Abstract
Meiosis in Ageneotettix deorum deorum is characterised by extensive pseudomultiple formation during prophase. The association of non-homologous chromosomes takes place prior to pairing and chiasma formation and occurs to a varying degree in all prophase cells. These pseudomultiples originate during interphase as a consequence of the association of heterochromatin. All autosomes carry procentric heterochromatic segments of variable size and the L1, L3 and M5 chromosomes also possess terminal heterochromatic regions. The association of non-homologous chromosomes during zygotene and pachytene does not appear to impede pairing or the frequency and distribution of chiasmata. — A majority of the pseudomultiples dissociate after diakinesis, during orientation and congression on the spindle. However in 4% of the cells examined, associations, mainly quadrivalents, persist through metaphase. — Heterochromatic associations of non-homologous chromosomes are again evident during second prophase, though here they involve only the centric heterochromatic regions; 9% of these associations persist through second metaphase. — The nature and behaviour of the pseudomultiples in Ageneotettix are pertinent to the interpretation of terminal associations in other Orthoptera and provide evidence that persistent associations can arise following a non-chiasmate association.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Callan, H. G., Spurway, H.: A study of meiosis in interracial hybrids of the newt, Triturus cristatus. J. Genet. 50, 235–249 (1951).
Cantrall, I. J.: An annotated list of the Dermaptera, Dictyoptera, Phasmoptera and Orthoptera of Michigan. Mich. Entomol 1, 299–346 (1968).
John, B., Hewitt, G. M.: Patterns and pathways of chromosome evolution within the Orthoptera. Chromosoma (Berl.) 25, 40–74 (1968).
—, Lewis, K. R.: Genetic speciation in the grasshopper, Eyprepocnemis plorans. Chromosoma (Berl.) 16, 308–344 (1965).
—, Shaw, D. D.: Karyotype variation in Dermestid beetles. Chromosoma (Berl.) 20, 371–385 (1967).
Nankivell, R. N.: A terminal association of two pericentric inversions in first-metaphase cells of the Australian grasshopper Austroicetes interioris (Acrididae). Chromosoma (Berl.) 22, 42–68 (1967).
Rothfels, K. H., Teshima, I.: Homologies among heterologous chromosomes of a grasshopper, Chloealtis conspersa. Can. J. Genet. Cytol. 6, 243 (1964).
Smith, S. G.: Evolutionary changes in the sex chromosomes of Coleoptera. Genetica ('s-Gravenhage) 25, 522–524 (1951).
Southern, D. A.: Pseudomultiple formation as a consequence of prolonged nonhomologous chromosome association in Metrioptera brachyptera. Chromosoma (Berl.) 21, 272–284 (1967).
—: Persistent heterochromatic association in Metrioptera brachyptera. I. Variation in the frequency of multiple formation, chiasma production and chromosome morphology. Chromosoma (Berl.) 25, 303–318 (1968).
White, M. J. D.: Cytogenetics of the grasshopper Moraba scurra. I. Meiosis of interracial and interpopulation hybrids. Austr. J. Zool. 5, 285–304 (1957).
—: The role of chromosomal translocations in Urodele evolution and speciation in the light of work on grasshoppers. Amer. Nat. 95, 315–321 (1961).
Author information
Authors and Affiliations
Additional information
On educational leave from the Forest Research Laboratory, Fredericton, N.B. Canada.
Rights and permissions
About this article
Cite this article
Shaw, D.D. Pseudomultiple production in Ageneotettix deorum deorum . Chromosoma 31, 421–433 (1970). https://doi.org/10.1007/BF00285833
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00285833