Is really endogenous ghrelin a hunger signal in chickens? Association of GHSR SNPs with increase appetite, growth traits, expression and serum level of GHRL, and GH

Serial passage of PDCoV in cell culture reduces its pathogenicity and its damage of gut microbiota homeostasis in piglets

Porcine deltacoronavirus (PDCoV) is an enteropathogenic coronavirus that mainly causes diarrhea in suckling piglets, and also has the potential for cross-species transmission. However, there are still no commercial vaccines available to prevent and control PDCoV infection. In this study, PDCoV strain HNZK-02 was serially propagated in vitro for up to 150 passages and the amino acid changes have mainly occurred in the S protein during serial passage which caused structure change. PDCoV HNZK-02-passage 5 (P5)-infected piglets exhibited acute and severe watery diarrhea, an obvious intestinal damage, while the piglets infected with PDCoV HNZK-02-P150 showed no obvious clinical signs, weak intestinal lesions, and lower viral loads in rectal swabs and various tissues. Compared with the PDCoV HNZK-02-P5 infection, HNZK-02-P150 infection resulted in a decrease in intestinal mucosal permeability and pro-inflammatory cytokines. Moreover, PDCoV HNZK-02-P5 infection had significantly reduced bacterial diversity and increased relative abundance of opportunistic pathogens, while PDCoV HNZK-02-P150 infection did not significantly affect the bacterial diversity, and the relative abundance of probiotics increased. Furthermore, the alterations of gut microbiota were closely related to the change of pro-inflammatory factor. Metagenomics prediction analysis demonstrated that HNZK-02-P150 modulated the tyrosine metabolism, Nucleotide-binding and oligomerization domain (NOD)-like receptor signaling pathway, and lipopolysaccharide biosynthesis, which coincided with lower inflammatory response and intestinal permeability in the piglets infected with HNZK-02-P150. In conclusion, the PDCoV HNZK-02 was successfully attenuated by serial passage in vitro, and the changes of S gene, metabolic function, and gut microbiota may contribute to the attenuation. The PDCoV HNZK-02-P150 may have the potential for developing live-attenuated vaccine.IMPORTANCEPorcine deltacoronavirus (PDCoV) is an enteropathogen causing severe diarrhea, dehydration, and death in nursing piglets, devastating great economic losses for the global swine industry, and has cross-species transmission and zoonotic potential. There are currently no approved treatments or vaccines available for PDCoV. In addition, gut microbiota has an important relationship with the development of many diseases. Here, the PDCoV virulent HNZK-02 strain was successfully attenuated by serial passage on cell cultures, and the pathogenesis and effects on the gut microbiota composition and metabolic function of the PDCoV HNZK-02-P5 and P150 strains were investigated in piglets. We also found the genetic changes in the S protein during passage in vitro and the gut microbiota may contribute to the pathogenesis of PDCoV, while their interaction molecular mechanism would need to be explored further.

Update on Feeding Regulation by Ghrelin in Birds: Focused on Brain Network

Ghrelin is known to be a feeding stimulatory hormone in mammals, but in birds, in contrast to mammals, the feeding behavior is regulated in inhibitory manners. This is because the neuropeptides associated with the regulation in the brain are different from those in mammals, i.e., it has been shown that, in chickens, a corticotropin-releasing hormone family peptide, urocortin, which is a feeding-inhibitory peptide, is mainly involved in the inhibitory mechanism. However, feeding is also regulated by various neurotransmitters in the brain, and recently, their interaction with the mechanisms underlying feeding inhibition by ghrelin in birds has been intensively studied and clarified. This review summarizes these findings.

