摘要: The Asian citrus psyllid, Diaphorina citri Kuwayama, is among the most important pests of citrus. It is the main vector of the Huanglongbing (HLB) pathogen Candidatus Liberibacter asiaticus (CLas), which causes severe losses in citrus crops. Control of D. citri is therefore of paramount importance to reduce the spread of HLB. In this regard, using RNA interference (RNAi) to silence target genes is a useful strategy to control psyllids. In this study, using RNAi, we examined the biological functions of the V-ATPase subunit E (V-ATP-E) gene of D. citri, including its effect on acquisition of CLas. The amino acid sequence of V-ATP-E from D. citri had high homology with proteins from other insects. V-ATP-E was expressed at all D. citri life stages analyzed, and the expression level in mature adults was higher than that of teneral adults. Silencing of V-ATP-E resulted in a significant increase in mortality, reduced body weight, and induced cell apoptosis of the D. citri midgut. The reduced expression of V-ATP-E was indicated to inhibit CLas passing through the midgut and into the hemolymph, leading to a majority of CLas being confined to the midgut. In addition, double-stranded RNA of D. citri V-ATP-E was safe to non-target parasitic wasps. These results suggest that V-ATP-E is an effective RNAi target that can be used in D. citri control to block CLas infection.

摘要: The Tibetan Partridge (Perdix hodgsoniae) is an endemic species distributed in high-altitude areas of 3600-5600 m on the Qinghai-Tibet Plateau. To explore how the species is adapted to the high elevation environment, we assembled a draft genome based on both the Illumina and PacBio sequencing platforms with its population genetics and genomics analysis. In total, 134.74 Gb short reads and 30.81 Gb long reads raw data were generated. The 1.05-Gb assembled genome had a contig N50 of 4.56 Mb, with 91.94% complete BUSCOs. The 17 457 genes were annotated, and 11.35% of the genome was composed of repeat sequences. The phylogenetic tree showed that P. hodgsoniae was located at the basal position of the clade, including Golden Pheasant (Chrysolophus pictus), Common Pheasant (Phasianus colchicus), and Mikado Pheasant (Syrmaticus mikado). We found that 1014, 2595, and 2732 of the 6641 one-to-one orthologous genes were under positive selection in P. hodgsoniae, detected using PAML, BUSTED, and aBSREL programs, respectively, of which 965 genes were common under positive selection with 3 different programs. Several positively selected genes and immunity pathways relevant to high-altitude adaptation were detected. Gene family evolution showed that 99 gene families experienced significant expansion events, while 6 gene families were under contraction. The total number of olfactory receptor genes was relatively low in P. hodgsoniae. Genomic data provide an important resource for a further study on the evolutionary history of P. hodgsoniae, which provides a new insight into its high-altitude adaptation mechanisms.

摘要: Chemical profiles of non-invasive biological material, such as feces, have great potential to study elusive animals or those with low population densities. Here, we use a metabolomic approach to evaluate Neotropical mustelids as a biological model to describe the diversity of the metabolites present in fecal samples, as well as to evaluate the potential of chemical profiles for taxonomic discrimination. We collected fecal samples from captive individuals of 5 species of mustelids occurring in Brazil and analyzed them by liquid chromatography coupled to high-resolution mass spectrometry. Over 200 compounds have been annotated; bile acids, alcohols and derivatives was the most expressive class in the metabolome of all the species. We successfully discriminated 3 taxonomic groups: 1-tayra (Eira barbara); 2-otters (Lontra longicaudis and Pteronura brasiliensis; 1); and 3-grisons (Galictis vittata and Galictis cuja). Several compounds seemed to be associated with food intake and the digestive process, while others were found for the first time in Neotropical mustelids. We concluded that mustelids show high metabolome diversity and that species-specific identification through metabolomic profiles is possible, thus contributing to the development and implementation of additional non-invasive approaches in the study of mustelids.

摘要: With the completion of the draft assembly of the giant panda genome sequence, RNA sequencing technology has been widely used in genetic research on giant pandas. We used RNA-seq to examine black and white hair follicle samples from adult pandas. By comparison with the giant panda genome, 75 963 SNP loci were labeled, 2426 differentially expressed genes (DEGs) were identified, and 2029 new genes were discovered, among which 631 were functionally annotated. A cluster analysis of the DEGs showed that they were mainly related to the Wnt signaling pathway, ECM-receptor interaction, the p53 signaling pathway, and ribosome processing. The enrichment results showed that there were significant differences in the regulatory networks of hair follicles with different colors during the transitional stage of hair follicle resting growth, which may play a regulatory role in melanin synthesis during growth. In conclusion, our results provide new insights and more data support for research on the color formation in giant pandas.

摘要: SOCS8, also known as CISHb, is a fish-specific type II SOCS. Because CISH binds to cytokine receptors and may inhibit STAT5 activation (a substrate of the insulin receptor), SOCS8 may be involved in the control of meta-flammation. The socs8-/- zebrafish were created, and both longer trunks and intestinal villi were observed in 1-month-old (mo) fish. Altered mucosal immunity and gut-liver metabolism were also found in socs8-/- fish. Increased intestinal neutrophils and macrophages, together with overexpression of cytokines and T cell markers in this mutant fish, suggested SOCS8's immunoregulating role. During modeling of soybean-induced enteritis using the 3 mo zebrafish, lower expression levels of inflammatory genes but more mucosa barrier disruption were discovered in socs8-/- zebrafish, compared with wide type counterparts. Furthermore, the shrunk villi at 6 mo in socs8-/- fish suggested that the mucosa might have been protected by SOCS8. This is also consistent with the assertion that metaflammation eventually leads to tissue degeneration and premature death. The fact that socs8-/ -fish had more hepatic oil droplets compared to their wild-type counterparts suggested SOCS8's role in inhibiting hepatic metaflammation. Transcriptomic analysis as well as 16S rRNA gene sequencing were done on 3 mo socs8-/- fish to methodically reveal the altered immunity and metabolic reprogramming in the gut and liver caused by socs8-/-. The enriched GO terms for the intestinal tract, such as cytokine-mediated signaling pathway and response to external biotic stimulus, as well as KEGG pathways in both gut and liver like carbon metabolism and glycolysis/gluconeogenesis, were consistent with previously revealed pathological clues and improved growth performance at early age, respectively. In addition, the microbiota in the socs8-/- strain had adapted to the host's increased carbohydrate metabolism, as evidenced by higher levels of Bacteroidota. Furthermore, Verrucomicrobiota associated with immunoregulation were found in lower abundance in socs8-/- fish. As a result, current findings indicate that SOCS8 plays immunoregulatory and mucosa-protective roles in the fish gut and liver by inhibiting carbohydrate metabolism.