Genetic mapping a meiotic driver that causes sex ratio distortion in the mosquito Aedes aegypti

An endogenous meiotic driver in the dengue and yellow fever vector mosquito Aedes aegypti can cause highly male-biased sex ratio distortion in crosses from suitable genetic backgrounds. We previously selected a strain that carries a strong meiotic drive gene (D) linked with the male-determining allele (M) on chromosome 1 in A. aegypti. Here we performed segregation analysis of the MD locus among backcross (BC1) progeny from a driver male and drive-sensitive females. Assessment of sex ratios among BC2 progeny showed ~5.2% recombination between the MD locus and the sex determination locus. Multipoint linkage mapping across this region revealed consistent marker orders and recombination frequencies with the existing reference linkage map and placed the MD locus within a 6.5 cM interval defined by the LF159 locus and microsatellite marker 446GAA, which should facilitate future positional cloning efforts.

登革热与黄热病的媒介昆虫埃及伊蚊（Aedes aegypti）中的内源减数分裂驱动因子，在适配其遗传背景的杂交实验中可引发强烈的雄性偏倚性别比例畸变。本团队此前已筛选获得一株携带强减数分裂驱动基因（D）的埃及伊蚊品系，该基因与1号染色体上的雄性决定等位基因（M）连锁。本研究对携带驱动因子的雄蚊与驱动敏感型雌蚊所产生的回交（BC1）子代中的MD位点开展了分离分析。对BC2子代的性别比例评估结果显示，MD位点与性别决定位点之间的重组率约为5.2%。针对该区域的多点连锁作图结果表明，标记顺序与重组频率均与现有参考连锁图谱一致，并将MD位点定位在由LF159位点与微卫星标记446GAA界定的6.5厘摩（cM）区间内，该成果将为后续的位置克隆研究提供重要助力。