title: Organization of Xenopus histone gene variants within clusters and their transcriptional expression.
abstract: Using previously cloned Xenopus nucleosomal core histone genes as hybridization probes, a genomic DNA library of Xenopus laevis was screened for histone gene clusters. From over 200 histone-gene containing clones identified, 36 were selected as possibly containing H1 histone genes by hybridization to a probe derived from a sea urchin H1 histone gene. These 36 clones were further analyzed by hybrid-selected translation for the definitive presence of H1 histone genes. The genes for three different H1 histone variants were found: H1A , H1B and H1C . Mapping of the histone genes within each clone showed that at least three different gene arrangements can occur within a cluster and that the type of H1 histone variant present in a cluster may be related to the cluster type. S1-mapping experiments indicated that histone genes found in different cluster-types can be expressed in oocytes. Also, the H1 gene found in one cluster-type was expressed in at least three different cell-types: oocytes, gastrula-stage embryos, and erythroblasts.
mesh_terms: D000818:Animals; D003001:Cloning, Molecular; D004262:DNA Restriction Enzymes; D005796:Genes; D014644:Genetic Variation; D005822:Genetic Vectors; D006657:Histones / Q000235:genetics*; D009693:Nucleic Acid Hybridization; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics; D014158:Transcription, Genetic; D014981:Xenopus
chemical_list: D006657:Histones; D012333:RNA, Messenger; D004262:DNA Restriction Enzymes