, Volume 43, Issue 2, pp 177–186 | Cite as

The heterochromatic B chromosome of maize: the segments affecting recombination

  • Edward J. Ward


The B chromosome of maize is known to increase recombination in specific regions of the genome. In an attempt to determine the portion of the B responsible for crossover enhancement, translocations between the B and A chromosomes were used to dissect the B into four distinct segments. The effects of the segments on crossing over were studied in a sensitive region composed of chromatin from chromosomes 3 and 9. The relatively euchromatic chromomeres terminating the B lacked enhancement activity, but the remaining segments, all of which possess large amounts of heterochromatin, were capable of elevating recombination. There was no localization of activity to a specific heterochromatic region, however.


Developmental Biology Specific Region Heterochromatic Region Sensitive Region Enhancement Activity 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Ayonoadu, U., Rees, H.: The influence of B chromosomes on chiasma frequencies in Black Mexican sweet corn. Genetica ('s-Gravenhage) 39, 75–81 (1968)Google Scholar
  2. Battaglia, E.: Cytogenetics of B chromosomes. Caryologia (Firenze) 17, 245–299 (1964)Google Scholar
  3. Bianchi, A., Bellini, G., Contin, M., Ottaviano, E.: Nondisjunction in presence of interchanges involving B-type chromosomes in maize and some phenotypical consequences of meaning in maize breeding. Z. Vererb.-Lehre 92, 213–232 (1961)Google Scholar
  4. Blackwood, M.: The inheritance of B chromosomes in Zea mays. Heredity 10, 353–366 (1956)Google Scholar
  5. Carlson, W. R.: A test of homology between the B chromosome of maize and abnormal chromosome 10, involving the control of nondisjunction in B's. Molec. gen. Genet. 104, 59–65 (1969)Google Scholar
  6. Hanson, G.: Some studies of crossing over in maize as influenced by accessory chromosomal elements. Ph.D. thesis, Indiana University (1965)Google Scholar
  7. Hanson, G.: B chromosome stimulated crossing over in maize. Genetics 63, 601–609 (1969)Google Scholar
  8. Longley, A. E.: The origin of diminutive B-type chromosomes in maize. Amer. J. Bot. 43, 18–22 (1956)Google Scholar
  9. Mather, K.: Competition for chiasmata in diploid and trisomic maize. Chromosoma (Berl.) 1, 119–129 (1939)Google Scholar
  10. Nel, P.: An effect of B chromosomes on crossing over in chromosome 5. Maize Genet. Co-op. News Letter 43, 54–55 (1969)Google Scholar
  11. Nel, P.: Studies on the genetic control of recombination in Zea mays. Ph. D. thesis, Indiana University (1971)Google Scholar
  12. Randolph, L. R.: Genetic characteristics of the B chromosome in maize. Genetics 26, 608–631 (1941)Google Scholar
  13. Rhoades, M. M.: Studies on the cytological basis of crossing over. In: Replication and recombination of genetic material (W. J. Peacock and R. D. Brock, eds.), p. 229–241. Australian Academy of Science 1968Google Scholar
  14. Rhoades, M. M., Dempsey, E.: On the mechanism of chromatin loss induced by the B chromosome of maize. Genetics 71, 73–96 (1972)Google Scholar
  15. Rhoades, M. M., Dempsey, E., Ghidoni, A.: Chromosome elimination in maize induced by supernumerary B chromosomes. Proc. nat. Acad. Sci. (Wash.) 57, 1626–1632 (1967)Google Scholar
  16. Robertson, D.: Crossing over and chromosomal segregation involving the B9 element of the A-B translocation B-9b in maize. Genetics 55, 433–449 (1967)Google Scholar
  17. Roman, H.: Mitotic nondisjunction in the case of interchanges involving the B-type chromosome in maize. Genetics 32, 391–409 (1947)Google Scholar
  18. Roman, H.: Directed fertilization in maize. Proc. nat. Acad. Sci. (Wash.) 34, 36–42 (1948)Google Scholar
  19. Ward, E. J.: Nondisjunction: Localization of the controlling site in the maize B chromosome. Genetics 73, 387–391 (1973)Google Scholar

Copyright information

© Springer-Verlag 1973

Authors and Affiliations

  • Edward J. Ward
    • 1
    • 2
  1. 1.Department of PediatricsMcMaster UniversityHamiltonCanada
  2. 2.Biology DepartmentUniversity of WinnipegWinnipegCanada

Personalised recommendations