Table 1

Elimination of cep-1 function causes meiotic X chromosome nondisjunction.

Genotype	Total F₁'s	Total dead eggs	Percent dead eggs	Total males^*	Percent males
unc-22(RNAi) ^†	3971	32	0.8	2	0.1
cep-1(RNAi) ^†	2355	113	4.8	33	1.4
N2^‡	2464	2	0.08	4	0.2
cep-1(w40) ^‡	3286	38	1.2	10	0.3

↵* Males produced by cep-1(RNAi) hermaphrodites mated normally and produced the expected frequency of male cross progeny (10), implying that CEP-1 is needed for a function in normal meiotic chromosome segregation and not for sexual identity per se.
↵† Between 15 and 20 L4-stage N2 hermaphrodites were soaked in cep-1 double-stranded RNA (∼5 mg/ml) for 16 to 18 hours at 20°C. Soaked adults were transferred every 24 hours, and dead eggs, males, and hermaphrodites were scored in the F₁generation. unc-22(RNAi) was used as a negative control; although this RNAi treatment invariably results in a penetrant Unc-22 phenotype, no significant effect on male production or viability was seen.
↵‡ N2 (wild-type) andcep-1(w40) strains were soaked in M9 buffer for 16 to 18 hours at 20°C and scored as described above.