TY - JOUR TI - Mesoderm formation by isolated and cultivated 8-cell stage blastomeres of the teleost, Leucopsarion ptersii (shiro-uo). AU - Saito, T AU - Kamimoto, M AU - Miyake, A AU - Yamaha, E AU - Suzuki, T AU - Nakatsuji, N AU - Nakatsuji, T T2 - The International Journal of Developmental Biology AB - Isolation of cleavage-stage blastomeres and the study of their developmental potential has been used extensively for analyzing the mechanisms of embryogenesis in vertebrates, including amphibians and echinoderms. We devised a method to isolate 8-cell stage blastomeres in the teleost, shiro-uo, by utilizing its unique cleavage pattern of the horizontal 3rd cleavage plane. Removal of all the upper blastomeres at the 8-cell stage allowed almost normal embryogenesis from the remaining lower blastomeres and yolk cell mass. Isolated upper or lower blastomeres formed vesicles and spherical bodies, which later showed morphological changes during cultivation. Mesoderm formation was detected not only in the cultivated lower blastomeres or whole blastomeres but also in the upper blastomeres isolated from the yolk cell mass at the 8-cell stage, although at a lower frequency than the lower blastomeres. These results indicated the presence of very early signaling for mesoderm induction, which is independent from the currently postulated signals from the yolk syncytial layer at later stages. This also indicated non-equivalence or differentiation of the blastomeres from the very early cleavage stage in teleost embryos. PY - 2001 VL - 45 IS - 4 SP - 661 EP - 668 J2 - Int. J. Dev. Biol. LA - en SN - 0214-6282 SN - 1696-3547 UR - https://ijdb.ehu.eus/article/11461002 Y2 - 2024/11/05/15:23:44 ER -