The zinc finger gene Xblimp1 controls anterior endomesodermal cell fate in Spemann's organizer

Abstract

The anterior endomesoderm of the early Xenopus gastrula is a part of Spemann's organizer and is important for head induction. Here we describe Xblimp1, which encodes a zinc finger transcriptional repressor expressed in the anterior endomesoderm. Xblimp1 represses trunk mesoderm and induces anterior endomesoderm in a cooperative manner with the pan-endodermal gene Mix.1. Furthermore, Xblimp1 can cooperate with the BMP inhibitor chordin to induce ectopic heads, while a dominant-negative Xblimp1 inhibits head formation. The head inducer cerberus is positively regulated by Xblimp1 and is able to rescue microcephalic embryos caused by dominant-negative Xblimp1. Our results indicate that Xblimp1 is required for anterior endomesodermal cell fate and head induction.

The B-cell maturation factor Blimp-1 specifies vertebrate slow-twitch muscle fiber identity in response to Hedgehog signaling

“…In contrast to ubo mutants, the ubo morphants generated with a high dose of morpholino oligonucleotide showed early developmental defects manifested in considerable abbreviation of their head primordium and shortening of the body axis (data not shown), consistent with a previously described role of Blimp-1 in regulating vertebrate gastrulation 15 . Examination of the slow muscle lineage in these morphants at early stages of somitogenesis showed that its development was completely impaired, as indicated by the total absence of slow MyHC; this contrasts with ubo tp39 mutants, in which we detected variable expression of slow MyHC (Fig.…”

Blimp1 and the Emergence of the Germ Line during Development in the Mouse

“…38,39 In the Xenopus and zebrafish, Blimp1 is expressed in the anterior mesendoderm and prechordal plate, where it is required for regulating appropriate functions of these tissues. 40,41 Notably, as stated above, germ cell specification in Xenopus and zebrafish is predetermined by the inheritance of germ plasm, and consequently, no defects in germ cell formation have been reported in these organisms in the absence of Blimp1. In mice, Blimp1 is expressed in the analogous anterior visceral endoderm (AVE) and anterior definitive endoderm (ADE)/prechordal plate.…”

Germline and Pluripotent Stem Cells

“…For example, it has a role in the development of several lineages in vertebrates such as the zebrafish and Xenopus (de Souza et al 1999;Roy and Ng 2004;Hernandez-Lagunas et al 2005), although not specifically in germ cell specification. This implies that the gene has acquired a new role in PGC specification in mice and perhaps in all mammals.…”