Investigating the Role of KLF6 in the Growth of Bovine Preadipocytes: Using Transcriptomic Analyses to Understand Beef Quality.

Intramuscular fat is a crucial determinant of carcass quality traits like tenderness and taste, which in turn is influenced by the proliferation of intramuscular preadipocytes. This study aimed to investigate the Krüppel-like factor 6 (KLF6)-mediated proliferation of bovine preadipocytes and identify underlying molecular mechanisms. Down-regulation of KLF6 by siKLF6 resulted in a significant (p < 0.01) suppression of cell cycle-related genes including CDK1, MCM6, ZNF4, PCNA, CDK2, CCNB1, and CDK6. Conversely, the expression level of p27 was significantly (p < 0.01) increased. Moreover, EdU (5-ethynyl-20-deoxyuridine) staining revealed a significant decrease in EdU-labeled cells due to KLF6 down-regulation. Collectively, these findings indicate that KLF6 down-regulation inhibits adipocyte proliferation. Furthermore, RNA sequencing of preadipocytes transfected with siKLF6 and NC, followed by differential gene expression analysis, identified 100 up-regulated and 70 down-regulated genes. Additionally, the differentially expressed genes also significantly influenced various Gene Ontology (GO) terms related to cell cycle, nuclear chromosomes, and catalytic activity on DNA. Furthermore, the top 20 pathways enriched in these DEGs included cell cycle, DNA replication, cellular senescence, and homologous recombination. These GO terms and KEGG pathways play key roles in bovine preadipocyte proliferation. In conclusion, the results of this study suggest that KLF6 positively regulates the proliferation of bovine preadipocytes.

Exploring Epigenetic and Genetic Modulation in Animal Responses to Thermal Stress.

There is increasing evidence indicating that global temperatures are rising significantly, a phenomenon commonly referred to as 'global warming', which in turn is believed to be causing drastic changes to the global climate. Global warming (GW) directly impacts animal health, reproduction, production, and welfare, presenting several challenges to livestock enterprises. Thermal stress (TS) is one of the key consequences of GW, and all animal species, including livestock, have diverse physiological, epigenetic and genetic mechanisms to respond to TS. As a result, TS can significantly affect an animals' health, immune responsiveness, metabolic pathways etc. which can also influence the productivity, performance, and welfare of animals. Moreover, prolonged exposure to TS can lead to transgenerational and intergenerational changes that are mediated by epigenetic changes. For example, in several animal species, the effects of TS are encoded epigenetically during the animals' growth or productive stage, and these epigenetic changes can be transmitted intergenerationally. Such epigenetic changes can affect animal productivity by changing the phenotype so that it aligns with its ancestors' environment, irrespective of its immediate environment. Furthermore, epigenetic and genetic changes can also help protect cells from the adverse effects of TS by modulating the transcriptional status of heat-responsive genes in animals. This review focuses on the genetic and epigenetic modulation and regulation that occurs in TS conditions via HSPs, histone alterations and DNA methylation.

The impact of different levels of wheat diets on hepatic oxidative stress, immune response, and lipid metabolism in Tibetan sheep (Ovis aries).

