Phenotype Characterization of sas-7(or1945) C. elegans

Merrick Hall Room 301

The ability to form a bipolar spindle is crucial for accurate cell division. In the nematode C. elegans several genes have been described with roles in spindle assembly including sas-7. The centriole is a key organizer of mitotic spindles. The sas-7 protein is a centriole component that regulates centriole duplication, elongation, and assembly. To date, most work on sas-7 was using a conditional non-null allele. In this study, phenotypes associated with the loss-of-function sas-7(or1945) null allele were characterized. Homozygous sas-7(or1945) hermaphrodites have reduced brood sizes with no viable embryos compared to wild-type and heterozygotes. When they do produce embryos, they become multinucleated suggesting failures in spindle formation and cell division. As adults, homozygous hermaphrodites also appear to have protruding vulvas with the eventual gut explosion from the vulva. Adult homozygous hermaphrodites also appear to have uncoordinated movement. Homozygous sas-7(or1945) males have misshapen tails, and they appear unable to mate. Whether they produce viable sperm is unknown at this time. We conclude that sas-7(or1945) C. elegans have phenotypes suggesting possible sterility. As cell division and developmental processes are well conserved in animals, what we learn from our studies in C. elegans may help us to understand these processes in other organisms as well.