Chromosome-level genome assembly of the Muscovy duck provides insight into fatty liver susceptibility.

The Muscovy duck (Cairina moschata) is an economically important poultry species, which is susceptible to fatty liver. Thus, the Muscovy duck may serve as an excellent candidate animal model of non-alcoholic fatty liver disease. However, the mechanisms underlying fatty liver development in this species are poorly understood. In this study, we report a chromosome-level genome assembly of the Muscovy duck, with a contig N50 of 11.8 Mb and scaffold N50 of 83.16 Mb. The susceptibility of Muscovy duck to fatty liver was mainly attributed to weak lipid catabolism capabilities (fatty acid ß-oxidation and lipolysis). Furthermore, conserved noncoding elements (CNEs) showing accelerated evolution contributed to fatty liver formation by down-regulating the expression of genes involved in hepatic lipid catabolism. We propose that the susceptibility of Muscovy duck to fatty liver is an evolutionary by-product. In conclusion, this study revealed the potential mechanisms underlying the susceptibility of Muscovy duck to fatty liver.

Genomic insights into local adaptation and phenotypic diversity of Wenchang chickens.

Wenchang chicken, a prized local breed in Hainan Province of China renowned for its exceptional adaptability to tropical environments and good meat quality, is deeply favored by the public. However, an insufficient understanding of its population architecture and the unclear genetic basis that governs its typical attributes have posed challenges in the protection and breeding of this precious breed. To address these gaps, we conducted whole-genome resequencing on 200 Wenchang chicken samples derived from 10 distinct strains, and we gathered data on an array of 21 phenotype traits. Population genomics analysis unveiled distinctive population structures in Wenchang chickens, primarily attributed to strong artificial selection for different feather colors. Selection sweep analysis identified a group of candidate genes, including PCDH9, DPF3, CDIN1, and SUGCT, closely linked to adaptations that enhance resilience in tropical island habitats. Genome-wide association studies (GWAS) highlighted potential candidate genes associated with diverse feather color traits, encompassing TYR, RAB38, TRPM1, GABARAPL2, CDH1, ZMIZ1, LYST, MC1R, and SASH1. Through the comprehensive analysis of high-quality genomic and phenotypic data across diverse Wenchang chicken resource groups, this study unveils the intricate genetic backgrounds and population structures of Wenchang chickens. Additionally, it identifies multiple candidate genes linked to environmental adaptation, feather color variations, and production traits. These insights not only provide genetic reference for the purification and breeding of Wenchang chickens but also broaden our understanding of the genetic basis of phenotypic diversity in chickens.

Plasma metabolites associated with physiological and biochemical indexes indicate the effect of caging stress on mallard ducks (Anas platyrhynchos).

OBJECTIVE: Cage rearing has critical implications for the laying duck industry because it is convenient for feeding and management. However, caging stress is a type of chronic stress that induces maladaptation. Environmental stress responses have been extensively studied, but no detailed information is available about the comprehensive changes in plasma metabolites at different stages of caging stress in ducks. We designed this experiment to analyze the effects of caging stress on performance parameters and oxidative stress indexes in ducks. METHODS: Liquid chromatography tandem mass spectrometry (LC/MS-MS) was used to determine the changes in metabolites in duck plasma at 5 (CR5), 10 (CR10), and 15 (CR15) days after cage rearing and traditional breeding (TB). The associated pathways of differentially altered metabolites were analyzed using Kyoto encyclopedia of genes and genomes (KEGG) database. RESULTS: The results of this study indicate that caging stress decreased performance parameters, and the plasma total superoxide dismutase levels were increased in the CR10 group compared with the other groups. In addition, 1,431 metabolites were detected. Compared with the TB group, 134, 381, and 190 differentially produced metabolites were identified in the CR5, CR10, and CR15 groups, respectively. The results of principal component analysis (PCA) show that the selected components sufficiently distinguish the TB group and CR10 group. KEGG analysis results revealed that the differentially altered metabolites in duck plasma from the CR5 and TB groups were mainly associated with ovarian steroidogenesis, biosynthesis of unsaturated fatty acids, and phenylalanine metabolism. CONCLUSION: In this study, the production performance, blood indexes, number of metabolites and PCA were compared to determine effect of the caging stress stage on ducks. We inferred from the experimental results that caging-stressed ducks were in the sensitive phase in the first 5 days after caging, caging for approximately 10 days was an important transition phase, and then the duck continually adapted.