Identification of Signatures of Positive Selection That Have Shaped the Genomic Landscape of South African Pig Populations

South Africa boasts a diverse range of pig populations, encompassing intensively raised commercial breeds, as well as indigenous and village pigs reared under low-input production systems. The aim of this study was to investigate how natural and artificial selection have shaped the genomic landscape of South African pig populations sampled from different genetic backgrounds and production systems. For this purpose, the integrated haplotype score (iHS), as well as cross population extended haplotype homozygosity (XP-EHH) and Lewontin and Krakauer's extension of the Fst statistic based on haplotype information (HapFLK) were utilised. Our results revealed several population-specific signatures of selection associated with the different production systems. The importance of natural selection in village populations was highlighted, as the majority of genomic regions under selection were identified in these populations. Regions under natural and artificial selection causing the distinct genetic footprints of these populations also allow for the identification of genes and pathways that may influence production and adaptation. In the context of intensively raised commercial pig breeds (Large White, Kolbroek, and Windsnyer), the identified regions included quantitative loci (QTLs) associated with economically important traits. For example, meat and carcass QTLs were prevalent in all the populations, showing the potential of village and indigenous populations' ability to be managed and improved for such traits. Results of this study therefore increase our understanding of the intricate interplay between selection pressures, genomic adaptations, and desirable traits within South African pig populations.

Enzymatically prepared alginate oligosaccharides improve broiler chicken growth performance by modulating the gut microbiota and growth hormone signals

BACKGROUND

Alginate oligosaccharide (AOS) holds great potential as a novel feed supplement in farm animals. However, the effects of AOS on chicken health and the underlying mechanisms are not fully understood. This study aimed to optimize the enzymatic preparation of AOS by using bacterial alginate lyases expressed in yeast, investigate the effects of the prepared AOS on the growth performance and gut health of broiler chickens, and reveal the underlying mechanisms.

RESULTS

Five alginate lyases from bacteria were cloned into Pichia pastoris GS115 and the alginate lyase PDE9 was expressed at relatively high yield, activity and stability in P. pastoris. Animal trials were carried out using 320 1-day-old male Arbor Acres broilers (four groups; 8 replicates/group × 10 chicks/replicate) receiving either a basal diet or the same diet supplemented with 100, 200 and 400 mg/kg PDE9-prepared AOS for 42 d. The results showed that dietary supplementation of 200 mg/kg AOS displayed the highest activity in promoting the birds' ADG and ADFI (P < 0.05). AOS ameliorated the intestinal morphology, absorption function and barrier function, as indicated by the enhanced (P < 0.05) intestinal villus height, maltase activity, and the expression of PEPT, SGLT1, ZNT1, and occludin. AOS also increased serum insulin-like growth factor-1, ghrelin (P < 0.05), and growth hormone (P < 0.1). Moreover, the concentrations of acetate, isobutyrate, isovalerate, valerate, and total SCFAs in cecum of birds fed AOS were significantly higher than the control birds (P < 0.05). Metagenomic analysis indicated that AOS modulated the chicken gut microbiota structure, function, and microbial interactions and promoted the growth of SCFAs-producing bacteria, for example, Dorea sp. 002160985; SCFAs, especially acetate, were found positively correlated with the chicken growth performance and growth-related hormone signals (P < 0.05). We further verified that AOS can be utilized by Dorea sp. to grow and to produce acetate in vitro.

CONCLUSIONS

We demonstrated that the enzymatically produced AOS effectively promoted broiler chicken growth performance by modulating the chicken gut microbiota structure and function. For the first time, we established the connections among AOS, chicken gut microbiota/SCFAs, growth hormone signals and chicken growth performance.

Aspergillus awamori attenuates ochratoxin A-induced renal and cardiac injuries in rabbits by activating the Nrf2/HO-1 signaling pathway and downregulating IL1β, TNFα, and iNOS gene expressions

