Staphylococcus aureus and biofilms:transmission, threats, and promising strategies in animal husbandry

Staphylococcus aureus(S. aureus) is a common pathogenic bacterium in animal husbandry that can cause diseases such as mastitis, skin infections, arthritis, and other ailments. The formation of biofilms threatens and exacerbates S. aureus infection by allowing the bacteria to adhere to pathological areas and livestock product surfaces, thus triggering animal health crises and safety issues with livestock products. To solve this problem, in this review, we provide a brief overview of the harm caused by S. aureus and its biofilms on livestock and animal byproducts(meat and dairy products). We also describe the ways in which S. aureus spreads in animals and the threats it poses to the livestock industry. The processes and molecular mechanisms involved in biofilm formation are then explained. Finally, we discuss strategies for the removal and eradication of S. aureus and biofilms in animal husbandry, including the use of antimicrobial peptides, plant extracts, nanoparticles, phages, and antibodies. These strategies to reduce the spread of S. aureus in animal husbandry help maintain livestock health and improve productivity to ensure the ecologically sustainable development of animal husbandry and the safety of livestock products.

Biological function of resveratrol and its application in animal production:a review

With the prohibition of antibiotics in feed,plant functional substances have been widely studied as feed additives.Resveratrol,a natural stilbene,and a non-flavonoid polyphenol found in plants,possesses antioxidant,anti-inflammatory,and metabolic regulatory features.Resveratrol generated intense scientific and public interest,primarily due to its widely reported ability to prevent cancer,delay aging and alleviate related metabolic diseases.Recently,resveratrol has been studied and applied as a feed additive in animal production.This review focuses on the outline of the absorption and metabolism and biological functions of resveratrol and summarizes the application of dietary resveratrol in animal production up to the present,including pigs,poultry,and ruminants.In pigs,dietary resveratrol improved intestinal health,mitochondrial function,meat quality,and more.In poultry,studies have shown that dietary resveratrol improves growth performance and meat and egg quality and alleviates heat stress induced adverse effects.There are few studies on dietary resveratrol in ruminants;however previous studies have indicated that dietary resveratrol increases nutrient digestibility and reduces methane emissions in sheep.It is hoped that this review could provide a specific theoretical basis and research ideas for the research and application of resveratrol.

A new start: Journal of Animal Science and Biotechnology re-launches with BioMed Central

Journal of Animal Science and Biotechnology （JASB） was founded in June 2010, as the first English language journal published in the field of animal science in China. The journal is supported by the Chinese Association of Animal Science and Veterinary Medicine, a well-respected and established society. Animal science and animal production have been developing rapidly in China over the past 20 years. China has become the largest meat and egg producer in the world. A group of scientists and researchers have emerged in this fast growing area, pro- ducing high-quality research results.

Dietary supplementation of laminarin improves the reproductive performance of sows and the growth of suckling piglets

Background Maternal nutrition is essential in keeping a highly efficient production system in the pig industry.Laminarin has been shown to improve antioxidant capacity,reduce the inflammatory response,and favor the homeostasis of intestinal microbiota.However,the effect of dietary supplementation of laminarin on the reproductive performance of sows and the growth of suckling offspring remains unknown.Methods A total of 40 Landrace×Yorkshire multiparous sows on d 85 of gestation,similar in age,body weight(BW),parity and reproductive performance,were randomly divided into four dietary treatments with 10 sows per treatment,receiving a control diet(basal pregnancy or lactating diets)and a basal diet supplemented with 0.025%,0.05%and 0.10%laminarin,respectively.The experiment lasted from d 85 of gestation to d 21 of lactation.Results Laminarin supplementation linearly increased number born alive per litter(P=0.03),average daily feed intake(ADFI,P<0.01),and total milk yield of sows during the lactation of 1–21 d(P=0.02).Furthermore,maternal laminarin supplementation increased the average daily gain(ADG)of piglets while tending to reduce the culling and death rate before weaning.In addition,alterations to the composition of colostrum and milk,as well as to serum inflammatory cytokines and immunoglobulins of sows were observed.The fecal microbiota profile of sows supported the improvement of reproductive performance in sows and the growth performance in suckling offspring.Conclusions Dietary supplementation of laminarin during late pregnancy and lactation could significantly improve reproductive performance of sows and growth performance of piglets.

