Population structure of Vietnamese pigs using mitochondrial DNA.

The D-loop region on mitochondrial DNA (mtDNA) is frequently used for analyses of maternal lineages within domestic animal species. There are many native pig breeds in Vietnam, but their origins remain unclear. This study investigated maternal lineages using the D-loop region on mtDNA of 260 samples collected from native pigs in 20 provinces across Vietnam. The D-loop region of all samples was amplified and sequenced. We obtained 713 bp sequences of the D-loop region for each sample excluding the repeat region, and variants on this region were used to construct a phylogenetic tree. We detected 50 haplotypes from Vietnamese native pigs, with 27 novel haplotypes. Phylogenetic tree analysis showed two haplotype groups: one for the MTSEA group, frequently found in domestic pigs in the mountainous areas of Cambodia and Laos; and the D2 group, found in pigs originating from Chinese pigs. No European haplotype was found. Haplotypes in northeast Vietnam comprised only haplotypes of the D2 group, whereas in areas from the northwest mountains to the south, we found haplotypes belonging to both the D2 and MTSEA groups. This study suggested that both origins contributed to maternal lineages of current populations of Vietnamese native pigs.

How public health insurance expansion affects healthcare utilizations in middle and low-income households: an observational study from national cross-section surveys in Vietnam.

Public health insurance (PHI) has been implemented with different levels of participation in many countries, from voluntary to mandatory. In Vietnam, a law amendment made PHI compulsory nationwide in 2015 with a tolerance phase allowing people a flexible time to enroll. This study aims to examine mechanisms under which the amendment affected the enrollment, healthcare utilization, and out-of-pocket (OOP) expenditures by middle- and low-income households in this transitioning process.Using the biennial Vietnam Household Living Standard Surveys, the study applied the doubly robust difference-in-differences approach to compare outcomes in the post-amendment period from the 2016 survey with those in the pre-amendment period from the 2014 survey. The approach inheriting advantages from its predecessors, i.e., the difference-in-differences and the augmented inverse-probability weighting methods, can mitigate possible biases in policy evaluations due to the changes within the group and between groups over time in the cross-section observational study.The results showed health insurance expansion with extensive subsidies in premiums and medical coverage for persons other than the full-time employed, young children or elderly members in the family, significantly increased enrollments in the middle- and low-income groups by 9% and 8%, respectively. The number of visits for PHI-eligible services also increased, approximately 0.5 more visit per person in the middle-income and 1 more visit per person in the low-income. The amendment, however, so far did not show any significant effect on reducing OOP payments, neither for the low nor the middle-income groups. To further expand PHI coverage and financial protections, policymakers should focus on improving public health facilities, contracting PHI to more accredited private health providers, and motivating the high-income group's enrollments.

Anodic Reactivity of Alkyl S-Glucosides.

A voltammetric study of a series of alkyl and aryl S-glucosides unveiled the reactivity patterns of alkyl S-glucosides toward anodic oxidation and found noteworthy differences with the trends followed by aryl derivatives. The oxidation potential of alkyl S-glucosides, estimated herein from square-wave voltammetry peak potentials (Ep), depends on the steric properties of the aglycone. Glucosides substituted with bulky groups exhibit Ep values at voltages more positive than the values of those carrying small aglycones. This relationship, observed in all analyzed alkyl series, is evidenced by good linear correlations between Ep and Taft's steric parameters (ES) of the respective alkyl substituents. Moreover, the role of the aglycone's steric properties as a primary reactivity modulator is backed by poor correlations between Ep and the radical stabilization energies (RSEs) of the aglycone-derived thiyl radicals (RS•). In contrast, aryl glucosides' Ep values exhibit excellent correlations with the aryl substituents' Hammett parameters (σ+) and the ArS• RSEs, evidencing the inherent stability of the reactive radical intermediate as the primary factor controlling aryl glucoside's electrochemical reactivity. The reactivity differences between alkyl and aryl S-glucosides also extend to the protective group's effect on Ep. Alkyl S-glucosides' reactivity proved to be more sensitive to protective group exchange.

Automated Radiographic Evaluation of Adenoid Hypertrophy Based on VGG-Lite.

