Expression of Mmachc and Mmadhc during mouse organogenesis

To examine whether Mmachc and Mmadhc, two genes involved in vitamin B12 (cobalamin) metabolism, show tissue-specific expression during mouse embryogenesis, we determined their sites of expression at 11.5 days post conception by in situ hybridization. There was ubiquitous expression of Mmadhc, but tissue and cell type-specific expression of Mmachc in the developing lung, heart, cardiovascular and nervous system. This suggests that during organogenesis Mmachc and Mmadhc may interact in only a subset of cells.