Proteo-transcriptomic profiles reveal key regulatory pathways and functions of LDHA in the ovulation of domestic chickens(Gallus gallus)

Background In poultry, the smooth transition of follicles from the preovulatory-to-postovulatory phase impacts egg production in hens and can benefit the poultry industry. However, the regulatory mechanism underlying follicular ovulation in avians is a complex biological process that remains unclear.Results Critical biochemical events involved in ovulation in domestic chickens(Gallus gallus) were evaluated by transcriptomics, proteomics, and in vitro assays. Comparative transcriptome analyses of the largest preovulatory follicle(F1) and postovulatory follicle(POF1) in continuous laying(CL) and intermittent laying(IL) chickens indicated the greatest difference between CL_F1 and IL_F1, with 950 differentially expressed genes(DEGs), and the smallest difference between CL_POF1 and IL_POF1, with 14 DEGs. Additionally, data-independent acquisition proteomics revealed 252 differentially abundant proteins between CL_F1 and IL_F1. Perivitelline membrane synthesis, steroid biosynthesis, lysosomes, and oxidative phosphorylation were identified as pivotal pathways contributing to ovulation regulation. In particular, the regulation of zona pellucida sperm-binding protein 3, plasminogen activator, cathepsin A, and lactate dehydrogenase A(LDHA) was shown to be essential for ovulation. Furthermore, the inhibition of LDHA decreased cell viability and promoted apoptosis of ovarian follicles in vitro.Conclusions This study reveals several important biochemical events involved in the process of ovulation, as well as crucial role of LDHA. These findings improve our understanding of ovulation and its regulatory mechanisms in avian species.

Effects of altering the ratio of C16:0 and cis-9 C18:1 in rumen bypass fat on growth performance, lipid metabolism, intestinal barrier, cecal microbiota, and inflammation in fattening bulls

Background C16:0 and cis-9 C18:1 may have different effects on animal growth and health due to unique metabolism in vivo.This study was investigated to explore the different effects of altering the ratio of C16:0 and cis-9 C18:1 in fat supplements on growth performance,lipid metabolism,intestinal barrier,cecal microbiota,and inflammation in fattening bulls.Thirty finishing Angus bulls(626±69 kg,21±0.5 months)were divided into 3 treatments according to the randomized block design:(1)control diet without additional fat(CON),(2)CON+2.5%palmitic acid calcium salt(PA,90%C16:0),and(3)CON+2.5%mixed fatty acid calcium salt(MA,60%C16:0+30%cis-9 C18:1).The experiment lasted for 104 d,after which all the bulls were slaughtered and sampled for analysis.Results MA tended to reduce 0–52 d dry matter intake compared to PA(DMI,P=0.052).Compared with CON and MA,PA significantly increased 0–52 d average daily gain(ADG,P=0.027).PA tended to improve the 0–52 d feed conversion rate compared with CON(FCR,P=0.088).Both PA and MA had no significant effect on 52–104 days of DMI,ADG and FCR(P>0.05).PA tended to improve plasma triglycerides compared with MA(P=0.077),significantly increased plasma cholesterol(P=0.002)and tended to improve subcutaneous adipose weight(P=0.066)when compared with CON and MA.Both PA and MA increased visceral adipose weight compared with CON(P=0.021).Only PA increased the colonization of Rikenellaceae,Ruminococcus and Proteobacteria in the cecum,and MA increased Akkermansia abundance(P<0.05).Compared with CON,both PA and MA down-regulated the m RNA expression of Claudin-1 in the jejunum(P<0.001),increased plasma diamine oxidase(DAO,P<0.001)and lipopolysaccharide(LPS,P=0.045).Compared with CON and MA,PA down-regulated the ZO-1 in the jejunum(P<0.001)and increased plasma LPS-binding protein(LBP,P<0.001).Compared with CON,only PA down-regulated the Occludin in the jejunum(P=0.013).Compared with CON,PA and MA significantly up-regulated the expression of TLR-4 and NF-κB in the visceral adipose(P<0.001)and increased plasma IL-6(P<0.001).Compared with CON,only PA up-regulated the TNF-αin the visceral adipose(P=0.01).Compared with CON and MA,PA up-regulated IL-6 in the visceral adipose(P<0.001),increased plasma TNF-α(P<0.001),and reduced the Ig G content in plasma(P=0.035).Compared with CON,PA and MA increased C16:0 in subcutaneous fat and longissimus dorsi muscle(P<0.05),while more C16:0 was also deposited by extension and desaturation into C18:0 and cis-9 C18:1.However,neither PA nor MA affected the content of cis-9 C18:1 in longissimus dorsi muscle compared with CON(P>0.05).Conclusions MA containing 30%cis-9 C18:1 reduced the risk of high C16:0 dietary fat induced subcutaneous fat obesity,adipose tissue and systemic low-grade inflammation by accelerating fatty acid oxidative utilization,improving colonization of Akkermansia,reducing intestinal barrier damage,and down-regulating NF-κB activation.

