Abstract
The effect on crossover frequency in maize of three hour heat treatment was studied when treatment was applied at zygotene (substantially later than the major DNA synthetic period) and at pachytene. Crossover frequency assay was based upon bridge and fragment frequency at anaphase I in heterozygotes for a short paracentric inversion. Effect of treatment was studied in three distinguishable synaptic classes: (1) overall crossover frequency within the inversion, (2) double crossover frequency where two separate events of pairing initiation are required (coincident crossovers within and proximal to the inversion) and (3) double crossover frequency within the inversion, where spreading of synapsis over a short distance from a single event of pairing initiation can provide the requisite pairing. Evidence is reported: (1) that overall crossover frequency within the inversion was very significantly increased by treatment at zygotene but not detectably affected by treatment at pachytene; (2) that double crossover frequency within the inversion was very significantly increased by treatment at pachytene and may have been somewhat increased by treatment at zygotene. Results are consistent with the model that most crossover sites may be established at, or approximately at, events of synaptic initiation but that establishment of infrequent second crossover sites near those formed first can follow or accompany the spreading of synapsis to adjoining regions.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Abel, W. O. (1968). Time of crossing over in Sphaerocarpus.Proc. XII Int. Congr. Genet. Tokyo 1: 170.
Burnham, C. R., J. T. Stout, W. H. Weinheimer, R. V. Knowles &R. L. Phillips, (1972). Chromosome pairing in maize.Genetics 71: 111–126
Church, K. &D. E. Wimber (1969). Meiosis in the grasshopper: Chiasma frequency after elevated temperature and X rays.Can. J. Genet. Cytol. 11: 209–216.
Grell, R. F. (1970). Regional and temporal specifications of temperature-induced alterations inX-chromosome exchange in Drosophila melanogaster.Genetics 64: s26.
Grell, R. F. (1971). Heat-induced exchange in the fourth chromosome of diploid females of Drosophila melanogaster.Genetics 69: 523–527.
Grell, R. F. (1973). Recombination and DNA replication in the Drosophila melanogaster oocyte.Genetics 73: 87–108.
Grell, R. F. &A. C. Chandley (1965). Evidence bearing on the coincidence of exchange and DNA replication in the oocyte of Drosophila melanogaster.Proc. natl. Acad. Sci. U.S.A. 53: 1340–1346.
Grell, R. F., H. Bank &G. Gassner (1972). Meiotic exchange without the synaptinemal complex.Nature New Biol. 240: 155–157.
Haldane, J. B. S. (1919). The combination of linkage values, and the calculation of distances between the loci of linked factors.J. Genet. 18: 299–309.
Henderson, S. A. (1966). Time of chiasma formation in relation to the time of deoxyribonucleic acid synthesis.Nature 211: 1043–1047.
Hotta, Y. &H. Stern (1971). Meiotic protein in spermatocytes of mammals.Nature 234: 83–86.
Howell, S. H. &H. Stern (1971). The appearance of DNA breakage and repair activities in the synchronous meiotic cycle in Lilium.J. molec. Biol. 55: 357–378.
Koch, E. A., P. A. Smith &R. C. King (1967). The division and differentiation of Drosophila cystocytes.J. Morph. 121: 55–70.
Lawrence, C. W. (1961a). The effect of irradiation of different stages in microsporogenesis on chiasma frequency.Heredity 16: 83–89.
Lawrence, C. W. (1961b). The effect of radiation on chiasma formation in Tradescantia.Radiat. Bot. 1: 92–96.
Longley, A. E. (1961). Breakage points for four corn translocation series and other corn chromosome aberrations.Crops Res. A. R. S. 34-16: 1–40.
Lu, B. C. (1969). Genetic recombination in Coprinus. I: Its precise timing as revealed by temperature treatment experiments.Canad. J. Genet. Cytol. 11: 834–847.
