title: Differential Evolution between Monotocous and Polytocous Species.
abstract: One of the most important traits for both animal science and livestock production is the number of offspring for a species. This study was performed to identify differentially evolved genes and their distinct functions that influence the number of offspring at birth by comparative analysis of eight monotocous mammals and seven polytocous mammals in a number of scopes: specific amino acid substitution with site-wise adaptive evolution, gene expansion and specific orthologous group. The mutually exclusive amino acid substitution among the 16 mammalian species identified five candidate genes. These genes were both directly and indirectly related to ovulation. Furthermore, in monotocous mammals, the EPH gene family was found to have undergone expansion. Previously, the EPHA4 gene was found to positively affect litter size in pigs and supports the possibility of the EPH gene playing a role in determining the number of offspring per birth. The identified genes in this study offer a basis from which the differences between monotocous and polytocous species can be studied. Furthermore, these genes may harbor some clues to the underlying mechanism, which determines litter size and may prove useful for livestock breeding strategies.
authors: Interdisciplinary Program in Bioinformatics, Seoul National University, Seoul 151-742, Korea .
authors: Hyeonju
authors: H
authors: Ahn
authors: Interdisciplinary Program in Bioinformatics, Seoul National University, Seoul 151-742, Korea .
authors: Kyu-Won
authors: KW
authors: Kim
authors: C&K Genomics, Seoul National University Research Park, Seoul 151-919, Korea .
authors: Hyeon Jeong
authors: HJ
authors: Kim
authors: C&K Genomics, Seoul National University Research Park, Seoul 151-919, Korea .
authors: Seoae
authors: S
authors: Cho
authors: Interdisciplinary Program in Bioinformatics, Seoul National University, Seoul 151-742, Korea .
authors: Heebal
authors: H
authors: Kim
keywords: Differential Evolution; Monotocous; Polytocous