Of mice and ... snakes

Vertebrates exhibit a remarkable variation in trunk and tail lengths. However, how this diversity comes about is mostly unknown. Rita Aires et al. report in Developmental Cell that Oct4 is a key regulator of vertebrate trunk length diversity. They show that snake embryos express Oct4 for longer periods than mouse embryos and provide evidence to suggest that differential genomic rearrangements of noncoding regions near the Oct4 locus may underlie this phenomenon in snakes. Also see Latest News in Science.