Haemonchus contortus poses a severe threat to livestock, leading to substantial economic losses. The extensive use of ivermectin (IVM), an effective anthelmintic drug, has resulted in the development of resistant strains, reducing the drug's effectiveness and making disease management more challenging. Hence, understanding the underlying mechanisms of IVM resistance is crucial. IVM has been shown to induce apoptosis and oxidative stress imbalance in cancer cells, thereby inhibiting tumor growth; however, whether there is a similar impact on H. contortus has not been well-documented. In this study, the biological functions of previously identified resistance-associated genes were investigated, revealing their involvement in apoptosis and oxidative stress. Experiments were conducted to compare cell apoptosis, mitochondrial function, and oxidative stress markers in IVM-treated and untreated sensitive and resistant strains isolated from the field. The findings demonstrated that mitochondrial dysfunction and increased apoptosis were induced by IVM treatment in sensitive strains, as indicated by elevated mitochondrial membrane potential and apoptosis rates. Conversely, stable mitochondrial function and apoptosis levels under IVM exposure were observed in resistant strains. These results provide novel insights into the resistance mechanisms of H. contortus and offer a theoretical basis for future research on overcoming IVM resistance.

Haemonchus contortus poses a severe hazard to the healthy development of the sheep industry and threatens the welfare of sheep. Ivermectin is the primary anthelmintic used for the prevention and treatment of H. contortus parasitism. However, the widespread and uncontrolled application of ivermectin has resulted in the development and spread of resistant strains of H. contortus. P-glycoprotein (P-gp) plays important roles in the pharmacology and toxicology of ivermectin, and changes in P-gp expression levels can be used to analyze the resistance of H. contortus to ivermectin. This study aimed to analyze the effects of ivermectin on P-gp expression in H. contortus L3 larvae isolated from China and to evaluate whether changes in P-gp expression levels can be used to analyze resistant H. contortus strains. In the absence of drug treatment, the ivermectin-resistant strains isolated in China showed increased expression of P-gp11 (p < 0.01) compared with sensitive strains from elsewhere, whereas the expressions of P-gp2 and P-gp9.1 were downregulated (p < 0.01). When the same strain was compared before and after drug treatment, obvious differences in expression were observed between the different strains. Ivermectin-induced P-gp expression was found to be very complex among the L3 larvae of different strains. In addition, it was confirmed that using P-gp to determine ivermectin resistance in H. contortus strains from different geographic environments can yield different results.

为了解捻转血矛线虫(Haemonchus contortus)耐伊维菌素(ivermectin,IVM)国内分离株是否同时存在对阿苯达唑(albendazole)的双重耐药性,本试验通过虫卵孵化幼虫试验和Ⅰ型β微管蛋白基因多态性分析方法,对实验室已分离保存的4个耐伊维菌素虫株及1个伊维菌素敏感虫株进行了阿苯达唑耐药性检测.结果显示,在虫卵孵化幼虫试验中,阿苯达唑对伊维菌素耐药株的EC50值均大于0.1 mg/L,而对敏感株的EC50小于0.1 mg/L.在阿苯达唑Ⅰ型β微管蛋白基因多态性分析试验中,所有耐伊维菌素分离株种群内有超过10％的个体携带198位点纯合耐药基因型;同时,还有超过10％的个体在198位点和200位点同时存在杂合子基因型;而在敏感分离株中,这2个指标均低于10％.结果表明,4个对伊维菌素耐药的捻转血矛线虫国内分离株对阿苯达唑同样耐药;而1个伊维菌素敏感分离株对阿苯达唑也敏感.

