lin-29 animals have defects in addition to an inability to form adult cuticle.
lin-29 null mutant males do not mate. To identify the defects in
lin-29 males, we have observed the male mating behaviors and aspects of male tail development using Nomarski optics.
lin-29 males exhibit "backing", "turning", and "vulva location" behaviors [1]. Since
lin-29 males respond to hermaphrodites, the cells of the sensory rays, the hook and associated sensilla are likely unaffected by lack of
lin-29. We found that 100% of
lin-29 null animals have short spicules. Because the B cell is the precursor of all of the cells that comprise the male spicules, it is likely that
lin-29 animals have a B cell lineage defect. The sensory rays are derived from cells of the V5, V6, and T cell lineages. Since V and T seam cell larval lineages are reiterated during supernumerary larval stages in
lin-29 mutant hermaphrodite animals, we are investigating whether the tail seam (set) cells of the male tail reiterate a larval cell division program. Ray formation occurs at the normal time, generating the proper number and type of rays (as indicated by position and morphology) in
lin-29 mutant animals. This result and the male mating behavior result suggest that ray cell differentiation does not require
lin-29 activity. However, during the L5 and later stages of
lin-29 mutants, the appearance of extra ray-like cells was observed. The presence of additional but abnormal rays suggests an L4-specific cell lineage reiteration in
lin-29 mutant male tails. Lineage analysis of the
lin-29 male tail will be presented. We have initiated
lin-29 protein accumulation studies in wild-type males.
lin-29 protein accumulates in many cells of the L4 and adult wild-type male tails. The position of the cells are consistent with those of B, F, and U descendants. Interestingly, the B, F, and U cells accumulate Lin-29 in hermaphrodites. [1]Liu, K. S. and Sternberg, P. W. (1995) Neuron 14:79-89.