Jc. Bettinger et al., THE TERMINAL DIFFERENTIATION FACTOR LIN-29 IS REQUIRED FOR PROPER VULVAR MORPHOGENESIS AND EGG-LAYING IN CAENORHABDITIS-ELEGANS, Development, 124(21), 1997, pp. 4333-4342
Caenorhabditis elegans vulval development culminates during exit from
the L4-to-adult molt with the formation of an opening through the adul
t hypodermis and cuticle that is used for egg laying and mating, Vulva
formation requires the heterochronic gene lin-29, which triggers hypo
dermal cell terminal differentiation during the final molt. lin-29 mut
ants are unable to lay eggs or mate because no vulval opening forms; i
nstead, a protrusion forms at the site of the vulva, We demonstrate th
rough analysis of genetic mosaics that lin-29 is absolutely required i
n a small subset of lateral hypodermal seam cells, adjacent to the vul
va, for wild-type vulva formation and egg laying. However, lin-29 func
tion is not strictly limited to the lateral hypodermis. First, LIN-29
accumulates in many non-hypodermal cells with known roles in vulva for
mation or egg laying, Second, animals homozygous for one lin-29 allele
, ga94, have the vulval defect and cannot lay eggs, despite having a t
erminally differentiated adult lateral hypodermis, Finally, vulval mor
phogenesis and egg laying requires lin-29 activity within the EMS line
age, a lineage that does not generate hypodermal cells.