Adenoid hypertrophy is a pathological hyperplasia of the adenoids, which may cause snoring and apnea, as well as impede breathing during sleep. The lateral cephalogram is commonly used by dentists to screen for adenoid hypertrophy, but it is tedious and time-consuming to measure the ratio of adenoid width to nasopharyngeal width for adenoid assessment. The purpose of this study was to develop a screening tool to automatically evaluate adenoid hypertrophy from lateral cephalograms using deep learning. We proposed the deep learning model VGG-Lite, using the largest data set (1,023 X-ray images) yet described to support the automatic detection of adenoid hypertrophy. We demonstrated that our model was able to automatically evaluate adenoid hypertrophy with a sensitivity of 0.898, a specificity of 0.882, positive predictive value of 0.880, negative predictive value of 0.900, and F1 score of 0.889. The comparison of model-only and expert-only detection performance showed that the fully automatic method (0.07 min) was about 522 times faster than the human expert (36.6 min). Comparison of human experts with or without deep learning assistance showed that model-assisted human experts spent an average of 23.3 min to evaluate adenoid hypertrophy using 100 radiographs, compared to an average of 36.6 min using an entirely manual procedure. We therefore concluded that deep learning could improve the accuracy, speed, and efficiency of evaluating adenoid hypertrophy from lateral cephalograms.

Evaluation of genetic richness among Vietnamese native pig breeds using microsatellite markers.

We have elucidated genetic relationships of Vietnamese native pigs (VNP) using preliminarily collected samples by a single-nucleotide polymorphism (SNP) array. In order to confirm our previous results and compare with the results of a previous study using microsatellite (MS) markers, we aimed to characterize genetic diversity and population structure in wider varieties (24 breeds from 21 Provinces) of VNP across the country using 20 polymorphic MS markers recommended by ISAG/FAO (International Society for Animal Genetics/Food and Agriculture Organization) for diversity study. In this study, we collected 1,136 DNA samples of the VNPs and three exotic breeds. Our results revealed that the average number of alleles and allelic richness across the loci in VNPs were 10.0 and 7.6, which were higher than those of exotic breeds. Genomic components among VNPs were subjected to the sampling locations. Interestingly, Co Binh Thuan showed remarkable genetic feature compared to the other VNPs, because the habitation of Co Binh Thuan was relatively far from the other breeds. The results of this study provided useful information for exploitation, conservation, and development trends of the VNP breeds. More recently, African swine fever caused significant damage to most of the VNP populations. Therefore, our findings will help a reconstruction scheme of the VNP genetic resources.

Identification of differential abundances of mRNA transcript in cumulus cells and CCND1 associated with yak oocyte developmental competence.

The development of an accurate and noninvasive preselection process for competent oocytes is essential to achieve a highly efficient in vitro production (IVP) of embryos. Cumulus cells (CCs) have important functions in oocyte growth, development, maturation, and fertilization. It, therefore, is important to know if the quality of oocytes can be ascertained by assessment of gene expression of the surrounding CCs or not. The aim of this study was to identify differentially expressed genes in yak CCs from oocytes with varying developmental competences as possible biomarkers for distinguishing oocyte competence. The isolated CCs were pooled into immature and mature groups in accordance with the maturation outcome of oocytes. A total of 9516 genes were differentially expressed in the two CC categories (P <  0.05). With a minimum change of 2.5-fold, 45 up-regulated and 79 down-regulated genes were observed in CCs belonging to the mature group compared with those in the immature group (P <  0.01). These genes were primarily enriched for the cell cycle, meiosis, cell signaling, metabolism, and apoptosis. The selected candidate genes (CCND1, BMP15, GDF9, H19, KLF4, GPC1, SYCP3, and CTSB) were validated using quantitative real-time polymerase chain reaction (RT-qPCR) and there were expression patterns similar to those detected with transcriptome analysis. The CCs from fertilized oocytes arrested at the 2-cell (2-cell group), or 8-cell (8-cell group) stages or that developed into blastocysts (the blastocyst group) had a 1.5-, 1.8-, and 2.3-fold increase, respectively, in mRNA relative abundance of CCND1 compared with CCs from unfertilized oocytes (P <  0.05). The results with the RT-qPCR analysis confirmed that the relative abundance of CCND1 mRNA in CCs was associated with oocyte developmental competence. In conclusion, RNA-Seq is useful in extracting transcriptomes and selecting markers associated with oocyte developmental competence. Furthermore, the expression of the CCND1 gene in yak CCs can be used to preselect oocytes for IVP efficiency.

Effect of diets with different energy and lipase levels on performance, digestibility and carcass trait in broilers.

