Hormad1 is a germ cell specific HORMA domain encoding gene that is a critical component of the axial elements of the synaptonemal complex. The Hormad1 knockout allele has a neo cassette replacing exons 4 and 5 of the gene. Male and female mice homozygous for the mutation are infertile. Testes from adult mutant males are small; seminiferous tubules are hypocellular and contain no post-meiotic germ cells such as spermatids and spermatozoa. The synaptonemal complex normally visible at the pachytene stage cannot be detected in 2 week old mutant spermatocytes resulting in meiotic arrest. In females, HORMAD1 deficiency causes disruption of second metaphase in oocytes (mis-orientation of chromatid attachment to spindle), aneuploidy in 2-cell and 8-cell embryos, arrest at the blastocyst stage, early embryo death, and failure of implantation.

These mice may be useful in studying synaptonemal complex formation, recombination and chromosome segregation in meiosis.

Homozygous Hormad1 knockout mice are infertile. Testes exhibit meiotic arrest at the pachytene stage and oocytes arrest at the blastocyst stage. These mice may be useful in studying synaptonemal complex formation, recombination and chromosome segregation in meiosis.

This strain is hosted by NIH's MMRRC, which partners with JAX for the distribution of this and other strains. For additional information and to purchase, please visit the MMRRC site.