Boyce Thompson Institute, Ithaca, New York.
Department of Entomology, Cornell University, New York State Agricultural Experiment Station, Geneva, New York.
Mol Ecol Resour. 2019 Mar;19(2):485-496. doi: 10.1111/1755-0998.12966. Epub 2019 Jan 11.
The cabbage looper, Trichoplusia ni, is a globally distributed highly polyphagous herbivore and an important agricultural pest. T. ni has evolved resistance to various chemical insecticides, and is one of the only two insect species that have evolved resistance to the biopesticide Bacillus thuringiensis (Bt) in agricultural systems and has been selected for resistance to baculovirus infections. We report a 333-Mb high-quality T. ni genome assembly, which has N50 lengths of scaffolds and contigs of 4.6 Mb and 140 Kb, respectively, and contains 14,384 protein-coding genes. High-density genetic maps were constructed to anchor 305 Mb (91.7%) of the assembly to 31 chromosomes. Comparative genomic analysis of T. ni with Bombyx mori showed enrichment of tandemly duplicated genes in T. ni in families involved in detoxification and digestion, consistent with the broad host range of T. ni. High levels of genome synteny were found between T. ni and other sequenced lepidopterans. However, genome synteny analysis of T. ni and the T. ni derived cell line High Five (Hi5) indicated extensive genome rearrangements in the cell line. These results provided the first genomic evidence revealing the high instability of chromosomes in lepidopteran cell lines known from karyotypic observations. The high-quality T. ni genome sequence provides a valuable resource for research in a broad range of areas including fundamental insect biology, insect-plant interactions and co-evolution, mechanisms and evolution of insect resistance to chemical and biological pesticides, and technology development for insect pest management.
菜粉蝶，Trichoplusia ni，是一种分布广泛的多食性植食性昆虫，也是一种重要的农业害虫。T. ni 已经对各种化学杀虫剂产生了抗性，是农业系统中唯一两种对生物农药苏云金芽孢杆菌 (Bt) 产生抗性的昆虫之一，并被选择用于对杆状病毒感染产生抗性。我们报告了一个 333-Mb 的高质量 T. ni 基因组组装，其支架和 contigs 的 N50 长度分别为 4.6 Mb 和 140 Kb，包含 14,384 个蛋白质编码基因。高密度遗传图谱被构建用于将组装体的 305 Mb（91.7%）锚定到 31 条染色体上。T. ni 与家蚕的比较基因组分析表明，在参与解毒和消化的家族中，T. ni 中的串联重复基因富集，这与 T. ni 的广泛宿主范围一致。在 T. ni 和其他已测序的鳞翅目昆虫之间发现了高水平的基因组同线性。然而，T. ni 和 T. ni 衍生的细胞系 High Five（Hi5）之间的基因组同线性分析表明，该细胞系中存在广泛的基因组重排。这些结果提供了第一个基因组证据，揭示了从核型观察中已知的鳞翅目细胞系中染色体的高度不稳定性。高质量的 T. ni 基因组序列为广泛的研究领域提供了有价值的资源，包括昆虫基础生物学、昆虫-植物相互作用和共同进化、昆虫对化学和生物农药的抗性机制和进化，以及昆虫害虫管理技术的发展。
