A novel meiotic drive locus almost completely distorts segregation in Mimulus (monkeyflower) hybrids
A novel meiotic drive locus almost completely distorts segregation in Mimulus (monkeyflower) hybrids
复制标题
DOI：
10.1534/genetics.104.032789
复制
发表时间：
2005-01-01
期刊：
影响因子：
3.3
通讯作者：
Willis, JH
中科院分区：
文献类型：
--
作者：
Fishman, L;Willis, JH
我们报告了一个减数分裂驱动基因座（D）的发现、定位和表征，该基因座在两种黄色猴花（异交Mimulus guttatus和自交M.鼻骨。杂种F-2中只有1%为M。nasutus纯合子与D.我们使用了一组相互回交，以区分男性特定的，女性特定的，和合子特定的传输比失真的来源。只有当杂合子F作为母本与亲本杂交时，传播才严重扭曲，排除了花粉竞争和合子死亡率作为驱动力的潜在来源。经过四代回交，M. nasutus，近等基因系在与D连锁的标记处仍>90%杂合，表明仅驱动基因座处的杂合性就足以进行非随机传播。缺乏戏剧性的女性健身成本在这些线路排除了涉及胚珠或种子死亡率的替代品，并指出一个真正的减数分裂机制的驱动器。该系统中驱动力的强度和方向与不同交配系统下自私因子进化的群体遗传理论相一致。这些结果是第一次实证证明了自私的着丝粒营业额的新模型预测的强大的女性特定的驱动器。
We report the discovery, mapping, and characterization of a meiotic drive locus (D) exhibiting nearly 100% nonrandom transmission in hybrids between two species of yellow monkeyflowers, outcrossing Mimulus guttatus and selfing M. nasutus. Only 1% of F-2 hybrids were M. nasutus homozygotes at the marker most tightly linked to D. We used a set of reciprocal backcrosses to distinguish among male-specific, female-specific, and zygote-specific sources of transmission ratio distortion. Transmission was severely distorted only when the heterozygous F, acted as the female parent in crosses to either parental species, ruling out pollen competition and zygote mortality as potential sources of drive. After four generations of backcrossing to M. nasutus, nearly isogenic lines were still >90% heterozygous at markers linked to D, suggesting that heterozygosity at the drive locus alone is sufficient for nonrandom transmission. A lack of dramatic female fitness costs in these lines rules out alternatives involving ovule or seed mortality and points to a truly meiotic mechanism of drive. The strength and direction of drive in this system is consistent with population genetic theory of selfish element evolution under different mating systems. These results are the first empirical demonstration of the strong female-specific drive predicted by new models of selfish centromere turnover.