Assessing the conservation impact of Chinese indigenous chicken populations between ex-situ and in-situ using genome-wide SNPs

Conservation programs require rigorous evaluation to ensure the preservation of genetic diversity and viability of conservation populations. In this study, we conducted a comparative analysis of two indigenous Chinese chicken breeds, Gushi and Xichuan black-bone, using whole-genome SNPs to understand their genetic diversity, track changes over time and population structure. The breeds were divided into five conservation populations(GS1, 2010, ex-situ;GS2, 2019, ex-situ;GS3, 2019, in-situ;XB1, 2010, in-situ;and XB2, 2019, in-situ) based on conservation methods and generations. The genetic diversity indices of three conservation populations of Gushi chicken showed consistent trends, with the GS3 population under in-situ strategy having the highest diversity and GS2 under ex-situ strategy having the lowest. The degree of inbreeding of GS2 was higher than that of GS1 and GS3. Conserved populations of Xichuan black-bone chicken showed no obvious changes in genetic diversity between XB1 and XB2. In terms of population structure, the GS3 population were stratified relative to GS1 and GS2. According to the conservation priority, GS3 had the highest contribution to the total gene and allelic diversity in GS breed, whereas the contribution of XB1 and XB2 were similar. We also observed that the genetic diversity of GS2 was lower than GS3, which were from the same generation but under different conservation programs(in-situ and ex-situ). While XB1 and XB2 had similar levels of genetic diversity. Overall, our findings suggested that the conservation programs performed in ex-situ could slow down the occurrence of inbreeding events, but could not entirely prevent the loss of genetic diversity when the conserved population size was small, while in-situ conservation populations with large population size could maintain a relative high level of genetic diversity.

Identification of porcine fast/slow myogenic exosomes and their regulatory effects on lipid accumulation in intramuscular adipocytes

Background Pork quality is affected by the type of muscle fibers, which is closely related to meat color, tenderness and juiciness. Exosomes are tiny vesicles with a diameter of approximately 30–150 nm that are secreted by cells and taken up by recipient cells to mediate communication. Exosome-mediated muscle-fat tissue crosstalk is a newly discovered mechanism that may have an important effect on intramuscular fat deposition and with that on meat quality. Various of adipose tissue-derived exosomes have been discovered and identified, but the identification and function of muscle exosomes, especially porcine fast/slow myotube exosomes, remain unclear. Here, we first isolated and identified exosomes secreted from porcine extensor digitorum longus(EDL) and soleus(SOL), which represent fast and slow muscle, respectively, and further explored their effects on lipid accumulation in longissimus dorsi adipocytes.Results Porcine SOL-derived exosomes(SOL-EXO) and EDL-derived exosomes(EDL-EXO) were first identified and their average particle sizes were approximately 84 nm with double-membrane disc-shapes as observed via transmission electron microscopy and scanning electron microscopy. Moreover, the intramuscular fat content of the SOL was greater than that of the EDL at 180 days of age, because SOL intramuscular adipocytes had a stronger lipid-accumulating capacity than those of the EDL. Raman spectral analysis revealed that SOL-EXO protein content was much greater than that of EDL-EXO. Proteomic sequencing identified 72 proteins that were significantly differentially expressed between SOL-EXO and EDL-EXO, 31 of which were downregulated and 41 of which were upregulated in SOL-EXO.Conclusions Our findings suggest that muscle-fat tissue interactions occur partly via SOL-EXO promoting adipogenic activity of intramuscular adipocytes.

