Enhancement of NiTiO3 piezocatalytic hydrogen evolution by doping with large radius elements.

Piezocatalysis is a direct method for converting mechanical vibration into chemical energy. Herein, NiTiO3 is used in the piezocatalytic hydrogen evolution field for the first time. The noncentral symmetry of NiTiO3 is enhanced by doping with large radius elements. It is demonstrated that when a metal element replaces the sites of nickel, it results in lattice distortion and a higher piezoelectric response. In particular, Cd-doped NiTiO3 exhibits the highest H2 generation rate (1.52 mmol g-1 h-1), which is 13 times that of original NiTiO3.

Genome-wide QTL and eQTL mapping reveal genes associated with growth rate trait of the Pacific white shrimp (Litopenaeus vannamei).

BACKGROUND: Growth rate is a crucial economic trait for farmed animals, but the genetic regulation of this trait is largely unknown in non-model organisms such as shrimp. RESULTS: In this study, we performed genome-wide phenotypic quantitative trait loci (QTL) and expression quantitative trait loci (eQTL) mapping analyses to identify genes affecting the growth rate of Pacific white shrimp (Litopenaeus vannamei), which is the most commercially-farmed crustacean worldwide. We used RNA-sequencing of 268 individuals in a mapping population, and subsequently validated our findings through gene silencing and shrimp growth experiments. We constructed a high-density genetic linkage map comprising 5533 markers spanning 44 linkage groups, with a total distance of 6205.75 cM and an average marker interval of 1.12 cM. Our analyses identified 11 QTLs significantly correlated with growth rate, and 117,525 eQTLs. By integrating QTL and eQTL data, we identified a gene (metalloreductase STEAP4) highly associated with shrimp growth rate. RNA interference (RNAi) analysis and growth experiments confirmed that STEAP4 was significantly correlated with growth rate in L. vannamei. CONCLUSIONS: Our results indicate that the comprehensive analysis of QTL and eQTL can effectively identify genes involved in complex animal traits. This is important for marker-assisted selection (MAS) of animals. Our work contributes to the development of shrimp breeding and available genetic resources.

The candidate proteins associated with keratoconus: A meta-analysis and bioinformatic analysis.

PURPOSE: Keratoconus (KC) is a multifactorial disorder. This study aimed to conduct a systematic meta-analysis to exclusively explore the candidate proteins associated with KC pathogenesis. METHODS: Relevant literature published in the last ten years in Pubmed, Web of Science, Cochrane, and Embase databases were searched. Protein expression data were presented as the standard mean difference (SMD) and 95% confidence intervals (CI). The meta-analysis is registered on PROSPERO, registration number CRD42022332442 and was conducted in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses statement (PRISMA). GO and KEGG enrichment analysis were performed, as well as the miRNAs and chemicals targeting the candidate proteins were predicted. PPI was analyzed to screen the hub proteins, and their expression was verified by RT-qPCR. RESULTS: A total of 21 studies were included in the meta-analysis, involving 346 normal eyes and 493 KC eyes. 18 deregulated proteins with significant SMD values were subjected to further analysis. In which, 7 proteins were up-regulated in KC compared with normal controls, including IL6 (SMD 1.54, 95%CI [0.85, 2.24]), IL1B (SMD 2.07, 95%CI [0.98, 3.16]), TNF (SMD 2.1, 95%CI [0.24, 3.96]), and MMP9 (SMD 1.96, 95%CI [0.68, 3.24]). While 11 proteins were down-regulated in KC including LOX (SMD 2.54, 95%CI [-4.51, -0.57]). GO and KEGG analysis showed that the deregulated proteins were involved in inflammation, extracellular matrix (ECM) remodeling, and apoptosis. MMP9, IL6, LOX, TNF, and IL1B were regarded as hub proteins according to the PPI analysis, and their transcription changes in stromal fibroblasts of KC were consistent with the results of the meta-analysis. Moreover, 10 miRNAs and two natural polyphenols interacting with hub proteins were identified. CONCLUSION: This study obtained 18 candidate proteins and demonstrated altered cytokine profiles, ECM remodeling, and apoptosis in KC patients through meta-analysis and bioinformatic analysis. It will provide biomarkers for further understanding of KC pathogenesis, and potential therapeutic targets for the drug treatment of KC.

Oxidative stress responses in two marine diatoms during sulfamethoxazole exposure and the toxicological evaluation using the IBRv2 index.

