The transmissions of antibodies across the gut of pouch-young marsupials.

The transmission of antibodies across the gut of suckling pouch-young was investigated in three species of marsupials ( and ) from Australia. Mother , immunized against flagella and Bacteriophage Φ × 174, transmitted the antibodies in milk to their young. In sucrose density gradient runs, the antibody activity in milk whey and in serum of pouch-young, of and was found to be in the 7S region only; antibody in the 11S and 19S regions was not detected. Chromatographic preparations of IgM antibodies were fed to pouch-young which were later bled and their serum titrated for anti- agglutinins and antiphage Φ × 174 activity. The IgM antibodies were not transmitted across the gut in detectable amounts. Antibodies were present in the blood of pouch-young within 15–60 minutes of gavage (feeding by stomach tube) of immune serum. In the capacity to absorb antibodies in the intestine was lost at an age between 170 and 200 days and in it was lost at an age between 98 and 145 days. At these ages the pouch-young were able to leave the marsupium for varying lengths of time. Antibodies did not traverse the rumen wall in a young whose rumen was isolated from the intestine with ligatures before immune serum was gavaged.