Patterns of alteration in boar semen quality from 9 to 37 months old and improvement by protocatechuic acid

Background Comprehending the patterns of alteration in boar semen quality and identifying effective nutritional interventions are crucial for enhancing the productivity of commercial pig systems.This study aimed to examine the alteration in semen quality in boars,and assess the impact of protocatechuic acid(PCA)on semen quality during the phase of declining semen quality.Methods In Exp.1,a total of 38 Pig Improvement Company(PIC)boars were selected and their semen quality data were recorded from the age of 9 to 37 months.In Exp.2,18 PIC boars(28 months old)were randomly assigned into three groups(n=6)and fed a basal diet,a basal diet containing 500 or 1,000 mg/kg PCA,respectively.The experiment lasted for 12 weeks.Results The semen volume,concentration,and total number of spermatozoa in boars exhibited an increase from 9 to 19 months old and showed a significant linear decreased trend in 28,24,and 22 months old.Sperm motility displayed an upward trajectory,reaching its peak at 20 months of age,and showed a significant linear decreased trend at 20 months old.Dietary supplementation of PCA demonstrated an effect to mitigate the decrease in semen volume,concentration of spermatozoa,total number of spermatozoa(P>0.05),and significantly increased the sperm motility(P<0.05).Moreover,supplementation of 1,000 mg/kg PCA significantly increased the sperm viability(P<0.05).Analysis on cellular signaling pathways revealed that PCA restored serum testosterone levels and alleviated oxidative damage by upregulating the expression of HO-1,SOD2,and NQO1 in testicular stromal cells.Notably,PCA can enhance phosphorylation by selectively binding to AMP-activated protein kinase(AMPK)protein,thereby improving sperm mitochondrial function and augmenting sperm motility via PGC-1/Nrf1.Conclusions These data elucidated the pattern of semen quality variation in boars within the age range of 9 to 37 months old,and PCA has the potential to be a natural antioxidant to enhance sperm quality through modulation of the AMPK/PGC-1/Nrf1 signaling pathway.

Oils with different degree of saturation:effects on ileal digestibility of fat and corresponding additivity and bacterial community in growing pigs

Background Oils are important sources of energy in pig diets.The combination of oils with different degree of saturation contributes to improve the utilization efficiency of the mixed oils and may reduce the cost of oil supplemented.An experiment was conducted to evaluate the effects of oils with different degree of saturation on the fat digestibility and corresponding additivity and bacterial community in growing pigs.Methods Eighteen crossbred(Duroc×Landrace×Yorkshire)barrows(initial body weight:29.3±2.8 kg)were surgically fitted with a T-cannula in the distal ileum.The experimental diets included a fat-free basal diet and 5 oil-added diets.The 5 oil-added diets were formulated by adding 6%oil with different ratio of unsaturated to saturated fatty acids(U:S)to the basal diet.The 5 oils were palm oil(U:S=1.2),canola oil(U:S=12.0),and palm oil and canola oil were mixed in different proportions to prepare a combination of U:S of 2.5,3.5 and 4.5,respectively.Results The apparent and standardized ileal digestibility(AID and SID)of fat and fatty acids increased linearly(P<0.05)as the U:S of dietary oils increased except for SID of fat and C18:2.The AID and SID of fat and fatty acids differed among the dietary treatments(P<0.05)except for SID of unsaturated fatty acids(UFA)and C18:2.Fitted one-slope broken-line analyses for the SID of fat,saturated fatty acids(SFA)and UFA indicated that the breakpoint for U:S of oil was 4.14(R^(2)=0.89,P<0.01),2.91(R^(2)=0.98,P<0.01)and 3.84(R^(2)=0.85,P<0.01),respectively.The determined SID of fat,C18:1,C18:2 and UFA in the mixtures was not different from the calculated SID of fat,C18:1,C18:2 and UFA.However,the determined SID of C16:0,C18:0 and SFA in the mixtures were greater than the calculated SID values(P<0.05).The abundance of Romboutsia and Turicibacter in pigs fed diet containing palm oil was greater than that in rapeseed oil treatment group,and the two bacteria were negatively correlated with SID of C16:0,C18:0 and SFA(P<0.05).Conclusions The optimal U:S for improving the utilization efficiency of mixed oil was 4.14.The SID of fat and UFA for palm oil and canola oil were additive in growing pigs,whereas the SID of SFA in the mixture of two oils was greater than the sum of the values of pure oils.Differences in fat digestibility caused by oils differing in degree of saturation has a significant impact on bacterial community in the foregut.

