Chromatin diminution and a chromosomal mechanism of sexual differentiation in Strongyloides papillosus (original) (raw)

Abstract

Eggs obtained from feces of rabbits infected with Strongyloides papillosus were squashed and the karyotypes were determined. They contained cells with either two long and two medium sized chromosomes (2L2M), or one long, three medium and one short chromosome (L3MS). Two types of parasitic female gonad could be distinguished on the basis of oocyte chromosome morphology at prometaphase of the maturation division. All the oocytes in a gonad contained either two upaired long chromosomes and two unpaired medium sized chromosomes, or two unpaired medium sized chromosomes and two unpaired chromosomes segmented into beads in one region. At the maturation division in mitotic parthenogenesis the beads appear to be lost from one of the chromosomes. This generates a medium sized and a shorter chromosome, which together with the undiminished chromosomes make up the L3MS karyotype. Animals with beaded oocyte chromosomes lay eggs that develop into males. It is suggested that males are heteromorphic for the long homologue due to chromatin diminution, that occurs in the maturation division of mitotic parthenogenesis.

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Authors and Affiliations

1. MRC Laboratory of Molecular Biology, Hills Road, CB2 2QH, Cambridge, England
   Donna G. Albertson & John E. Sulston
2. Department of Clinical Veterinary Medicine, University of Cambridge, Madingley Road, CB3 OES, Cambridge, England
   Obioma C. Nwaorgu

Authors

1. Donna G. Albertson
2. Obioma C. Nwaorgu
3. John E. Sulston

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Albertson, D.G., Nwaorgu, O.C. & Sulston, J.E. Chromatin diminution and a chromosomal mechanism of sexual differentiation in Strongyloides papillosus.Chromosoma 75, 75–87 (1979). https://doi.org/10.1007/BF00330626

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• Received: 02 March 1979
• Accepted: 23 May 1979
• Issue date: October 1979
• DOI: https://doi.org/10.1007/BF00330626

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