College of Life Science, Institute of Life Science and Green Development, Hebei University, Baoding 071002, China.
Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing 100101, China.
Proc Natl Acad Sci U S A. 2023 Jan 31;120(5):e2216851120. doi: 10.1073/pnas.2216851120. Epub 2023 Jan 26.
The phase transition from solitary to gregarious locusts is crucial in outbreaks of locust plague, which threaten agricultural yield and food security. Research on the regulatory mechanisms of phase transition in locusts has focused primarily on the transcriptional or posttranslational level. However, the translational regulation of phase transition is unexplored. Here, we show a phase-dependent pattern at the translation level, which exhibits different polysome profiles between gregarious and solitary locusts. The gregarious locusts exhibit significant increases in 60S and polyribosomes, while solitary locusts possess higher peaks of the monoribosome and a specific "halfmer." The polysome profiles, a molecular phenotype, respond to changes in population density. In gregarious locusts, ten genes involved in the cytosolic ribosome pathway exhibited increased translational efficiency (TE). In solitary locusts, five genes from the mitochondrial ribosome pathway displayed increased TE. The high expression of large ribosomal protein 7 at the translational level promotes accumulation of the free 60S ribosomal subunit in gregarious locusts, while solitary locusts employ mitochondrial small ribosomal protein 18c to induce the assembly of mitochondrial ribosomes, causing divergence of the translational profiles and behavioral transition. This study reveals the translational regulatory mechanism of locust phase transition, in which the locusts employ divergent ribosome pathways to cope with changes in population density.
群居型和散居型蝗虫的相变是蝗灾爆发的关键，这威胁着农业产量和粮食安全。关于蝗虫相变的调控机制的研究主要集中在转录或翻译后水平。然而，相变的翻译调控还没有被探索。在这里，我们在翻译水平上展示了一个与相位相关的模式，表明群居型和散居型蝗虫之间的多核糖体图谱不同。群居型蝗虫的 60S 和多核糖体显著增加，而散居型蝗虫的单核糖体和特定的“半mer”峰较高。多核糖体图谱是一种分子表型，对种群密度的变化有反应。在群居型蝗虫中，10 个参与细胞质核糖体途径的基因表现出翻译效率（TE）的增加。在散居型蝗虫中，线粒体核糖体途径的 5 个基因显示出 TE 的增加。大核糖体蛋白 7 在翻译水平上的高表达促进了群居型蝗虫中游离 60S 核糖体亚基的积累，而散居型蝗虫则利用线粒体小核糖体蛋白 18c 诱导线粒体核糖体的组装，导致翻译图谱的发散和行为的转变。本研究揭示了蝗虫相变的翻译调控机制，其中蝗虫利用不同的核糖体途径来应对种群密度的变化。