Sulfamethoxazole (SMX) is widely present in water systems, and its stable properties and poor biodegradability can result in high residues of SMX in the water environment. This, in turn, can have detrimental effects on the entire aquatic habitat and human life and health. This study aimed to investigate the toxic effects of SMX on the growth, photosynthetic pigment content, and oxidative stress of two marine microalgae species: Skeletonema costatum and Phaeodactylum tricornutum. SMX demonstrated a significant inhibitory effect on microalgae proliferation, with 96-h median effective concentration (EC50) values of 0.93 mg/L and 4.65 mg/L for S. costatum and P. tricornutum, respectively. At low concentrations, SMX significantly increased the production of Chl a in both microalgae species. However, in the higher concentration SMX treatment group, Chl a content in P. tricornutum experienced a significant decrease, whereas Chl c showed no sensitivity to SMX. The activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), along with the glutathione (GSH) content, exhibited a significant increasing trend in response to higher SMX concentrations. However, these changes effectively inhibited the accumulation of malondialdehyde (MDA) content. In the treatment group with the highest SMX concentration, MDA content in both microalgae species was significantly higher compared to the control group. The Integrated Biomarker Response Version 2 (IBRv2) index showed a significant positive correlation with SMX concentration, suggesting its potential for assessing the ecotoxicological effects of lower SMX concentrations on marine microalgae.

Efficacy of Diosmin in Reducing Lower-Extremity Swelling and Pain After Total Knee Arthroplasty: A Randomized, Controlled Multicenter Trial.

BACKGROUND: Many patients experience lower-extremity swelling following total knee arthroplasty (TKA), which impedes recovery. Diosmin is a semisynthetic flavonoid that is often utilized to treat swelling and pain caused by chronic venous insufficiency. We aimed to evaluate the efficacy and safety of diosmin in reducing lower-extremity swelling and pain as well as in improving functional outcomes following TKA. METHODS: This study was designed as a randomized, controlled multicenter trial and conducted in 13 university-affiliated tertiary hospitals. A total of 330 patients undergoing TKA were randomized to either receive or not receive diosmin postoperatively. The diosmin group received 0.9 g of diosmin twice per day for 14 consecutive days starting on the day after surgery, whereas the control group received neither diosmin nor a placebo postoperatively. The primary outcome was lower-extremity swelling 1, 2, 3, and 14 days postoperatively. The secondary outcomes were postoperative pain assessed with use of a visual analogue scale, Hospital for Special Surgery score, range of knee motion, levels of the inflammatory biomarkers C-reactive protein and interleukin-6, and complications. RESULTS: At all postoperative time points, diosmin was associated with significantly less swelling of the calf, thigh, and upper pole of the patella as well as with significantly lower pain scores during motion. However, no significant differences in postoperative pain scores at rest, Hospital for Special Surgery scores, range of motion, levels of inflammatory biomarkers, or complication rates were found between the diosmin and control groups. CONCLUSIONS: The use of diosmin after TKA reduced lower-extremity swelling and pain during motion and was not associated with an increased incidence of short-term complications involving the outcomes studied. However, further studies are needed to continue exploring the efficacy and safety of diosmin use in TKA. LEVEL OF EVIDENCE: Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.

The male and female genomes of golden pompano (Trachinotus ovatus) provide insights into the sex chromosome evolution and rapid growth.

INTRODUCTION: Golden pompano (Trachinotus ovatus) is economically significant important for offshore cage aquaculture in China and Southeast Asian countries. Lack of high-quality genomic data and accurate gene annotations greatly restricts its genetic breeding progress. OBJECTIVES: To decode the mechanisms of sex determination and rapid growth in golden pompano and facilitate the sex- and growth-aimed genetic breeding. METHODS: Genome assemblies of male and female golden pompano were generated using Illumina, PacBio, BioNano, genetic maps and Hi-C sequencing data. Genomic comparisons, whole genome re-sequencing of 202 F1 individuals, QTL mapping and gonadal transcriptomes were used to analyze the sex determining region, sex chromosome evolution, SNP loci, and growth candidate genes. Zebrafish model was used to investigate the functions of growth candidate gene. RESULTS: Female (644.45 Mb) and male (652.12 Mb) genomes of golden pompano were assembled and annotated at the chromosome level. Both genomes are highly conserved and no new or highly differentiated sex chromosomes occur. A 3.5 Mb sex determining region on LG15 was identified, where Hsd17b1, Micall2 and Lmx1a were putative candidates for sex determination. Three SNP loci significantly linked to growth were pinpointed, and a growth-linked gene gpsstr1 was identified by locus BSNP1369 (G â†’ C, 17489695, Chr23). Loss of sstr1a (homologue of gpsstr1) in zebrafish caused growth retardation. CONCLUSION: This study provides insights into sex chromosome evolution, sex determination and rapid growth of golden pompano.

