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Four-eyed sleeper (Bostrychus sinensis) is a commercially important sea water fish, and the male individuals exhibit significant advantages in somatic growth and stress resistance, so developing sex control strategy to create all-male progeny will produce higher economic value. However, little is known about the genetic background associated with sex differentiation in this species. In this study, we investigated gonadal development and uncovered critical window stages of sexual differentiation (about 2 mph), transition from proliferation to differentiation in female germ stem cells (GSCs) (2–3 mph) and male GSCs (3–4 mph). De novo transcriptome analysis revealed candidate genes and signaling pathways associated with sexual differentiation and gonadal development in four-eyed sleeper. The results showed that sox9 and zglp1 were the earliest sex-biased transcription factors during sex differentiation. Down-regulation of chemokine, cytokines-cytokine receptors and up-regulation of cellular senescence pathway might be involved in GSC differentiation. Weighted gene correlation network analysis showed that metabolic pathway and occludin were the hub signaling and gene in ovarian development, meanwhile the MAPK signaling pathways, cellular senescence pathway and ash1l (histone H3-lysine4 N -trimethyltransferase) were the hub pathways and gene in testicular development. The present work elucidated the developmental processes of sexual differentiation and gonadal development and revealed their associated revealed genes and signaling pathways in four-eyed sleeper, providing theoretical basis for developing sex-control techniques. [Display omitted] • Characterization of somatic growth and gonadal development in four-eyed sleeper • Revealing the timing of sexual differentiation, transition from mitosis to meiosis • Uncovering critical genes and signalings associated with gonadal development • Revealing hub signalings and associated hub genes for sexual development [ABSTRACT FROM AUTHOR]

Malaria and schistosomiasis are two of the most socioeconomically devastating parasitic diseases in tropical and subtropical countries. Since current chemotherapeutic options are limited and defective, there is an urgent need to develop novel antiplasmodials and antischistosomals. Hemozoin is a disposal product formed from the hemoglobin digestion by some blood-feeding parasites. Hemozoin formation is an essential process for the parasites to detoxify free heme, which is a reliable therapeutic target for identifying novel antiparasitic agents. A series of novel carbazole aminoalcohols were designed and synthesized as potential antiplasmodial and antischistosomal agents, and several compounds showed potent in vitro activities against Plasmodium falciparum 3D7 and Dd2 strains and adult and juvenile Schistosoma japonicum . Investigations on the dual antiparasitic mechanisms showed the correlation between inhibitory activity of β -hematin formation and antiparasitic activity. Inhibiting hemozoin formation was identified as one of the mechanisms of action of carbazole aminoalcohols. Compound 7 displayed potent antiplasmodial ( Pf 3D7 IC 50 = 0.248 μM, Pf Dd2 IC 50 = 0.091 μM) and antischistosomal activities (100% mortality of adult and juvenile schistosomes at 5 and 10 μg/mL, respectively) and exhibited low cytotoxicity (CC 50 = 7.931 μM), which could be considered as a promising lead for further investigation. Stoichiometry determination and molecular docking studies were also performed to explain the mode of action of compound 7 . [ABSTRACT FROM AUTHOR]

Abstract: The Maculatus group of Anopheles mosquitoes (Diptera: Culicidae) comprises eight known species, including important malaria vectors in Southeast Asia. The sequences of the second internal transcribed spacer (ITS2) and third domain (D3) of ribosomal DNA, and cytochrome oxidase subunit II (COII) of mitochondrial DNA were obtained for five species of the group from China, as An. maculatus, An. willmori, An. pseudowillmori, An. sawadwongporni and An. dravidicus. The variation within taxon is much smaller than that between taxa. A diagnostic PCR assay for distinguishing the five members was developed based on the interspecific ITS2 variation. The phylogenetic relationships for the group were estimated on the ITS2 and D3 data. The Maculatus group appears monophyletic with An. pseudowillmori at a basal position, the Sawadwongporni subgroup and the Maculatus subgroup form sister clades. Our data concludes that An. dispar and An. greeni belong to the Maculatus subgroup, and An. willmori is not closer to either of the subgroups. [Copyright &y& Elsevier]

Osmotic stress is associated with heightened immune functions and altered microbiota in the fish intestine. In this study, we explored the effects of hypoosmotic stress on the intestine of euryhaline yellowfin seabream (Acanthopagrus latus) after acute exposure to brackish water, low-saline water, and freshwater environments. The results showed that hypoosmotic stress reshaped the composition of the microbial community and altered the gene expression in the intestine. Probiotics Lactobacillus and Pseudomonas showed higher relative abundance in a brackish water environment, whereas pathogenic bacteria, including Vibrio and Aeromonas , were more abundant in the freshwater environment. At the transcriptional level, osmoregulation-related genes were identified as up/down regulated differentially expressed genes (DEGs) as well as a series of immune-related DEGs associated with pathogen recognition, antimicrobial ability, pro-inflammatory cytokines, cell apoptosis, and antioxidant defense. Physiological analysis showed that Na+ K+-ATPase activity was significantly inhibited by hypoosmotic stress in freshwater. Meanwhile, the intestinal antioxidant defense system of yellowfin seabream was challenged. Correlation network analysis demonstrated the close interactions among intestinal microbes, differentially expressed genes, and physiological parameters. This study provides the critical insights into the function of the intestine fish encountering hypoosmotic stress. Unlabelled Image • Intestinal response of yellowfin seabream to hypoosmotic stress was investigated. • Pathogens were more abundant in response of hypoosmotic stress in fish intestine. • The expression patterns of osmoregulation- and immune-related genes altered. • The intestinal antioxidant defense system was weakened under hypoosmotic stress. • Correlations were observed between microbes, DEGs, and physiological parameters. [ABSTRACT FROM AUTHOR]

