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Abstract Background Toxoplasma gondii is an obligate intracellular protozoan parasite that causes severe threats to humans and livestock. Macrophages are the cell type preferentially infected by T. gondii in vivo. Protein phosphorylation is an important posttranslational modification involved in diverse cellular functions. A rapidly accelerated fibrosarcoma kinase (A-Raf) is a member of the Raf family of serine/threonine protein kinases that is necessary for MAPK activation. Our previous research found that knockout of A-Raf could reduce T. gondii-induced apoptosis in porcine alveolar macrophages (3D4/21 cells). However, limited information is available on protein phosphorylation variations and the role of A-Raf in macrophages infected with T. gondii. Methods We used immobilized metal affinity chromatography (IMAC) in combination with liquid chromatography tandem mass spectrometry (LC–MS/MS) to profile changes in phosphorylation in T. gondii-infected 3D4/21 and 3D4/21-ΔAraf cells. Results A total of 1647 differentially expressed phosphorylated proteins (DEPPs) with 3876 differentially phosphorylated sites (DPSs) were identified in T. gondii-infected 3D4/21 cells (p3T group) when compared with uninfected 3D4/21 cells (pho3 group), and 959 DEPPs with 1540 DPSs were identified in the p3T group compared with infected 3D4/21-ΔAraf cells (p3KT group). Venn analysis revealed 552 DPSs corresponding to 406 DEPPs with the same phosphorylated sites when comparing p3T/pho3 versus p3T/p3KT, which were identified as DPSs and DEPPs that were directly or indirectly related to A-Raf. Conclusions Our results revealed distinct responses of macrophages to T. gondii infection and the potential roles of A-Raf in fighting infection via phosphorylation of crucial proteins. Graphical Abstract

Given the extensive application of artificial intelligence (AI) within the educational domain, college teachers’ behavioral intention to adopt AI-assisted teaching systems (AIATS) has emerged as a critical topic, with gaps in the breadth of samples and the diversity of methods. To further delve into the principal elements affecting college teachers’ inclination towards AIATS, this research constructs an integrative theoretical framework that synthesizes the Technology Acceptance Model (TAM) with the Innovation Diffusion Theory (IDT), while comprehensively considering internal and external factors. The investigation collected sample data from a questionnaire survey, which reached 529 college teachers in China, and undertook data analysis employing SPSS 27.0 and AMOS 26.0. The findings revealed that: 1) college teachers’ behavioral intention to embrace AIATS is directly and significantly shaped by perceived ease of use, perceived usefulness, trust and subjective norms; 2) factors such as observability, relative advantage and compatibility indirectly impact college teachers’ adoption willingness of AIATS through their perceived ease of use and perceived usefulness; 3) complexity of AIATS positively affects perceived ease of use by means of perceived time cost, thereby influencing behavioral intention; 4) sociocultural factors significantly impact the adoption and promotion of AIATS in China. By extending the applicability of TAM and IDT within the realm of educational technology acceptance, this study offers strategic recommendations geared towards educational policymakers and technology developers to promote the implementation of AIATS, and sheds light on educational technology adoption across diverse sociocultural landscapes.

