Asynchronous regulation of mouse H-2D and beta-2 microglobulin RNA transcripts

Abstract

The major transplantation (or H-2) antigens in the mouse are cell-surface glycoproteins composed of a heavy chain and a light chain, the beta-2 microglobulin (beta 2m). The expression of these proteins is regulated during development. Embryonic cells at early stages of development do not express these proteins. On the other hand, these molecules are present on the surface of all adult somatic cells. We investigated whether the expression of both chains was coordinately regulated. Using specific single-stranded DNA probes in an S1 nuclease analysis, we compared the relative amounts of H-2D and beta 2m transcripts in normal tissues, in transformed cells, and during embryonic development. Our results show that (1) the steady state level of beta 2m transcripts varies from one adult organ to another, while that of H-2D transcripts stays approximately the same; (2) upon transformation, the amount of H-2D-specific mRNA increases drastically, while the beta 2m mRNA level remains constant; (3) whereas the quantity of beta 2m mRNA increases during early development, the amount of H-2D mRNA remains at a very low level. These data suggest that the regulation of H-2D and beta 2m genes are not identical and that their activation during development is not synchronous.

Developmental expression of AUF1 and HuR, two c-myc mRNA binding proteins

“…All experiments described in this manuscript have been repeated at least once or twice. The following single-stranded uniformly radiolabelled probes were constructed: b2 microglobulin (b2m) A 200 bp EcoRI ± RsaI fragment of the cb2 m recombinant plasmid was subcloned into the M13mp8 vector (Morello et al, 1985). A radiolabelled single-stranded DNA was prepared and used as an internal control in S1 nuclease experiments because b2 m mRNA levels of expression are similar in the tissues analysed, except in brain (Morello et al, 1985).…”

“…The following single-stranded uniformly radiolabelled probes were constructed: b2 microglobulin (b2m) A 200 bp EcoRI ± RsaI fragment of the cb2 m recombinant plasmid was subcloned into the M13mp8 vector (Morello et al, 1985). A radiolabelled single-stranded DNA was prepared and used as an internal control in S1 nuclease experiments because b2 m mRNA levels of expression are similar in the tissues analysed, except in brain (Morello et al, 1985). AUF1 (19 7 49 7 ) The mu-AUF1-3 plasmid (Ehrenman et al, 1994) which does not include the 147 bp insert was ampli®ed using the two primers A (5'-GGAGGCCT-TAGCTGGGACACC-3') and B (5'-AACTGCAGCTCG-CCTGGATAC-3') shown in Figure 4a.…”

Developmental and tissue-specific expression of the Q5 k gene

“…Some recent data point to a start of class I transcription in the preimplantation embryo (Morello et al 1985). On postimplantation stages, however, H-2 class I gene expression is clearly detectable (Morello et al 1985;Ozato et al 1985;Fahrner et al 1987). In this study we were able to detect Q5 k message in embryos of gestation day 6 and onward.…”

“…The status of expression of these genes on preimplantation mouse embryos remains controversial and it is not clear yet whether the failure to detect H-2 antigen reflects a true absence of these determinants or is caused by the limited sensitivity of the techniques employed (Searle et al 1976;Webb et al 1977;Sawicki et al 1981). Some recent data point to a start of class I transcription in the preimplantation embryo (Morello et al 1985). On postimplantation stages, however, H-2 class I gene expression is clearly detectable (Morello et al 1985;Ozato et al 1985;Fahrner et al 1987).…”

“…By hybridization with a H-2K k specific oligonucleotide, K k transcripts were reproducibly found in eight day embryos, a result which has also been described by Fahrner and co-workers (1987) for 8.5 day embryos using RNAse protection analysis. By S1 nuclease mapping (Morello et al 1985) detected H-2D d mRNA even in preimplantation embryos (blastocysts). Thus, it is likely that Q5 ~' activation might also take place even before implantation of the embryo.…”