Ochratoxin A (OTA) is one of the most dangerous and that pollute agricultural products, inducing a variety of toxic effects in humans and animals. The current study explored the protective effect of different concentrations of Aspergillus awamori (A. awamori) against OTA (0.3 mg/kg diet) induced renal and cardiac damage by exploring its mechanism of action in 60 New Zealand white male rabbits. Dietary supplementation of A. awamori at the selected doses of 50, 100, and 150 mg/kg diet, respectively, for 2 months significantly improved the rabbit's growth performance; modulated the suppressed immune response and restored the altered hematological parameters; reduced the elevated levels of renal injury biomarkers such as urea, creatinine, and alkaline phosphatase; and increased serum total proteins concentrations. Moreover, it also declined enzymatic activities of cardiac injury biomarkers, including AST, LDH, and CK-MB. A. awamori alleviated OTA-induced degenerative and necrotic changes in the kidney and heart of rabbits. Interestingly, A. awamori upregulated Nrf2/OH-1 signaling pathway. Therefore enhanced TAC, CAT, and SOD enzyme activities and reduced OTA-induced oxidative and nitrosative stress by declining iNOS gene expression and consequently lowered MDA and NO levels. In addition to attenuating renal and cardiac inflammation via reducing IL-1β, TNF-α gene expressions in a dose-dependent response. In conclusion,this is the first report to pinpoint that dietary incorporation of A. awamori counteracted OTA-induced renal and cardiac damage by potentiating the rabbit's antioxidant defense system through its potent antioxidant, free radical scavenging, and anti-inflammatory properties in a dose-dependent response. Based on our observations, A. awamori could be utilized as a natural protective agent against ochratoxicosis in rabbits.

Polymorphisms of the PRLR Gene and Their Association with Milk Production Traits in Egyptian Buffaloes

Simple Summary

The two non-synonymous g.11685G>A and g.11773T>C SNPs of PRLR(L2) were significantly associated with milk yield, fat%, and protein%, and mRNA and protein levels of PRL and PRLR in milk somatic cells. GT-animals had the best milk performance; however, AC-animals had inferior milk production. Thus, the selection of buffaloes with GT haplotypes may enhance milk performance in Egyptian buffaloes.

Abstract

Prolactin (PRL) and its receptor (PRLR) were considered as potential genetic markers for milk production and quality traits in cattle. However, little information is available regarding PRLR genetic diversity and association studies with milk traits in Egyptian water buffaloes. Therefore, the present study was conducted to search for mutations in PRLR and determine their associations with milk performance in these animals. Exon3 (E3) and E10 of PRLR were screened for polymorphisms using single strand conformation polymorphism (SSCP) and sequencing in 400 buffaloes. The associations between haplotypes and milk production (fat%, protein%, lactose%, and solid%) traits as well as mRNA and protein levels of PRL and PRLR were studied. Two single nucleotide polymorphisms (SNPs) in E10 were detected: g.11685G>A (p.Ala494Thr) and g.11773T>C (p.Val523Aal). The G and T alleles were wild (ancestral) alleles, while the A and C alleles were mutant alleles. These SNPs resulted in four haplotypes; AC, AT, GC, and GT. Buffaloes with wild GT haplotypes showed significantly higher milk yield, fat% and protein%, mRNA and protein levels of PRL and PRLR in milk somatic cells than other animals. Animals carrying mutant AC haplotype had inferior milk traits and lowest levels of associated mRNAs and proteins. With these results, we could conclude that the selection of buffaloes with wild GT haplotypes for g.11685G>A and g.11773T>C SNPs of the PRLR gene might improve the milk production traits of Egyptian water buffaloes.

Association of GH polymorphisms with growth traits in buffaloes

Members of the somatotrophic axis, especially GH and IGF1, are essential for growth. The association between GH polymorphisms and growth traits was numerously studied in cattle; however, no data are available for such association studies in buffalo. Therefore, this study was conducted to screen for polymorphisms in the GH gene and to study their putative association with growth traits in 200 Egyptian buffaloes. Polymerase chain reaction single-strand conformation polymorphism and sequencing were applied to look for polymorphisms in 3 loci spanning all exons and introns of buffalo GH. The C (MspI+) >T (MspI-) SNP in intron3, which is well known in cattle, was not detected in the examined buffaloes. However, 2 missense mutations were detected in exon5: one previously detected p.Leu153Val SNP, with very low frequencies for the mutant (Val) allele and one novel p.Asn174His SNP. At weaning age, the p.Leu153Val SNP was significantly associated with weaning body weight and gain with the positive effect of the wild allele (Leu) and higher GH serum, mRNA, and protein levels in animals with Leu/Asn and Leu/His haplotypes. At yearling age, the 2 SNPs associated with yearling weight and gain with positive effect for the mutant (Val and His) alleles with increased GH, and IGF1 serum, mRNA, and protein and GHR mRNA and protein levels in animals with Val/Asn haplotype. Therefore, the selection of Egyptian buffaloes with the Val/Asn haplotype could improve the growth traits of Egyptian buffaloes at yearling age which is the target age for perfect growing.

