Comprehensive Analysis of Insect Peptide Hormones/Neuropeptides by Next-Generation Sequencing

DNA sequencing technologies have been pivotal in genome analysis. Technological advances over the years, particularly the advent of next-generation sequencing, have drastically increased the scale and speed of genomic and transcriptomic data collection. These developments have enabled in-depth studies of peptide hormones/neuropeptides (PHs/NPs) and receptors across various insect species without whole-genome sequences. Techniques such as RNA sequencing and mass spectrometry have further enhanced our understanding of insect NPs, leading to the discovery of new PHs/NPs and expanding our knowledge of their evolutionary biology and physiology. Insect PHs/NPs show remarkable diversity and evolutionary adaptations across different lineages. The desert locust has many PHs/NPs that regulate complex behaviors and survival strategies. The PH/NP profiles vary among Hemiptera, possibly to adapt to different habitats of each species. Some PHs/NPs that are commonly present in many insects have been lost in holometabolous insects, which may be due to neutral evolution or functional redundancy. Variable and rapid evolutionary changes are observed within some PH/NP families, such as AST-CC, PK/PBAN, and EFLamide. However, many unknown aspects exist regarding the relationship between the loss/gain of PHs/NPs in individual species and their adaptation to diverse habitats.