title: Differential appearance of DNase I-hypersensitive sites correlates with differential transcription of Pgk genes during spermatogenesis in the mouse.
abstract: Two functional genes encoding phosphoglycerate kinase are differentially expressed during spermatogenesis in the mouse. Expression of the X-linked Pgk-1 gene is repressed coincident with X chromosome inactivation during prophase of meiosis I. At this same stage, expression of the autosomal Pgk-2 gene is initiated by tissue-specific mechanisms. To investigate the role of chromatin structure in these processes, we have examined the appearance and disappearance of DNase I-hypersensitive (DH) sites in each gene, and correlated this with transcriptional activity as measured by nuclear run-off analysis at specific stages of spermatogenesis. Our results demonstrate that the occurrence of DH sites is related to periods of active transcription. Results with the Pgk-1 gene indicate that transcriptional inactivation of the X chromosome in spermatogenic cells may not be as complete as that in somatic cells, and that maximum repression may be limited to a very transient period during the pachytene stage of first meiotic prophase. Results with the Pgk-2 gene indicate that DH sites appear coincident with, or just prior to, transcriptional activation of this gene. The implications of these results are discussed with respect to the role of X chromosome inactivation in spermatogenic cells and the developmental order of molecular events that regulate differential gene expression during spermatogenesis.
authors.affiliation: Department of Genetics, Southwest Foundation for Biomedical Research, San Antonio, Texas 78245, USA.
authors.forename: M
authors.initials: M
authors.lastname: Kumari
authors.forename: J C
authors.initials: JC
authors.lastname: Stroud
authors.forename: A
authors.initials: A
authors.lastname: Anji
authors.forename: J R
authors.initials: JR
authors.lastname: McCarrey
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism; D002874:Chromosome Mapping; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D003850:Deoxyribonuclease I; D004706:Endodeoxyribonucleases / Q000378:metabolism; D008099:Liver / Q000201:enzymology; D008297:Male; D008540:Meiosis; D051379:Mice; D010735:Phosphoglycerate Kinase / Q000096:biosynthesis* / Q000235:genetics*; D011401:Promoter Regions, Genetic; D012708:Sertoli Cells / Q000201:enzymology; D013090:Spermatocytes / Q000201:enzymology; D013091:Spermatogenesis; D013093:Spermatogonia / Q000201:enzymology; D013094:Spermatozoa / Q000166:cytology / Q000201:enzymology*; D014158:Transcription, Genetic; D014960:X Chromosome
chemical_list: D004247:DNA; D010735:Phosphoglycerate Kinase; D004706:Endodeoxyribonucleases; C038407:exonuclease Bal 31; D003850:Deoxyribonuclease I