Springer Online Journal Archives 1860-2000
Summary Previousin situ hybridization studies from our laboratory have shown that expression of certain milk protein genes, e.g. α-lactalbumin, is very high in most parts of the mammary glands of sheep and cattle, while in other areas containing an abundance of fat globules it is virtually zero (Molenaaret al., 1992). One possible explanation is that some areas of the mammary gland are dedicated to protein synthesis and some to fat synthesis. To check this possibility, the cRNA for butyrophilin, a milk-fat globule membrane protein, and hence a putative marker of milk fat synthesis, was used as a probe inin situ hybridization studies. The results show quite clearly that the patterns of expression for this gene are similar, cell type for cell type, as those for milk protein genes such as α-lactalbumin and αs1casein. In addition, we found that butyrophilin gene expression more closely matches that of αS1casein than that of α-lactalbumin. If it is shown in the future that butyrophilin is indeed a marker for milk fat synthesis, then these results support the current assumption that fat and protein synthesis do occur in the same cell.
Type of Medium: