The core histone (H2a, H2b and H3) mRNAs, whose levels are correlated with DNA synthesis, were studied in mouse cells by S1 nuclease analysis. These mRNAs are transcribed from a family (10-20 members) of genes that have highly conserved protein coding regions but vary extensively in the transcribed, untranslated regions. Thus, the products of individual genes can be readily distinguished by the S1 nuclease assay. Eight histone genes from 3 mouse histone gene clusters (MM221, MM291 and MM614) were used as probes. One of these clusters--MM614--encodes about 40% of the H2a or H3 mRNA found in cultured mouse cells, while the other 2 clusters--MM221 and MM291--encode only 5-10% of the H2a, H2b or H3 mRNA in the same cells. MM614 maps to chromosome 3, while MM221 and MM291 map to chromosome 13. Although the relative contribution of a specific gene to the family of histone mRNAs is the same in several different cultured mouse cell lines and 18-day fetal mouse cells, a different situation is observed in mouse eggs and blastocysts. In blastocysts, the H3 mRNAs encoded by the three clusters are of similar relative abundance--about 5%, while in eggs the H3-614 and the H3.2-221 mRNA represent 40% and 25% of the H3 mRNA, respectively. / The levels of all of these histone mRNAs are reduced about ten fold, when mouse cells are treated with DNA synthesis inhibitors. This decay occurs with a half-life of twelve minutes. The transcription of this family of genes is altered within ten minutes after experimental inhibition or initiation of DNA synthesis. Both of these effects can be readily reversed either by reinitiation of DNA synthesis or by inhibition of protein synthesis. The relative abundance of specific histone mRNAs to the family of histone mRNAs detected does not change. This demonstrates that the MM614 histone mRNAs are transcribed at higher rates than are the MM221 or MM291 mRNAs. The data are not consistent with a tight coupling between DNA synthesis and histone mRNA metabolism but suggest that the correlation of the two processes may be mediated by deoxynucleotide metabolism. / Source: Dissertation Abstracts International, Volume: 45-04, Section: B, page: 1176. / Thesis (Ph.D.)--The Florida State University, 1984.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_75318 |
| Contributors | GRAVES, REED ANTHONY., Florida State University |
| Source Sets | Florida State University |
| Detected Language | English |
| Type | Text |
| Format | 189 p. |
| Rights | On campus use only. |
| Relation | Dissertation Abstracts International |
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