Advances in gene technology : molecular biology of the immune system proceedings of the Seventeenth Miami Winter Symposium, Miami, Florida, U.S.A., February 11-15, 1985 / edited by J. Wayne Streilein [and others].

  • Miami Winter Symposium 1985 : Miami, Fla.)
Date:
1985
Catalogue details

Licence: Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)

Credit: Advances in gene technology : molecular biology of the immune system proceedings of the Seventeenth Miami Winter Symposium, Miami, Florida, U.S.A., February 11-15, 1985 / edited by J. Wayne Streilein [and others]. Source: Wellcome Collection.

    45/416 (page 15)
    15 Regulation of Immunoglobulin Gene Expression in Transgenic Mice и. Storb, К. А. Ritchie, R. L. O'Brien, В. Arp and R. L. Brinster*. Department of Microbiology and Immunology, University of Washington, Seattle, WA 98195, and Laboratory of Reproductive Physiology* School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104 Functional immunoglobulin (Ig) genes arise by rearrangement of sets of germ line sequences which specify portions of the variable (V) and constant (C) regions (Hozumi and Tonegawa, 1976; Sakano et al., 1979; Seidman et al., 1979). Expression of Ig genes is therefore under even more complex control than expression of other structural genes. We have begun to use transgenic mice to dissect some para¬ meters of Ig gene expression. In this report, we concentrate on two aspects. The tissue specific expression of Ig genes and the mechanism for allelic exclusion of Ig genes. Transgenic mice were produced by microinjection of a cloned rearranged к-депе (isolated from the myeloma MOPC-21, (Wal fi eld et al., 1980) into fertilized mouse eggs (Brinster et al., 1983). The resultant mice which carried the transgene were bred with normal mice, and positive offspring were analyzed for expression of the transgene. Status of the microinjected gene. All six original transgenic mice and their positive offspring contain multiple copies (16-64) of the microinjected M.21 gene. As is generally observed in transgenic mice or cell transfection, most of the multiple copies are integrated at a single integration site in tandem head-to-tail fashion. The site of integration is different in the six original transgenic mice. One of the original mice has two different integration sites, namely in chromosomes 2 and 11 (Storb et al., 1984b). Neither of these chromosomes carries endogenous < genes (they are located on chromosome 6 of the mouse (Swan et al., 1979)). The c-transgenes from the two sites segregate independently in the offspring. We therefore have seven different transgenic integrations. All seven are expressed (see below). Expression of the <-transgene. Expression was determined by studying serum <-chains and <-mRNAs in various organs. All transgenic mice show a large amount of K-chains encoded by the transgene in their blood serum determined by 2-D protein gels, where the M.21 <-chain produces two differently glycosylated characteristic spots (Storb et al., 1984b). These ic-chains are undetectable in serum of normal mice. Since we do not have an antiserum against the specific V-region, we have not accurately quantitated the transgenic к-protein. However, inspection of the 2-D gels suggests that about 50% of the serum <-chains are encoded by the transgene. Expression of the <-transgene on the RNA level was determined accurately by determining the amount of V,^ homologous to М.21-к: