石刁柏雄性偏向核质体DNA的克隆与分析

该研究以雌雄异株植物石刁柏为材料，利用基因组消减杂交技术对石刁柏雌雄核基因组中的性别差异核质体DNA（nuclear plastid DNA，NUPTs）进行了分离和分析。结果表明：（1）通过构建消减杂交文库共获得了52个雄性偏向序列，序列长度分布在63~297 bp之间，其中有19个差异序列属于叶绿体来源序列（命名为Ao1~Ao19），且这些序列与石刁柏叶绿体基因组的相似性均大于84%，Ao19与石刁柏叶绿体基因组相似性为100%。（2）利用基因组半定量PCR对19个NUPTs序列的性别差异分析表明，有4条序列为稳定的雄性偏向NUPTs序列，分别为Ao1、Ao3、Ao10和Ao18。（3）序列比对表明，转移到核基因组的NUPTs主要来源于叶绿体基因组的反向重复区（包含IRa和IRb区），说明石刁柏叶绿体基因组重复区序列更容易向核基因组进行转移形成雄性偏向的NUPTs序列。

Cloning and Analysis of Male biased Nuclear Integrants of Plastid DNA from Asparagus officinalis

In this study, male biased NUPTs (nuclear integrants of plastid DNA) were isolated and analyzed in the genome of Asparagus officinalis, a dioecious plant, by using genome substractive hybridization method. (1) 52 male biased sequences with size ranged from 63 bp to 297 bp were obtained from the substractive hybridization library. Among these sequences, 19 were originated from chloroplast genome, which were designated as Ao1-Ao19. These sequences all showed high similarity (>84%) with the corresponding sequences in asparagus chloroplast genome, while Ao19 showed 100% similarity with the corresponding sequence in the asparagus chloroplast genome. (2) Genome semi quantitative PCR revealed that four (Ao1, Ao3, Ao10, and Ao18) out the 19 sequences were stable male biased NUPTs. (3) Sequence alignment showed the NUPTs were mainly derived from the inverted repeat region (IR) (containing IRa and IRb) of the asparagus chloroplast genome, indicating that the sequences of IR region of chloroplast genome were more preferred to transfer to nuclear genome to form male biased NUPTs sequences.