Notes and Comment | Published:

Cross-overs, sperm redundancy and their close association

Heredity volume 31, pages 408413 (1973) | Download Citation



Numbers of chiasmata in the production of each gamete are closely related to the proportion of gametes which fail to function (r = 0·81 for 24 species). Gamete redundancy and chiasma frequency fail to correlate with chromosome number, DNA weight/nucleus, or the weight or age of the animal at puberty, as closely as with each other. Implications and corollaries are considered, and it is concluded that most gametes are functionless by-products of a necessarily faulty production system.


  1. 1970. Copulatory behaviour can inhibit pregnancy in female rats. Science, 168, 1480–1482.

  2. 1970. Chromosome number, structure and autosomal polymorphism in the marine mussels Mytilus edulis and Mytilus californianus. Biol Bull, 138, 1–13.

  3. 1964. Transmission ratios at the T-locus in the mouse: inter-and intra-male heterogeneity. Aust J Biol Sci, 17, 921–934.

  4. 1967. Correlation between sperm “redundancy” and chiasma frequency. Nature, 215, 862–863.

  5. 1969. Why so many sperms? An essay on the arithmetic of reproduction. Sci Prog, Oxf, 57, 23–41.

  6. 1971. Comparative physiology of gamete populations. Advances in Comp. Physiol Biochem, 4, 268–380.

  7. 1970. Re-investigation of meiosis in the male goat, Capra hircus. Linn. Cytologia, 35, 344–353.

  8. 1967. The meiotic chromosomes of the male dog. Hereditas, 58, 135–135.

  9. 1968. Personal communication.

  10. 1970. Probable haploid expression of HL-A antigens on human spermatozoan. Nature, 225, 191–193.

  11. 1972. Gross genome unbalance in mouse spermatozoa: does it influence the capacity to fertilize? In Edinburgh Symposium on the Genetics of the Spermatozoon (ed. R. A. Beatty and Salome Gluecksohn-Waelsch), 359–369. Published by University of Edinburgh.

  12. 1967. Chromosome complement of the American oyster Crassostrea virginica as seen in meiotic and cleaving eggs. Can J Genet Cytol, 9, 845–856.

  13. 1968. Fertilisation and Completion of Meiosis in Spawned Eggs of the American oyster (Crassostrea virginica Emelin). Caryologia, 21, 65–73.

  14. 1969. Relationships between recombination and mutation. In Mutation as a Cellular Process (ed. G. E. W. Wolstenholme and M. O'Connor), 186–198. Churchill, London.

  15. 1972. Insemination of protogynes of Acutus cornutus from spermatophores and description of the sperm cell. Ann Ent Soc Amer, 65, 1080–1084.

  16. 1959. Genetics of die domestic cat. Bibliographica Genetica, 18, 273–355.

  17. 1970. The mechanism of genetic recombination. Biol Rev, 45, 265–315.

  18. 1965. Sperm transfer and utilization by the arrhenotokous wasp Dahlbominus fuscipennis. (Zett.) (Hymenoptera, Eulophidae). Can Entomol, 97, 647–657.

Download references

Author information


  1. Department of Zoology and Comparative Physiology, The University, Birmingham B15 2TT, England

    • Jack Cohen


  1. Search for Jack Cohen in:

About this article

Publication history




Further reading