Abstract
A male grasshopper, Camnula pellucida (Scudder), was found to be heterozygous for a paracentric inversion occupying approximately 10% of the length of one of the two longest chromosomes. Analysis of 297 cells in pachytene revealed inversion loops, suspected inversion loops, asynapsis, and straight pairing in 1.0, 2.7, 8.4, and 87.9% of the analyzable cells, respectively. The frequency of straight pairing (87.9%) indicated a high degree of non-homologous pairing. Analysis of 603 cells in anaphase I and II, and in telophase I and II for the presence of acentric fragments and dicentric chromatid bridges indicated that crossing over within the inversion region occured in about 8% of the cells. The difference between the frequency of the observed plus suspected inversion loops in pachytene and that of the dicentric chromatid bridges and acentric fragments in anaphase I or subsequent stages was not statistically significant. The correspondence between the presence of inversion loops and crossovers within the region of the inversion is thus similar to that observed by Maguire (1966) for a short paracentric inversion in maize. The reasons for this correspondence are considered.
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References
Brown, S. W., and D. Zohary: The relationship of chiasmata and crossing over in Lilium formosanum. Genetics 40, 850–873 (1955).
Burnham, C. R.: Discussions in cytogenetics. Minneapolis: Burgess Publ. Co. 1962.
Carrol, M.: An extra dyad and an extra tetrad in the spermatogenesis of Camnula pellucida (Orthoptera): Numerical variation in the chromosome complex within the individual. J. Morph. 34, 375–455 (1920).
Darlington, C. D.: Crossing-over and its mechanical relationships in Chorthippus and Stauroderus. J. Genet. 33, 465–500 (1936).
Grell, R. F., and A. C. Chandley: Evidence bearing on the coincidence of exchange and DNA replication in the oocyte of Drosophila melanogaster. Proc. nat. Acad. Sci. (Wash.) 53, 1340–1346 (1965).
Henderson, S. A.: Chiasma distribution at Diplotene in a locust. Heredity 18, 173–190 (1963).
—: Time of chiasma formation in relation to the time of deoxyribonucleic acid synthesis. Nature (Lond.) 211, 1043–1047 (1966).
John, B., and S. A. Henderson: Asynapsis and polyploidy in Schistocerca paranensis. Chromosoma (Berl.) 13, 111–147 (1962).
-, and K. R. Lewis: The meiotic system. Protoplasmatologia VI/F/1, 1–335 (1965).
Lewis, K. R., and B. John: The meiotic consequences of spontaneous chromosome breakage. Chromosoma (Berl.) 18, 287–304 (1966).
Maguire, M. P.: The relationship of crossover frequency to synapsis extent at pachytene in maize. Genetics 51, 23–40 (1965).
—: The relationship of crossing over to chromosome synapsis in a short paracentric inversion. Genetics 53, 1071–1077 (1966).
McClintock, B.: The association of non-homologous parts of chromosomes in the mid-prophase of meiosis in Zea mays. Z. Zellforsch. 19, 191–237 (1933).
—: The fusion of broken ends of sister half-chromatids following chromatid breakage at meiotic anaphases. Univ. Missouri Coll. Agr. Exp. Stat. Res. Bull. 290, 1–48 (1938).
Nur, U.: Meiotic behavior of an unequal bivalent in the grasshopper Calliptamus palaestinensis Bdhr. Chromosoma (Berl.) 12, 272–279 (1961).
Pritchard, R. H.: Localized negative interference and its bearing on models of gene recombination. Genet. Res. (Camb.) 1, 1–24 (1960).
Snow, R.: Hydrochloric acid-carmine as a stain for chromosomes in squash preparations. Stain Technol. 38, 9–13 (1963).
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Supported by grants GB 1585 and GB 6745 from the National Science Foundation, Washington, D.C.
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Nur, U. Synapsis and crossing over within a paracentric inversion in the grasshopper, Camnula pellucida . Chromosoma 25, 198–214 (1968). https://doi.org/10.1007/BF00327178
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DOI: https://doi.org/10.1007/BF00327178