OBJECTIVE: A 28-d trial was conducted to evaluate the effect of diets with different energy and lipase levels on performance, nutrient digestibility, serum profiles, gut health, and carcass quality in broilers. METHODS: A total of 720 one-day-old male Ross 308 broilers (45.4±0.5 g) were randomly assigned to one of the following four treatments: i) RET, reduced energy treatment (metabolizable energy = 2,950 and 3,100 kcal/kg for starter and finisher diet), ii) BDT, basal diet treatment (metabolizable energy = 3,050 and 3,200 kcal/kg for starter and finisher diet, iii) RET015, RET+0.15 g/kg lipase, and iv) RET03, RET+0.3 g/kg lipase. There were 10 replications (cages) per treatment with 18 birds per cage. RESULTS: During d 1 to 14, broilers fed BDT, RET015, and RET03 diets had higher (p<0.05) body weight gain than those fed RET diet. During d 1 to 14, 15 to 28 and the overall experiment, feed conversion ratio in RET03 treatment was lower (p<0.05) compared with RET treatment. On d 14, the apparent total tract digestibility (ATTD) of dry matter (DM), ether extract (EE), and gross energy in RET03 treatment was higher (p<0.05) than those in RET treatment, while the ATTD of N was increased (p<0.05) by RET03 treatment. On d 28, broilers fed RET03 diet had higher (p<0.05) ATTD of DM than those fed RET and RET015 diets, while the ATTD of EE in BDT and RET03 treatments was increased (p<0.05) compared with RET and RET015 treatments. Broilers fed RET03 diet had higher villus height (VH) and VH:crypt depth (CD) ratio than those fed RET and BDT diets. The activity of pancreatic lipase in BDT and RET03 treatments was higher (p<0.05) than that in RET treatment. CONCLUSION: Taken together, lipase supplementation (3,000 U/kg feed) increased growth performance, nutrient digestibility, VH, VH:CD ratio and lipase activity, but decreased triglyceride, low-density lipoprotein cholesterol and the abdominal fat percentage in broilers fed reduced energy diet.

Comparative analysis of ovarian transcriptomes between prolific and non-prolific goat breeds via high-throughput sequencing.

To increase the current understanding of the gene expression in the pre-ovulatory ovary and identify the key genes involved in the regulation of ovulation rate, we compared the transcriptomes of ovaries from the prolific Jintang black goat (JTG) and the non-prolific Tibetan goat (TBG) during the follicular phase using the Illumina RNA-Seq method. Three ovarian libraries were constructed for each breed. On average, we obtained approximately 49.2 and 45.9 million reads for each individual ovary of TBGs and JTGs, respectively, of which 79.76% and 78.67% reads were covered in the genome database. A total of 407 differentially expressed genes (DEG) were detected between these two breeds, in which 316 were upregulated, and 91 were downregulated in the ovaries of JTGs versus TBGs. Based on the results of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment, some of these DEGs potentially play an important role in controlling the development of ovarian follicles. SRD5A2, MSMB, STAR and 3BHSD, etc. were the most significantly differentially expressed between these two distinct breeds. In addition, each ovary expressed 1,066 versus 989 novel transcripts, and 171,829 versus 140,529 putative SNPs in TBGs versus JTBs, respectively. All data sets (GEO and dbSNP) were available via public repositories. Our study provides insight into the transcriptional regulation of the ovaries of two distinct breeds of goats that might serve as a key resource for understanding goat fecundity. SRD5A2, MSMB, STAR and 3BHSD may be associated with the high fecundity of JTGs.

Molecular characterization, expression, and functional analysis of chicken TRAF6.

Tumor necrosis factor receptor-associated factor 6 (TRAF6) is a crucial adaptor molecule of the interleukin-1 receptor/Toll-like receptor (IL-1/TLR) superfamily, which can trigger downstream signaling cascades involved in innate immunity. The function of TRAF6 has been clarified in mammals but is poorly understood in chicken. In our study, we investigated TRAF6 function in birds, particularly in chicken innate immune responses, by cloning and characterizing chicken TRAF6 (chTRAF6). The full-length coding sequence of chTRAF6 comprised 1638 bp and encoded a 545-amino acid protein, which shares high sequence similarity with TRAF6 of other species and consists of four structurally conserved domains. Quantitative real-time polymerase chain reaction revealed that chTRAF6 was widely expressed in all tested tissues and its expression was induced in chicken embryo fibroblast cells treated with poly(I:C) and poly(dA:dT). Increased expression of chTRAF6 was observed both in vitro and in vivo following infection with Newcastle disease virus in chickens. Taken together, these results suggest that chTRAF6 plays a vital role in host defense against viral infection in chicken.

