title: The hyperactive X chromosome is not early replicating in mitotically active somatic cells of Drosophila nasuta males.
abstract: The temporal order of replication of the X chromosome(s) in mitotically dividing male and female cells in early embryos and in brain ganglia of Drosophila nasuta larvae was examined using [3H]thymidine pulse labelling and autoradiography. Both the X chromosomes in female cells and the single X chromosome in male cells replicated in complete synchrony with the autosome set in the nucleus. Thus, unlike the well-known early completion of replication by the hemizygous X chromosome in polytene nuclei in the salivary glands of male Drosophila larvae, the single X chromosome in mitotically dividing cells does not replicate earlier than the autosomes. We conclude that transcriptional hyperactivity of the single X chromosome required for dosage compensation in somatic cells of male Drosophila is not dependent upon its early replication.
authors.affiliation: Department of Zoology, Banaras Hindu University, Varanasi, Republic of India.
authors.forename: S C
authors.initials: SC
authors.lastname: Lakhotia
authors.forename: J K
authors.initials: JK
authors.lastname: Roy
mesh_terms: D000818:Animals; D004261:DNA Replication / Q000235:genetics; D004303:Dosage Compensation, Genetic; D004330:Drosophila / Q000166:cytology / Q000235:genetics* / Q000378:metabolism; D005260:Female; D008297:Male; D008938:Mitosis / Q000235:genetics; D013936:Thymidine / Q000378:metabolism; D014960:X Chromosome
chemical_list: D013936:Thymidine