Three chromosome-level duck genome assemblies provide insights into genomic variation during domestication.

Domestic ducks are raised for meat, eggs and feather down, and almost all varieties are descended from the Mallard (Anas platyrhynchos). Here, we report chromosome-level high-quality genome assemblies for meat and laying duck breeds, and the Mallard. Our new genomic databases contain annotations for thousands of new protein-coding genes and recover a major percentage of the presumed "missing genes" in birds. We obtain the entire genomic sequences for the C-type lectin (CTL) family members that regulate eggshell biomineralization. Our population and comparative genomics analyses provide more than 36 million sequence variants between duck populations. Furthermore, a mutant cell line allows confirmation of the predicted anti-adipogenic function of NR2F2 in the duck, and uncovered mutations specific to Pekin duck that potentially affect adipose deposition. Our study provides insights into avian evolution and the genetics of oviparity, and will be a rich resource for the future genetic improvement of commercial traits in the duck.

[Expression characteristics of prolactin gene in Eastern Zhejiang white geese].

This study was conducted to clone the prolactin gene (PRL) in Eastern Zhejiang White Geese and to investigate the PRL gene expression characteristics during egg-laying, out-of-lay and incubating periods by real time PCR. Comparisons were made respectively of concentration of prolactin mRNA in the hypothalamus, pituitary gland and ovary of the adult female geese at different reproductive periods. The result indicated that there were significant differences (P<0.05) in PRL mRNA expression between different reproductive periods of the geese. The lowest level of PRL expression was found in out-of-lay geese, higher in the egg-laying geese, and the highest in incubating geese. Furthermore, the analysis of PRL expression in different tissues indicated that the highest levels of PRL was expressed in the pituitary gland, followed in hypothalamus, and the least in ovary of the geese. There were significant difference (P<0.01) expression of PRL between the pituitary gland/hypothalamus and ovary of the geese, whereas no any difference was observed between the pituitary gland and hypothalamus (P>0.05). In summary, the PRL mRNA expression had variance in different reproductive periods of the geese.

Biomarkers and potential pathogenesis of colorectal cancer-related ischemic stroke.

AIM: To investigate the specific biomarkers and potential pathogenesis of colorectal cancer-related ischemic stroke (CRCIS). METHODS: A retrospective study was conducted on CRCIS patients (colorectal cancer patients with ischemic stroke without conventional stroke risk factors) registered at seven centers between January 2007 and December 2017. Clinical data and laboratory and imaging findings were compared with age- and sex- matched patients with colorectal cancer (CRC) without ischemic stroke that were admitted to the same hospital during the same period. Univariate and multivariate analyses were performed to analyze the independent risk factors for CRCIS. A receiver operator characteristic curve was configured to calculate the optimal cut-off value of the products of the independent risk factors for CRCIS. RESULTS: A total of 114 CRCIS patients and 114 CRC patients were included. Multiple lesions in multiple vascular territories were common in CRCIS patients (71, 62.28%). The levels of plasma D-dimer, carcinoembryonic antigen (CEA), cancer antigen 125, and neutrophil count were significantly higher in CRCIS patients than in CRC patients. Multiple logistic regression analysis revealed that plasma D-dimer levels [odds ratio (OR) = 1.002, 95% confidence interval (CI): 1.001-1.003, P < 0.001], CEA levels (OR = 1.011, 95%CI: 1.006-1.015, P < 0.001), and neutrophil count levels (OR = 1.626, 95%CI: 1.268-2.087, P < 0.001) were independent risk factors for CRCIS. In addition, receiver operator characteristic curve revealed that the area under curve for the products of plasma D-dimer, CEA, and neutrophil count was 0.889 ± 0.022 (95%CI: 0.847-0.932, P < 0.001), and the optimal cut-off value for the product was 252.06, which was called the CRCIS Index, with a sensitivity of 86.0% and specificity of 79.8%. CONCLUSION: Hypercoagulability induced by elevated CEA and neutrophils may be an important cause of CRCIS. The CRCIS index, which serves as a biomarker of CRCIS, needs further study.

