H2afy and H2afy2 or macroH2A1/2 (H2A histone family, member Y and Y2, respectively) encode an alternative H2A histone that includes a unique C-terminal non-histone domain. The macroH2A histones function in a subset of nucleosomes where they are involved in the regulation of gene expression. Mice homozygous for both alleles are viable and fertile, but exhibit reduced lean body mass and are shorter in length than wild type controls. Mice remain small throughout adulthood. On the 129S6 background, double KO mice exhibit an abnormally large eyelid opening (macroblepharon), some eyelid inflammation, and darkened fur on the back (by 6 weeks of age).
Double mutant mice on the C57BL/6 background breed poorly by either failing to reproduce or exhibiting high rates (29%) of perinatal lethality. 


This strain may be useful for studying the involvement of H2A histones in the regulation of gene expression.

These H2afy and H2afy2 or macroH2A1/2 knockout mice exhibit reduced lean body mass, shortened body length, an abnormally large eyelid opening (macroblepharon), and darkened back fur. They may be useful for studying the involvement of H2A histones in the regulation of gene expression.

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.