Expression of Mmachc and Mmadhc during mouse organogenesis.

To examine whether Mmachc and Mmadhc, two genes involved in vitamin B(12) (cobalamin) metabolism, show tissue-specific expression during mouse embryogenesis, we determined their sites of expression at 11.5days 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.