Expression Analysis of a Bovine .BETA.-Casein/Human Lactoferrin Hybrid Gene in Transgenic Mice.

Abstract

Abstract. In our previous study, using a bovine β-casein/human lactoferrin hybrid gene, transgenic mice were generated to target the expression of human lactoferrin (hLF) into the mammary glands. Here, we report the fidelity of transgene expression by eleven transgenic mice and their progeny. Expression of hLF in lactating mice was demonstrated by northern and western blots, ELISA, and immunohistochemical staining. Northern blot analysis in five different tissues revealed that the transgene was expressed in the mammary gland. hLF was expressed in five of eight transgenic mouse lines analyzed by ELISA. The expression level of hLF in milk at day 10 of lactation ranged from 2.5 to 200 µg/ml. The apparent molecular weight of the recombinant hLF was indistinguishable from the native form upon immunoblotting. Immunohistochemical staining revealed that hLF in transgenic mice was exclusively expressed in the epithelial cells of mammary gland. The transgenic mice produced in this study provide a model for the eventual generation of transgenic farm animals producing high levels of hLF in their milk.

Lactoferrin a multiple bioactive protein: An overview

“…Using microinjection and direct infection with viral vectors in the mammary gland, transgenic animals have been created that produce milk containing recombinant Lf. These animals include goats [223,224], mice [225,226], rabbits [227] and cows [228,229]. Levels of up to 2 g/L have been achieved in transgenic goat milk.…”

Expression of Human Serum Albumin in Milk of Transgenic Mice Using Goat β-casein/Human Serum Albumin Fusion Gene

“…The regulatory fragment GB562 (from -4,044 to +2,123 bp) contains 6.2 kb of 5'-regulatory region, exon 1, 2 and intron 1 of goat β-casein gene. The sequences have been identified to have several regulatory elements (Roberts et al, 1992;Ebert et al, 1994;Kim et al, 1994;Cerdan et al, 1998), which could drive the coding gene to express. In vitro and ex vivo expression of GFP derived by the GB562 promoter in alveolar mammary epithelial cells and mammary glands had been confirmed by our prior studies .…”