Chromosomal and Genic Barriers to Introgression in Helianthus (original) (raw)

Abstract

The sexual transfer of genes between taxa possessing different structural karyotypes must involve the passage of genes through a chromosomal sterility barrier. Yet little is known about the effects of structural differences on gene introgression within or adjacent to the rearranged chromosomal fragments or about the patterns of introgression in collinear regions. Here, we employ 197 mapped molecular markers to study the effects of chromosomal structural differences on introgression in backcrossed progeny of the domesticated sunflower, Helianthus annuus, and its karyotypically divergent wild relative, H. petiolaris. Forty percent of the genome from the seven collinear linkages introgressed, whereas only 2.4% of the genome from the 10 rearranged linkages was transferred. Thus, chromosomal rearrangements appear to provide an effective mechanism for reducing or eliminating introgression in rearranged chromosomal segments. On the other hand, observations that 60% of the markers from within the collinear portion of the genome did not introgress suggests that genic factors also resist introgression in Helianthus. That is, selection against H. petiolaris genes in concert with linkage may have reduced or eliminated parts of the genome not protected by structural changes. Thus, barriers to introgression in Helianthus appear to include both chromosomal structural and genic factors.

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Selected References

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  1. Arnold M. L., Buckner C. M., Robinson J. J. Pollen-mediated introgression and hybrid speciation in Louisiana irises. Proc Natl Acad Sci U S A. 1991 Feb 15;88(4):1398–1402. doi: 10.1073/pnas.88.4.1398. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Arnold M. L., Shaw D. D., Contreras N. Ribosomal RNA-encoding DNA introgression across a narrow hybrid zone between two subspecies of grasshopper. Proc Natl Acad Sci U S A. 1987 Jun;84(11):3946–3950. doi: 10.1073/pnas.84.11.3946. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Coyne J. A., Meyers W., Crittenden A. P., Sniegowski P. The fertility effects of pericentric inversions in Drosophila melanogaster. Genetics. 1993 Jun;134(2):487–496. doi: 10.1093/genetics/134.2.487. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Garcia G. M., Stalker H. T., Kochert G. Introgression analysis of an interspecific hybrid population in peanuts (Arachis hypogaea L.) using RFLP and RAPD markers. Genome. 1995 Feb;38(1):166–176. doi: 10.1139/g95-021. [DOI] [PubMed] [Google Scholar]
  5. Hanson W D. Early Generation Analysis of Lengths of Heterozygous Chromosome Segments around a Locus Held Heterozygous with Backcrossing or Selfing. Genetics. 1959 Sep;44(5):833–837. doi: 10.1093/genetics/44.5.833. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Hanson W D. The Breakup of Initial Linkage Blocks under Selected Mating Systems. Genetics. 1959 Sep;44(5):857–868. doi: 10.1093/genetics/44.5.857. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Keim P., Paige K. N., Whitham T. G., Lark K. G. Genetic analysis of an interspecific hybrid swarm of Populus: occurrence of unidirectional introgression. Genetics. 1989 Nov;123(3):557–565. doi: 10.1093/genetics/123.3.557. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Parsons T. J., Olson S. L., Braun M. J. Unidirectional spread of secondary sexual plumage traits across an avian hybrid zone. Science. 1993 Jun 11;260(5114):1643–1646. doi: 10.1126/science.260.5114.1643. [DOI] [PubMed] [Google Scholar]
  9. Paterson A. H., Damon S., Hewitt J. D., Zamir D., Rabinowitch H. D., Lincoln S. E., Lander E. S., Tanksley S. D. Mendelian factors underlying quantitative traits in tomato: comparison across species, generations, and environments. Genetics. 1991 Jan;127(1):181–197. doi: 10.1093/genetics/127.1.181. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Rieseberg L. H., Beckstrom-Sternberg S., Doan K. Helianthus annuus ssp. texanus has chloroplast DNA and nuclear ribosomal RNA genes of Helianthus debilis ssp. cucumerifolius. Proc Natl Acad Sci U S A. 1990 Jan;87(2):593–597. doi: 10.1073/pnas.87.2.593. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Whittemore A. T., Schaal B. A. Interspecific gene flow in sympatric oaks. Proc Natl Acad Sci U S A. 1991 Mar 15;88(6):2540–2544. doi: 10.1073/pnas.88.6.2540. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Williams C. E., Wielgus S. M., Haberlach G. T., Guenther C., Kim-Lee H., Helgeson J. P. RFLP analysis of chromosomal segregation in progeny from an interspecific hexaploid somatic hybrid between Solanum brevidens and Solanum tuberosum. Genetics. 1993 Dec;135(4):1167–1173. doi: 10.1093/genetics/135.4.1167. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Williams J. G., Kubelik A. R., Livak K. J., Rafalski J. A., Tingey S. V. DNA polymorphisms amplified by arbitrary primers are useful as genetic markers. Nucleic Acids Res. 1990 Nov 25;18(22):6531–6535. doi: 10.1093/nar/18.22.6531. [DOI] [PMC free article] [PubMed] [Google Scholar]