(Uploaded by Plazi for the Bat Literature Project) Bats are mammals of the order Chiroptera, which represents about 20% of all mammalian species worldwide. Bats have evolved various reproductive strategies, such as delayed sperm maturation, sperm storage, delayed fertilization, delayed implantation and delayed development. The strategies of delayed sperm maturation allow female bats, especially hibernating species, to reproduce successfully. Alpha-L-Fucosidase 1 gene (FUCA1) has been proved to be involved in the processes of sperm maturation and sperm-egg interactions in mammals. It is still not clear how the FUCA1 gene evolved in bats. Therefore, it is important to determine the evolutionary pattern of FUCA1 gene and positively selected sites which affect the reproductive activity of bats. In this work, we cloned the coding regions of FUCA1 from 7 species of bats and performed an evolutionary study of this gene. Although selection pressure varied among different lineages, FUCA1 gene underwent positive selection in the ancestral species leading to Old World fruit bats. Our results demonstrated that FUCA1 is basically conserved in hibernating bats but has evolved within the ancestral species of Old World fruit bats to adapt their survival environments.