Abstract Background The durable oocyst wall formed from the contents of wall-forming bodies (WFBs) protects Eimeria parasites from harsh conditions and enhances parasite transmission. Comprehending the contents of WFBs and proteins involved in oocyst wall formation is pivotal to understanding the mechanism of the oocyst wall formation and the search for novel targets to disrupt parasite transmission. Methods Total proteins extracted from WFBs and the oocyst wall of Eimeria necatrix were subjected to comparative proteomic analysis using tandem mass tag in conjunction with liquid chromatography tandem-mass spectrometry techniques. After functional clustering analysis of the identified proteins, three proteins, including E. necatrix disulfide isomerase (EnPDI), thioredoxin (EnTrx) and phosphoglycerate kinase (EnPGK), were selected for further study to confirm their potential roles in oocyst wall formation. Results A total of 3009 and 2973 proteins were identified from WFBs and the oocyst wall of E. necatrix, respectively. Among these proteins, 1102 were identified as differentially expressed proteins, of which 506 were upregulated and 596 downregulated in the oocyst wall compared to the WFBs. A total of 108 proteins, including compositional proteins of the oocyst wall, proteases, oxidoreductases, proteins involved in glycosylation, proteins involved in synthesis of the acid-fast lipid layer and proteins related to transport, were proposed to be involved in oocyst wall formation. The approximate molecular sizes of native EnPDI, EnTrx and EnPGK proteins were 55, 50 and 45 kDa, respectively. EnPDI was present in both type 1 and type 2 WFBs, EnTrx was present only in type 2 WFB2 and EnPGK was present only in type 1 WFBs, whereas all of them were localized to the outer layer of the oocyst wall, indicating that all of them participate in the formation of the oocyst wall. Conclusions To the best of our knowledge, this is the first report on the proteomes of WFBs and the oocyst wall of E. necatrix. The data obtained from this study form a basis for deciphering the molecular mechanisms underlying oocyst wall formation of Eimeria parasites. They also provide valuable resources for future studies on the development of novel therapeutic agents and vaccines aimed at combating coccidian transmission. Graphical Abstract

Abstract Background Toxoplasmosis is a zoonosis with a worldwide presence that is caused by the intracellular parasite Toxoplasma gondii. Active regulation of apoptosis is an important immune mechanism by which host cells resist the growth of T. gondii or avoid excessive pathological damage induced by this parasite. Previous studies found that upregulated expression of microRNA-185 (miR-185) during T. gondii infection has a potential role in regulating the expression of the ARAF gene, which is reported to be associated with cell proliferation and apoptosis. Methods The expression levels of miR-185 and the ARAF gene were evaluated by qPCR and Western blot, respectively, in mice tissues, porcine kidney epithelial cells (PK-15) and porcine alveolar macrophages (3D4/21) following infection with the T. gondii ToxoDB#9 and RH strains. The dual luciferase reporter assay was then used to verify the relationship between miR-185 and ARAF targets in PK-15 cells. PK-15 and 3D4/21 cell lines with stable knockout of the ARAF gene were established by CRISPR, and then the apoptosis rates of the cells following T. gondii infection were detected using cell flow cytometry assays. Simultaneously, the activities of cleaved caspase-3, as a key apoptosis executive protein, were detected by Western blot to evaluate the apoptosis levels of cells. Results Infection with both the T. gondii ToxoDB#9 and RH strains induced an increased expression of miR-185 and a decreased expression of ARAF in mice tissues, PK-15 and 3D4/21 cells. MiR-185 mimic transfections showed a significantly negative correlation in expression levels between miR-185 and the ARAF gene. The dual luciferase reporter assay confirmed that ARAF was a target of miR-185. Functional investigation revealed that T. gondii infection induced the apoptosis of PK-15 and 3D4/21 cells, which could be inhibited by ARAF knockout or overexpression of miR-185. The expression levels of cleaved caspase-3 protein were significantly lower in cells with ARAF knockout than in normal cells, which were consistent with the results of the cell flow cytometry assays. Conclusions Toxoplasma gondii infection could lead to the upregulation of miR-185 and the downregulation of ARAF, which was not related to the strain of T. gondii and the host cells. Toxoplasma gondii infection could regulate the apoptosis of host cells via the miR-185/ARAF axis, which represents an additional strategy used by T. gondii to counteract host-cell apoptosis in order to maintain survival and reproduce in the host cells. Graphical Abstract