Analysis of the cytochrome c oxidase subunit II (COX2) gene in giant panda, Ailuropoda melanoleuca.

The giant panda, Ailuropoda melanoleuca (Ursidae), has a unique bamboo-based diet; however, this low-energy intake has been sufficient to maintain the metabolic processes of this species since the fourth ice age. As mitochondria are the main sites for energy metabolism in animals, the protein-coding genes involved in mitochondrial respiratory chains, particularly cytochrome c oxidase subunit II (COX2), which is the rate-limiting enzyme in electron transfer, could play an important role in giant panda metabolism. Therefore, the present study aimed to isolate, sequence, and analyze the COX2 DNA from individuals kept at the Giant Panda Protection and Research Center, China, and compare these sequences with those of the other Ursidae family members. Multiple sequence alignment showed that the COX2 gene had three point mutations that defined three haplotypes, with 60% of the sequences corresponding to haplotype I. The neutrality tests revealed that the COX2 gene was conserved throughout evolution, and the maximum likelihood phylogenetic analysis, using homologous sequences from other Ursidae species, showed clustering of the COX2 sequences of giant pandas, suggesting that this gene evolved differently in them.

Identification of candidate miRNAs and expression profile of yak oocytes before and after in vitro maturation by high-throughput sequencing.

Small RNA represents several unique non-coding RNA classes that have important function in a wide range of biological processes including development of germ cells and early embryonic, cell differentiation, cell proliferation and apoptosis in diverse organisms. However, little is known about their expression profiles and effects in yak oocytes maturation and early development. To investigate the function of small RNAs in the maturation process of yak oocyte and early development, two small RNA libraries of oocytes were constructed from germinal vesicle stage (GV) and maturation in vitro to metaphase II-arrested stage (M II) and then sequenced using small RNA high-throughput sequencing technology. A total of 9,742,592 and 12,168,523 clean reads were obtained from GV and M II oocytes, respectively. In total, 801 and 1,018 known miRNAs were acquired from GV and M II oocytes, and 75 miRNAs were found to be significantly differentially expressed: 47 miRNAs were upregulated and 28 miRNAs were downregulated in the M II oocytes compared to the GV stage. Among the upregulated miRNAs, miR-342 has the largest fold change (9.25-fold). Six highly expressed miRNAs (let-7i, miR-10b, miR-10c, miR-143, miR-146b and miR-148) were validated by real-time quantitative PCR (RT-qPCR) and consistent with the sequencing results. Furthermore, the expression patterns of two miRNAs and their potential targets were analysed in different developmental stages of oocytes and early embryos. This study provides the first miRNA profile in the mature process of yak oocyte. Seventy-five miRNAs are expressed differentially in GV and M II oocytes as well as among different development stages of early embryos, suggesting miRNAs involved in regulating oocyte maturation and early development of yak. These results showed specific miRNAs in yak oocytes had dynamic changes during meiosis. Further functional and mechanistic studies on the miRNAs during meiosis may beneficial to understanding the role of miRNAs on meiotic division.

Molecular characterization and expression analysis of the NLR family CARD containing five transcripts in the pig.

The NOD-like receptor (NLR) family caspase recruitment domain-containing 5 (NLRC5) is one of the newly discovered and largest NLR family members. The NLRC5 has recently received extensive attention because of its important role in regulating innate and adaptive immune responses. The NLRC5 in many vertebrates, such as humans, mice, cattle, and horses, has already been proven and studied. However, the NLRC5 gene characteristics of pigs remain unclear. Thus, we completely cloned the NLRC5 cDNA sequence of the pig using the rapid amplification of cDNA ends(RACE) technology. A characteristic and tissue expression analysis was also conducted on the pig sequence. The sequence analysis showed that the complete cDNA sequence of the NLRC5 of the pig is 6638 bp, and the open reading frame is 5538 bp which encoded 1846 amino acids. The protein prediction analysis indicates that the overall performance of the NLRC5 protein of the pig is hydrophilic and possesses a typical nucleotide binding and oligomerization domain(NBD) and 20 leucine-rich repeats(LRRs). The homology analysis result indicates that the NLRC5 transcript in pigs is highly homologous to cattle, sheep, macaques, and humans, and accounts for around 80%. The genetic evolutionary tree analysis shows that the NLRC5 transcript in pigs has the closest evolutionary relationship with cattle and sheep. Further tissue expression analysis shows that immune organ systems (e.g., lymph node and spleen) and mucosa organs (e.g., intestinal lymph node, stomach, and lungs) possess high expressions with NLRC5 mRNA. The result of this study indicates that the NLRC5 transcript in pigs is relatively conservative among mammals and may play a vital role in immune reaction, which provides a basis for further studies on the NLRC5 function in the pig immune system and the role in comparative immunity.

