Figure 1.

Pms2 ATPase activity is not necessary for male fertility. A) Diagram of Pms2 gene targeting. Exon 2, which contains the ATPase domain, was removed after targeting Pms2 allele in both the Pms2^ko and Pms2^cre mice. Thus homozygous mice (Pms2^ko/ko or Pms2^cre/cre) do not have fully functional Pms2. Pms2^ko targeted allele has insertion of a neomycin cassette (NEO). Pms2^cre targeted allele has insertion of a splice acceptor (SA), internal ribosome entry site (IRES), Cre gene, and neomycin cassette. B) Images of seminiferous tubules. Pms2^ko/ko testes do not have fully functional spermatids, as evidenced by the lack of flagella in the lumen (arrows). Pms2^cre/cre testes look similar to Pms2^+/+ testes. C) The total testis volume is only minimally changed in Pms2^cre/cre (n=4 testes) or Pms2^ko/ko (n=3 testes) mice compared to Pms2^+/+ (n=5 testes). Mlh1^−/− testis were significantly smaller (n=3) (ANOVA p=0.05). D) The numbers of spermatocytes and gonia were similar between Pms2^cre/cre (n=3 seminiferous tubule sections) or Pms2^ko/ko (n=4 seminiferous tubule sections) testes compared to Pms2^+/+ (n=3 seminiferous tubule sections), but the numbers of spermatids were decreased in Pms2^ko/ko testes (ANOVA p=0.001).