Maguire, M. P. (1965). The relationship of crossover frequency to synaptic extent at pachytene in maize.Genetics 51: 23–40.
Maguire, M. P. (1966). The relationship of crossing over to chromosome synapsis in a short paracentric inversion.Genetics 53: 1071–1077.
Maguire, M. P. (1968a). Evidence on the stage of heat induced crossover effect in maize.Genetics 60: 353–362.
Maguire, M. P. (1968b). Chromosome pairing in altered constitutions and models of synapsis and crossing over.Genet. Res. 12: 21–27.
Maguire, M. P. (1968c). The effect of synaptic partner change on crossover frequency in adjacent regions of a trivalent.Genetics 59: 381–390.
Maguire, M. P. (1969). Unexpected similarities of synaptic and chiasma frequency in material with trivalent formation potential.J. Cell Biol. 43: 84a.
Maguire, M. P. (1972a). The temporal sequence of synaptic initiation, crossing over and synaptic completion.Genetics 70: 353–370.
Maguire, M. P. (1972b). Premeiotic mitosis in maize: Evidence for pairing of homologues.Caryologia 25: 17–24.
Maguire, M. P. (1973). Effect of position within the tassel on crossover frequency in microsporocytes.Maize Genet. Coop. News Lett. 47: 175–176.
Nur, U. (1968). Synapsis and crossing over within a paracentric inversion in the grasshopper, Camnula pellucida.Chromosoma 25: 198–214.
Parchman, L. G. &T. F. Roth (1971). Pachytene synaptonemal complexes and meiotic achiasmatic chromosomes.Chromosoma 33: 129–145.
Parchman, L. G. &H. Stern (1969). The inhibition of protein synthesis in meiotic cells and its effect on chromosome behavior.Chromosoma 26: 298–311.
Peacock, W. J. (1970). Replication, recombination, and chiasmata in Goniaea australasiae (Orthoptera: Acrididae).Genetics 65: 593–617.
Raju, N. B. &B. C. Lu (1973). Genetic recombination in Coprinus. III. Influence of gamma-irradiation and temperature treatments on meiotic recombination.Mutation Res. 17: 37–48.
Rhoades, M. M. &E. Dempsey (1953). Cytogenetic studies of deficient-duplicate chromosomes derived from inversion heterozygotes in maize.Am. J. Bot. 40: 405–424.
Roth, T. F. &L. G. Parchman (1971). Alterations of meiotic chromosome pairing and synaptonemal complexes by cycloheximide.Chromosoma 35: 9–27.
Shaw, D. D. (1971). Genetic and environmental components of chiasma control I. Spatial and temporal variation in Schistocerca and Stethophyma.Chromosoma 34: 9–20.
Sokal, R. R. &F. J. Rohlf (1969). Biometry. The Principles and Practice of Statistics in Biological Research. Freeman, San Francisco.
Steel, R. G. D. &J. H. Torrie (1960). Principles and Procedures of Statistics. McGraw-Hill New York, Toronto, London.
Stern, H. &Y. Hotta (1969). DNA synthesis in relation to chromosome pairing and chiasma formation.Genetics 61 (no. 1, part 2) Suppl.: 27–39.
Sved, J. A. (1966). Telomere attachment of chromosomes, some genetical and cytological consequences.Genetics 53: 747–756.
Westerman, M. (1967). The effect of X irradiation on male meiosis in Schistocerca gregaria (Forskal). I. Chiasma frequency response.Chromosoma 22: 401–416.
Westerman, M. (1971). The effect of X-irradiation on chiasma frequency in Chorthippus brunneus.Heredity 27: 83–91.
Westerman, M. (1972). Dose-response of chiasma frequency to X-radiation in Chorthippus brunneus.Mutation Res. 15: 55–65.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Maguire, M.P. Synaptic initiation and extension as prerequisites for crossing over. Genetica 45, 11–28 (1974). https://doi.org/10.1007/BF01508929
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF01508929