Abstract
A method is described that permits the recovery of a well-synchronized population of oocytes. Utilizing this pupal system, the heat-responsive period for increasing crossing-over in the Drosophila genome has been defined for the X chromosome and a portion of chromosome 2. The response is initiated close to the time of oocyte formation (premeiotic interphase) and is terminated after ∼36 hr. During the 36-hr period different regions show characteristic responses, which vary in degree, in duration, and in initiation and termination points, so as to generate the beginning of a thermal recombination map for the Drosophila genome. Centromere regions exhibit the greatest increases in crossing-over for their respective chromosomes but are distinctly asynchronous in time; interstitial regions respond the least. Correlated autoradiographic studies have localized DNA replication in the oocyte to a ∼24-hr period, which also begins close to oocyte formation (premeiotic interphase); late labeling in restricted regions, undetectable with the present method, could extend the period, as could prolonged synthesis in the oocyte. The results demonstrate that DNA replication and the heat-sensitive period for enhancement of crossing-over are coincident processes over most and possibly all of their length.
Full Text
The Full Text of this article is available as a PDF (1.7 MB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Comings D. E., Okada T. A. Mechanism of chromosome pairing during meiosis. Nature. 1970 Aug 1;227(5257):451–456. doi: 10.1038/227451a0. [DOI] [PubMed] [Google Scholar]
- Crone M., Levy E., Peters H. The duration of the premeiotic DNA synthesis in mouse oocytes. Exp Cell Res. 1965 Sep;39(2):678–688. doi: 10.1016/0014-4827(65)90071-6. [DOI] [PubMed] [Google Scholar]
- Erickson R. J., Braun W. Apparent dependence of transformation on the stage of deoxyribonucleic acid replication of recipient cells. Bacteriol Rev. 1968 Dec;32(4 Pt 1):291–296. [PMC free article] [PubMed] [Google Scholar]
- Grell R. F. The Meiotic Origin of Temperature-Induced Crossovers in DROSOPHILA MELANOGASTER Females. Genetics. 1966 Aug;54(2):411–421. doi: 10.1093/genetics/54.2.411. [DOI] [PMC free article] [PubMed] [Google Scholar]
- KING R. C., RUBINSON A. C., SMITH R. F. Oogenesis in adult Drosophila melanogaster. Growth. 1956 Jun;20(2):121–157. [PubMed] [Google Scholar]
- Koch E. A., Smith P. A., King R. C. The division and differentiation of Drosophila cystocytes. J Morphol. 1967 Jan;121(1):55–70. doi: 10.1002/jmor.1051210106. [DOI] [PubMed] [Google Scholar]
- Maguire M. P. Evidence on the stage of heat induced crossover effect in maize. Genetics. 1968 Oct;60(2):353–362. doi: 10.1093/genetics/60.2.353. [DOI] [PMC free article] [PubMed] [Google Scholar]