Verification of specific selection SNPs between broiler and layer chicken in Chinese indigenous chicken breeds.

The direction of production for indigenous chicken breeds is currently unknown and this knowledge, combined with the development of chicken genome-wide association studies, led us to investigate differences in specific loci between broiler and layer chicken using bioinformatic methods. In addition, we analyzed the distribution of these seven identified loci in four Chinese indigenous chicken breeds, Caoke chicken, Jiuyuan chicken, Sichuan mountain chicken, and Tibetan chicken, using DNA direct sequencing methods, and analyzed the data using bioinformatic methods. Based on the results, we suggest that Caoke chicken could be developed for meat production, while Jiuyuan chicken could be developed for egg production. As Sichuan mountain chicken and Tibetan chicken exhibited large polymorphisms, these breeds could be improved by changing their living environment.

Pre-B-cell colony-enhancing factor is markedly elevated in childhood hemophagocytic lymphohistiocytosis.

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening syndrome involving a final common pathway of hypercytokinemia, in which tumor necrosis factor (TNF)-α, interferon (IFN)-γ, and soluble interleukin 2-receptor-alpha (sIL-2Rα) are the key cytokines. Pre-B-cell colony-enhancing factor (PBEF) is an inflammatory cytokine involved in several inflammatory diseases. However, its role in HLH is unknown. In this study, we examined the role of PBEF in HLH. Plasma was collected from 22 children with HLH and 14 healthy children. The concentrations of plasma PBEF, TNF-α, IFN-γ, and sIL-2Rα were determined using an enzyme-linked immunosorbent assay. All clinical data were derived from medical records. In the acute phase, children with HLH had much higher PBEF, TNF-α, IFN-γ, and sIL- 2Rα levels than did healthy children (P < 0.05). After treatment, 13 HLH children improved and PBEF, TNF-α, and IFN-γ levels decreased to normal levels (P < 0.05); sIL-2Rα levels also decreased (P < 0.05), but remained above the normal level (P < 0.05). Two patients were lost to follow-up, while 7 patients showed a bad response to therapy and eventually died, showing high PBEF levels above those of the survivors (P < 0.01). PBEF level was significantly positively correlated with TNF-α, IFN-γ, sIL-2Rα, serum ferritin, and triglycerides (all P < 0.05), and was negatively correlated with fibrin (P < 0.05). PBEF appears to be involved in the inflammatory process of HLH, and elevated PBEF is related to disease activity. We are currently evaluating the role of PBEF as a marker for the diagnosis and management of patients.

Identification and association of single-nucleotide polymorphisms in gonadotropin-inhibitory hormone (GnIH) gene with egg production traits in Erlang mountainous chickens.

Gonadotropin-inhibitory hormone (GnIH) gene is an important gene in reproduction. In this study, we screened single-nucleotide polymorphisms (SNPs) in the chicken GnIH gene among 204 individuals in Erlang mountainous chickens. We then analyzed the associations between polymorphisms of the GnIH gene and 5 egg production traits in chickens. Five SNPs (T3305C, T3310C, G3403C, G3411A, and T3591C) were detected. Associations between polymorphic loci and age at first egg, body weight at first egg, weight at first egg, egg weight in 300 days, and egg production in 300 days were analyzed using analysis of covariance. The results showed that SNP1, SNP3, and SNP4 had large effects on age at first egg, while SNP5 had a large effect on body weight at first egg; of the effect of the TT genotype was significantly higher than that of CT (P < 0.01). Further analysis show that the highest frequency (0.2353) haplotype H1H1 was associated with the latest age at first egg. The H4H5 haplotype had a positive effect on egg production in 300 days and a negative effect on weight at first egg. We observed no association between the H3H3 haplotype and body weight at first egg.

Autophagy facilitates multidrug resistance development through inhibition of apoptosis in breast cancer cells.