IntroductionApicomplexan AP2 family of proteins (ApiAP2) are transcription factors (TFs) that regulate parasite growth and development, but little is known about the ApiAP2 TFs in Eimeria spp. ENH_00027130 sequence is predicted to encode a Eimeria necatrix ApiAP2 protein (EnApiAP2).MethodsThe cDNAs encoding full-length and truncated EnApiAP2 protein were cloned and sequenced, respectively. Then, the two cDNAs were cloned into the pET28a(+) expression vector and expressed expressed in Escherichia coli BL21. The mouse polyclonal antibody (pAb) and monoclonal antibody (mAb) against recombinant EnApiAP2 (rEnApiAP2) and EnApiAP2tr (rEnApiAP2tr) were prepared and used to localize the native EnApiAP2 protein in E. necatrix, respectively. Finally, the recombinant pEGFP-C1-ΔNLS-EnApiAP2s (knockout of a nuclear localization sequence, NLS) and pEGFP-C1-EnApiAP2 plasmid were constructed and transfected into DF-1 cells, respectively, to further observe subcellular localization of EnApiAP2 protein.ResultsThe EnApiAP2 gene had a size of 5019 bp and encoded 1672 amino acids, containing a conserved AP2 domain with a secondary structure consisting of an α-helix and three antiparallel β-strands. The rEnApiAP2 and rEnApiAP2tr were predominantly expressed in the form of inclusion bodies, and could be recognized by the 6×His tag mAb and the serum of convalescent chickens after infection with E. necatrix, respectively. The native EnApiAP2 protein was detected in sporozoites (SZ) and second generation merozoites (MZ-2) extracts, with a size of approximately 210 kDa. A quantitative real-time PCR (qPCR) analysis showed that the transcription level of EnApiAP2 was significantly higher in SZ than in MZ-2, third generation merozoites (MZ-3) and gametocytes (P

Abstract Background Eimeria parasite infection occurs via ingestion of oocysts. The robust, bilayer oocyst wall is formed from the contents of wall-forming bodies (WFBs), WFB1 and WFB2, located exclusively in macrogametocytes. Eimeria necatrix gametocyte proteins 22 and 59 (EnGAM22 and EnGAM59) have been found to localize to WFBs and the oocyst wall. However, the exact localization of these two proteins is not clear. Methods WFBs of E. necatrix were extracted from purified gametocytes using a cutoff filter and the extracts of purified WFBs and gametocytes were analyzed using sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting. Then, the localization of EnGAM22 and EnGAM59 proteins was determined using an indirect immunofluorescence assay. Finally, the development of macrogametocytes and the oocyst wall of E. necatrix was analyzed using laser confocal microscopy and scanning electron microscopy. Results Purified WFBs had the same shape and size as those observed in macrogametocytes. EnGAM22 protein localized to WFB1, whereas EnGAM59 protein localized to WFB2. Both EnGAM22 and EnGAM59 native proteins were detected in the extracts of WFBs and gametocytes. The outer layer of the oocyst wall was formed by the release of the contents of WFB1 at the surface of the macrogametocyte to form an anti-EnGAM22 positive layer. WFB2 then appeared to give rise to the inner layer, which was anti-EnGAM59 positive. Conclusions EnGAM22 and EnGAM59 proteins localized to WFB1 and WFB2 and were involved in the formation of the outer and inner layers of the oocyst wall of E. necatrix, respectively. The processes of macrogametogenesis and oocyst wall formation of E. necatrix are similar to other Eimeria parasites. The anti-EnGAM22 antibody could be used as a tool to track the transport and secretion of proteins in WFB1 during oocyst development. Graphical Abstract