The most important and broad-spectrum drug used to control the parasitic worms to date is ivermectin (IVM). Resistance against IVM has emerged in parasites, and preserving its efficacy is now becoming a serious issue. The parasitic nematode Haemonchus contortus (Rudolphi, 1803) is economically an important parasite of small ruminants across the globe, which has a successful track record in IVM resistance. There are growing evidences regarding the multigenic nature of IVM resistance, and although some genes have been proposed as candidates of IVM resistance using lower magnification of genome, the genetic basis of IVM resistance still remains poorly resolved. Using the full magnification of genome, we herein applied a population genomics approach to characterize genome-wide signatures of selection among pooled worms from two susceptible and six ivermectin-resistant isolates of H. contortus, and revealed candidate genes under selection in relation to IVM resistance. These candidates also included a previously known IVM-resistance-associated candidate gene HCON_00148840, glc-3. Finally, an RNA-interference-based functional validation assay revealed the HCON_00143950 as IVM-tolerance-associated gene in H. contortus. The possible role of this gene in IVM resistance could be detoxification of xenobiotic in phase I of xenobiotic metabolism. The results of this study further enhance our understanding on the IVM resistance and continue to provide further evidence in favor of multigenic nature of IVM resistance.

Haemonchus contortus is a hematophagous endoparasite of small ruminants, which is responsible for huge economic losses in livestock sector. Hyaluronidase produced by infective larvae of H. contortus can degrade hyaluronic acid present in the host’s abomasal tissue. Thus, it facilitates larval tissue invasion and early establishment. We herein explored this ability of hyaluronidase in H. contortus , and tested whether hyaluronidase is utilized as a virulence factor by H. contortus while establishing the infection. We first successfully blocked the hyaluronidase gene in L3 larvae by RNA interference (RNAi), which was subsequently confirmed by qPCR, enzymatic activity, and immunohistochemistry assays. Using these larvae we then conducted in vivo and in vitro assays on sheep to assess the effects of hyaluronidase suppression on larval invasion and establishment of infection. The in vivo assay showed a significant drop in worm burden in siRNA treated group in comparison to control group. During in vitro assay we applied an ovine ex vivo model where siRNA treated group of larvae showed significantly reduced invasion of the abomasal tissue explants as compared to control group. These findings indicate that hyaluronidase plays a key role in host’s tissue invasion and larval establishment, and it is used as a virulence factor by H. contortus while establishing the infection. As an invasive virulence molecule, its functional research is thus conducive to the prevention of haemonchosis.

Pakistan is one of a few sites, associated with the earliest known independent domestication event in the evolutionary history of chicken, which is socio-economically and historically the most important poultry bird in the country. However, the divergence, past population dynamics, and demographic history of Pakistani chickens have not been addressed so far. Therefore, we herein investigated the indigenous Pakistani chickens using mitogenomic markers. We first prepared individual DNA samples from the chicken feathers, and generated nucleotide sequence data, which was then subjected to various population genetics analyses. In molecular phylogenetic analysis, the Pakistani chickens were clustered under nine different clades. Among the wild fowls, the Indian red jungle fowl (IRJF) shared very close affinities to Pakistani chickens. The Bayesian skyline plot showed an increase in the effective population size of Pakistani chickens during the last 50 years. Finally, a time-calibrated phylogeny inferred molecular divergence of the Pakistani chickens. A molecular rate of 3.6 x 10(-6) mutations/site/year (95% HPD interval: 2.28 x 10(-8) to 9.32 x 10(-6)) was estimated for the data set. In a rooted tree with root-age of 12058 years (95% HPD interval: 1161-38411), the Pakistani chicken haplotypes showed divergence from IRJF haplotypes around 6987 years (95% HPD interval: 1132-20746) ago, and they shared their most recent common ancestor with Gallus gallus spadiceus, and G. g. jabouillei at the root of the tree. Overall, these results suggest that Pakistani chicken haplotypes share their ancestral gene pool with the IRJF as compared to other red jungle fowl subspecies.

The parasitic nematode Haemonchus contortus is one of the world’s most important parasites of small ruminants that causes significant economic losses to the livestock sector. The population structure and selection in its various strains are poorly understood. No study so far compared its different populations using genome-wide data. Here, we focused on different geographic populations of H. contours from China (Tibet, TB; Hubei, HB; Inner Mongolia, IM; Sichuan, SC), UK and Australia (AS), using genome-wide population-genomic approaches, to explore genetic diversity, population structure and selection. We first performed next-generation high-throughput 2b RAD pool sequencing using Illumina technology, and identified single-nucleotide polymorphisms (SNPs) in all the strains. We identified 75,187 SNPs for TB, 82,271 for HB, 82,420 for IM, 79,803 for SC, 83,504 for AS and 78,747 for UK strain. The SNPs revealed low-nucleotide diversity (π = 0.0092–0.0133) within each strain, and a significant differentiation level (average Fst = 0.34264) among them. Chinese populations TB and SC, along with the UK strain, were more divergent populations. Chinese populations IM and HB showed affinities to the Australian strain. We then analysed signature of selection and detected 44 (UK) and 03 (AS) private selective sweeps containing 49 and 05 genes, respectively. Finally, we performed the functional annotation of selective sweeps and proposed biological significance to signature of selection. Our data suggest that 2b-RAD pool sequencing can be used to assess the signature of selection in H. contortus.

The parasitic nematode Haemonchus contortus is economically an important parasite of small ruminants across the globe. China is the world's largest producer, consumer, and importer of mutton. With ubiquitous distribution across the country H. contortus is one of the potential candidates to cause huge economic losses to small ruminant farming industry in China. We herein investigated genetic diversity and population structure of six farm populations of H. contortus in northern China, and also compared them to H. contortus isolates from UK and Australia. We first prepared individual DNA samples from 240 adult worms, and generated genotyping data using eight microsatellite markers. Obtained data was then subjected to allelic frequency and population genetic analyses. The overall allelic richness (mean/locus/pop = 7.375 +/- 0.844-10.125 +/- 1.109), and expected heterozygosity (mean/locus/pop = 0.646 +/- 0.040-0.735 +/- 0.025) indicated high degree of population genetic variation across the Chinese isolates. Low level of genetic differentiation (Fst = 0.010-0.066) was observed across all the populations. AMOVA results showed high level of variation (93%) within the populations. PCA analysis revealed mixed clustering of all the populations with no visible geographical sub-structuring. Finally the population admixture analysis resulted in extensive admixing of genotypes across all the populations. With these findings we conclude that there is no obvious population genetic structure with extensive gene flow across all the farm populations of H. contortus in northern China.

捻转血矛线虫病是由主要寄生于反刍动物皱胃的捻转血矛线虫引起的一种重要的寄生线虫病,在我国草地牧区普遍流行,可引起宿主消瘦、贫血等慢性消耗性症状,严重感染甚至可引起死亡,给我国养殖业带来巨大的经济损失.由于基层养殖人员常常忽视寄生线虫病的危害,缺乏基本的防控常识和驱虫意识,从而错过了预防和治疗该病的最佳时机,最终导致动物大批感染,极大的降低了动物的品质和养殖的经济效益.本文从捻转血矛线虫的形态和生活史着手,介绍了捻转血矛线虫病的危害和症状、诊断和治疗、防控方法及感染和致病的相关分子机制研究进展,希望能为该病的防控提供一定的指导.

Wnts are secreted signaling molecules that are implicated in a variety of growth-related processes. Frizzled proteins have been identified as receptors for Wnt ligands in vertebrates and invertebrates, but a functional role for dioecious flatworm Frizzleds has not been determined. To evaluate the endogenous role of Frizzled proteins during development, we have identified and characterized a Schistosoma japonicum frizzled gene (Sjfz7). We found that Sjfz7 encodes a 698 amino acid protein with typical characteristics of Frizzled proteins. The immunohistochemical localization pattern showed that Sjfz7 protein was extensively distributed in almost all tissues of S. japonicum, including subtegumental muscle cells, parenchymal cells, intestinal epithelial cells and male and female germ cells. This indicated that Sjfz7-mediated Wnt signaling might be associated with the development of musculature, intestinal tract and reproductive organs in schistosome. Comparing mRNA levels between frizzled family members showed that Sjfz7 mRNA was consistently higher in the developmental stages analyzed, suggesting that Sjfz7 may be responsible for more functional tasks than other frizzled family members. Comparing frizzled mRNA levels between not fully developed and normal worms suggested that Wnt signaling might be abnormal in not fully developed worms.

Despite the unique geographic, ethnic, social and cultural features of Kohistan in Pakistan, the origin and descent of Kohistanis remain still obscure. In an effort to address questions concerning the genetic structure, origin and genetic affinities of Kohistanis, we herein applied an ethnogenetic approach consisting on mitochondrial DNA (mtDNA) analysis and dental morphology analysis. We sequenced HVS1 of mtDNA, observed 14 haplotypes and assigned a total of 9 haplogroups belonging to macrolineages M (17%) and N (83%). Genetic diversity estimates in Kohistanis (Hd = 0.910 ± 0.014; Pi = 0.019 ± 0.001; θw = 0.019 ± 0.006) were similar to that of previous studies in other Pakistani populations. Overall, the analyses of dental morphology and mtDNA profile of Kohistanis resulted in similar findings. All the analyses indicate that Kohistanis share affinities to populations from Europe, Near East, Central Asia and South Asia. The Kohistani HVS1 haplotype 2 shares 100% identity to HVS1 haplotypes across the Europe. These results in light of recent insights into ancient genomics lead us to conclude that ancestry from Eurasian Steppe genetically linked Kohistanis to all these populations in the Bronze Age. This is consistent with linguistic evidence and also with the Indo-Aryan migration model for the peopling of South Asia.

During amplifying the new Frizzled receptor member of Wnt signling pathway in Schistosoma japonicum, a new gene which encoded a seven transmembrane protein containing 1141 amino acid which was only similar to Frizzled receptor family protein was obtained. The N terminal of SjSTMP also has a CRD structure, so it has the structural basis to act as a cell surface receptors. SjSTMP was regulated along with the development. There were differences in the levels of SjSTMP mRNA in different developmental stages and different genders, and these differences were also found in normal worms and dysplasia worms. The SjSTMP protein was widely distributed in almost all kinds of tissues of Schistosoma japonicum, and it had no tissue specificity. Further identification of the function of SjSTMP protein will be helpful to understand the developmental regulation of Schistosoma at molecular level.

Chicken is the most important poultry bird in Pakistan that not only provides nutrition but also contributes to country's economy. The Pakistani chicken and its germplasm resources are not genetically characterized and explored. Here, we focused at rural and commercial chickens of Pakistan and explored genetic diversity, population structure and phylogeny. We first collected feather samples from Rural and Broiler populations of Pakistani chickens, isolated DNA and sequenced complete D-loop of mtDNA. The length of complete D-loop ranged from 1231 to 1234 bp in Pakistani chickens. The GC content was 39%. Hotspots of mutations were three hypervariable sites (HVS). Most of the variations (77%) were in HVS1. In a total, 26 polymorphic sites defined 12 haplotypes and all major haplogroups (A-I) in genetic structure of Pakistani chickens. Genetic diversity remained relatively very low in Broiler (Pi = 0.00212 +/- 0.00136). There was a low sharing of matrilineages between the two populations (Fst = 0.170). With high Hd value (0.825 +/- 0.051) and presence of all nine major haplogroups the rural chicken population showed relatively rich genepool. Finally we did molecular phylogenetic analysis and inferred phylogeny. Presence of subcontinent specific haplogroups E3 and I and clustering of Indian red junglefowl closely with Pakistani chickens in Bayesian inference tree, provide further evidence for an independent domestication event of chicken in subcontinent.

Wnt signaling as mediated by the Frizzled family receptors plays a vital role in the early development of animal embryos, organ formation, tissue regeneration and other physiological processes. In the present study, a novel Frizzled member, SjFz8, was isolated and characterized in Schistosoma japonicum. SjFz8 encodes an 1162-amino-acid protein with typical characteristics of Frizzled proteins. Quantitative real-time polymerase chain reaction analysis indicated that SjFz8 transcript level was highest in 7-day-old schistosomula. In adult stages, SjFz8 mRNA expression remained at a low level after male-female pairing. The immunohistochemical localization of the Fz8 protein revealed that it existed in almost all tissues of S. japonicum, including subtegumental muscle, parenchyma, oral suckers, ventral suckers, testes of the male and ovaries of the female. We speculated that the Wnt signaling pathway that was mediated by Fz8 might take part in regulating histogenesis and organogenesis during the schistosomulum period, and play an important role in regulating further growth and development of male and female worms.

BACKGROUND:It is well known that immunization of radiation-attenuated (RA) schistosoma cercariae or schistosomula can induce high levels of protective immunity against schistosoma cercariae reinfection in many animals. Many studies have shown that the Th1 cellular immune response is crucial for the protective effect elicited by RA schistosomula. However, the molecular mechanism of this strong protective immunity remains unclear.METHODS:The expression profiles of Schistosoma japonicum calreticulin (SjCRT) in RA and normal schistosoma-derived cells were investigated by flow cytometry. The effect of recombinant SjCRT (rSjCRT) on mouse dendritic cells (DCs) was determined by FACS, ELISA and RT-PCR analysis. We also analyzed the effects of SjCRT on the activation of spleen cells from mice immunized with rSjCRT by detecting lymphocyte proliferation and the cytokine profiles of splenocytes.RESULTS:We found that the expression level of SjCRT in the cells from RA larvae was significantly higher than that in cells from normal schistosomula at early stages of development (day 4). The results of effect of rSjCRT on mouse DCs showed that rSjCRT could induce phenotypic and functional maturation of DCs, and SjCRT bound to the surface of DCs through the CD91 receptor and could be engulfed by DCs. The results of activation of splenocytes from mice immunized with rSjCRT also demonstrate that rSjCRT can effectively stimulate the proliferative response of splenic lymphocytes, elicit splenocytes from immunized mice to secrete high levels of IFN-γ, TNF-α and IL-4, and activate CD4+ T cells to produce high levels of IFN-γ.CONCLUSION:SjCRT is one of the immunostimulatory molecules released from RA schistosomula cells, might play a crucial role in conferring a Th1-polarized immune response induced by RA cercariae/schistosomula in mice, and is a candidate molecule responsible for the high levels of protective immunity induced by RA schistosomula.

BACKGROUND:The excessive and uncontrolled use of anthelmintics, e.g. ivermectin (IVM) for the treatment of livestock parasites has led to widespread resistance in gastrointestinal nematodes, such as Haemonchus contortus. There is an urgent need for better management of drug-use in nematode control and development of novel anthelmintics. Discovery and identification of anthelmintic resistance-associate molecules/markers can provide a basis for rational anthelmintics-use and development of novel drugs. Recent studies have shown that ivermectin resistance in H. contortus is likely to be multi-genic in nature except for several genes coding for IVM target and efflux pump. However, no other IVM resistance-associated genes were characterized by conventional methods or strategies. In the present study we adopted a new strategy, i.e. using genome-wide single nucleotide polymorphism (SNP) analysis based on 2b-RAD sequencing, for discovering SNPs markers across the genomes in both IVM susceptible and resistant isolates of H. contortus and identifying potential IVM resistance-associated genes.RESULTS:We discovered 2962 and 2667 SNPs within both susceptible and resistant strains of H. contortus, respectively. A relative lower and similar genetic variations were observed within both resistant and susceptible strains (average π values were equal to 0.1883 and 0.1953, respectively); whereas a high genetic variation was found across both strains (average π value was equal to 0.3899). A significant differentiation across 2b-RAD tags nucleotide sites was also observed between the two strains (average FST value was equal to 0.3076); the larger differences in average FST were observed at SNPs loci between coding and noncoding (including intronic) regions. Comparison between resistant and susceptible strains revealed that 208 SNPs loci exhibited significantly elevated FST values, 24 SNPs of those loci were located in the CDS regions of the nine genes and were likely to have signature of IVM directional selection. Seven of the nine candidate genes were predicted to code for some functional proteins such as potential IVM target and/or efflux pump proteins, component proteins of receptor complex in membrane on neuromuscular cells, and transcriptional regulation proteins. Those genes might be involved in resistance to IVM.CONCLUSIONS:Our data suggest that candidate genes putatively associated with resistance to IVM in H. contortus may be identified by genome-wide SNP analysis using 2b-RAD sequencing.

