Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu Province, China.
Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture and Rural Affairs, The Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang, Jiangsu Province, China.
Insect Sci. 2024 Aug;31(4):1041-1054. doi: 10.1111/1744-7917.13294. Epub 2023 Nov 20.
The diversity of cell types in the brain and how these change during different developmental stages, remains largely unknown. The life cycle of insects is short and goes through 4 distinct stages including embryonic, larval, pupal, and adult stages. During postembryonic life, the larval brain transforms into a mature adult version after metamorphosis. The silkworm, Bombyx mori, is a lepidopteran model insect. Here, we characterized the brain cell repertoire of larval and adult B. mori by obtaining 50 708 single-cell transcriptomes. Seventeen and 12 cell clusters from larval and adult brains were assigned based on marker genes, respectively. Identified cell types include Kenyon cells, optic lobe cells, monoaminergic neurons, surface glia, and astrocyte glia. We further assessed the cell type compositions of larval and adult brains. We found that the transition from larva to adult resulted in great expansion of glial cells. The glial cell accounted for 49.8% of adult midbrain cells. Compared to flies and ants, the mushroom body kenyon cell is insufficient in B. mori, which accounts for 5.4% and 3.6% in larval and adult brains, respectively. Analysis of neuropeptide expression showed that the abundance and specificity of expression varied among individual neuropeptides. Intriguingly, we found that ion transport peptide was specifically expressed in glial cells of larval and adult brains. The cell atlas dataset provides an important resource to explore cell diversity, neural circuits and genetic profiles.
大脑中的细胞类型多样性及其在不同发育阶段的变化在很大程度上尚不清楚。昆虫的生命周期很短，经历了 4 个不同的阶段，包括胚胎期、幼虫期、蛹期和成虫期。在胚胎后生命阶段，幼虫大脑在变态后转化为成熟的成虫版本。家蚕（Bombyx mori）是鳞翅目昆虫的模式生物。在这里，我们通过获得 50708 个单细胞转录组，对幼虫和成虫 B. mori 的脑细胞库进行了特征描述。基于标记基因，从幼虫和成虫脑中分别鉴定出 17 个和 12 个细胞簇。鉴定出的细胞类型包括肯尼恩细胞、视神经细胞、单胺能神经元、表面神经胶质细胞和星形胶质细胞。我们进一步评估了幼虫和成虫大脑的细胞类型组成。我们发现，从幼虫到成虫的转变导致神经胶质细胞的大量扩张。神经胶质细胞占成年中脑细胞的 49.8%。与果蝇和蚂蚁相比，家蚕的蘑菇体肯尼恩细胞不足，分别占幼虫和成虫大脑的 5.4%和 3.6%。神经肽表达分析表明，单个神经肽的丰度和表达特异性存在差异。有趣的是，我们发现离子转运肽在家蚕幼虫和成虫大脑的神经胶质细胞中特异性表达。该细胞图谱数据集为探索细胞多样性、神经回路和遗传特征提供了重要资源。
