Comparative transcriptome analysis of Tamarixia radiata (Hymenoptera: Eulophidae) reveals differentially expressed genes upon heat shock

Comparative proteomic analysis of regenerative mechanisms in mouse retina to identify markers for neuro-regeneration in glaucoma

The retina is part of the central nervous system (CNS). Neurons in the CNS and retinal ganglion cells lack the ability to regenerate axons spontaneously after injury. The intrinsic axonal growth regulators, their interaction and roles that enable or inhibit axon growth are still largely unknown. This study endeavored to characterize the molecular characteristics under neurodegenerative and regenerative conditions. Data-Independent Acquisition Mass Spectrometry was used to map the comprehensive proteome of the regenerative retina from 14-day-old mice (Reg-P14) and adult mice after lens injury (Reg-LI) both showing regrowing axons in vitro, untreated adult mice, and retina from adult mice subjected to two weeks of elevated intraocular pressure showing degeneration. A total of 5750 proteins were identified (false discovery rate < 1%). Proteins identified in both Reg-P14 and Reg-LI groups were correlated to thyroid hormone, Notch, Wnt, and VEGF signaling pathways. Common interactors comprising E1A binding protein P300 (EP300), CREB binding protein (CBP), calcium/calmodulin dependent protein kinase II alpha (CaMKIIα) and sirtuin 1 (SIRT1) were found in both Reg-P14 and Reg-LI retinas. Proteins identified in both regenerating and degenerative groups were correlated to thyroid hormone, Notch, mRNA surveillance and measles signaling pathways, along with PD-L1 expression and the PD-1 checkpoint pathway. Common interactors across regenerative and degenerative retinas comprising NF-kappa-B p65 subunit (RELA), RNA-binding protein with serine-rich domain 1 (RNPS1), EP300 and SIN3 transcription regulator family member A (SIN3A). The findings from our study provide the first mapping of regenerative mechanisms across postnatal, mature and degenerative mouse retinas, revealing potential biomarkers that could facilitate neuro-regeneration in glaucoma.

Heat Shock Protein 70 Genes Are Involved in the Thermal Tolerance of Hippodamia variegata

Previous studies have shown that the survival and reproduction of Hippodamia variegata are increasingly harmed by progressive increases in temperature (from 32 °C to 35 °C and 38 °C). In this study, transcriptome sequencing analysis was performed on H. variegata, after being exposed to different temperatures (from 32 to 38 °C) for 24 h, using high-throughput sequencing technology. We found the largest number of differentially expressed genes (DEGs) in the 35 °C vs. 32 °C group (1151) followed by the 38 °C vs. 32 °C group (1054) and then the 38 °C vs. 35 °C group (901), indicating that H. variegata expressed the largest number of newly mobilized genes under medium-high temperature (35 °C). Gene functional analysis showed that a large number of DEGs were involved in "Catalytic activity", "Oxidoreductase activity", "Metabolic pathways", and "Longevity regulating pathway-multiple species" gene groups. We randomly selected nine DEGs for validation using qRT-PCR. The results of qRT-PCR were consistent with the transcriptome data, confirming their reliability. Finally, the RNAi results showed that adult survival, longevity, and fecundity were lower in the group in which gene expression of the heat shock proteins (Hsp70-01 and Hsp68) was suppressed than in the control group (injection ds-GFP) at all the experimental temperatures (32, 35, and 38 °C). Our results indicate the important role of the heat shock proteins (Hsp70-01 and Hsp68) in resistance to high-temperature stress in H. variegata and provide a molecular basis for analyzing its thermotolerance mechanism.

Comparative Transcriptome Analysis of Galeruca daurica Reveals Cold Tolerance Mechanisms

Galeruca daurica (Joannis) is a pest species with serious outbreaks in the Inner Mongolian grasslands in recent years, and its larvae and eggs are extremely cold-tolerant. To gain a deeper understanding of the molecular mechanism of its cold-tolerant stress response, we performed de novo transcriptome assembly of G. daurica via RNA-Seq and compared the differentially expressed genes (DEGs) of first- and second-instar larvae grown and developed indoors and outdoors, respectively. The results show that cold tolerance in G. daurica is associated with changes in gene expression mainly involved in the glycolysis/gluconeogenesis pathway, the fatty acid biosynthesis pathway and the production of heat shock proteins (HSPs). Compared with the control group (indoor), the genes associated with gluconeogenesis, fatty acid biosynthesis and HSP production were up-regulated in the larvae grown and developed outdoors. While the changes in these genes were related to the physiological metabolism and growth of insects, it was hypothesized that the proteins encoded by these genes play an important role in cold tolerance in insects. In addition, we also investigated the expression of genes related to the metabolic pathway of HSPs, and the results show that the HSP-related genes were significantly up-regulated in the larvae of G. daurica grown and developed outdoors compared with the indoor control group. Finally, we chose to induce significant expression differences in the Hsp70 gene (Hsp70A1, Hsp70-2 and Hsp70-3) via RNAi to further illustrate the role of heat stress proteins in cold tolerance on G. daurica larvae. The results show that separate and mixed injections of dsHSP70A1, dsHsp70-2 and dsHsp70-3 significantly reduced expression levels of the target genes in G. daurica larvae. The super-cooling point (SCP) and the body fluid freezing point (FP) of the test larvae were determined after RNAi using the thermocouple method, and it was found that silencing the Hsp70 genes significantly increased the SCP and FP of G. daurica larvae, which validated the role of heat shock proteins in the cold resistance of G. daurica larvae. Our findings provide an important theoretical basis for further excavating the key genes and proteins in response to extremely cold environments and analyzing the molecular mechanism of cold adaptation in insects in harsh environments.

The role of cytochrome P450 3A2 and 4V2 in response to high-temperature stress in Tetranychus truncatus (Acari: Tetranychidae)

Temperature is an important factor influencing the physiological activities of agricultural pests. Therefore, understanding pest physiological activities and the molecular response to high-temperature stress is of paramount importance for pest management. Tetranychus truncatus Ehara (Acari: Tetranychidae) is a harmful organism, that may cause serious harm to crops such as corn and cotton in high-temperature environments. Cytochrome P450 (CYP450) is induced by high-temperature stress, and it plays an important role in the resistance of spider mites to high temperatures. Because of their role in high-temperature tolerance, the cytochrome P450 genes of the spider mite are attracting more and more attention. In this study, we identified and analyzed CYP450 genes in T. truncatus to investigate their potential roles in growth and development and the resistance to high-temperature stress. Based on phylogenetic and structural analyses, we identified 17 CYP450 genes in T. truncatus. RNA-seq and real-time quantitative PCR (RT-qPCR) revealed differential expression patterns of these genes at different developmental stages and levels of high-temperature stress resistance. The RNA interference results of selected CYP450 showed that when TtCYP3A2 and TtCYP4V2 were silenced by feeding on dsRNA, respectively, the high-temperature resistance of T. truncatus was decreased, which indicated that the expression of these two CYP450 genes in this species may be related to high-temperature tolerance. Our results provide potential evidence for the response of spider mites to high-temperature stress and help to improve the understanding of T. truncatus's ability to resist high-temperature stress.