Gastrointestinal (GI) parasites in small ruminants, especially goats and sheep, have caused significant socio-economic and public health challenges worldwide. The aim of the present study was to investigate the diversity and prevalence of GI parasites in goats and sheep in Jiangsu, Shaanxi and Hunan provinces of China, and to assess whether the age of animals, sampling season and feeding mode influence the distribution and infection of GI parasites. A total of 1,081 fecal samples collected from goats (n = 835) and sheep (n = 246) were detected by saturated saline flotation technique and nylon sifter elutriation and sieving method for eggs/oocysts, respectively. Based on the morphological observation of eggs and oocysts, one tapeworm, five nematodes, three trematodes and nineteen coccidia were identified, of which seven helminths belong to zoonotic parasites. The infection rate of parasites was 83.4% (902/1081) in total samples, 91.6% (765/835) in goats, and 55.7% (137/246) in sheep. The infection rate of coccidia was 71.0% (767/1081), and that of helminths was 56.2% (607/1081). The dominant species was E. alijeri (67.3%, 562/835) in goats, E. parva (30.1%, 74/246) in sheep. The highest prevalent helminths were Trichostrongylidae spp. in goats (58.3%, 487/835), and Moniezia spp. in sheep (22.76%, 56/246). Of 902 positive samples, 825 (91.5%, 825/902) contained multiple (2–10) parasites. The feeding mode, sampling season and regions were relevant risk factors which have significant influence on the occurrence of GI parasites in goats and sheep. The risk coefficient of parasite infection in autumn was 2.49 times higher than spring (Odds ratio = 2.49, 95% CI = 1.51–4.09, p

The burden of gastrointestinal parasites in zoo animals has serious implications for their welfare and the health of veterinarians and visitors. Zhuyuwan Zoo is located in the eastern suburb of Yangzhou city in eastern China, in which over 40 species of zoo animals are kept. In order to understand the infection status of GI parasites in Zhuyuwan Zoo, a total of 104 fresh fecal samples collected randomly from birds (n = 19), primates (n = 19), and non-primate mammals (n = 66) were analyzed using the saturated saline flotation technique and nylon sifter elutriation and sieving method for eggs/oocysts, respectively. Two Ascaris species were molecularly characterized. The results showed that the overall prevalence of parasitic infection was 42.3% (44/104). The parasitic infection rate in birds, primates, and non-primate mammals were 26.3% (5/19), 31.6% (6/19), and 50.0% (33/66), respectively. A total of 11 species of parasites were identified, namely, Trichostrongylidae, Capillaria sp., Trichuris spp., Strongyloides spp., Amidostomum sp., Toxascaris leonina, Baylisascaris transfuga, Parascaris equorum, Paramphistomum spp., Fasciola spp., and Eimeria spp. Paramphistomum spp. eggs were first detected from the captive Père David’s deer, and Fasciola spp. eggs were first reported from sika deer in zoo in China. A sequence analysis of ITS-2 and cox1 showed that the eggs isolated from the African lion (Panthera leo Linnaeus, 1758) were T. leonina, and the eggs from the brown bear (Ursus arctos Linnaeus, 1758) were B. transfuga. The public health threat posed by these potential zoonotic parasitic agents requires attention. These results lay a theoretical foundation for prevention and control of wild animal parasitic diseases at zoos in China.

Abstract Background Eimeria coccidiosis is a significant intestinal parasitic disease, which can lead to weight loss, disease and even death of many animals. At present, there is no information about the prevalence of Eimeria among the world’s endangered species of Père David’s deer (Elaphurus davidianus). Therefore, the purpose of this study is to identify an unknown Eimeria genus in the Père David’s deer in Dafeng Milu National Nature Reserve, China. Results A new Eimeria species is described from Père David’s deer. Sporulated oocysts (n = 54) are pyriform, with a rough, yellowish brown, 2-layered oocyst wall (2.5 μm thick). A numerous small granules are dispersed randomly on the wall. Oocysts measured 41.2 (39.2–42.8) μm × 29.5 (27.9–30.5) μm, oocyst length/width (L/W) ratio, 1.4. Oocyst residuum, a polar granule and a polar cap are absent. The micropyle (3.5 μm wide) is present. Sporocysts are spindle shaped, 18.2 (16.5–20.0) μm × 10.5 (9.8–11.9) μm, sporocyst L/W ratio, 1.7 (1.5–1.9). A thin convex Stieda body is present and the sporocyst residuum is composed of numerous small granules less than 2.0 μm in diameter dispersed randomly. Each sporocyst contained 2 comma-shaped sporozoites in head-to-tail arrangement. A nucleus is located immediately anterior to the posterior, strong refractive and subspherical refractile body (~ 8 μm). Molecular analysis was conducted at the 18S, ITS-1 and COI loci. Conclusion Based on the morphological and molecular data, this isolate is a new species of coccidian parasite, which is named Eimeria davidianusi after its host, the Père David’s deer (Elaphurus davidianus).

