Pou5f1/Oct4 promotes cell survival via direct activation of mych expression during zebrafish gastrulation.

Myc proteins control cell proliferation, cell cycle progression, and apoptosis, and play important roles in cancer as well in establishment of pluripotency. Here we investigated the control of myc gene expression by the Pou5f1/Oct4 pluripotency factor in the early zebrafish embryo. We analyzed the expression of all known zebrafish Myc family members, myca, mycb, mych, mycl1a, mycl1b, and mycn, by whole mount in situ hybridization during blastula and gastrula stages in wildtype and maternal plus zygotic pou5f1 mutant (MZspg) embryos, as well as by quantitative PCR and in time series microarray data.

A Pou5f1/Oct4 dependent Klf2a, Klf2b, and Klf17 regulatory sub-network contributes to EVL and ectoderm development during zebrafish embryogenesis.

In mammalian ES cells, the transcription factors Klf4 and Klf2 contribute to maintenance of pluripotency and self-renewal and are regulated by Pou5f1/Oct4. In the early zebrafish embryo Pou5f1/Oct4 is necessary for expression of three Klf2/4 family members, klf2a, klf2b and klf17 (previously klf4b), similar to the regulation reported for mammalian ES cells. In this study, we analyzed blastula and gastrula stage Klf regulatory networks and their influence on zebrafish embryonic patterning.

Apparent role of Tribolium orthodenticle in anteroposterior blastoderm patterning largely reflects novel functions in dorsoventral axis formation and cell survival.

In the short-germ beetle Tribolium castaneum, the head gap gene orthodenticle (Tc-otd) has been proposed to functionally substitute for bicoid, the anterior morphogen unique to higher dipterans. In this study we reanalyzed the function of Tc-otd. We obtained a similar range of cuticle phenotypes as in previously described RNAi experiments; however, we noticed unexpected effects on blastodermal cell fates.