title: Patterns of incorporation of tritiated thymidine by the dorsal polytene foot-pad nuclei of Sarcophaga bullata (Sarcophagidae:Diptera).
abstract: The incorporation of tritiated thymidine into the DNA of the dorsal foot-pad nuclei of Sarcophaga bullata, during pharate adult development, was studied by scintillation counting and autoradiography. Incorporation was maximal on day 4 and showed a progressive temporal decline on days 5 to 8. Autoradiographs of chromosomal arms A1, A2 and D1, from late stages of the prolonged S period, showed discontinuous incorporation. On days 7 and 8 loci which incorporated the radio-labeled precursor were almost exclusively associated with DNA granules. DNA granules were associated with 8 specific loci in chromosomal arm A1, 10 in A2, and 8 in D1. The relationship between patterns of incorporation of tritiated thymidine and DNA granules is discussed.
mesh_terms: D000818:Animals; D001345:Autoradiography; D002875:Chromosomes / Q000378:metabolism* / Q000648:ultrastructure; D004247:DNA / Q000096:biosynthesis*; D004175:Diptera / Q000166:cytology* / Q000254:growth & development; D008297:Male
chemical_list: D004247:DNA