Abstract Background Toxoplasma gondii is an obligate intracellular protozoan parasite that can cause a geographically widespread zoonosis. Our previous splenocyte microRNA profile analyses of pig infected with T. gondii revealed that the coordination of a large number of miRNAs regulates the host immune response during infection. However, the functions of other miRNAs involved in the immune regulation during T. gondii infection are not yet known. Methods Clustering analysis was performed by K-means, self-organizing map (SOM), and hierarchical clustering to obtain miRNA groups with the similar expression patterns. Then, the target genes of the miRNA group in each subcluster were further analyzed for functional enrichment by Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Reactome pathway to recognize the key signaling molecules and the regulatory signatures of the innate and adaptive immune responses of the host during T. gondii infection. Results A total of 252 miRNAs were successfully divided into 22 subclusters by K-means clustering (designated as K1–K22), 29 subclusters by SOM clustering (designated as SOM1–SOM29), and six subclusters by hierarchical clustering (designated as H1–H6) based on their dynamic expression levels in the different infection stages. A total of 634, 660, and 477 GO terms, 15, 26, and 14 KEGG pathways, and 16, 15, and 7 Reactome pathways were significantly enriched by K-means, SOM, and hierarchical clustering, respectively. Of note, up to 22 miRNAs mainly showing downregulated expression at 50 days post-infection (dpi) were grouped into one subcluster (namely subcluster H3-K17-SOM1) through the three algorithms. Functional analysis revealed that a large group of immunomodulatory signaling molecules were controlled by the different miRNA groups to regulate multiple immune processes, for instance, IL-1-mediated cellular response and Th1/Th2 cell differentiation partly depending on Notch signaling transduction for subclusters K1 and K2, innate immune response involved in neutrophil degranulation and TLR4 cascade signaling for subcluster K15, B cell activation for subclusters SOM17, SOM1, and SOM25, leukocyte migration, and chemokine activity for subcluster SOM9, cytokine–cytokine receptor interaction for subcluster H2, and interleukin production, chemotaxis of immune cells, chemokine signaling pathway, and C-type lectin receptor signaling pathway for subcluster H3-K17-SOM1. Conclusions Cluster analysis of splenocyte microRNAs in the pig revealed key regulatory properties of subcluster miRNA molecules and important features in the immune regulation induced by acute and chronic T. gondii infection. These results contribute new insight into the identification of physiological immune responses and maintenance of tolerance in pig spleen tissues during T. gondii infection. Graphical Abstract