Vitamin A regulates mitochondrial biogenesis and function through p38 MAPK‑PGC‑1α signaling pathway and alters the muscle fiber composition of sheep

Background Vitamin A(VA)and its metabolite,retinoic acid(RA),are of great interest for their wide range of physiological functions.However,the regulatory contribution of VA to mitochondrial and muscle fiber composition in sheep has not been reported.Method Lambs were injected with 0(control)or 7,500 IU VA palmitate into the biceps femoris muscle on d 2 after birth.At the age of 3 and 32 weeks,longissimus dorsi(LD)muscle samples were obtained to explore the effect of VA on myofiber type composition.In vitro,we investigated the effects of RA on myofiber type composition and intrinsic mechanisms.Results The proportion of type I myofiber was greatly increased in VA-treated sheep in LD muscle at harvest.VA greatly promoted mitochondrial biogenesis and function in LD muscle of sheep.Further exploration revealed that VA elevated PGC-1αmRNA and protein contents,and enhanced the level of p38 MAPK phosphorylation in LD muscle of sheep.In addition,the number of type I myofibers with RA treatment was significantly increased,and type IIx myofibers was significantly decreased in primary myoblasts.Consistent with in vivo experiment,RA significantly improved mitochondrial biogenesis and function in primary myoblasts of sheep.We then used si-PGC-1αto inhibit PGC-1αexpression and found that si-PGC-1αsignificantly abrogated RA-induced the formation of type I myofibers,mitochondrial biogenesis,MitoTracker staining intensity,UQCRC1 and ATP5A1 expression,SDH activity,and enhanced the level of type IIx muscle fibers.These data suggested that RA improved mitochondrial biogenesis and function by promoting PGC-1αexpression,and increased type I myofibers.In order to prove that the effect of RA on the level of PGC-1αis caused by p38 MAPK signaling,we inhibited the p38 MAPK signaling using a p38 MAPK inhibitor,which significantly reduced RA-induced PGC-1αand MyHC I levels.Conclusion VA promoted PGC-1αexpression through the p38 MAPK signaling pathway,improved mitochondrial biogenesis,and altered the composition of muscle fiber type.

Supplementation of Lycium barbarum residue increases the growth rate of Tan sheep by enhancing their feed intake and regulating their rumen microbiome and metabolome

Lycium barbarum residue(LBR),a by-product of L.barbarum processing,is packed with bioactive components and can be potentially utilized as a feed additive in animal husbandry.However,the fundamental understanding of its effectiveness on livestock animals is still lacking,particularly in ruminants.To explore the effects of LBR on the growth performance,rumen fermentation parameters,ruminal microbes and metabolites of Tan sheep,sixteen fattening rams(aged 4 mon)were fed a basal diet(CON,n=8)or a basal diet supplemented with 5%LBR(LBR,n=8).The experiment lasted for 70 d,with 10 d adaptation period and 60 d treatment period.The results showed that the LBR enhanced the average daily feed intake,average daily gain(P<0.05),and ruminal total volatile fatty acids(P<0.01)while decreasing ammonia-nitrogen concentration and rumen pH value(P<0.05).Additionally,the LBR improved the relative abundances of Prevotella,Succiniclasticum,Ruminococcus,Coprococcus,Selenomonas,and Butyrivibrio(P<0.05)and reduced the relative abundances of Oscillospira and Succinivibrio(P<0.05).The LBR altered the ruminal metabolome(P<0.01)by increasing the abundances of ruminal metabolites involved in amino acids(e.g.,L-proline,L-phenylalanine,L-lysine,and L-tyrosine),pyrimidine metabolism(e.g.,uridine,uracil,and thymidine),and microbial protein synthesis(e.g.,xanthine and hypoxanthine).In conclusion,LBR had positive effects on the growth rate of Tan sheep as well as on rumen fermentation parameters,rumen microbiome and rumen metabolome.

Gut microbiome and serum metabolome analyses identify Bacteroides fragilis as regulators of serotonin content and PRL secretion in broody geese

Broody behavior is regulated by hypothalamic prolactin secretion,which seriously affects egg production in poulty production.Numerous studies have provided evidence that animal behavior is governed by dynamic bidirectional communication between specific gut bacteria and their host via the brain-gut-microbiome axis.However,little research focused on how the gut microbiota influence broody behavior in poultry.In this study,Zhedong white geese in laying and brooding phases were selected.Ten differentially abundant bacteria in cecum were detected between brooding and laying geese through metagenomic analyses and 16S rRNA sequencing(P<0.05),and Bacteroides fragilis was specifically identified as a key driver species in the brooding geese.Moverover,the serum metabolites were quantified,and the 313 differentially abundant metabolites were found between the two groups of different physiological geese.They were primarily enriched in the tryptophan metabolism pathways.Pearson correlation analyses revealed there was a significant positive correlation between B.fragilis abundance and the context of 11 tryptophan metabolism-related metabolites(such as serotonin,etc.)in broody geese,which hinted that those tryptophan metabolites might be produced or driven by B.fragilis.Finally,the serum hormone levels were also measured.We found there was a positive correlation between B.fragilis abundance and content of serotonin.Besides,prolactin secreted by the pituitary gland was greater in brooding geese than that in laying geese,which was also highly correlated with B.fragilis abundance.This result implied that B.fragilis could promote the secretion of prolactin by the pituitary gland.Together,the current study findings provided the information on gut microbiota influencing broody behavior,B.fragilis produced or driven more serum serotonin,and stimulated the pituitary gland to secret more prolactin,which potentially offered a new enlightenment for the intervention of broody behavior in poultry.

