pEg6, a spire family member, is a maternal gene encoding a vegetally localized mRNA in Xenopus embryos.

Background Information: In Xenopus, during oocyte maturation and the segmentation period, cell cycle progression is independent of new transcription, but requires de novo translation. This suggests that the completion of oocyte maturation and then the rapid cell division period is controlled exclusively at a post-transcriptional level by specific gene products. To isolate these maternal genes, a differential screening of a Xenopus egg cDNA library was performed.