Assignment of CCR7 gene to chicken chromosome 27 by radiation hybrid panel mapping.

The protein encoded by CC chemokine receptor 7 (CCR7) is a member of the G protein-coupled receptor family. This receptor was identified as a gene induced by the Epstein-Barr virus (EBV), and is thought to be a mediator of EBV effects on B lymphocytes. This receptor is expressed in various lymphoid tissues and activates B and T lymphocytes. It has been shown to control the migration of memory T cells to inflamed tissues, as well as stimulate dendritic cell maturation. To map the CCR7 gene in chicken chromosome, a 6 000 rads chicken-hamster radiation hybrid panel (ChickRH6) was used. PCR of samples from ChickRH6 revealed that the location of CCR7 gene is linked to the maker SEQ0347 (6 cR away) with LOD score of 16.6 and that the marker SEQ0347 is located on chromosome 27 at 27 cR of RH (radiation hydrid) map. We compared the corresponding human mRNA sequence with the predicted coding sequence of chicken CCR7 gene, and found that the assembled contig shared a high percentage of similarity with that of the human gene.

[Progresses in inheritance of genes for avian eggshell color].

Eggshell has three colors: white, blue and brown. Chicken and duck eggs with blue eggshell have superior market for its better appearance, delicious taste, abundant nutrition and higher eggshell thickness and strength compared to those with white eggshell. However, error was often made when breeding blue-eggshell chicken or duck lines based on phenotypes. Studies on the forming and controlling mechanism of eggshell color had important theoretic and practical value. This review mainly discussed the types of eggshell color, its pigment composition and synthesis. Inheritance and heritability, genetic model, the number of genes, and the dominant-recessive relationship between genes for eggshell color were also reviewed. Information described in this review is useful for understanding the forming mechanism of eggshell color.

[Advance in association studies of major histocompatibility complex (MHC) gene polymorphisms with traits of resistance against infectious disease in chickens].

Chicken is a main poultry in China. Molecular breeding for disease resistance plays an important role in the control of diseases, especially infectious diseases. Choice of genes for disease resistance is the key technology of molecular breeding. The MHC is of great interest to poultry breeding scientists for its extraordinary polymorphism and close relation with traits of resistance against infectious diseases. The article gives a detailed introduction about the association of MHC gene polymorphisms with traits of resistance against infectious diseases in chickens and looks towards the future of application of MHC in molecular breeding of chicken for disease resistance.

Early prevention and treatment of biliary tract complications after orthotopic liver transplantation.