The chemical characteristics of different sodium iron ethylenediaminetetraacetate sources and their relative bioavailabilities for broilers fed with a conventional corn‑soybean meal diet

Background Our previous studies demonstrated that divalent organic iron(Fe)proteinate sources with higher complexation or chelation strengths as expressed by the greater quotient of formation(Qf)values displayed higher Fe bioavailabilities for broilers.Sodium iron ethylenediaminetetraacetate(NaFeEDTA)is a trivalent organic Fe source with the strongest chelating ligand EDTA.However,the bioavailability of Fe when administered as NaFeEDTA in broilers and other agricultural animals remains untested.Herein,the chemical characteristics of 12 NaFeEDTA products were determined.Of these,one feed grade NaFeEDTA(Qf=2.07×10^(8)),one food grade NaFeEDTA(Qf=3.31×10^(8)),and one Fe proteinate with an extremely strong chelation strength(Fe-Prot ES,Qf value=8,590)were selected.Their bioavailabilities relative to Fe sulfate(FeSO_(4)·7H_(2)O)for broilers fed with a conventional corn-soybean meal diet were evaluated during d 1 to 21 by investigating the effects of the above Fe sources and added Fe levels on the growth performance,hematological indices,Fe contents,activities and gene expressions of Fe-containing enzymes in various tissues of broilers.Results NaFeEDTA sources varied greatly in their chemical characteristics.Plasma Fe concentration(PI),transferrin saturation(TS),liver Fe content,succinate dehydrogenase(SDH)activities in liver,heart,and kidney,catalase(CAT)activity in liver,and SDH mRNA expressions in liver and kidney increased linearly(P<0.05)with increasing levels of Fe supplementation.However,differences among Fe sources were detected(P<0.05)only for PI,liver Fe content,CAT activity in liver,SDH activities in heart and kidney,and SDH mRNA expressions in liver and kidney.Based on slope ratios from multiple linear regressions of the above indices on daily dietary analyzed Fe intake,the average bioavailabilities of Fe-Prot ES,feed grade NaFeEDTA,and food grade NaFeEDTA relative to the inorganic FeSO_(4)·7H_(2)O(100%)for broilers were 139%,155%,and 166%,respectively.Conclusions The bioavailabilities of organic Fe sources relative to FeSO_(4)·7H_(2)O were closely related to their Qf values,and NaFeEDTA sources with higher Qf values showed higher Fe bioavailabilities for broilers fed with a conventional corn-soybean meal diet.

miR-24-3p promotes proliferation and inhibits apoptosis of porcine granulosa cells by targeting P27

Ovarian follicle development is associated with the physiological functions of granulosa cells(GCs),including proliferation and apoptosis.The level of miR-24-3p in ovarian tissue of high-yielding Yorkshire×Landrace sows was significantly higher than that of low-yielding sows.However,the functions of miR-24-3p on GCs are unclear.In this study,using flow cytometry,5-ethynyl-2′-de-oxyuridine(EdU)staining,and cell count,we showed that miR-24-3p promoted the proliferation of GCs increasing the proportion of cells in the S phase and upregulating the expression of cell cycle genes,moreover,miR-24-3p inhibited GC apoptosis.Mechanistically,on-line prediction,bioinformatics analysis,a luciferase reporter assay,RT-qPCR,and Western blot results showed that the target gene of miR-24-3p in proliferation and apoptosis is cyclin-dependent kinase inhibitor 1B(P27/CDKN1B).Furthermore,the effect of miR-24-3p on GC proliferation and apoptosis was attenuated by P27 overexpression.These findings suggest that miR-24-3p regulates the physiological functions of GCs.