BACKGROUND: Compared with corn, wheat contains higher crude protein, amino acids concentration. However, wheat contains a mass of anti-nutritional factors, resulting in increased of the digesta viscosity and impaired the intestinal function in ruminant. OBJECTIVE: This study aimed to investigate the effects of substitution of different amounts of wheat for corn on hepatic metabolism in the Tibetan lamb. METHODS: Ninety Tibetan lambs (Body weight = 12.37 ± 0.92 kg) were randomly assigned to three groups: 0% wheat diet (Control), 10% wheat diet (Low group), and 15% wheat diet (High group). The feeding trial lasted for 130 d, including a 10 d adaption period. Hepatic gene expression profiling was performed via RNA sequencing after the conclusion of the feeding trials. RESULTS: Results showed that greater level of glutathione peroxidase levels in L group compared with those of the C and H groups (P < 0.05). The immune indexes, including interleukin-1ß (IL-1ß), immunoglobulin A (IgA), and IgM were also elevated in L group compared with the other groups (P < 0.05). Compared with H group, the hepatocytes were arranged radially, and hepatic plates anastomosed with each other to form a labyrinth-like structure in L group. Transcriptomic analysis showed 872 differentially expressed genes (DEG) between H and L group, of which 755 were down-regulated and 117 were up-regulated. Through Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, 32 pathways were significantly enriched (Q-value < 0.05), such as the cAMP signaling pathway, Th1 and Th2 cell differentiation, leukocyte transendothelial migration, platelet activation and adipocytokine signaling pathway. Additionally, the expression of comment DEGs were verified via quantitative reverse-transcription polymerase chain reaction. CONCLUSION: In summary, our findings suggest that wheat can be supplemented up to 10% in Tibetan sheep, contributing to improve the hepatic oxidative stress, immune response and lipid metabolism through regulating the expression of related genes.

Effect of feeding corn silage on semen quality and spermatogenesis of bulls.

Bovine reproduction, including male fertility traits like semen quality, are influenced by a variety of different factors like breed, nutrition, environment, and feeding management. Diet in a crucial determinant, and in this regard although corn silage is generally considered to be a favorable roughage for fattening meat type breeds, it tends to have a negative impact on semen quality. In the current study, alfalfa hay was substituted by corn silage as a roughage source in the diet of bulls to investigate its effects on the fertility of breeding bulls. A feeding trail spanning 140 days was conducted, with semen collection occurring twice a week commencing 60 days after the start of trial. Semen quality parameters, serum antioxidant indexes, sex hormone content in semen, rumen microflora, and sperm transcriptome were characterized. Feeding corn silage enhanced host antioxidant capacity, significantly decreased spermatozoal motility and increased sperm deformity rate in bulls. Furthermore, follicle-stimulating hormone (FSH) and luteinizing hormone (LH) content in semen were significantly decreased (P < 0.05), and the inhibin B (INHB) content was significantly increased (P < 0.01). Feeding corn silage led to significant changes in the diversity of rumen microbiota of cattle at the phylum and genus levels, some of which were significantly correlated with semen quality. Subsequent RNA sequencing indicated that DHH and PITHD1, two genes related to sperm and reproductive development, were differentially expressed, and enrichment analysis also identified several pathways and biological functions relevant to sperm development and reproduction. These results indicate that feeding corn silage modulates semen quality via different pathways. Firstly, corn silage metabolites likely affect the secretion of INHB through the testicular capillaries, which affects semen quality by regulating genes involved in spermatogenesis. Secondly, low lignin content in silage corn appears to reduce abundance of rumen flora that are positively correlated with semen quality. Overall, results indicate that feeding bulls corn silage as the primary source of forage could negatively impact semen quality and may not be appropriate as the primary roughage of forage for breeding bulls.

Wound healing of experimental equine skin wounds and concurrent microbiota in wound dressings following topical propylene glycol gel treatment.

Introduction: Topical wound treatments rely on carrier formulations with little to no biological impact. The potential for a common vehicle, a propylene glycol (PG) gel, to affect wound healing measures including microbiota is not known. Microbiome characterization, based on next generation sequencing methods is typically performed on tissue or directly obtained wound fluid samples. The utility for primary wound dressings to characterize equine wound microbiota in the context of topical treatments is currently unknown. This investigation reports the topical effect of an 80% PG based gel on wound healing and microbiota in wound dressings. Methods: Experiments were performed in six mature horses utilizing a surgical, distal limb wound model, histology of sequential wound biopsies, photographic wound measurements and microbiota profiling via 16s rRNA sequencing of wound dressing samples. Experimental wounds were surveyed for 42 days and either treated (Day 7, 14, 21 and 28; at 0.03 ml/cm2) or unexposed to the PG gel. Wound surface area, relative and absolute microbial abundances, diversity indices and histologic parameters were analyzed in the context of the experimental group (treatment; control) using qualitative or quantitative methods depending on data characteristics. Results: Compared to controls, treatment slowed the wound healing rate (17.17 ± 4.27 vs. 18.56 ± 6.3 mm2/day), delayed the temporal decline of polymorphonucleated cells in wound beds and operational taxonomic units (OTU) in wound dressings and lowered alpha-diversity indices for microbiota in primary wound dressing. Relative abundances of OTUs were in line with those previously reported for equine wounds. Clinical outcomes 42 days post wounding were considered similar irrespective of PG gel exposure. Discussion: Results highlight the potential for vehicle exposure to alter relevant wound outcome measures, imposing the need for stringent experimental control measures. Primary wound dressings may represent an alternate sample source for characterization of the wound microbiome alleviating the need for additional interventions. Further studies are warranted to contrast the microbiome in wound dressings against that present on wound surfaces to conclude on the validity of this approach.