OBJECTIVE: To investigate the prevention and treatment of biliary complications after orthotopic liver transplantation (OLT). METHODS: OLT was performed in 18 patients with end-stage liver disease, including 6 patients with primary liver cancer. Except 1 patient was infused only through the portal vein, others were infused through the portal vein and hepatic artery of the donor. The biliary tract was reconstructed using choledochocholedostomic anastomosis in 17 patients, and using Roux-en-Y choledochojejunostomic anastomosis in 1 patient. RESULTS: Four patients with biliary complication were found. In one patient, biliary leakage was found around the T-tube on day 14 postoperatively, and disappeared after re-opening of the tube. In one patient undergoing Roux-en-Y choledochojejunostomic anastomosis, biliary leakage was found on day 12 postoperatively and reoperation was performed. The T-tube was removed from the anastomosis after reoperation, and abdominal infection was controlled, but high fever recurred on day 49 postoperatively. The patient died on day 52 postoperatively. Autopsy revealed biliary leakage and biliary tract necrosis. In another patient, biliary leakage was found on day 3 after operation, and was treated by adequate drainage. Four months after operation, biliary sludge in the common tract was found and treated successfully with oral chemolysis. But biliary sludge or stone recur on one and half year after OLT. Spincterotomy and basket extraction were performed via endoscopic retrograde cholangiopancreatography, and the biliary sludge or stone was cleared out. In case 4, biliary drainage tube cholangiogram showed anastomotic stenosis one month after operation. Three months later, biliary sludge or stone was found beyond anastomotic stenosis. After oral chemolysis (ursodeoxycholic acid) and irrigation with heparinized saline solution via the biliary drainage tube, the biliary sludge disappeared. CONCLUSIONS: To reduce the incidence of biliary complications, adequate infusion of the hepatic artery, complete slushing of the biliary tract, and reduction of injury to the blood supply of the donor biliary tract are essential. Most biliary complications can be treated successfully by non-operative treatment or minimally invasive operation.

Effects of heat stress on antioxidant defense system, inflammatory injury, and heat shock proteins of Muscovy and Pekin ducks: evidence for differential thermal sensitivities.

Rising temperatures are severely affecting the mortality, laying performance, and meat quality of duck. Our aim was to investigate the effect of acute heat stress on the expression of heat shock proteins (HSPs: HSP90, 70, 60, 40, and 10) and inflammatory factors (nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2)) and antioxidant enzyme activity (superoxide dismutase (SOD), malondialdehybe (MDA), catalase (CAT), total antioxidant capacity (T-AOC)) in livers of ducks and to compare the thermal tolerance of Pekin and Muscovy ducks exposed to acute heat stress. Ducks were exposed to heat at 39 ± 0.5 °C for 1 h and then returned to 20 °C for 1 h followed by a 3-h recovery period. The liver and other tissues were collected from each individual for analysis. The mRNA levels of HSPs (70, 60, and 40) increased in both species, except for HSP10, which was upregulated in Muscovy ducks and had no difference in Pekin ducks after heat stress. Simultaneously, the mRNA level of HSP90 decreased in the stress group in both species. Morphological analysis indicated that heat stress induced tissue injury in both species, and the liver of Pekin ducks was severely damaged. The activities of several antioxidant enzymes increased in Muscovy duck liver, but decreased in Pekin duck. The mRNA levels of inflammatory factors were increased after heat stress in both duck species. These results suggested that heat stress could influence HSPs, inflammatory factors expression, and the activities of antioxidant enzymes. Moreover, the differential response to heat stress indicated that the Muscovy duck has a better thermal tolerance than does the Pekin duck.

Antioxidant effect of a phytoestrogen equol on cultured muscle cells of embryonic broilers.

Previous studies have shown that the in ovo injection of equol can markedly improve the water-holding capacity of muscles of broilers chickens at 7 wk of age through promotion of the antioxidant status. We aimed to investigate directly the antioxidant effects of equol on muscle cells in broilers. Muscle cells were separated from leg muscle of embryos on the 11th day of incubation and treated with equol and H(2)O(2), either alone or together. Cells were pretreated with medium containing 1, 10, or 100 µM equol for 1 h prior to the addition of 1 mM H(2)O(2) for a further 1 h. Photomicrographs of cells were obtained. Cell viability, malondialdehyde (MDA) content, and L-lactate dehydrogenase (LDH) activity in the cell supernatant, as well as intracellular total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-Px) activities were determined. Treatment with 1 mM H(2)O(2) caused serious damage to cells, indicated by comets with no clear head region but a very apparent tail of DNA fragments. Pretreatment with low (1 µM) but not high concentrations of equol (10 µM) inhibited cell damage, while 100 µM equol caused more serious damage than H(2)O(2) alone. Pretreatment with 1 µM equol had no effect on cell viability, while pretreatment with 10 and 100 µM equol significantly decreased cell viability in a dose-dependent manner. Compared with H(2)O(2) alone, pretreatment with low-dosage equol markedly decreased LDH activity and MDA production in the supernatant, significantly increased intracellular T-SOD activity (P < 0.05) and tended to increase intracellular GSH-Px activity (0.05 < P < 0.1). Pretreatment with high-dosage equol (10 and 100 µM) significantly enhanced LDH activity, but had no effect on MDA content, T-SOD or GSH-Px activity induced by H(2)O(2,) except for an obvious increase in GSH-Px activity caused by 10 µM equol. These results indicate that equol at low dosage can prevent skeletal muscle cell damage induced by H(2)O(2), while pretreatment with high-dosage equol shows a synergistic effect with H(2)O(2) in inducing cell damage.