Recognition of Invasive Prostate Cancer Using a GHRL Polypeptide Probe Targeting GHSR in a Mouse Model In Vivo

BACKGROUND

Ghrelin (GHRL) is a polypeptide that can specifically bind to the growth hormone secretagogue receptor (GHSR). The expression of GHSR is significantly different in normal and prostate cancer (PC) tissues in humans. It is important to find an effective diagnostic method for the diagnosis and prognosis of invasive PC/neuroendocrine prostate cancer (NEPC).

METHODS

GHRL and GHSR mRNA levels were determined by a quantitative real-time polymerase chain reaction in PC tissues. The expression of GHRL and GHSR proteins was assessed by Western blot assay and immunohistochemistry. A GHRL polypeptide probe was synthesized by standard solid-phase polypeptide synthesis, and labeled with Alexa Fluor 660. Confocal microscopy was used to capture fluorescence images. Living imaging analysis showed tumor areas of different invasiveness in mice models.

RESULTS

The levels of GHRL and GHSR copy number amplification and mRNA expression were increased in invasive PC/NEPC, and the protein expression levels of GHRL and GHSR were similarly increased in NEPC. The GHRL polypeptide probe could effectively bind to GHSR. In PC3 cells, it was found that the GHRL probe specifically binds to GHSR on the cell membrane and accumulates in the cells through internalization after binding. Live imaging in mice models showed that there were different signal intensities in tumor areas with different invasiveness.

CONCLUSION

GHSR and GHRL might be used in molecular imaging diagnosis for invasive PC/NEPC in the future.

Association of LEPR polymorphisms with egg production and growth performance in female Japanese quails

This study aimed to screen intron 8 of the leptin receptor (LEPR) gene for polymorphisms in female Japanese quails. Two adjacent novel SNPs (A277G and A304G) were detected using PCR-SSCP and sequencing. These SNPs produced three haplotypes (AA/AA, AG/AG, and GG/GG) that were significantly (p ≤ 0.05) associated with growth and egg production traits. GG/GG haplotype-quails had significantly (p ≤ 0.05) lower egg production, feed intake, growth performance, lipid profile, serum levels of sex hormones (estradiol, progesterone, FSH, LH), and ovarian expressions of survivin, FSHR, and IGF1 than other quails. However, GG/GG quails had significantly (p ≤ 0.05) higher serum levels of LEP and mRNA levels of LEPR, LEP, and caspase 3 in the hypothalamus and ovaries. These higher levels of LEP/LEPR could not only reduce feed intake and body weight gain but also could induce apoptosis of ovarian cells (as indicated by lower survivin and IGF1 and higher caspase3 expression) which could inhibit the development of the follicles and the release of sex hormones with a subsequent decrease in egg production in GG/GG quails. Therefore, with these results, we suggest selecting Japanese quails with AA/AA and AG/AG haplotypes to improve the reproduction and growth performance of this flock.

Evaluation of the Relationship between Adipose Metabolism Patterns and Secretion of Appetite-Related Endocrines on Chicken

Simple Summary

The weight of an animal conforms to a certain growth pattern. Among others, feed, environment, and body composition, in addition to genetics, affect the animal’s feed consumption and body weight. Under normal circumstances, the body weight of an animal is mainly affected by feed intake, and body composition may significantly influence feed intake. Therefore, this report sets out the effects of fat accumulation on lipid metabolism and appetite, and finally introduces the effects of feeding patterns on animal feed intake.

Abstract

In addition to the influence of genes, the quality of poultry products is mainly controlled by the rearing environment or feed composition during rearing, and has to meet human use and economical needs. As the only source of energy for poultry, feed considerably affects the metabolic pattern of poultry and further affects the regulation of appetite-related endocrine secretion in poultry. Under normal circumstances, the accumulation of lipid in adipose reduces feed intake in poultry and increases the rate of adipose metabolism. When the adipose content in cells decreases, endocrines that promote food intake are secreted and increase nutrient concentrations in serum and cells. By regulating the balance between appetite and adipose metabolism, the poultry’s growth and posture can maintain a balanced state. In addition, increasing fiber composition in feed can effectively increase poultry welfare, body weight, lean composition and antioxidant levels in poultry. According to this, the concept that proper fiber content should be added to feed should be considered for better economic benefits, poultry welfare and meat productivity.

