Camk4^tm2Arm

The calspermin proximal promoter and testis-specific exon were replaced with a floxed TK-neo cassette via homologous recombination. Transient expression of cre recombinase in correctly targeted ES cells removed the selection cassette leaving behind a single loxP site. The gene targeting strategy is designed to specifically delete calspermin expression but not Camk4 kinase expression. Northern blot of testis RNA confirmed the absence of calspermin transcript. Northern blot of testis and thymus RNA showed that Camk4 kinase expression was unaffected. (J:70856)