This study aimed at determining the activation of high mobility group boxl protein (SjHMGB 1)of Schistosomajaponicum on mouse macrophagocyte.When Recombinant SfHMGB 1 protein from eukaryotic cell expression system was incubated with macrophage for 48 h,the expression of macrophage surface molecules and chemokine receptors were detected by flow cytometry.TNF-α and IL-10 in the culture supernatant were detected by ELISA,and the content of NO in supernatant was assayed by Griess method.Results showed that,compared with the control group,the expression levels of MHC-11 molecules,TLR4 receptor and chemokine receptor CCR7 on the surface of macrophage stimulated by SjHMGB1 group were significantly increased (P ＜ 0.01),while TLR2 receptor was signi ficantly decreased (P＜0.05).The results of test by ELISA demonstrated that SjHMGB 1 could stimulate the secretion of inflammatory factor TNF-α,and fail to promote the release of IL-10 on macrophage.The result of test using Griess method showed that SjHMGB 1 could promote the secretion of NO on macrophage.The data suggest that SjHMGB1 could activate mouse macrophages via TLR4 and induce macrophages to undergo M l-type inflammatory polarization.

The role of Schistosoma japonicum high mobility group protein B1 (SjHMGB1) in the induction of macrophages to M1 type polarization was investigated through the analysis of expression of phenotype-related molecules on stimulated macrophages. The mouse RAW264.7 macrophages induced by LPS and IFN-γ or IL-4 respectively to M1 or M2 type were set as positive control groups. Griess, FCM, RT-PCR and enzyme activities were analyzed to detect the expression of major marker molecules including iNOS, CD16/32,arginaseⅠand CD206 in macrophages. As compared with the positive control groups, a few changes were observed, including significant increase of the NO secretion of macrophages in SjHMGB1 treatment group and M1 group, slight increase in the activity of arginaseⅠand opposite phenotype of M2 type macrophages. In addition, flow cytometry analysis showed significant up-regulation of the expression of iNOS and CD16/32 of macrophages in SjHMGB1 group and M1 group except CD206. RT-PCR results also indicated up-regulated expression of iNOS in SjHMGB1 group and M1 group as well as CD206 and enzyme activities of M2 macrophages. However, the expression level and arginase I did not change significantly. In conclusion,SjHMGB1 induced the differentiation of macrophages into M1 type polarization.

To explore the structural basis that might cause diverse responses to biological treatments, the ultrastructures of worms at different developmental stages and genders of Schistosoma japonicum were compared in the present study. The teguments and intestinal epitheliums, through which worms contacted with the outside world directly, were thinner and more compact in schistosomulums than in adults. The teguments of female worms were more compact than in male worms at the same stage while the basal lamina of female worms were thicker than male worms at the same stage. The differences on ultrastructures may help explain different biological responses at different developmental stages or different genders of Schistosoma japonicum.

Secreted extracellular vesicles play an important role in pathogen-host interactions. Increased knowledge of schistosome extracellular vesicles could provide insights into schistosome-host interactions and enable the development of novel intervention strategies to inhibit parasitic processes and lessen disease transmission. Here, we describe biochemical characterization of Schistosoma japonicum exosome-like vesicles ( S. japonicum EVs). A total of 403 proteins were identified in S. japonicum EVs, and bioinformatics analyses indicated that these proteins were mainly involved in binding, catalytic activity, and translation regulatory activity. Next, we characterized the population of small RNAs associated with S. japonicum EVs. Further studies demonstrated that mammalian cells could internalize S. japonicum EVs and transfer their cargo miRNAs to recipient cells. Additionally, we found that a specific miRNA, likely originating from a final host, ocu-miR-191–5p, is also associated with S. japonicum EVs. Overall, our findings demonstrate that S. japonicum EVs could be implicated in the pathogenesis of schistosomiasis via a mechanism involving the transfer of their cargo miRNAs to hosts. Our findings provide novel insights into the mechanisms of schistosome-host interactions.