UNLABELLED: Acquired multidrug resistance (MDR) is the main mechanism of chemotherapeutic drugs resistance. Nevertheless, the mechanisms of MDR are complex and still not very clear. Recently, including our previous study, several studies have revealed that macroautophagy (here referred to as autophagy) induced by anti-cancer drugs in breast cancer cells may facilitate the development of resistance to epirubicin (EPI), paclitaxel (PTX), tamoxifen or herceptin. Whereas there are a few studies on the relationship between autophagy and MDR, especially the studies designed directly employing induced resistant breast cancer cells. Based on previous study, we explored the relationship between autophagy and MDR. The results showed that induced EPI-resistant MCF-7er and SK-BR-3er cells were simultaneously resistant to PTX and vinorelbine (NVB), which demonstrated that the cells obtained MDR phenotype. Furthermore, PTX and NVB could also induce autophagy in MCF-7er and SK-BR-3er cells, and the induced autophagy protected the cells from apoptosis, which facilitated the development of resistance to PTX and NVB. Thus, autophagy promoted the development of MDR in breast cancer cells through inhibition of apoptosis. In addition, we found that P-glycoprotein (Pgp) was overexpressed in MCF-7er and SK-Br-3er cells. And we preliminarily investigated the relationship between autophagy and P-glycoprotein (Pgp). The results showed that the expression of the protein did not obviously change despite the inhibition of autophagy. Therefore, the role of Pgp in the development of MDR might be independent of autophahy. Also this finding implies that autophagy might be a target to overcome MDR in breast cancer cells, and clinical use autophagy inhibitors might be one of the important strategies for overcoming MDR in breast cancer therapy. KEYWORDS: Autophagy, apoptosis, multidrug resistance, breast cancer, chemotherapy.

Simultaneous labyrinthectomy with cochlear implantation in patients with bilateral Ménière's disease.

OBJECTIVE: The development of second-side Ménière's disease in the only remaining serviceable ear is difficult to treat. We describe an intervention to control disabling disease combining a labyrinthectomy and cochlear implant to restore hearing. METHODS: Following a thorough preoperative assessment and consenting process, 2 patients underwent labyrinthectomy of the affected ear with simultaneous cochlear implantation. RESULTS: Both patients achieved control of Ménière's attacks with improved hearing rehabilitation. Oscillopsia was noted by both patients. Both patients were pleased to have undergone the treatment. CONCLUSION: Severe symptomatic second-side Ménière's disease in the only hearing ear is uncommon. We report the successful treatment of 2 patients in this difficult management scenario, by simultaneous surgical labyrinthectomy and cochlear implantation. We propose this as a potential management strategy in this rare but complex group of patients in whom all less destructive measures have failed.

Serological investigations on West Nile virus in birds and horses in Shanghai, China.

West Nile virus (WNV) infection is an emerging zoonosis that threatens global public health. In this study, a total of 95 bird serum samples from 14 species and 341 horse serum samples were collected from 2008 to 2010 in Shanghai, China. All serum samples were screened initially for WNV-reactive antibodies using a competitive ELISA. The positive samples detected by ELISA were further confirmed using a plaque-reduction neutralization test (PRNT) for WNV and its most closely related flaviviruses in the area to avoid false positives due to cross-reactivity. Five (5·3%) of the bird serum samples and none (0·0%) of the horse serum samples tested positive for WNV antibodies. The findings strongly suggest that some of the birds, specifically the resident birds in China, had been exposed to WNV.

Segmentation expression of capsid protein as an antigen for the detection of avian nephritis virus infection in chicken flocks.

Subclinical pathological changes in the kidneys of broiler chickens and suppression of growth caused by the avian nephritis virus (ANV) affect poultry flocks worldwide. A test for detection of virus-specific antibodies in serum would be useful for epidemiological investigations, however the poor propagation in cell cultures has restricted the development of serological tests based on the use of ANV particles as antigens. An enzyme-linked immunosorbent assay (ELISA) was developed for detection of ANV-specific antibodies in chicken serum, using a recombinant protein antigen prepared by segmentation expression of the capsid protein antigen epitope of ANV (HM029238) transfected into Escherichia coli. The expressed fusion protein was detected by Western blotting with ANV-positive serum, and the optimal immunoreactive fusion P1 protein was determined. Using the optimized P1-ELISA, ANV-specific antibodies were detected in commercial chicken flocks aged 10-25 days obtained from the Liaoning Province, China. Out of 960 serum samples, 459 (47.8%) were positive for infection with ANV. These results indicate that the P1-ELISA is helpful for preliminary serological diagnosis of ANV infection, and could be used to for screening in ANV infection and for determining antibodies against ANV.