Metamorphosis - the end of a tail Available to Purchase

How a tadpole metamorphoses into an adult is a captivating process. But how does the tail disappear? Now Chambon et al., on p. 1203, identify a gene network together with a cell-cell communication protein called Ci-sushi that are required for apoptosis in the regressing tail of Cionatadpoles. From a microarray expression profiling analysis of Cionalarvae treated with inhibitors of the MAP kinase and JNK pathways, which regulate apoptosis, these investigators uncovered a network of genes that show expression changes during metamorphosis. Ci-sushi, one such gene, is expressed in the tail epithelia and is downregulated by JNK inhibitors - when knocked down by a morpholino, tail cell death and regression are prevented. The authors propose that JNK activity in the CNS (which escapes cell death)causes apoptosis in adjacent cells through Ci-sushi activity. Given their basic chordate body plan, similar studies of Ciona larvae might shed light on...