TY - JOUR
T1 - Cloning and pattern of expression of the shiro-uo vasa gene during embryogenesis and its roles in PGC development
AU - Miyake, Akimitsu
AU - Saito, Taiju
AU - Kashiwagi, Tohru
AU - Ando, Daisuke
AU - Yamamoto, Akitsugu
AU - Suzuki, Tohru
AU - Nakatsuji, Norio
AU - Nakatsuji, Takako
PY - 2006
Y1 - 2006
N2 - The vasa genes are expressed in the germ cell lineage in many organisms, but their expression patterns show large variations. Recent studies suggest that vasa transcripts are involved in germ cell lineage development. In this paper, we isolated the vasa cDNA clone from a teleost, shiro-uo, Leucopsarion petersii and examined its expression pattern during embryogenesis. Then, we examined the functional significance of vasa mRNA during the formation of primordial germ cells (PGCs). The amino acid sequence of shiro-uo VASA is 61.1% identical to that of zebrafish. In whole-mount in situ hybridization, vasa transcripts appeared at the 4- and 8-cell stages as four spots at both ends of two cleavage planes between the lower tier of blastomeres and the yolk cell mass. At the 16-cell stage, eight spots were observed. After the blastula stage, shiro-uo vasa transcripts showed similar localization as in the zeblafish. Ultrastructural analysis of 4-cell stage embryos revealed the presence of a subcellular organelle that resembled "nuage" in the germ cell lineage observed in the embryos of various organisms. We carried out micromanipulation of 4- or 8-cell stage embryos to remove the vasa mRNA-containing spots and then measured the number of the vasa-expressing PGCs in the genital ridge of the manipulated embryos. The numbers decreased when all of the four spots were removed, indicating that the vasa-containing spots at early cleavage stages have important functions in the development of PGCs.
AB - The vasa genes are expressed in the germ cell lineage in many organisms, but their expression patterns show large variations. Recent studies suggest that vasa transcripts are involved in germ cell lineage development. In this paper, we isolated the vasa cDNA clone from a teleost, shiro-uo, Leucopsarion petersii and examined its expression pattern during embryogenesis. Then, we examined the functional significance of vasa mRNA during the formation of primordial germ cells (PGCs). The amino acid sequence of shiro-uo VASA is 61.1% identical to that of zebrafish. In whole-mount in situ hybridization, vasa transcripts appeared at the 4- and 8-cell stages as four spots at both ends of two cleavage planes between the lower tier of blastomeres and the yolk cell mass. At the 16-cell stage, eight spots were observed. After the blastula stage, shiro-uo vasa transcripts showed similar localization as in the zeblafish. Ultrastructural analysis of 4-cell stage embryos revealed the presence of a subcellular organelle that resembled "nuage" in the germ cell lineage observed in the embryos of various organisms. We carried out micromanipulation of 4- or 8-cell stage embryos to remove the vasa mRNA-containing spots and then measured the number of the vasa-expressing PGCs in the genital ridge of the manipulated embryos. The numbers decreased when all of the four spots were removed, indicating that the vasa-containing spots at early cleavage stages have important functions in the development of PGCs.
KW - Primordial germ cell (PGC)
KW - Shiro-uo
KW - Teleost
KW - Vasa
KW - mRNA localization
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U2 - 10.1387/ijdb.062172am
DO - 10.1387/ijdb.062172am
M3 - Article
C2 - 16892175
AN - SCOPUS:33749631971
VL - 50
SP - 619
EP - 625
JO - International Journal of Developmental Biology
JF - International Journal of Developmental Biology
SN - 0214-6282
IS - 7
ER -