Truncated beta-lactoglobulin transgenes are expressed in the kidney

The major milk whey protein of ruminants is beta-lactoglobulin. Ovine beta-lactoglobulin-encoding gene expression is restricted to the sheep mammary gland. This report describes the expression profile of a truncated beta-lactoglobulin transgene which, although not expressed in the mammary gland, is expressed in the kidney in the majority of lines generated. The high frequency of ectopic kidney expression may relate to the ability of the larger beta-lactoglobulin transgenes to be expressed in a position-independent manner in the mammary gland of transgenic mice.