One allele of the major histone gene cluster is enough for cell proliferation of the DT40 chicken B cell line.
Thirty-nine of the 44 chicken histone genes are located in a major histone gene cluster of 110 kb, the others residing in four separate regions. We generated a heterozygous chicken DT40 mutant, 1/2 delta110 kb, devoid of one allele of the cluster, using gene targeting techniques. Analyses of the mutant revealed that the growth rate of DT40 cells was unchanged even in the absence of one allele of the cluster. Moreover, analyses involving a RNase protection assay, SDS-PAGE or Triton-acid-urea-PAGE revealed not only that in the 1/2 delta110 kb mutant the steady-state levels of total mRNAs of gene families H1, H2A, H2B, H3 and H4 remained constant, but also that the amounts of histones H1, H2A, H2B, H3 and H4 were not changed. A comparison by 2D-PAGE revealed no changes in total cellular protein patterns of the mutant. These observations demonstrate that all the histone gene families have the inherent ability to compensate for the disruption of one allele of the gene cluster, with no influence on cell functions.
Takami
Y
Y
Department of Biochemistry, Miyazaki Medical College, Kiyotake, Japan.
Nakayama
T
T
D000483:Alleles; D000818:Animals; D001402:B-Lymphocytes / Q000737:chemistry / Q000166:cytology* / Q000378:metabolism; D015139:Blotting, Southern; D002455:Cell Division; D002460:Cell Line; D002645:Chickens; D015180:Electrophoresis, Gel, Two-Dimensional; D004591:Electrophoresis, Polyacrylamide Gel; D018390:Gene Targeting; D006579:Heterozygote; D006657:Histones / Q000032:analysis / Q000235:genetics*; D005810:Multigene Family; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011995:Recombination, Genetic; D014162:Transfection / Q000235:genetics
D006657:Histones; D012333:RNA, Messenger