Heat treatment of milk causes the heat-denaturable whey proteins to aggregate with kappa-casein (kappa-CN) via thiol-disulfide bond interchange reactions. The particular disulfide bonds that are important in the aggregates are uncertain, although Cys(121) of beta-lactoglobulin (beta-LG) has been implicated. The reaction at 60 degrees C between beta-LG A and an activated kappa-CN formed small di...

beta-Casein milk protein expression is regulated synergistically by the lactogenic hormones dexamethasone, insulin, and prolactin. This regulation has been observed in vivo and in the mammary epithelial cell line HC11. An important mediator of hormone action on beta-casein gene transcription is the mammary gland specific transcription factor MGF. Epidermal growth factor is a potent growth promo...

To determine whether a foreign unrearranged immunoglobulin gene can be functionally rearranged and expressed in vivo, a rabbit b9 kappa light chain gene construct containing a single germ-line kappa chain variable (V) region gene (V kappa), the five kappa chain joining (J) segments (J kappa), and the kappa chain constant (C) region germ-line gene (C kappa) was introduced into fertilized mouse e...

In order to characterize the actions of xenoestrogens, it is essential to possess a solid portrait of the physiological effects of exogenous estradiol. We assessed effects of three doses of exogenous estradiol (E2) (0.1, 1.0 and 10 µg/kg/day) given between postnatal days 21 and 33 on the mammary gland morphology and gene expression profiles of male and female rats compared to vehicle-treated co...

The 5’-flanking regions (promoters) of the bovine αs1-, αs2and β-casein genes were analysed for DNA sequence variants using PCR/RFLP in Polish Red (PR) and Black-and-White (BW) cattle. The polymorphic sites occurred at positions –1084 and –186 in the promoter region of the αs2-casein gene and at –728 and –109 in the αs1and β-casein genes, respectively. These polymorphic sites were located withi...