Boosting photocatalytic conversion of formic acid to CO over P-doped CdS.

In this work, NaH2PO2, Na2S2O3 and CdCl2 were used to synthesize P-doped CdS samples for the photocatalytic decomposition of formic acid to CO reaction. The CO production rates and selectivity of P-doped CdS are as high as 24.5 mmol g-1 h-1 and 92.4%, in which the rate is 7 times higher than that of the pure CdS. Multiple characterizations show that the P-doping increases the specific surface area, widens the band gap and shifts the energy band position of CdS, resulting in enhanced photocatalytic activity.

[Rac1 promotes the formation of heterotypic cell-in-cell structure].

Heterotypic cell-in-cell structures (heCICs) are closely related to tumor development and progression, and have become a new frontier in life science research. Ras-related C3 botulinum toxin substrate 1 (Rac1) belongs to the classic Rho GTPase, which plays a key role in regulating the cytoskeleton and cell movement. To investigate the role and mechanism of Rac1 in the formation of heCICs, tumor cells and immune killer cells were labeled with cell-tracker, respectively, to establish the heCICs model. Upon treatment with the Rac1 inhibitor NSC23766, the formation of heCICs between tumor and immune cells was significantly reduced. The plasmid pQCXIP-Rac1-EGFP constructed by gene cloning was packaged into pseudoviruses that subsequently infect tumor cells to make cell lines stably expressing Rac1. As a result, the formation of heCICs was significantly increased upon Rac1 overexpression. These results demonstrated a promotive role of Rac1 in heCICs formation, which may facilitate treating cell-in-cell related diseases, such as tumors, by targeting Rac1.

Effects of o-cresol on the growth and biochemical compositions in marine microalgae.

To assess the toxic effects of o-cresol on marine organisms, Skeletonema costatum and Phaeodactylum tricornutum were chosen as test subjects to investigate its impact on growth and biochemical compositions. The results indicated that the 96-h EC50 values for o-cresol in S. costatum and P. tricornutum were 7.99 mg/L and 13.28 mg/L, respectively, demonstrating a moderate and slight toxicity level. Conversely, the maximum no-effect concentration (NOEC) for o-cresol in S. costatum and P. tricornutum were 2.43 mg/L and 0.43 mg/L, respectively, classifying their chronic toxicity grades as negligible and low toxic. Following a 96-h exposure period, the content of photosynthetic pigments in S. costatum did not significantly differ from the control group (P > 0.05). Conversely, the levels of total protein, total lipid, and carbohydrate in microalgae were significantly induced (P < 0.05) as the concentration of o-cresol increased. Higher concentrations of o-cresol generally stimulated the synthesis of biochemical compositions in algae cells, which serves as an active defense mechanism in response to pollution stress. To comprehensively evaluate the potential risk of o-cresol to marine ecosystems, it is crucial to strengthen its toxicity studies on marine fish and crustaceans in the future.

Photoluminescence Anisotropy in Eutectic Crystals of Polynuclear Lanthanide Complexes and Silver Clusters.

Anisotropy is an intrinsic property of crystalline materials. However, the photoluminescence anisotropy in eutectic crystals of organometallic complexes has remained unexplored. Herein, the eutectic of polynuclear lanthanide complexes and Ag clusters was prepared, and the crystal shows significant photoluminescence anisotropy. The polarization anisotropy of emission δ and degree of excitation polarization P are 2.62 and 0.53, respectively. The rare excitation polarization properties have been proved to be related to the regular arrangement of electric transition dipole moments of luminescent molecules in the crystal. Our design provides a reference for developing new photoluminescence anisotropy materials and expanding their applications.

Integrated Analysis of DNA Methylome and Transcriptome Reveals Epigenetic Regulation of Cold Tolerance in Litopenaeus vannamei.

