Search Results (4)

Within the context of global warming, understanding the molecular mechanisms behind physiological plasticity and local adaptation is essential for insect populations. This study performed an integrated miRNA and mRNA analysis on Aquatica leii larvae exposed to temperatures of 20 °C, 24 °C, 28 °C, and 32 °C. Under varying thermal conditions, 1983 genes exhibited differential expression (i.e., DEGs). These genes showed significant enrichment in Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways related to carbohydrate metabolism, glycan biosynthesis and metabolism. Notably, we detected that the “neuroactive ligand–receptor interaction” signaling pathway, which is involved in environmental information processing, was significantly upregulated in the 28 °C and 32 °C treatment groups. This indicates that starting at 28 °C, A. leii needs to maintain normal cellular physiological functions by regulating ligand–receptor binding and signal transduction. Furthermore, 220 differentially expressed miRNAs (DEMs) were detected under the different temperature treatment conditions. An interaction network was constructed between key DEMs and DEGs, revealing 12 significant DEM-DEG regulatory pairs in A. leii under different temperature treatments. We found three miRNA-mRNA candidate modules that could be involved in A. leii’s response to high temperature, including ggo-miR-1260b and ptr-miR-1260b/RN001_010114, CM069438.1_43851/RN001_014852, and CM069438.1_43851/RN001_014877. Our data provide deeper insights into the molecular responses of A. leii to the high temperature at the miRNA and mRNA levels. Full article

While adult fireflies are terrestrial, their larvae inhabit various habitat types, and a lack of comprehensive research on the feeding habits of these larvae across different habitats has greatly impeded the development of artificial diets. Here, we tested 14 types of foods, primarily covering gastropods, vertebrates, and fruit, to survey feed for aquatic (Aquatica leii and Sclerotia substriata), semi-aquatic (Pygoluciola qingyu and Pygoluciola sp.), and terrestrial (Pyrocoelia analis) fireflies. The results show that A. leii, S. substriata, P. qingyu, Pygoluciola sp., and P. analis fed on 12, 6, 10, 10, and 7 different foods, respectively, showing an obvious difference in feeding range among various inhabit types of fireflies. Aquatic lineages preferred to consume freshwater snails, followed by pork meat and land slugs, while semi-aquatic fireflies favored freshwater snails, followed by fish and shrimp. Favorite foods were thus freshwater snails such as Cipangopaludina chinensis for both aquatic and semi-aquatic fireflies, but feeding preference differed for second favorite foods (e.g., pork vs. fish meat). Terrestrial Pyrocoelia analis showed different feeding preferences compared withthe other two habitat lineages, with terrestrial snails and slugs as their favorite foods, followed by freshwater snails, such as C. chinensis. These findings not only uncovered larval feeding habits of fireflies across various inhabit types but also indicated that readily available and affordable C. chinensis products can serve as wild snail alternatives in the artificial feeding of fireflies. This study is the first to explore the feeding habits of firefly species inhabiting water and land habitat types, adding to the understanding of the feeding characteristics of fireflies. Full article

Aquatic insects are well-adapted to freshwater environments, but metabolic mechanisms of such adaptations, particularly to primary environmental factors (e.g., hypoxia, water pressure, dark light, and abundant microbes), are poorly known. Most firefly species (Coleoptera: Lampyridae) are terrestrial, but the larvae of a few species are aquatic. We generated 24 global metabolomic profiles of larvae and adults of Aquatica leii (freshwater) and Lychnuris praetexta (terrestrial) to identify freshwater adaptation-related metabolites (AARMs). We identified 110 differentially abundant metabolites (DAMs) in A. leii (adults vs. aquatic larvae) and 183 DAMs in L. praetexta (adults vs. terrestrial larvae). Furthermore, 100 DAMs specific to aquatic A. leii larvae were screened as AARMs via interspecific comparisons (A. leii vs. L. praetexta), which were primarily involved in antioxidant activity, immune response, energy production and metabolism, and chitin biosynthesis. They were assigned to six categories/superclasses (e.g., lipids and lipid-like molecules, organic acids and derivatives, and organoheterocyclic compound). Finally, ten metabolic pathways shared between KEGG terms specific to aquatic fireflies and enriched by AARMs were screened as aquatic adaptation-related pathways (AARPs). These AARPs were primarily involved in energy metabolism, xenobiotic biodegradation, protection of oxidative/immune damage, oxidative stress response, and sense function (e.g., glycine, serine and threonine metabolism, drug metabolism-cytochrome P450, and taste transduction), and certain aspects of morphology (e.g., steroid hormone biosynthesis). These results provide evidence suggesting that abundance changes in metabolomes contribute to freshwater adaptation of fireflies. The metabolites identified here may be vital targets for future work to determine the mechanism of freshwater adaptation in insects. Full article

Aquatica leii Fu and Ballantyne is a species of rare aquatic firefly and endemic in China. It is considered good material to study the molecular mechanism of sexual flash communication systems. To improve conservation and behavioral research strategies, large-scale genetic studies involving gene-expression analysis are required and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) is the most commonly used method. However, there have been very few reports on appropriate reference genes in any species of firefly. Here, we evaluated eight widely utilized reference genes including 18S, Actin, Reep5, Odc1, Tub, Gapdh, Ef1a and S27Ae for their expression stabilities in A. leii under three different conditions, i.e., life stage, tissue and dsRNA injection. Based on the gene stability ranking calculated by RefFinder, which integrates four algorithms (geNorm, delta Ct method, NormFinder, and BestKeeper), we recommend S27Ae and Reep5 as the most appropriate reference genes for molecular studies in different life stages; Ef1a and Odc1 for different tissues; Tub and Odc1 for RNAi studies. The most appropriate reference genes in all treatments are S27Ae and Tub. The results of this study will help improve accuracy and reliability to normalize RT-qPCR data in A. leii for further molecular analysis. Full article