck is unestablished. The interdigital membranes of waterfowls and bats are products of convergent evolution. According to our previous studies on bat interdigital membranes and the relevant references, we propose that waterfowl foot webbing is controlled by unique expression patterns of multiple genes. Thus, to study the development and evolution of waterfowls, we will compare the embryonic development of chickens and ducks, find their corresponding stages, and establish an embryonic staging system for the duck. We will also perform mRNA-Seq, in situ hybridization and gene overexpression to find out the key genes controlling the interdigital membranes. As a result, this study will reveal the developmental and evolutionary mechanism of waterfowl webbed feet at molecular level, and the similarity and difference of the convergent evolution mechanisms between waterfowl webbed feet and bat wings.