Live-cell microscopy of meiosis in spermatocytes

For the analysis of the molecular mechanisms underlying mammalian meiosis, the establishment of a transient gene expression system for meiocytes has been long awaited. We have established an efficient in vivo electroporation method for live mouse testis and demonstrate short-term transgene expression in spermatocytes. By expressing specific marker proteins fused with GFP, this technique is applicable not only to fixed cell observations after transgene expression but also to live imaging to dissect dynamic cellular events in live spermatocytes. The protocol is also adapted to the dissection of mutant phenotypes with defective chromosome movement during meiotic prophase I, as well as a phenotype rescue assay by expressing functional cDNAs in mutant testes.