DNA methylation is an important epigenetic modification that has been shown to be associated with responses to non-biological stressors. However, there is currently no research on DNA methylation in response to environmental signals in shrimp. In this study, we conducted a comprehensive comparative analysis of DNA methylation profiles and differentially expressed genes between two strains of Litopenaeus vannamei with significantly different cold tolerance through whole genome bisulfite sequencing (WGBS) and transcriptome sequencing. Between Lv-C and Lv-T (constant temperature of 28 °C and low temperatures of 18 °C and 10 °C) under cytosine-guanine (CG) environments, 39,100 differentially methylated regions (DMRs) were identified, corresponding to 9302 DMR-related genes (DMRGs). The DMRs were mainly located in the gene body (exons and introns). Gene Ontology (GO) analysis showed that these DMRGs were significantly enriched in cell parts, catalytic activity, and metabolic processes. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed significant enrichment of these DMRGs in pathways such as proteasome (ko03050), oxidative phosphorylation (ko00190), mTOR signaling pathway (ko04150), fatty acid metabolism (ko01212), and fatty acid degradation (ko00071). The comprehensive results suggested that L. vannamei mainly regulates gene expression in response to low temperatures through hypermethylation or demethylation of some genes involved in thermogenesis, glycolysis, the autophagy pathway, the peroxisome, and drug metabolism pathways. These results provide important clues for studying DNA methylation patterns and identifying cold tolerance genes in shrimp.

Changes in expression levels of Nod-like receptors in the spleen of ewes.

Nucleotide-binding oligomerization domain receptors (NOD-like receptors, NLRs) have critical effects on interfaces of the immune and reproductive systems, and the spleen plays a key role in both innate and adaptive immune functions. It is hypothesized that NLR family participates in maternal splenic immune regulation during early pregnancy in sheep. In this study, maternal spleens were collected on day 16 of the estrous cycle, and days 13, 16 and 25 of gestation (n = 6 for each group) in ewes. Expression of NLR family, including NOD1, NOD2, class II transactivator (CIITA), NLR family apoptosis inhibitory protein (NAIP), nucleotide-binding oligomerization domain, Leucine rich repeat and Pyrin domain containing 1 (NLRP1), NLRP3 and NLRP7, was analyzed using quantitative real-time PCR, Western blot and immunohistochemistry analysis. The results revealed that expression levels of NOD1, NOD2, CIITA and NLRP3 were downregulated at days 13 and 16 of pregnancy, but expression of NLRP3 was increased at day 25 of pregnancy. In addition, expression values of NAIP and NLRP7 mRNA and proteins were improved at days 16 and 25 of pregnancy, and NLRP1 was peaked at days 13 and 16 of pregnancy in the maternal spleen. Furthermore, NOD2 and NLRP7 proteins were limited to the capsule, trabeculae and splenic cords. In summary, early pregnancy changes expression of NLR family in the maternal spleen, which may be related with the maternal splenic immunomodulation during early pregnancy in sheep.

Intelligent Colorimetric Indicators for Quality Monitoring and Multilevel Anticounterfeiting with Kinetics-Tunable Fluorescence.

The spoilage and forgery of perishable products such as food, drugs, and vaccines cause serious health hazards and economic loss every year. Developing highly efficient and convenient time-temperature indicators (TTIs) to realize quality monitoring and anticounterfeiting simultaneously is urgent but remains a challenge. To this end, a kind of colorimetric fluorescent TTI, based on CsPbBr3@SiO2 nanoparticles with tunable quenching kinetics, is developed. The kinetics rate of the CsPbBr3-based TTIs is easily regulated by adjusting temperature, concentration of the nanoparticles, and addition of salts, stemming from the cation exchange effect, common-ion effect, and structural damage by water. Typically, when combined with europium complexes, the developed TTIs show an irreversible dynamic change in fluorescent colors from green to red upon increasing temperature and time. Furthermore, a locking encryption system with multiple logics is also realized by combining TTIs with different kinetics. The correct information only appears at specific ranges of time and temperature under UV light and is irreversibly self-erased afterward. The simple and low-cost composition and the ingenious design of kinetics-tunable fluorescence in this work stimulate more insights and inspiration toward intelligent TTIs, especially for high-security anticounterfeiting and quality monitoring, which is really conducive to ensuring food and medicine safety.

De novo genome assembly and annotation of Holothuria scabra (Jaeger, 1833) from nanopore sequencing reads.