Insights into the interplay between gut microbiota and lipid metabolism in the obesity management of canines and felines

Obesity is a prevalent chronic disease that has significant negative impacts on humans and our companion animals,including dogs and cats.Obesity occurs with multiple comorbidities,such as diabetes,hypertension,heart disease and osteoarthritis in dogs and cats.A direct link between lipid metabolism dysregulation and obesity-associated diseases has been implicated.However,the understanding of such pathophysiology in companion animals is lim-ited.This review aims to address the role of lipid metabolism in various metabolic disorders associated with obesity,emphasizing the involvement of the gut microbiota.Furthermore,we also discuss the management of obesity,including approaches like nutritional interventions,thus providing novel insights into obesity prevention and treatment for canines and felines.

Biology of Hippo signaling pathway:Skeletal muscle development and beyond

Global demand for farm animals and their meat products i.e.,pork,chicken and other livestock meat,is steadily incresing.With the ongoing life science research and the rapid development of biotechnology,it is a great opportunity to develop advanced molecular breeding markers to efficiently improve animal meat production traits.Hippo is an important study subject because of its crucial role in the regulation of organ size.In recent years,with the increase of research on Hippo signaling pathway,the integrative application of multi-omics technologies such as genomics,transcriptomics,proteomics,and metabolomics can help promote the in-depth involvement of Hippo signaling pathway in skeletal muscle development research.The Hippo signaling pathway plays a key role in many biological events,including cell division,cell migration,cell proliferation,cell differentiation,cell apoptosis,as well as cell adhesion,cell polarity,homeostasis,maintenance of the face of mechanical overload,etc.Its influence on the development of skeletal muscle has important research value for enhancing the efficiency of animal husbandry production.In this study,we traced the origin of the Hippo pathway,comprehensively sorted out all the functional factors found in the pathway,deeply analyzed the molecular mechanism of its function,and classified it from a novel perspective based on its main functional domain and mode of action.Our aim is to systematically explore its regulatory role throughout skeletal muscle development.We specifically focus on the Hippo signaling pathway in embryonic stem cell development,muscle satellite cell fate determination,myogenesis,skeletal muscle meat production and organ size regulation,muscle hypertrophy and atrophy,muscle fiber formation and its transformation between different types,and cardiomyocytes.The roles in proliferation and regeneration are methodically summarized and analyzed comprehensively.The summary and prospect of the Hippo signaling pathway within this article will provide ideas for further improving meat production and muscle deposition and developing new molecular breeding technologies for livestock and poultry,which will be helpful for the development of animal molecular breeding.

Effects of dietary Clostridium butyricum and rumen protected fat on meat quality,oxidative stability,and chemical composition of finishing goats

Background Clostridium butyricum(CB)is a probiotic that can regulate intestinal microbial composition and improve meat quality.Rumen protected fat(RPF)has been shown to increase the dietary energy density and provide essential fatty acids.However,it is still unknown whether dietary supplementation with CB and RPF exerts beneficial effects on growth performance and nutritional value of goat meat.This study aimed to investigate the effects of dietary CB and RPF supplementation on growth performance,meat quality,oxidative stability,and meat nutritional value of finishing goats.Thirty-two goats(initial body weight,20.5±0.82 kg)were used in a completely randomized block design with a 2 RPF supplementation(0 vs.30 g/d)×2 CB supplementation(0 vs.1.0 g/d)factorial treatment arrangement.The experiment included a 14-d adaptation and 70-d data and sample collection period.The goats were fed a diet consisted of 400 g/kg peanut seedling and 600 g/kg corn-based concentrate(dry matter basis).Result Interaction between CB and RPF was rarely observed on the variables measured,except that shear force was reduced(P<0.05)by adding CB or RPF alone or their combination;the increased intramuscular fat(IMF)content with adding RPF was more pronounced(P<0.05)with CB than without CB addition.The pH24h(P=0.009),a*values(P=0.007),total antioxidant capacity(P=0.050),glutathione peroxidase activities(P=0.006),concentrations of 18:3(P<0.001),20:5(P=0.003)and total polyunsaturated fatty acids(P=0.048)were increased,whereas the L*values(P<0.001),shear force(P=0.050)and malondialdehyde content(P=0.044)were decreased by adding CB.Furthermore,CB supplementation increased essential amino acid(P=0.027),flavor amino acid(P=0.010)and total amino acid contents(P=0.024)as well as upregulated the expression of lipoprotein lipase(P=0.034)and peroxisome proliferator-activated receptorγ(PPARγ)(P=0.012),and downregulated the expression of stearoyl-CoA desaturase(SCD)(P=0.034).The RPF supplementation increased dry matter intake(P=0.005),averaged daily gain(trend,P=0.058),hot carcass weight(P=0.046),backfat thickness(P=0.006),concentrations of 16:0(P<0.001)and c9-18:1(P=0.002),and decreased the shear force(P<0.001),isoleucine(P=0.049)and lysine content(P=0.003)of meat.In addition,the expressions of acetyl-CoA carboxylase(P=0.003),fatty acid synthase(P=0.038),SCD(P<0.001)and PPARγ(P=0.022)were upregulated due to RPF supplementation,resulting in higher(P<0.001)content of IMF.Conclusions CB and RPF could be fed to goats for improving the growth performance,carcass traits and meat quality,and promote fat deposition by upregulating the expression of lipogenic genes of Longissimus thoracis muscle.

