Position-independent expression of the ovine β-lactoglobulin gene in transgenic mice
| Autor: | J. P. Simons, S. Harris, A. J. Clark, C. B. A. Whitelaw, M. McClenaghan |
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| Rok vydání: | 1992 |
| Předmět: |
Male
Genetically modified mouse Transcription Genetic Transgene Restriction Mapping DNA Recombinant Gene Expression Mice Transgenic Lactoglobulins Biology Biochemistry law.invention Mice Mammary Glands Animal Transcription (biology) law Gene expression Animals Deoxyribonuclease I Promoter Regions Genetic Molecular Biology Gene Sheep DNA Cell Biology Molecular biology Chromatin Blotting Southern Organ Specificity Regulatory sequence Recombinant DNA Female Research Article |
| Zdroj: | Biochemical Journal. 286:31-39 |
| ISSN: | 1470-8728 0264-6021 |
| DOI: | 10.1042/bj2860031 |
| Popis: | The major milk whey protein of sheep, beta-lactoglobulin (BLG), is expressed specifically in the mammary gland in a developmentally regulated pattern. To identify the cis-acting DNA regions involved in the regulation of BLG expression, resected gene constructs were analysed in transgenic mice. BLG transgenes which contain at least the proximal 406 bp of the 5′ flanking region were expressed in all mice analysed, at levels related to transgene copy number, and thus were expressed in a position-independent manner. Expression was restricted to the mammary gland, except in a few lines where low-level expression was also detected in the salivary gland. In these mice, BLG transgenes were expressed during pregnancy and lactation in the appropriate temporal pattern. Further resection of the 5′ proximal region to -146 bp resulted in a dramatically reduced frequency of expression, without affecting tissue specificity, while a construct which retained only 79 bp of 5′ flanking region was not expressed. Chromatin analysis of isolated sheep nuclei showed that the promoter resides within a DNAaseI-hypersensitive region in the mammary gland but not in the liver. A BLG transgene displayed a similar tissue-specific pattern of DNAaseI hypersensitivity in mice. These data demonstrate an essential role of the proximal DNAaseI-hypersensitive sequences for position-independent expression of the BLG gene. |
| Databáze: | OpenAIRE |
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