1Nanae Fresh-Water Laboratory, Field Science Center for Northern Biosphere, Hokkaido University, Nanae, Japan, 2Laboratory of Breeding Science, Graduate School of Fisheries Sciences, Hokkaido University, Hakodate, Japan, 3Department of Biology, University of Pennsylvania, Philadelphia, USA, 4Department of Biology, Faculty of Science, Kobe University, Kobe, Japan and 5Laboratory of Molecular Genetics for Reproduction, National Institute for Basic Biology, Okazaki, Japan
In some teleost fish, primordial germ cells (PGCs) inherit specific maternal cytoplasmic factors such as vasa and nanos 1 (nos1) mRNA. It has been shown that the 3'untranslated regions (UTRs) of vasa and nos1 have critical roles for stabilization of these RNAs in zebrafish PGCs. In this study, to determine whether this role of the nos 1 3'UTR is conserved between teleost species, we injected artificially synthesized mRNA, combining green fluorescent protein (GFP) and the zebrafish nos 1 3'UTR(GFP-nos 1 3'UTR mRNA), into the fertilized eggs of various fish species. The 3'UTR of the Oryzias latipesvasa homologue(olvas ) mRNA was assayed in the same manner. We demonstrate that the PGCs of seven teleost species could be visualized using GFP-nos 1 3'UTR mRNA. GFP-olvas 3'UTR mRNA did not identify PGCs in herring or loach embryos, but did enable visualization of the PGCs in medaka embryos. Our results indicate that the 3'UTR of the zebrafish nos1 mRNA can promote maintenance of RNAs in the PGCs of different fish species. Finally, we describe and compare the migration routes of PGCs in seven teleost species.