Dynamic transcriptome profiles and novel markers in bovine spermatogenesis revealed by single-cell sequencing

Testicular development is an important biological process in male and requires interaction between the male germ cells and somatic cells.However,the mechanisms of testicular development in livestock,particularly in cattle,are poorly understood.Furthermore,cellular heterogeneity hinders the profiling of different cell types at different developmental stages.In this study,we first performed a single-cell transcriptomic study of the bovine testis development during puberty by using 10×genomics single-cell RNA sequencing(scRNA-seq).By collecting the scRNA-seq data from 11,083 cells from prepubertal and pubertal bovine testes,a high-resolution scRNA-seq atlas was described,identifying 9 somatic and 13 spermatogenic clusters.We also distinguished several stage-specific marker genes for bovine germ cells and somatic cells,such as GRAF2 and MORC1 for SSC(spermatogonial stem cells),HJURP and TCF19 for differentiating spermatogonia,ARSE for immature Sertoli,CLEC12B for mature Sertoli,LOC112441470 for Leydig.In conclusion,we have examined the transcription levels and constructed the single-cell developmental maps of germ cells and somatic cells during testicular development in Angus cattle.The datasets provided new insights into spermatogenesis and testicular somatic cell development in cattle.

A cell transcriptomic profile p ovides insights into adipocytes of porcine mammary gland across development

Background Studying the composition and developmental mechanisms in mammary gland is crucial for healthy growth of newborns. The mammary gland is inherently heterogeneous, and its physiological function dependents on the gene expression of multiple cell types. Most studies focused on epithelial cells, disregarding the role of neighboring adipocytes.Results Here, we constructed the largest transcriptomic dataset of porcine mammary gland cells thus far. The dataset captured 126,829 high-quality nuclei from physiological mammary glands across five developmental stages(d 90 of gestation, G90;d 0 after lactation, L0;d 20 after lactation, L20;2 d post natural involution, PI2;7 d post natural involution, PI7). Seven cell types were identified, including epithelial cells, adipocytes, endothelial cells, fibroblasts cells, immune cells, myoepithelial cells and precursor cells. Our data indicate that mammary glands at different developmental stages have distinct phenotypic and transcriptional signatures. During late gestation(G90), the differentiation and proliferation of adipocytes were inhibited. Meanwhile, partly epithelial cells were completely differentiated. Pseudo-time analysis showed that epithelial cells undergo three stages to achieve lactation, including cellular differentiation, hormone sensing, and metabolic activation. During lactation(L0 and L20), adipocytes area accounts for less than 0.5% of mammary glands. To maintain their own survival, the adipocyte exhibited a poorly differentiated state and a proliferative capacity. Epithelial cells initiate lactation upon hormonal stimulation. After fulfilling lactation mission, their undergo physiological death under high intensity lactation. Interestingly, the physiological dead cells seem to be actively cleared by immune cells via CCL21-ACKR4 pathway. This biological process may be an important mechanism for maintaining homeostasis of the mammary gland. During natural involution(PI2 and PI7), epithelial cell populations dedifferentiate into mesenchymal stem cells to maintain the lactation potential of mammary glands for the next lactation cycle.Conclusion The molecular mechanisms of dedifferentiation, proliferation and redifferentiation of adipocytes and epithelial cells were revealed from late pregnancy to natural involution. This cell transcriptomic profile constitutes an essential reference for future studies in the development and remodeling of the mammary gland at different stages.