Bérubé Yanik, Ritland Carol, Ritland Kermit
Department of Forest Sciences, 2424 Main Mall, Room 3330, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
Genome. 2003 Jun;46(3):353-61. doi: 10.1139/g03-014.
Chamaecyparis nootkatensis is an ecologically and economically important conifer of the north Pacific coastal forests. To aid in studies of clonal structure and genetic differentiation of this and related species, we isolated and characterized microsatellites from C. nootkatensis. A microsatellite-enriched library yielded 75 repeat-containing sequences for which primer pairs were designed. Only five showed reliable amplification and polymorphism, with an average of 13.7 alleles/locus and a mean expected heterozygosity of 0.592. In progeny tests with four families, few null alleles were directly detected and loci segregated according to Mendelian expectations. However, in one primer pair, high heterozygote deficiency was observed, suggesting the presence of a null allele. The ability of primer pairs to cross amplify was tested on 18 species of the Cupressaceae sensu lato; three primer pairs yielded polymorphic loci in Cupressus and Juniperus species, but not in other Chamaecyparis species. This also supports recent findings of a closer affinity of C. nootkatensis with Cupressus over other Chamaecyparis species.
诺特卡扁柏是北太平洋沿岸森林中一种具有重要生态和经济价值的针叶树。为了辅助对该物种及相关物种的克隆结构和遗传分化进行研究,我们从诺特卡扁柏中分离并鉴定了微卫星。一个富含微卫星的文库产生了75个含重复序列,针对这些序列设计了引物对。只有5个显示出可靠的扩增和多态性,平均每个位点有13.7个等位基因,平均期望杂合度为0.592。在对四个家系的子代测试中,几乎没有直接检测到无效等位基因,并且位点按照孟德尔预期进行分离。然而,在一对引物中,观察到高杂合子缺失,表明存在无效等位基因。对18种广义柏科植物测试了引物对的交叉扩增能力;三对引物在柏木属和刺柏属物种中产生了多态性位点,但在其他扁柏属物种中未产生。这也支持了最近的研究结果,即与其他扁柏属物种相比,诺特卡扁柏与柏木属的亲缘关系更近。