Association of GHR Polymorphisms with Milk Production in Buffaloes

Simple Summary

The present study reported two missense mutations in the buffalo GHR gene: A novel (c.380G>A) and (c.836T>A) which was described in previous studies. These two single nucleotide polymorphisms (SNPs) were found to be associated with milk yield, fat %, protein %, and 305 day-milk, fat and protein yield, with higher performance for AA haplotype animals. Therefore, selection of buffaloes with AA haplotype would more likely improve milk production traits. Consequently, this would allow breeders to take more precise selection decisions, leading to significantly higher productivity and profitability within the Egyptian buffalo herds.

Abstract

For its role in the mediation of growth hormone (GH) galactopoietic effect, growth hormone receptor (GHR) was considered a functional candidate gene for milk performance in cattle. However, its genetic variation and potential effect have not been investigated in Egyptian buffaloes. This study aimed to screen GHR for polymorphisms and study their associations with milk traits in Egyptian buffaloes. Polymerase chain reaction, single-strand conformation polymorphism, and sequencing were used to identify mutations in 4 exons (E4–E6 and E8) of the GHR gene in 400 Egyptian buffaloes. No polymorphisms were found in E4, while 2 SNPs (c.380G>A/p.Arg127Lys and c.387C>T/p.Gly129) in E5, one silent mutation (c.435A>G/p.Pro145) in E6, and another missense mutation (c.836T>A/p.Phe279Tyr) in E8 were detected. The c.380G>A SNP in the extracellular domain was associated with milk yield, fat %, protein %, and 305-day milk, fat and protein yield, with higher levels in animals carrying the mutant A allele. The c.836T>A SNP in the transmembrane domain was associated with milk yield, fat %, protein %, and 305-day milk, fat and protein yield, with higher milk yield and lower fat %, protein %, fat and protein yield in the mutant A allele-animals. Interestingly, animals with the two mutant AA alleles produced higher milk yield, fat %, protein %, fat and protein yield, accompanied with upregulated expressions of GHR, GH, insulin-like growth factor 1 (IGF1), prolactin (PRL), prolactin receptor (PRLR), β-casein (encoded by CSN2 gene), and diacylglycerol acyltransferase-1 (DGAT1) genes and proteins in milk somatic cells. Therefore, selection of Egyptian buffaloes with mutant AA haplotypes for the novel c.380G>A SNP and the well-known c.836T>A SNP could improve milk yield and quality in buffaloes.

Association of MHC IIA polymorphisms with disease resistance in Aeromonas hydrophila-challenged Nile tilapia

The major histocompatibility complex (MHC) genes show high polymorphisms in vertebrates depending on animal immunity status. Herein, MHC class IIA gene in Aeromonas hydrophila-challenged Nile tilapia was screened for presence of polymorphisms using sequencing. Twelve nucleotides deletion polymorphism was determined with a PCR product size of 267 bp in the resistant fish and 255 bp in the control and susceptible/diseased fish. Additionally, a non-synonymous right frameshift c.712 T > G (P. 238 * > G) SNP was detected at the stop codon (*). SNP-susceptibility association analysis revealed that fish carrying GG genotype and allele G were high susceptible (risk) for A. hydrophila, and had lower immune response as indicated by significant reduction in non-specific immune parameters (total protein, globulin, IgM, phagocytic activity, phagocytic index, and lysosome activity) and mRNA level of MHC IIA, interleukin 1 beta (IL1β), tumor necrosis factor alfa (TNFα), and toll-like receptor 7 (TLR7) in the spleen and head kidney. Thus, G allele could be considered as a risk (recessive or mutant) allele for c. 712 T > G (P. 238 * > G) SNP and so selection of Nile tilapia with protective allele (T) for this SNP could improve the disease resistant of the fish.

