Mta, a maternally inherited cell surface antigen of the mouse, is transmitted in the egg

Mta is a maternally transmitted cell surface antigen found in most mouse strains. It serves as a target for unrestricted T killer cells. All 49 embryos transferred between positive and negative mothers, even as early as 10-15 hr after fertilization, developed into mice with the Mta type of their original mothers. Therefore the genetic element that determines expression of Mta must be transmitted by the egg. Mta+ and Mta- lymphocytes, coexisting for months in lethally irradiated F1 mice reconstituted with a mixture of parental bone marrow cells, retained their Mta type. Thus Mta does not spread by infection.