Centromere-associated meiotic drive and female fitness variation in Mimulus

Abstract Differential success of sperm is likely to be an important component of fitness. Extensive variation among male genotypes in competitive success of sperm in multiply mated females has been documented for Drosophila melanogaster. However, virtually all previous studies considered the female to be a passive vessel. Nevertheless, under certain conditions female fitness could be determined by her role in mediating use of sperm from multiple males. Here we ask whether females differ among genotypes in their tendency to exhibit last-male precedence. Competition of sperm from two tester male genotypes (bwD and B3-09, a third-chromosome isogenic line from Beltsville, MD) was quantified by doubly mating female lines that had been rendered homozygous for X, second, or third chromosomes isolated from natural populations. The composite sperm displacement parameter, P2′, was highly heterogeneous among lines, whether or not viability effects were compensated, implying the presence of polymorphic genes affecting access of sperm to eggs. Genetic variation of this type is completely neutral in the absence of pleiotropy or interaction between variation in the two sexes.

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Male Sterility and Meiotic Drive Associated With Sex Chromosome Rearrangements in Drosophila: Role of X-Y Pairing

Genetics ◽

10.1093/genetics/149.1.143 ◽

1998 ◽

Vol 149 (1) ◽

pp. 143-155 ◽

Cited By ~ 3

Author(s):

Bruce D McKee ◽

Kathy Wilhelm ◽

Cynthia Merrill ◽

Xiao-jia Ren

Keyword(s):

Male Sterility ◽

Sex Chromosome ◽

Meiotic Drive ◽

Repeated Sequence ◽

Meiotic Pairing ◽

Intergenic Spacers ◽

Male Specific ◽

The Relationship ◽

Novel Model

Abstract In Drosophila melanogaster, deletions of the pericentromeric X heterochromatin cause X-Y nondisjunction, reduced male fertility and distorted sperm recovery ratios (meiotic drive) in combination with a normal Y chromosome and interact with Y-autosome translocations (T(Y;A)) to cause complete male sterility. The pericentromeric heterochromatin has been shown to contain the male-specific X-Y meiotic pairing sites, which consist mostly of a 240-bp repeated sequence in the intergenic spacers (IGS) of the rDNA repeats. The experiments in this paper address the relationship between X-Y pairing failure and the meiotic drive and sterility effects of Xh deletions. X-linked insertions either of complete rDNA repeats or of rDNA fragments that contain the IGS were found to suppress X-Y nondisjunction and meiotic drive in Xh−/Y males, and to restore fertility to Xh−/T(Y;A) males for eight of nine tested Y-autosome translocations. rDNA fragments devoid of IGS repeats proved incapable of suppressing either meiotic drive or chromosomal sterility. These results indicate that the various spermatogenic disruptions associated with X heterochromatic deletions are all consequences of X-Y pairing failure. We interpret these findings in terms of a novel model in which misalignment of chromosomes triggers a checkpoint that acts by disabling the spermatids that derive from affected spermatocytes.

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Natural selection increases female fitness by reversing the exaggeration of a male sexually selected trait

Nature Communications ◽

10.1038/s41467-021-23804-7 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Kensuke Okada ◽

Masako Katsuki ◽

Manmohan D. Sharma ◽

Katsuya Kiyose ◽

Tomokazu Seko ◽

...

Keyword(s):

Sexual Selection ◽

Natural Selection ◽

Experimental Evolution ◽

Genetic Correlations ◽

Lifetime Reproductive Success ◽

Fundamental Theory ◽

Female Fitness ◽

Male Trait ◽

Flour Beetles ◽

Male Specific

AbstractTheory shows how sexual selection can exaggerate male traits beyond naturally selected optima and also how natural selection can ultimately halt trait elaboration. Empirical evidence supports this theory, but to our knowledge, there have been no experimental evolution studies directly testing this logic, and little examination of possible associated effects on female fitness. Here we use experimental evolution of replicate populations of broad-horned flour beetles to test for effects of sex-specific predation on an exaggerated sexually selected male trait (the mandibles), while also testing for effects on female lifetime reproductive success. We find that populations subjected to male-specific predation evolve smaller sexually selected mandibles and this indirectly increases female fitness, seemingly through intersexual genetic correlations we document. Predation solely on females has no effects. Our findings support fundamental theory, but also reveal unforseen outcomes—the indirect effect on females—when natural selection targets sex-limited sexually selected characters.

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Further Evidence Consistent With Stellate's Involvement in Meiotic Drive

Genetics ◽

10.1093/genetics/142.2.641 ◽

1996 ◽

Vol 142 (2) ◽

pp. 641-643 ◽

Cited By ~ 5

Author(s):

Laurence D Hurst

Keyword(s):

Meiotic Drive

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