Dietary propionic acid enhances antibacterial and immunomodulatory effects of oxytetracycline on Nile tilapia, Oreochromis niloticus

This study was carried out to evaluate the potential antibacterial and immunomodulatory effects of the dietary acidifier propionic acid (PA) when given alone or in combination with oxytetracycline (OTC) on Nile tilapia (Oreochromis niloticus). Apparently healthy O. niloticus (n = 240; 52 ± 3.75 g) were randomly allocated into four equal groups (n = 60/group): control group fed a basal diet alone and the other three groups fed basal diets supplemented with either PA (200 mg /kg of diet, PA group) or OTC (500 mg/kg of diet, OTC group) alone or in combination (PA + OTC group). Each group was subdivided into two subgroups (n = 30/subgroup, each subgroup had triplicate of 10 fish); subgroup (A) was used to evaluate the antibacterial effects with the aforementioned 2 weeks feeding regime, and subgroup (B) was used to evaluate the immunomodulatory effects against Aeromonas hydrophila infection with similar 2 weeks feeding regime. Among the four groups, PA + OTC group showed the highest significant (p < 0.0001) antibacterial activity as indicated by widest inhibition zones against A. hydrophila and lowest total gastrointestinal bacterial counts. Additionally, this group had the best immunomodulatory effect as noticed by a significant (p < 0.05) increase in total serum protein, globulin, IgM, phagocytic activity and index, lysosome activity, and significant (p < 0.05) upregulation in the expression levels of immunity-related genes (MHC I, MHC IIA, MHC IIB, Tlr7, IgM heavy chain, TNFα, and IL1β) in head-kidney. Notably, the combined dietary PA and OTC improved the hematological parameters and reduced the oxidative damage of hepatopancreas and head-kidney induced by OTC. This data suggests dietary PA as potential adjuvant to OTC in O. niloticus diets to get maximal antibacterial and immunomodulatory effects.

Dexamethasone and insulin stimulate ghrelin secretion of broilers in a different way

Ghrelin is one of the most important appetite regulating peptides, involved in the regulation of energy homeostasis. The role of ghrelin on the appetite and fat metabolism in chickens is different from that of ghrelin in mammals. Glucocorticoids and insulin are important hormones and work differently in energy regulation of body. In this study, the effects of dexamethasone (DEX, 2.0 mg/kg BW), subcutaneous insulin injection (40 µg/kg BW), and glucose load on ghrelin secretion and expression were determined in broilers. DEX treatment increased circulating ghrelin concentration in broiler fed with either a low-energy diet (11.05 MJ/kg of metabolizable energy) or a high-energy diet (14.44 MJ/kg of metabolizable energy). The expression levels of ghrelin were increased while both ghrelin and its receptor GHS-R1a expression levels were stimulated by DEX. A single subcutaneous insulin injection (40 µg/kg BW) or oral glucose infusion (2 g/kg BW) rise circulating ghrelin level. Ghrelin expression in the proventriculus was increased by insulin treatment but unchanged by glucose load. DEX had no detectable influence on ghrelin and GHS-R1a expression in the hypohtalamus, whereas insulin suppressed their expression. In conclusion, both insulin and glucocorticoid stimulate ghrelin secretion in chickens, in contrast to mammals. Glucocorticoids evoke peripheral ghrelin/GHS-R1a system while insulin increases peripheral ghrelin expression and suppress the activation of central ghrelin/GHS-R1a system. The result suggests that ghrelin involved in the modulating network of energy homeostasis in concert with glucocorticoids and insulin.