BACKGROUND: Holothuria scabra is a costly gourmet and traditional Chinese tonic medicine. However, the lack of high-quality genome information hinders the genetic, phylogenetic, and bioactivator researches. OBJECTIVE: To construct high-quality genomic data of H. scabra and conduct genome-wide phylogenetic analysis. METHODS: The whole genome of a male H. scabra was sequenced based on Nanopore MinION platform, and the sequence was assembled by wtdbg2. Transcriptome sequencing was used to aid the gene annotation. Repeat sequences, non-coding RNA, pseudogene and gene functional annotation were analyzed. 750 single-copy gene families from ten species were applied to construct phylogenetic tree for evolutionary analysis by using the ML method. RESULTS: The H. scabra genome of 1.18 Gb (N50 = 1557,492 bp) with 500.42 Mb of putative repetitive sequences was assembled from a male H. scabra individual, and 16,642 protein-coding genes, 951 pseudogenes, 1791 motifs and 45,400 domains from the generated assembly were identified. The divergence time between H. scabra and its ancestor was estimated approximately 192.6 million years ago. H. scabra and A. japonicas joined together while sea urchin and sea star diverged about 440 Mya ago. Some key genes involved in notochord and gill slits development, skeleton degeneration and nervous system, as well as homeobox genes differ between H. scabra and Apostichopus japonicas. CONCLUSION: We report the first whole genome of H. scabra with expectation that this will be a valuable resource for genetic, phylogenetic, breading, molecular biology and bioactivator studies of sea cucumbers and other invertebrates.

Two Short Repeats in the 5' Untranslated Region of Insulin-like Androgenic Gland Factor in Procambarus clarkii (PcIAG) That Regulate PcIAG Expression.

Insulin-like androgenic gland factor (IAG) plays an important role in sex manipulation in decapods. Understanding the molecular regulation mechanism of IAG in Procambarus clarkii (PcIAG) is important for realizing its sex control. In this study, the promoter and gene structure of PcIAG, mRNA, and miRNA expression profiles after interfering with two siRNAs synthesized according to the two short repeats in the 5' untranslated regions (5'UTR) of PcIAG were analyzed, and miRNAs of exosomes were investigated to explore the role of repeated sequences with tandem two short repeats located in the 5'UTR of PcIAG isolated from the androgenic gland (AG) in the regulation of IAG expression. The results showed that the repeated sequences of 5'UTR only occurred completely in the cDNA from AG, and the function of the two repeats was different in regulating the expression of PcIAG, in which the Wnt signaling pathway may be involved. Furthermore, we found that six miRNAs including miR-133, miR-193, miR-34, miR-1, miR-100, and let-7 might be involved in the regulation of the expression of PcIAG, wherein miR-133 might directly be related with the repeated sequences of 5'UTR.

Prussian Blue Type Cocatalysts for Enhancing the Photocatalytic Water Oxidation Performance of BiVO4.

The efficiency of photocatalytic overall water splitting reactions is usually limited by the high energy barrier and complex multiple electron-transfer processes of the oxygen evolution reaction (OER). Although bismuth vanadate (BiVO4 ) as the photocatalyst has been developed for enhancing the kinetics of the water oxidation reaction, it still suffers from challenges of fast recombination of photogenerated electron-hole pairs and poor photocatalytic activity. Herein, six MII -CoIII Prussian blue analogues (PBAs) (M=Mn, Fe, Co, Ni, Cu and Zn) cocatalysts are synthesized and deposited on the surface of BiVO4 for boosting the surface catalytic efficiency and enhancing photogenerated carries separation efficiency of BiVO4 . Six MII -CoIII PBAs@BiVO4 photocatalysts all demonstrate increased photocatalytic water oxidation performance compared to that of BiVO4 alone. Among them, the Co-Co PBA@BiVO4 photocatalyst is employed as a representative research object and is thoroughly characterized by electrochemistry, electronic microscope as well as multiple spectroscopic analyses. Notably, BiVO4 coupling with Co-Co PBA cocatalyst could capture more photons than that of pure BiVO4 , facilitating the transfer of photogenerated charge carriers between BiVO4 and Co-Co PBA as well as the surface catalytic efficiency of BiVO4 . Overall, this work would promote the synthesis strategy development for exploring new types of composite photocatalysts for water oxidation.

Efficient water splitting over a hybrid photocatalyst with (002) active facets and heterostructure.

