Region-Specific Cis- and Trans-Acting Factors Contribute to Genetic Variability in Meiotic Recombination in Maize

[摘要] Understanding the genetic basis for variability in recombination rates is important for general genetic studies and plant-breeding efforts. Earlier studies had suggested increased recombination frequencies in particular F2 populations derived from the maize inbred A188. A detailed phenotypic and molecular analysis was undertaken to extend these observations and dissect the responsible factors. A heritable increase in recombination in the sh1-bz1 interval was observed in these populations. A factor causing an approximate twofold increase mapped to the A188 Sh1-Bz1 region, behaved as a dominant, cis -acting factor, affected recombination equally in male and female sporogenesis and did not reduce the well-studied complete interference in the adjacent bz1-wx interval. This factor also did not increase recombination frequencies in the c1-sh1 and bz1-wx intervals, demonstrating independent control of recombination in adjacent intervals. Additional phenotypic analysis of recombination in the c1-sh1 and bz1-wx intervals and RFLP analysis of recombination along chromosomes 7 and 5 suggested that heritable factors controlling recombination in these intervals act largely independently and in trans . Our results show that recombination in these populations, and possibly maize in general, is controlled by both cis - and trans -acting factors that affect specific chromosomal regions.

[学科分类] 医学（综合）