Gene bashing of ceh-6 locus identifies genomic regions important for ceh-6 rectal cell expression and rescue of its mutant lethality

Loss of the activity of certain genes, such as ceh-6, can lead to lethality at early developmental stages, precluding the study of their function later on during development. Indeed, it was reported that more than 80% of ceh-6(mg60) animals died during embryogenesis exhibiting various phenotypes, including an abnormal rectal area and absent excretory canal cell (Bürglin and Ruvkun 2001). mg60 is a 1.4kb deletion allele that removes ceh-6 second exon and is believed to cause the null phenotype. The expression pattern of ceh-6 is complex and matches the reported defects. Most of the ceh-6 expressing cells, which include head neurons, dividing Pn.a cells in the ventral cord, the excretory cell, and rectal cells, are not related by cell lineage nor by function (Bürglin and Ruvkun 2001).