Summary
Genetic incompatibilities between two races of the grasshopper Podisma pedestris, which differ by a Robertsonian fusion involving the sex chromosome, have been investigated. Crosses were made between four populations spanning the chromosomal cline; F1 hybrids between the races, though not between separated populations of the same race, showed markedly reduced hatching success. Observations of the fate of chromosomes transplanted across the cline supported this finding. Crosses between grasshoppers from a mixed population in the cline showed a lower average hatching success, but no correlation of this inviability with the chromosomal polymorphism. The karyotypes of pre-diapause embryos from both types of cross gave no evidence for non-disjunction of the sex chromosome trivalent in heterozygous females; an upper limit of 1ยท6 per cent can be set on the non-disjunction rate. These findings suggest that the karyotypic difference is only a weakly selected marker for more fundamental changes in genotype.
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Barton, N H. 1979a. A narrow hybrid zone in the alpine grasshopper Podisma pedestris. Ph.D. thesis, Univ. of East Anglia, Norwich.
Barton, N H. 1979b. Gene flow past a cline. Heredity, 43, 333โ339.
Barton, N H, and Hewitt, G M. 1980a. A chromosomal dine in the grasshopper Podisma pedestris. In prep.
Barton, N H, and Hewitt, G M. 1980b. A measurement of the dispersal rate in the grasshopper Podisma pedestris. Ms. submitted to Evolution.
Barton, N H, and Hewitt, G M. 1980c. Hybrid zones and speciation. In Essays on evolution and speciation in honour of M J D White, ed. W. Atchley and D. S. Woodruff. Cambridge Univ. Press.
Bengtsson, B O, and Bodmer, W F. 1976. On the increase of chromosome mutation under random mating. Theor Popln Biol, 9, 260โ281.
Charlesworth, B, and Charlesworth, D. 1975. An experiment on recombination load in Drosophila melanogaster. Genet Res Camb, 25, 267โ274.
Hewitt, G M. 1973. Evolution and maintenance of B chromosomes. Chromosomes Today, 4, 351โ369.
Hewitt, G M. 1975. A sex-chromosome hybrid zone in the grasshopper Podisma pedestris (Orthoptera:Acrididae). Heredity, 35, 375โ387.
Hewitt, G M, and Barton, N H. 1979. The structure and maintenance of hybrid zones as exemplified by Podisma pedestris. In Royal Entomological Society 10th Symposium: Insect cytogenetics, Blackwells.
Hewitt, G M, and East, T M. 1978. Effects of B chromosomes on development in grasshopper embryos. Heredity, 41, 347โ356.
Hewitt, G M, and John, B. 1972. Interpopulation sex chromosome polymorphism in the grasshopper Podisma pedestris. II Population parameters. Chromosoma, 37, 23โ42.
John, B, and Hewitt, G M. 1970. Interpopulation sex chromosome polymorphism in the grasshopper Podisma pedestris. I Fundamental facts. Chromosoma, 31, 291โ308.
Kelly-Stebbings, A, and Hewitt, G M. 1972. The laboratory breeding of British grasshoppers. Acrida, 1, 233โ275.
Mrongovius, M J. 1979. Cytogenetics of the hybrids of three members of the grasshopper genus Vandiemenella (Orthoptera:Eumastacidae:Morabinae). Chromosoma, 71, 81โ107.
Nevo, E, and Bar-El, H. 1976. Hybridization and speciation in fossorial mole rats. Evolution, 30, 831โ840.
Nicklas, R B. 1967. Chromosome micromanipulation. II Induced reorientation and the experimental control of segregation at meiosis. Chromosoma, 21, 17โ50.
White, M J D. 1973. Animal cytology and evolution, 3rd ed. Cambridge University Press.
White, M J D, Key, K H L, Andrรฉ, M J, and Cheney, J. 1969. Cytogenetics of the viatica group of morabine grasshoppers. II Kangaroo Island populations. Austral J Zool, 77, 313โ328.
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Barton, N. The fitness of hybrids between two chromosomal races of the grasshopper Podisma pedestris. Heredity 45, 47โ59 (1980). https://doi.org/10.1038/hdy.1980.49
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DOI: https://doi.org/10.1038/hdy.1980.49
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