Histomonas meleagridis is a protozoan parasite that causes histomonosis in gallinaceous birds such as turkeys and chickens. Since the banning and restricted usage of effective drugs such as nitarsone, 80–100% morbidity and mortality occur in turkeys and 20–30% mortality in chickens. New ideas are needed to resolve the re-emergence of histomonosis in poultry. In this study, the α-actinin encoding gene from H. meleagridis was cloned. The 1839-bp gene encoding 612 amnio acids showed close phylogenetic relationships with Trichomonas vaginalis and Tritrichomonas foetus. It was then inserted into the prokaryotic expression vector pET28a(+) and induced with isopropyl-β-D-thiogalactopyranoside. A 73 kDa recombinant protein rHmα-actinin 1 was obtained and purified with a Ni-NTA chromatography column. rHmα-actinin 1 was recognized by mouse anti-rHmα-actinin 1 polyclonal antibody, mouse anti-rHmα-actinin 1 monoclonal antibody, and rehabilitation sera from H. meleagridis infected chickens. Native α-actinin 1 in the total proteins of H. meleagridis can also be detected with mouse anti-rHmα-actinin monoclonal antibody. Immunolocalization assays showed that Hmα-actinin 1 was mainly distributed in the cytoplasm of virulent histomonads JSYZ-D9 and in the peripheral regions (near the plasma membrane) of attenuated histomonads JSYZ-D195. Based on in vivo experiment, when chickens were subcutaneously immunized with rHmα-actinin 1 at 5 and 12 days old and then challenged with H. meleagridis at 19 days old, rHmα-actinin 1 reduced the lesion scores 12 days after infection (31 days old) and increased the body weight gain during the challenged period (19–31 days old). Furthermore, it also strengthened the cellular and humoral immune responses 7 days after the second immunization (19 days old). In conclusion, Hmα-actinin 1 could be used as a candidate antigen to develop vaccines against chicken histomonosis.

Toxoplasma gondii (T. gondii) is an obligate intracellular parasitic protozoan that can cause toxoplasmosis in humans and other endotherms. T. gondii can manipulate the host gene expression profile by interfering with miRNA expression, which is closely associated with the molecular mechanisms of T. gondii-induced brain injury. However, it is unclear how T. gondii manipulates the gene expression of central nervous system (CNS) cells through modulation of miRNA expression in vivo during acute and chronic infection. Therefore, high-throughput sequencing was used to investigate expression profiles of brain miRNAs at 10, 25, and 50 days post-infection (DPI) in pigs infected with the Chinese I genotype T. gondii strain in this study. Compared with the control group 87, 68, and 135 differentially expressed miRNAs (DEMs) were identified in the infected porcine brains at 10, 25, and 50 DPI, respectively. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis showed that a large number significantly enriched GO terms and KEGG pathways were found, and were mostly associated with stimulus or immune response, signal transduction, cell death or apoptosis, metabolic processes, immune system or diseases, and cancers. miRNA–gene network analysis revealed that the crucial connecting nodes, including DEMs and their target genes, might have key roles in the interactions between porcine brain and T. gondii. These results suggest that the regulatory strategies of T. gondii are involved in the modulation of a variety of host cell signaling pathways and cellular processes, containing unfolded protein response (UPR), oxidative stress (OS), autophagy, apoptosis, tumorigenesis, and inflammatory responses, by interfering with the global miRNA expression profile of CNS cells, allowing parasites to persist in the host CNS cells and contribute to pathological damage of porcine brain. To our knowledge, this is the first report on miRNA expression profile in porcine brains during acute and chronic T. gondii infection in vivo. Our results provide new insights into the mechanisms underlying T. gondii-induced brain injury during different infection stages and novel targets for developing therapeutic agents against T. gondii.

Abstract Background Toxoplasma gondii is an obligate intracellular parasite that infects humans and other warm-blooded animals. Previous quantitative proteomic analyses of infected host cells revealed that the expression of many host proteins is modulated by T. gondii infection. However, at present limited data are available on the differentially expressed miRNAs (DEMs) associated with the pathology and host immune responses induced by acute and chronic infection with T. gondii in pigs in vivo. In this study, high-throughput sequencing was used to investigate expression profiles of spleen miRNAs at 10, 25 and 50 days post-infection (DPI) in pigs infected with Chinese I genotype strain T. gondii isolated from a dead pig. Results When compared to the control group, 34, 6 and 86 DEMs were found in spleens of infected pigs at 10, 25 and 50 DPI, respectively. Gene Ontology (GO) enrichment analysis of the target genes of DEMs showed that no GO terms were enriched at 25 DPI, whereas 28 and 241 GO terms, of which two and 215 were sample-specific, were significantly enriched at 10 and 50 DPI, respectively. The top 20 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways of the target genes of DEMs included signal transduction, immune system, metabolism and diseases. miRNA–gene network analysis revealed that the DEMs played important roles in the host immune response to T. gondii infection by modulating expression levels of cellular immunity-related cytokines and immune-related C-type lectins. Conclusion Our results not only showed that host miRNA expression is altered by T. gondii but also revealed differences in the regulation of key biological processes and pathways involved in host responses to acute versus chronic T. gondii infection. This will aid future research into miRNA-target interactions during T. gondii infection in pigs and the development of novel therapies against T. gondii.

