Figure 1. MST-knockout mice production.

(a) The targeting vector, Vector 1 and Vector 2 were designed for generating a conventional and a conditional KO mouse, respectively. A loxP sequence and an FRT-neo-FRT-loxP sequence were inserted at the initiation codon, ATG and 3608 bp from the ATG, respectively in EX2. The Cre/loxP site-specific recombination system was applied. An ES cell line derived from C57BL/6 mice was used. neo, neomycin resistance gene; exon-R-p, a reverse probe on the EX1 for PCR genotyping; long-F-p, a forward probe on the long arm for PCR genotyping; neo-F-p, a forward probe on the neo for PCR genotyping; Up-R-p, a reverse probe on the upstream of the short arm for PCR genotyping; short-R-p, a reverse probe on the short arm for PCR genotyping; 3′-ps, a forward probe on the long arm for Southern analysis; 5′-ps, a reverse probe on the upstream of the short arm for Southern analysis; neo′-ps, a forward probe on the neo for Southern analysis. (b) Pathologic findings (HE staining) of the testis of a heterozygous KO (Cre+) mouse. (i), normal testis (a wild-type); (ii) and (iii) abnormal testis (mouse ID#44-T-3-2 and #44-3-11-6-T-1, respectively); (iv), a magnified view of (iii). Bars, 200 μm. (c) PCR genotyping of offspring produced from mating between heterozygous KO (Cre−). Genomic DNA was obtained from #44-T-7-3-4-1 (male heterozygous), #44-T-7-3-4-2 (male homozygous), #44-T-7-3-4-3 (female heterozygous), #44-T-7-3-4-4 (female homozygous), and #44-T-7-3-4-5 (female wild-type) (lanes 1 to 5, in the above order). MM, 100-bp DNA ladder molecular marker; Cont, control genome; Hetero, heterozygous KO mouse; Wild, wild-type mouse.