Expression of the Guinea Pig Alpha-Lactalbumin Gene in Transgenic Mice

The study investigated the regulation of the α-lactalbumin gene by analyzing the guinea pig α-lactalbumin gene in transgenic mice. In vitro assays showed non-specific complex formation with nuclear proteins from various tissues, making this approach non-instructive. However, in vivo studies with two lines of transgenic mice, created by microinjecting a 3.5kb guinea pig α-lactalbumin genomic fragment, demonstrated successful expression of the transgene at levels similar to guinea pigs. The transgene was expressed exclusively in the mammary glands and skin, with guinea pig α-lactalbumin secreted into the milk but not detected in the skin. In situ hybridization revealed expression in the secretory acini of mammary glands and sebaceous gland ducts in the skin, indicating tissue-specific expression relevant to milk protein production.