Picq Sandrine, Lumley Lisa, Šíchová Jindra, Laroche Jérôme, Pouliot Esther, Brunet Bryan M T, Levesque Roger C, Sperling Felix A H, Marec František, Cusson Michel
Laurentian Forestry Centre, Natural Resources Canada, Quebec City, Quebec, Canada, G1V 4C7
Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Quebec City, Quebec, Canada, G1V 0A6.
G3 (Bethesda). 2018 Jul 31;8(8):2539-2549. doi: 10.1534/g3.118.200263.
Genome structure characterization can contribute to a better understanding of processes such as adaptation, speciation, and karyotype evolution, and can provide useful information for refining genome assemblies. We studied the genome of an important North American boreal forest pest, the spruce budworm, , through a combination of molecular cytogenetic analyses and construction of a high-density linkage map based on single nucleotide polymorphism (SNP) markers obtained through a genotyping-by-sequencing (GBS) approach. Cytogenetic analyses using fluorescence hybridization methods confirmed the haploid chromosome number of n = 30 in both sexes of and showed, for the first time, that this species has a WZ/ZZ sex chromosome system. Synteny analysis based on a comparison of the genome and the linkage map revealed the presence of a neo-Z chromosome in the latter species, as previously reported for other tortricid moths. In this neo-Z chromosome, we detected an () gene that has been associated with insecticide resistance. Sex-linkage of the gene provides a genomic context favorable to selection and rapid spread of resistance against serotype (Btk), the main insecticide used in Canada to control spruce budworm populations. Ultimately, the linkage map we developed, which comprises 3586 SNP markers distributed over 30 linkage groups for a total length of 1720.41 cM, will be a valuable tool for refining our draft assembly of the spruce budworm genome.
基因组结构表征有助于更好地理解适应、物种形成和核型进化等过程，并可为完善基因组组装提供有用信息。我们通过分子细胞遗传学分析以及基于通过简化基因组测序（GBS）方法获得的单核苷酸多态性（SNP）标记构建高密度连锁图谱，对北美重要的北方森林害虫云杉芽虫的基因组进行了研究。使用荧光原位杂交方法的细胞遗传学分析证实了云杉芽虫雌雄两性的单倍体染色体数均为n = 30，并首次表明该物种具有WZ/ZZ性染色体系统。基于云杉芽虫基因组与连锁图谱比较的共线性分析揭示，如先前在其他卷蛾科蛾类中所报道的那样，后一物种中存在一条新Z染色体。在这条新Z染色体中，我们检测到一个与抗药性相关的细胞色素P450（CYP）基因。该CYP基因的性连锁提供了一个有利于对加拿大用于控制云杉芽虫种群的主要杀虫剂苏云金芽孢杆菌血清型（Btk）产生抗性进行选择和快速传播的基因组背景。最终，我们构建的连锁图谱包含分布在30个连锁群上的3586个SNP标记，总长度为1720.41厘摩，将成为完善我们的云杉芽虫基因组草图组装的宝贵工具。