Abstract Background Eimeria is a common genus of apicomplexan parasites that infect diverse vertebrates, most notably poultry, causing serious disease and economic losses. Eimeria species have complex life-cycles consisting of three developmental stages. However, the molecular basis of the Eimeria reproductive mode switch remains an enigma. Methods Total RNA extracted from second- (MZ-2) and third-generation merozoites (MZ-3) of Eimeria necatrix was subjected to transcriptome analysis using RNA sequencing (RNA-seq) followed by qRT-PCR validation. Results A total of 6977 and 6901 unigenes were obtained from MZ-2 and MZ-3, respectively. Approximately 2053 genes were differentially expressed genes (DEGs) between MZ-2 and MZ-3. Compared with MZ-2, 837 genes were upregulated and 1216 genes were downregulated in MZ-3. Approximately 95 genes in MZ-2 and 48 genes in MZ-3 were further identified to have stage-specific expression. Gene ontology category and KEGG analysis suggested that 216 upregulated genes in MZ-2 were annotated by 70 GO assignments, 242 upregulated genes were associated with 188 signal pathways, while 321 upregulated genes in MZ-3 were annotated by 56 GO assignments, 322 upregulated genes were associated with 168 signal pathways. The molecular functions of upregulated genes in MZ-2 were mainly enriched for protein degradation and amino acid metabolism. The molecular functions of upregulated genes in MZ-3 were mainly enriched for transcriptional activity, cell proliferation and cell differentiation. Conclusions To the best of our knowledge, this is the first RNA-seq data study of the MZ-2 and MZ-3 stages of E. necatrix; it demonstrates a high number of differentially expressed genes between the MZ-2 and MZ-3 of E. necatrix. This study forms a basis for deciphering the molecular mechanisms underlying the shift from the second to third generation schizogony in Eimeria. It also provides valuable resources for future studies on Eimeria, and provides insight into the understanding of reproductive mode plasticity in different Eimeria species.

Toxoplasma gondii is an obligate intracellular parasite with worldwide distribution. Virulence of T. gondii is a multigenic trait. Genetic and virulence data for T. gondii isolates from humans and animals in China have been reported. However, almost all biological materials used for genotyping of T. gondii from humans and pigs were DNA samples prepared from tissues, and T. gondii strains used for virulence analysis were isolated mainly from cats. In this study, one isolate from a dead human fetus was identified as type I (ToxoDB #10) while the two isolates from dead pigs were type Chinese I (ToxoDB #9) with PCR-restriction fragment length polymorphism using 10 markers (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico). Three isolates were comfirmed as virulent strains in mice. By cloning and sequences analysis, all isolates contained a Pvu II restriction site (572-577 bp) in the KHB fragment and five tandem repeats in the 5' UTR region of SAG1, which were associated with T. gondii virulence. The type Chinese I isolates contained two deletions of 15 and 3 bp at positions 635 to 649 and 658 to 660 in the GRA6, which were correlated with genotype, but not with virulence. To our knowledge, this is the first report on the systematic analysis of murine virulence of type Chinese I strain from pigs, and the associations of sequences of the KHB fragment and SAG1 with virulence of type Chinese I strain. The Chinese I genotype was more closely related to type II strains. [ABSTRACT FROM AUTHOR]