A series of P-CdS@P-MWOx (M = Ni, Mn, Co, Zn, Fe, Cu) hybrid photocatalysts was constructed using different transition metal polyoxometalates [SiW11M(H2O)O39]n- as precursors via a pyrolysis-phosphidation strategy. Under visible light irradiation (λ = 420 nm), P-CdS@P-NiWOx shows a good H2 evolution rate of 418.4 µmol g-1 h-1 and an AQE of 29.9% at 420 nm without adding a sacrificial reagent, which is a nearly 140-fold enhancement over CdS. This study provides a feasible strategy for designing efficient photocatalysts with highly active facets and heterostructure.

Reclamation and Ecological Service Value Evaluation of Coastal Wetlands Using Multispectral Satellite Imagery.

There are special locational value and natural resources in coastal wetlands. Studying their changes and evaluating their ecosystem service value (ESV) is beneficial for protecting the ecology of coastal wetlands and for maintaining sustainable human development. In this paper, the coastal wetland of Jiaozhou Bay is selected as the research area, an object-oriented method is used to extract shoreline and wetland information, and the coastal wetland reclamation process in Jiaozhou Bay is evaluated. The value equivalent method and market value method are used to evaluate the service value of wetland ecosystems from the perspective of ecological economics. The results show that the reclamation area of Jiaozhou Bay reached 75.2 km2 in 40 years, with nearly 23% of the bay area eroding. Reclamation engineering, estuary engineering, policy implementation and urbanization are the main factors affecting the changes in the Jiaozhou Bay wetland, and the main direction of wetland succession is natural wetlands→artificial wetlands→nonwetlands. Wetland reclamation in Jiaozhou Bay has led to the continuous extension of the coastline to the sea, especially during the 2005-2020 period, and the wetland area has declined in area by 116 km2. The changes in the wetland in the past 40 years have affected the changes in the ESV of Jiaozhou Bay, and there have been different synergistic/trade-off relationships in different periods. This research provides data to support the comprehensive ecological management of coastal areas, which is conducive to maximizing the utilization value of wetlands and promoting wetland protection.

Complement regulation in ovine lymph nodes during early pregnancy.

A fetus changes immune responses in the uterus and the maternal immune system, and lymph nodes are associated with regulating maternal adaptive immunity. Complement activation is associated with abnormal pregnancy in mice and humans. The aim of the present study was to explore the expression levels of complement components in maternal lymph nodes during early pregnancy in sheep. Maternal inguinal lymph nodes were sampled on day 16 of the estrous cycle, and days 13, 16 and 25 of gestation in ewes. Reverse transcription-quantitative PCR, western blotting and immunohistochemical analyses were used to detect the expression levels of complement components C1q, C1r, C1s, C2, C3, C4a, C5b and C9 in the lymph nodes. The results revealed that the protein and mRNA levels of C1q, C1s and C5b were enhanced during early pregnancy, and that C1r and C4a were upregulated at day 25 of pregnancy. The mRNA and protein levels of C2 and C9 peaked at day 16 of pregnancy, but C3 was decreased at day 25 of pregnancy. C3 protein was located in the subcapsular sinuses and lymph sinuses of the maternal lymph node. In summary, the present study detected changes in the expression levels of complement components in maternal lymph nodes, which may be associated with maternal immune regulation during early pregnancy in sheep.

Effects of early pregnancy on the complement system in the ovine thymus.

The complement system is crucial for the innate immune system, and complement activation is related to abnormal pregnancy in mice and humans. It is hypothesized that the complement system participates in maternal thymic immune regulation during early pregnancy in sheep. In this study, maternal thymuses were sampled on day 16 of the estrous cycle, and days 13, 16 and 25 of gestation in sheep. Quantitative real-time PCR, Western blot and immunohistochemistry analyses were used to analyze the expression of the complement components C1q, C1r, C1s, C2, C3, C4a, C5b and C9 in the maternal thymus. The results revealed that the mRNA and protein expression of C1r, C1s, C2, C3 and C4a was inhibited by early pregnancy, and the pregnancy recognition signal induced upregulation of C1q, C5b and C9 expression at day 16 of gestation. Furthermore, C3 protein was mostly located in epithelial reticular cells and thymic corpuscles, which may be involved in immune regulation. In summary, early pregnancy inhibits the complement system in the maternal thymus, which may be essential for the maternal immune regulation and successful pregnancy in sheep.