MSc Exit Seminar – Victor Lao (Saltzman Lab)

Germline immortality describes the ability of the germ cell lineage to be continuously passed down and, in C. elegans, is protected by proper regulation of histone modifications and small RNA pathways. Loss of two C. elegans chromodomain containing proteins that are able to recognize histone H3 Lysine(K) 9 (H3K9) and H3K27 methylation in vitro, CEC-3 and CEC-6, results in transgenerational progressive sterility. To understand how CEC-3 and CEC-6 protect germline immortality, I used several established phenotypic and transgenic reporter assays for gene silencing. I found roles of CEC-3 and CEC-6 in silencing of repetitive transgenes. I also identified roles in regulating nuclear RNA interference and the duration of inheritance of a germline directed RNA interference response. Together, my results suggest a role for chromodomain proteins in the small RNA and chromatin silencing pathways that protect germline immortality.