Effect of dietary fatty acids on serum parameters, fatty acid compositions, and liver histology in Shaoxing laying ducks.

The effects of different fatty acid (FA) contents in diet on serum parameters, FA compositions of eggs and meat, and liver morphological changes were studied in Shaoxing laying ducks. A total of 264 ducks at 17 weeks were fed a control diet or a diet containing 30 g/kg fish oil (FO), 25 g/kg sunflower oil (SO), or 30 g/kg palm oil with 20 g/kg beef tallow (PBO). Malondialdehyde (MDA) content in the liver and the serum of ducks fed the PBO diet was significantly (P<0.05) higher than that of ducks fed the other diets. Triglyceride (TG) and total cholesterol (TC) levels were significantly lower (P<0.05) in ducks fed the FO diet. Serum TC also was lower in ducks fed the SO diet. Superoxide dismutase (SOD) activity was also affected by diets. The contents of polyunsaturated FAs (PUFAs) in eggs and meat were significantly higher (P<0.001) in ducks fed the FO and SO diets than in ducks fed the control diet. The level of C22:6 (n-3) FA in ducks fed the FO diet was significantly higher than that in ducks fed the other diets. However, the conversion efficiency of the longer-chain C20:5 (n-3) FA was higher than that of C22:6 (n-3). Ducks fed the PBO diet exhibited lipid droplet accumulation in the liver. These results demonstrate that a diet enriched with different FAs has strong effects on serum lipid levels and the deposition of PUFAs into tissue lipids.

Changes of cyclic AMP levels and phosphodiesterase activities in the rat ovary.

Cyclic AMP (cAMP) is a second messenger that plays a critical role in follicular recruitment, development and luteinization in the mammalian ovary. The cellular level of cAMP is largely dependent on the activity of phosphodiesterase (PDE), which degrades cAMP into 5'-AMP. The present study was conducted to investigate the level of cAMP and the activity of cAMP-PDE in postnatal rats; immature rats during gonadotropin-primed follicular development, ovulation and luteinization; adult rats during normal estrous cycling; and aged rats that spontaneously developed persistent estrous (PE) by radioimmunoassay (RIA). All four rat models were confirmed by histological examination of one ovary and assayed using the other ovary by RIA. In the postnatal rats, the ovarian cAMP level was high on day 10 after birth, while ovarian cAMP-PDE activity was highest at 21 days of age. In the immature female rats, both the ovarian cAMP level and cAMP-PDE activity increased remarkably after treatment with equine chorionic gonadotropin (eCG), increased continuously 24 h after injection of human chorionic gonadotropin (hCG) for induction of ovulation and luteinization, and then declined significantly. In the adult rats during the normal estrous cycle, the ovarian cAMP levels were low on the day of estrus, and there were no significant changes in ovarian cAMP-PDE activity throughout the estrous cycle. In the PE rats, the ovarian cAMP levels were similar to those of the adult rats on the day of estrus but were lower than those on the other days of the estrous cycle; ovarian cAMP-PDE activity was lower than that in the adult rats on any day of the estrous cycle. Together, these findings indicate that the ovarian cAMP level and cAMP-PDE activity were regulated in a stage-dependent manner during ovarian follicular development, atresia and luteinization and providing evidences that cAMP and cAMP-specific PDEs are involved in these physiological processes.