Abstract Schistosomiasis japonica caused by Schistosoma japonicum infection is recognized as a considerable economic and public health concern in Asia. Oncomelania hupensis is the sole intermediate host of S. japonicum. The only molluscicide recommended by World Health Organization (WHO) since 1960s is relative toxic to other aquatic species. In this article, we evaluated the novel molluscicide PPU07 in field trials on their efficiency against O. hupensis and toxicity for local fish. 25% PPU07 sulfate WP exhibited similar molluscicidal effect at 2.0 g/m2 and 2.0 g/m3 in the spraying and immersion trials with the WHO recommended molluscicide niclosamide (1 g/m2 and 1 g/m3). The mortality rates reached 95% and 96%, respectively. Moreover, little toxicity was observed for local fish and other aquatic organisms at the effective molluscicidal concentrations. In all, 25% PPU07 sulfate WP is a promising molluscicide for snail control, particularly in semi-commercial or commercial aquaculture ponds. Graphical abstract Image 10233 Highlights • PPU07 was a newly-synthesized compound. • Two dosing forms of PPU07, namely hydrochloride and 25% sulfate WP formulation were obtained. • 25% PPU07 sulfate WP exhibited similar molluscicidal effects with the only WHO recommended molluscicide – niclosamide. • In contrast to niclosamide, no obvious toxicity was observed for local fish at the molluscicidal concentrations of PPU07. [ABSTRACT FROM AUTHOR]

[Display omitted] • Comparative proteomics explored the molluscicidial mechanism of PBQ against P. canaliculata. • A total of 245 DEPs were identified in snails following the exposure of PBQ. • DEPs were enriched in the ribosome, translation process and purine biosynthesis pathway. Angiostrongylus cantonensis is a zoonotic parasitic nematode that is the most common cause of human eosinophilic meningitis. The invasive apple snail Pomacea canaliculata is an important intermediate host of A. cantonensis and contributes to its spread. P. canaliculata control will help prevent its invasion and transmission of A. cantonensis. The new molluscicide PBQ (1-(4-chlorophenyl)-3-(pyridin-3-yl)urea) exhibits great potency against P. canaliculata and has low toxicity against mammals and non-target aquatic organisms. We studied the mode of action of PBQ using TMT-based comparative quantitative proteomics analysis between PBQ-treated and control P. canaliculata snails. A total of 3151 proteins were identified, and 245 of these proteins were significantly differentially expressed with 135 downregulated and 110 upregulated. GO and KEGG enrichment analyses identified GO terms and KEGG pathways involved in de novo purine biosynthesis, ribosome components and translation process were significantly enriched and downregulated. The results indicated that PBQ treatment had substantial effects on the synthesis of genetic material, translation process, and protein synthesis of P. canaliculata and were likely the main cause of snail mortality. [ABSTRACT FROM AUTHOR]

• The combined toolbox (Wondfo RDTs plus microscopy) improved the surveillance system sensitivity for malaria in Anhui province. • The improvement was mainly attributed to the excellent ability of RDTs to detect P. falciparum infections. On the other hand, microscopy compensates for some limitations of the use of RDTs in field practice. • Using more than one diagnostic tool to strengthen the surveillance system was effective in the post-elimination stage. Background: In the Anhui Province, China, efforts to interrupt the local malaria transmission were successful, with no endemic cases reported since 2014. Contrastingly, imported malaria cases are still being reported, indicating a disease reintroduction risk after years of elimination. A good surveillance system is key for avoiding the risk, detecting imported cases and possible cases associated with local transmission early. Therefore, rapid diagnostic tests (RDTs) were combined with microscopy to strengthen malaria surveillance in the province. Herein, we aimed to evaluate the efficacy of this surveillance strategy. Methods: We conducted a retrospective study using malaria surveillance data from January 2016 to June 2020. Epidemiological characteristics and diagnostic information were analysed using descriptive and comparative statistics. The diagnostic performance of the combined toolbox (Wondfo RDTs plus microscopy) was evaluated based on its sensitivity, specificity, positive and negative predictive values, and Cohen's kappa coefficient, using real-time polymerase chain reaction as the gold standard. Results: The combined toolbox displayed a higher overall sensitivity for malaria cases than that of microscopy alone (93.74% vs 89.37%; p adj <0.05), which could detect 94.65%, 88.16%, 95.00%, and 100.00% of Plasmodium falciparum, P. ovale, P. vivax , and P. malariae infections, respectively. In clinical practice, Wondfo RDTs ability to detect P. falciparum infections was better than that of microscopy (97.55% vs 89.67%, p adj < 0.05). In contrast, microscopy displayed a higher specificity than that of Wondfo RDTs (81.82% vs 63.28%, p adj <0.05). Moreover, the consistency between microscopy and the gold standard results was also better than that of RDTs (Kappa value:0.669 vs 0.596). Conclusions: The combination of microscopy and RDTs is an effective strategy for malaria surveillance because it possibly detected more P. falciparum infections due to the introduction of RDTs. In contrast, microscopy is complementary to some limitations related to the use of RDTs in field practice. Thus, monitoring malaria cases in non-endemic areas may require employing more than one diagnostic tool in surveillance strategies. Moreover, further understanding of the advantages and disadvantages of different detection methods is necessary for applying optimum combinations in field settings. [ABSTRACT FROM AUTHOR]

