EXPRESSION OF MURINE H1 HISTONE GENES DURING POSTNATAL-DEVELOPMENT

Murine genes encoding the seven H1 histone isoforms H1.1-H1.5, H1 degr ees and Hit have been isolated and sequenced. We have established expr ession patterns of these genes in several tissues during postnatal dev elopment. For that analysis, RNase protection assay rather than Northe rn blot hybridization was used, since the sequences of these genes are highly similar and would cross-hybridize under Northern blot conditio ns. Expression patterns of H1.1 to H1.5 and H1 degrees were determined in tissues of animals at days 5, 9 and 20 after birth and of adult mi ce. In addition, RNA was analyzed in three mouse cell lines (NIH3T3, P 19, TM4). Transcription of the subtype genes H1.2 and H1.4 was found i n all tissues and cell lines studied. The most varied expression patte rns were obtained with the H1.1 subtype. H1.1 mRNA was found at high c oncentrations in thymus and spleen throughout development and in testi s beginning with a low expression in 5-day-old animals and increasing levels in testis RNA from 9- and 20-day-old and adult mice. H1 degrees mRNA was found primarily in highly differentiated tissues with concen trations decreasing from 5-day-old to adult animals. (C) 1998 Elsevier Science B.V. All rights reserved.