AFLP分子标记构建中国对虾遗传连锁图谱的初步研究

利用AFLP分子标记结合“拟测交”策略,以中国对虾的单对杂交亲本及其F1代为作图群体,应用MAPMAKER EXP／3．0软件,分别构建了中国对虾雌、雄的遗传连锁图谱。在中国对虾的雄性连锁图谱中,74个标记组成了5个连锁群(遗传标记数量大于3)、7个三联体、13个连锁对,总图距为951．5eM,最大连锁群的长度为206．2eM,最短的为7．4eM,标记间的平均距离为12．8eM;雌性连锁图谱中,由66个标记组成的5个连锁群,4个三联体,13个连锁对,总图距为712．7eM,连锁群的长度介于7．7eM～128．2eM之间,标记间的平均距离为10．7eM。估算的中国对虾基因组总长度为2000eM,所构建的连锁图谱分别覆盖了基因组长度的47．5％和35．6％。中国对虾遗传连锁图谱的构建为分子标记辅助育种、比较基因组作图以及基因定位与克隆创造了条件,并对今后其他海洋生物遗传图谱的构建具有理论价值和实践意义。

Construction of Genetic Linkage Maps of Fenneropenaeus chinensis Based on "Double Pseudo-testcross" Strategy and AFLP Markers

Genetic linkage maps of Fenneropenaeus.chinensis have been constructed using "double pseudo testcross" strategy with AFLP markers. The F. chinensis parents and F1 progeny (full sib family) was used as segregating population. A total of 135 and 118 markers that conformed to expected Mendelian segregation ratios for paternal and maternal parent was produced from 40 primer combinations. The markers were used to construct separate male and female linkage maps, respectively. The paternal parent linkage map consisted of 74 markers distributed in 5 linkage groups (four or more markers), 7 triples and 13 pairs, which covered a total length of 951.5cM. The longest and shortest linkage group was 206.2 cM and 7.4 cM respectively. The maternal linkage map consisted of 66 marker loci in 22 groups, which cover the map distance about 712.7 cM. The size of the linkage groups ranged from 7.7 to 128.2 cM. The average resolution of the paternal and maternal parent was 12.8 and 10.7 cM, respectively. The estimated genome length of F. chinensis is about 2000 cM, and the map covered the 47.5% and 35.6% of the genome, respectively. The map developed here provide a first step in producing a saturated linkage map of F.chinensis and open the way for marker assisted selection, comparative genomics and gene location and clone.