Figure 2.—

Altered CO distribution and increased incidence of DCO meiotic products following partial depletion of SYP-1. (A) Genetic maps of the X chromosome, derived from SNP marker analysis of crossover frequencies in control (top) and syp-1 RNAi worms (bottom). (B) SNP genotypes of DCO chromosomes detected in male (pale blue) and hermaphrodite (pink) progeny. Blue indicates the Bristol N2-derived allele, and yellow indicates the Hawaiian-derived allele. For six of the seven DCOs detected in hermaphrodites, the intervals containing the two COs could be deduced unambiguously from the genotype of the hermaphrodite, as the other X chromosome present in those hermaphrodites was an NCO chromosome. For worm 13-3, the position of one of the two COs on the DCO chromosome was ambiguous (occurring either in interval G–F or in interval F–E, as indicated by blue/yellow diagonal hatching) because the other X chromosome in that hermaphrodite also had a CO in the G–E interval.