The innate immunity is the most important defense against pathogen of insects, and the peptidoglycan recognition proteins (PGRPs) play an important role in the processes of immune recognition and initiation of Toll, IMD and other signal pathways. In fig wasps, pollinators and non-pollinators present different evolutionary histories and lifestyles, even though both are closely associated with fig syconia, which may indicate their different patterns in the evolution of PGRPs. By manual annotation, we got all the PGRP genes of 12 fig wasp species, containing seven pollinators and five non-pollinators, and investigated their putative different evolutionary patterns. We found that the number of PGRP genes in pollinators was significantly lower than in non-pollinators, and the number of catalytic PGRP presented a declining trend in pollinators. More importantly, PGRP-SA is associated with initiating the Toll pathway, as well as gram-negative bacteria-binding proteins (GNBPs), which were completely lost in pollinators, which led us to speculate that the initiation of Toll pathway was simpler in pollinators than in non-pollinators. We concluded that fig pollinators owned a more streamlined innate immune recognition system than non-pollinators. Our results provide molecular evidence for the adaptive evolution of innate immunity in insects of host specificity.

Background/Objectives: The largemouth bass (Micropterus salmonides) is a farmed fish of significant economic value, and studying its adaptability is crucial for enhancing the economic benefits of aquaculture. The largemouth bass changes gene expression pattern to rapidly adapt to environmental changes and maintain normal physiological function. Methods: In this study, largemouth bass from two distinct environmental backgrounds—Huzhou and Xingtai—were used as experimental materials, and they have significantly different breeding conditions. Comparative transcriptomics was used to analyze the gene expression patterns in largemouth bass from both backgrounds. Results: In the female, there were 1678 differentially expressed genes, of which 541 were upregulated and 1137 were downregulated. Meanwhile, in the male, there were 1287 differentially expressed genes, including 542 upregulated genes and 745 downregulated genes. The differentially expressed genes were mainly enriched in biological processes such as metabolic process, biological regulation, response to stimulus, developmental process, signaling, reproduction and immune system process. The enriched pathways included carbon metabolism, glycolysis/gluconeogenesis, purine metabolism, biosynthesis of amino acids, starch and sucrose metabolism, fructose and mannose metabolism, pyrimidine metabolism, MAPK signaling pathway, spliceosome, protein processing in the endoplasmic reticulum, ribosome biogenesis in eukaryotes, etc. Conclusions: We speculated that largemouth bass in Xingtai may adapt to the environment by downregulating metabolism- and reproduction-related genes and altering the expression of immune-related genes. Our study provided molecular evidence for the adaptation research of largemouth bass and provided a scientific basis for optimizing largemouth bass breeding technology.

Wolbachia are widely distributed in arthropods and nematodes, acquiring nutrients from the hosts, and inducing remarkable reproductive modulations on the hosts. To investigate the interaction of Wolbachia and insects, Wolbachia are often artificially eliminated from Wolbachia-infected hosts, which may produce negative effects of antibiotics. In the present study, based on the transcriptomic data of a fig wasp species Ceratosolen solmsi with two sibling lineages, one natively infected and the other noninfected with Wolbachia, we investigated the expression patterns of genes. The comparison results of differently expressed genes (DEGs) between Wolbachia infected and noninfected samples show that males have many more DEGs than females. The male unique upregulated genes are enriched in biological processes mainly related to biosynthesis, transport, positive regulation of I-kappaB kinase/NF-kappaB signaling, MAPK cascade, and pathogenesis; the male unique downregulated genes are enriched in biological processes mainly related to transport, oxidation–reduction, cellular responses to oxidative stress, lipid oxidation, cytoskeleton organization, actin filament-based process, and localization. In addition, for the Wolbachia’s gene expression, the number of genes up-regulated in males is higher than that in females. The results revealed divergent patterns of the host–Wolbachia interactions between males and females in the fig wasp species.

Cryptic species are morphologically indistinguishable but possess genetically distinct taxa. Alternative splicing (AS) regulates physiological processes, thereby facilitating ecological adaptation and evolution. To explore the sex-specific differences in transcriptional regulation among cryptic species, we profiled both AS and gene expression in two cryptic species of Wiebesia pumilae (WPDZ19 and WPHS), which differ in Wolbachia infection status. The results showed that 101 and 71 differentially alternatively spliced genes (DASs) were identified in female and male groups, respectively. Functional enrichment revealed that female DASs were significantly enriched in mitotic cell cycle process, cytoskeleton organization, cellular component organization, and DNA damage. On the other hand, male DASs were predominantly related to actin, cytoskeleton, and muscle development. Gene set enrichment analysis of DASs also revealed that the regulation of mitotic nuclear division and meiotic nuclear division were enriched in female and male groups, respectively. We identified 4509 DEGs in females and 3645 in males, with minimal overlap between DASs and DEGs. Moreover, RT-PCR has been used to validate the key genes. Our results revealed sexually divergent transcriptional regulation patterns between WPDZ19 and WPHS, suggesting a potential association with Wolbachia persistence. Our findings provide new insights into the study of adaptive evolution of cryptic species.

Leptoglossus occidentalis (Heidemann, 1910) (Figure 1) (Hemiptera: Coreidae) is an important invasive pest that originated from western North America and has spread eastward (Zhao et al. 2015, Xu e...