Animal trypanosomiasis, caused by the members of subgenus Trypanozoon (Trypanosoma brucei brucei, T. evansi and T. equiperdum), has reduced animal productivity leading to significant negative economic impacts in endemic regions. Due to limited drug discovery and the emergence of drug-resistance over many recent decades, novel and effective compounds against animal trypanosomiasis are urgently required. This study was conducted to evaluate the antitrypanosomal potential of a batch of carbazole aminoalcohol derivatives. Among them, we found that the most effective compound was H1402, which exhibited potent trypanocidal efficacy against the bloodstream-form of T. b. brucei (EC 50 = 0.73 ± 0.05 µM) and presented low cytotoxicity against two mammalian cell lines with CC 50 > 30 µM. Using a murine model of acute infection, oral administration with H1402 demonstrated a complete clearance of T. b. brucei and all the infected mice were cured when they were treated twice daily for 5 days at a dose of 100 mg/kg. Furthermore, parasites were not detected in mice infected with T. evansi and T. equiperdum (the causative agents of surra and dourine, respectively, in animals) within 30 days following the same regimen with H1402. In addition, H1402 caused severe morphological and ultrastructural destruction to trypanosomes, as well as causing phosphatidylserine externalization, which are suggested to be the most likely cause of cell death. Overall, the present data demonstrated that H1402 could be promising as a rapid, safe and orally active lead compound for the development of new chemotherapeutics for animal trypanosomiasis. [ABSTRACT FROM AUTHOR]

Oncomelania hupensis plays a significant role in the transmission of schistosomiasis japonica, which remains a major public health concern in China. Understanding the biological characteristics of O. hupensis is a prerequisite for its control; however, there are currently no studies investigating the intestinal microbiota of the O. hupensis snail. This study aimed to profile the intestinal microbiome of O. hupensis across different ecological landscapes in mainland China. DNA was extracted from the intestines of the collected snails and the bacterial communities were detected using 454 pyrosequencing. A total of 3,799 operational taxonomic units (OTUs) were obtained, and Proteobacteria, Firmicutes, and Actinobacteria were identified as the dominant bacterial taxa at the phylum level. Bacillus and Lactococcus were the most common genera in samples obtained from the four ecological landscapes. Snail specimens were clustered into three clades according to microbial community diversity, and thirty-seven genera that contributed to differential microbiota distributions were identified. Co-occurrence network analysis indicated a symbiotic relationship for the intestinal microbiota of O. hupensis , and PICRUSt analysis predicted forty-one metabolic functions in all snail samples, including membrane transport, amino acid metabolism, carbohydrate metabolism, replication and repair, energy metabolism, as well as xenobiotics biodegradation and metabolism. These findings improve our understanding of bacterial ecology in the O. hupensis intestine; further studies will focus on the relationship between O. hupensis intestinal microbiota and the microbiota in their specific ecological environments. [ABSTRACT FROM AUTHOR]

This study aimed to assess the competency of health professionals on helminthiasis control in China. The assessment system comprised of two parts, one being the parasitological knowledge test and the other a technical skills assessment. The knowledge test mainly examined morphology, epidemiology, life history and diagnosis of common and important parasites. The skills assessment consisted of sample slides making and species identification using microscopy. From 2012 to 2016, a total of 616 participants from different levels of parasitic diseases prevention and control departments of CDC took part in the assessment. The results had shown a high level of academic knowledge among participants. Accuracy rates of schistosomiasis, echinococcosis, food-borne helminthiases, and soil-transmitted helminthiasis were all above 60%. This showed an excellent knowledge level of helminthiases by participants. However, among all 616 participants, 94.97% passed the thick-smear passing test (>= 60%), while in microscopy tests the equivalent was only 43.67%. Competencies in different districts varied. It is imperative to set up a North-South skill exchange mechanism of helminthiases diagnostic techniques and to apply new diagnostic tools widely to strengthen helminthiases prevention and control in China. [ABSTRACT FROM AUTHOR]