Association of CYP19A1 gene polymorphisms with anoestrus in water buffaloes

Cytochrome P450 aromatase (encoded by the CYP19A1 gene) regulates oestrogen biosynthesis and so plays an essential role in female fertility. We investigated the genetic association of CYP19A1 with the risk of anoestrus in Egyptian water buffaloes. A total of 651 animals (326 anoestrous and 325 cycling) were used in this case-control study. Using single-strand conformation polymorphisms and sequencing, four single nucleotide polymorphisms (SNPs) were detected; c.−135T > C SNP in the 5′UTR and three non-synonymous SNPs: c.559G > A (p. V187M) in Exon 5, c.1285C > T (p. P429S) and c.1394A > G (p. D465G) in Exon 10. Individual SNP-anoestrus association analyses revealed that genotypes (CC, AA and GG) and alleles (C, A and G) of the −135T > C, c.559G > A and c.1394A > G SNPs respectively were high risk for anoestrus. A further analysis confirmed that these three SNPs were in linkage disequilibrium. Additionally, haplotypes with two (TAG/122 and CAA/221) or three (CAG/222) risk alleles were significantly associated with susceptibility to anoestrus, lower blood levels of both oestradiol and antioxidant enzymes (superoxide dismutase, glutathione peroxidase (GPX) and catalase) and downregulated expression levels of CYP19A1, oestrogen receptor α and Gpx3 in the ovary, as well as increased serum level of malondialdehyde. This suggests the occurrence of a high incidence of oxidative ovarian damage and subsequently ovarian inactivity in buffaloes carrying risk alleles. Therefore, with this study we suggest the selection of buffaloes with protective alleles at these SNPs to improve the reproductive efficiency of the herd.

The ameliorative effect of Aspergillus awamori on aflatoxin B1-induced hepatic damage in rabbits

This study was conducted to investigate the effect of dietary supplementation of Aspergillus awamori on aflatoxin B1 (AFB1)-induced liver damage in rabbits. Administration of AFB1 (0.3 mg/kg diet) led to a significant reduction in body weight, body weight gain, total feed intake, total serum proteins, albumin, high density lipoprotein-cholesterol, phagocytic activity, phagocytic index, and the antioxidant enzyme, glutathione peroxidase (GPx). Moreover, AFB1 administration was associated with a significant increase in feed conversion ratio, lipid peroxidation and serum levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, gamma-glutamyl transferase, lactate dehydrogenase and total bilirubin. In addition, livers of AFB1-supplemented animals showed fatty degeneration with vacuolisation, focal areas of necrosis, mononuclear cells infiltration hyperplasia of bile ducts and sinusoids. A significant increase in the hepatic expression of the biotransformation gene (Cyp3A6), stress-sensitive genes (HO1 and SOD1), and inflammation-related genes (IL6, TNFa, NF-kB, and Cox2) was also observed. Supplementation of the diets with 0.05, 0.1 or 0.15% A. awamori ameliorated all AFB1 deleterious effects with the best improvement observed at the lowest concentration. This is the first investigation to report that supplementation of rabbit diets with A. awamori has an ameliorative effect against AFB1-induced liver damage possibly through preventing hepatic oxidative stress, promoting the antioxidant defence systems, and inhibiting expression of Cyp3A6, HO1, SOD1, IL6, TNFa, NF-kB, and Cox2. Therefore, A. awamori could be used as a potential preventive or therapeutic agent for aflatoxicosis.

Linking Stress and Infertility: A Novel Role for Ghrelin

Infertility affects a remarkable one in four couples in developing countries. Psychological stress is a ubiquitous facet of life, and although stress affects us all at some point, prolonged or unmanageable stress may become harmful for some individuals, negatively impacting on their health, including fertility. For instance, women who struggle to conceive are twice as likely to suffer from emotional distress than fertile women. Assisted reproductive technology treatments place an additional physical, emotional, and financial burden of stress, particularly on women, who are often exposed to invasive techniques associated with treatment. Stress-reduction interventions can reduce negative affect and in some cases to improve in vitro fertilization outcomes. Although it has been well-established that stress negatively affects fertility in animal models, human research remains inconsistent due to individual differences and methodological flaws. Attempts to isolate single causal links between stress and infertility have not yet been successful due to their multifaceted etiologies. In this review, we will discuss the current literature in the field of stress-induced reproductive dysfunction based on animal and human models, and introduce a recently unexplored link between stress and infertility, the gut-derived hormone, ghrelin. We also present evidence from recent seminal studies demonstrating that ghrelin has a principal role in the stress response and reward processing, as well as in regulating reproductive function, and that these roles are tightly interlinked. Collectively, these data support the hypothesis that stress may negatively impact upon fertility at least in part by stimulating a dysregulation in ghrelin signaling.