Here we describe the cloning and expression pattern of Ci-isl, a homologue of vertebrate genes, in the ascidian. Early in development, Ci-isl expression occurs in the primordia of palps and brain vesicle, then in the tailbud embryo it is transiently extended to the notochord cells. At larva stage, the expression is down-regulated in the notochord, and it persists predominantly in the compartmen...

Does tightening your belt make you taller? You might be tempted to conclude so after learning the results of an intriguing study of how notochord cells elongate in embryos of a primitive sea creature. Embryonic development involves two basic processes: cell multiplication and cell shape changes. Elongation in particular is a crucial process for development of the notochord, which serves as a ‘‘...

We report the isolation of a recessive ENU-induced short-tailed mutant in the ascidian Ciona intestinalis that is the product of a premature stop in the brachyury gene. Notochord differentiation and morphogenesis are severely disrupted in the mutant line. At the larval stage, variable degrees of ectopic endoderm staining were observed in the homozygous mutants, indicating that loss of brachyury...

Gastrula and neurula embryos of Cynops pyrrhogaster were dissociated into cell suspensions with ethylenediaminetetraacetic acid (EDTA), trypsin, and solution. The cells were cultured in Niu-Twitty's balanced salt solution and their aggregates were examined histologically. The results indicated that the capacity of amphibian embryonic cells for aggregate formation, sorting out, and notochord dif...

Mll, Brg1 and Brm are vertebrate homologues of Drosophila trithorax group (trxG) genes. We isolated chicken Mll cDNA clones, and examined patterns of Mll, Brg1 and Brm expression in chick embryos. All three genes were expressed from embryonic stage 2 onwards. Mll transcripts were just detectable in all tissues by in situ hybridization, with highest level in dorsal neural tube and notochord. Brg...