Fitness Costs and Variation in Transmission Distortion Associated with the Abnormal Chromosome 10 Meiotic Drive System in Maize

Genetics: A Periodical Record of Investigations Bearing on Heredity and Variation

David W. Hall^2¹  Philip W. Becraft^3²  Elizabeth G. Lowry^2³  R. Kelly Dawe^4⁵  David M. Higgins^1⁶  Lisa B. Kanizay^1⁷ 

[1]Department of Agronomy, Iowa State University, Ames, Iowa 50011^3

[2]Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, Iowa 50011

[3]Department of Genetics, University of Georgia, Athens, Georgia 30604^2

[4]Department of Genetics, University of Georgia, Athens, Georgia 30604^4

[5]Department of Plant Biology, University of Georgia, Athens, Georgia 30604

[6]Department of Plant Biology, University of Georgia, Athens, Georgia 30604^1

[7]Plant Biology Program, Iowa State University, Ames, Iowa 50011

关键词: preferential segregation;    segregation distortion;    meiotic drive;    maize;    haplotype;    K10;    Ab10;    knobs;    heterochromatin;    kinesin;    deleterious alleles;   

DOI  :  10.1534/genetics.117.300060

学科分类：医学（综合）

来源: Genetics Society of America

【 摘 要 】

Meiotic drive describes a process whereby selfish genetic elements are transmitted at levels greater than Mendelian expectations. Maize abnormal chromosome 10 (Ab10) encodes a meiotic drive system that exhibits strong preferential segregation through female gametes. We performed transmission assays on nine Ab10 chromosomes from landraces and teosinte lines and found a transmission advantage of 62–79% in heterozygotes. Despite this transmission advantage, Ab10 is present at low frequencies in natural populations, suggesting that it carries large negative fitness consequences. We measured pollen transmission, the percentage of live pollen, seed production, and seed size to estimate several of the possible fitness effects of Ab10. We found no evidence that Ab10 affects pollen transmission, i.e. , Ab10 and N10 pollen are transmitted equally from heterozygous fathers. However, at the diploid (sporophyte) level, both heterozygous and homozygous Ab10-I-MMR individuals show decreased pollen viability, decreased seed set, and decreased seed weight. The observed fitness costs can nearly but not entirely account for the observed frequencies of Ab10. Sequence analysis shows a surprising amount of molecular variation among Ab10 haplotypes, suggesting that there may be other phenotypic variables that contribute to the low but stable equilibrium frequencies.

【 授权许可】

CC BY