Tracing of Xenopus tropicalis germ plasm and presumptive primordial germ cells with the Xenopus tropicalis DAZ-like gene.

A gamete is derived initially from a presumptive primordial germ cell (pPGC) and transmits genetic potential to the next generation. Xenopus tropicalis, which is a close relative of Xenopus laevis, has a diploid genome and advantages for genetic and genomic research; however, little is known about the developmental mechanism of its germinal lineage. Here, we identified the Xenopus tropicalis DAZ-like gene (Xtdazl), which encodes RNA-binding proteins homologous to Xdazl in Xenopus laevis and examined the expression patterns of Xtdazl transcripts during embryogenesis. In this work, we showed that Xtdazl mRNA was localized in the germ plasm and was expressed from the previtellogenic oocyte to early tadpole, in testis and ovary. The same localization patterns have been reported in Xenopus laevis germ plasm and pPGCs. These results indicate that Xtdazl mRNA is the first specific marker of germ plasm and pPGCs in Xenopus tropicalis and is very useful to trace Xenopus tropicalis pPGCs, including germ plasm until the early tadpole stage.