Increased Yearling Weight Gain Is Associated with a Distinct Faecal Microbial Profile.

Microbial communities inhabiting the gut have the ability to influence physiological processes contributing to livestock production and performance. Livestock enterprises rely on animal production traits such as growth performance for profit. Previous studies have shown that gut microbiota are correlated to growth performance and could even influence it. The aim of this study was to characterise the faecal microbial profiles of Angus steers with high and low ADG at both weaning and yearling stages by profiling 16S rRNA gene sequences from rectal faecal samples. When microbial profiles were compared in terms of relative abundances, LEfSe analysis, alpha diversity metrics, and beta diversity, at the weaning stage, few significant differences were found between the high and low ADG groups. However, at yearling stage, microbial profiles significantly differed between the high and low ADG groups. The relative abundances of eight phyla and six genera significantly differed between the two groups. Alpha diversity metrics showed a significant decrease (p = 0.001) in species richness in the high ADG group. Similarly, beta diversity analysis showed that samples clustered clearly according to high and low ADG groups at yearling stage, indicating that phylogenetic similarity between the two ADG groups was significantly reduced (p = 0.005).

Based on the Cancer Genome Atlas Database Development of a prognostic model of RNA binding protein in stomach adenocarcinoma.

The purpose of this study was to identify potential RNA binding proteins associated with the survival of gastric adenocarcinoma, as well as the corresponding biological characteristics and signaling pathways of these RNA binding proteins. RNA sequencing and clinical data were obtained from the cancer genome map (N = 32, T = 375) and the comprehensive gene expression database (GSE84437, N = 433). The samples in The Cancer Genome Atlas were randomly divided into a development group and a test group. A total of 1495 RNA binding protein related genes were extracted. Using nonparametric tests to analyze the difference of RNA binding protein related genes, 296 differential RNA binding proteins were obtained, 166 were up-regulated and 130 were down regulated. Twenty prognosis-related RNA binding proteins were screened using Cox regression, including 14 high-risk genes (hazard ratio > 1.0) and 6 low-risk genes (hazard ratio < 1.0). Seven RNA binding protein related genes were screened from the final prognostic model and used to construct a new prognostic model. Using the development group and test group, the model was verified with survival analysis, receiver operating characteristics curves and prognosis analysis curves. A prediction nomogram was finally developed and showed good prediction performance.

QTLs and Candidate Genes Associated with Semen Traits in Merino Sheep.

Ram semen traits play a significant role in conception outcomes, which in turn may influence reproductive efficiency and the overall productivity and profitability of sheep enterprises. Since hundreds of ewes may be inseminated from a single ejaculate, it is important to evaluate semen quality prior to use in sheep breeding programs. Given that semen traits have been found to be heritable, genetic variation likely contributes to the variability observed in these traits. Identifying such genetic variants could provide novel insights into the molecular mechanisms underlying variability in semen traits. Therefore, this study aimed to identify quantitative trait loci (QTLs) associated with semen traits in Merino sheep. A genome-wide association study (GWAS) was undertaken using 4506 semen collection records from 246 Merino rams collected between January 2002 and May 2021. The R package RepeatABEL was used to perform a GWAS for semen volume, gross motility, concentration, and percent post-thaw motility. A total of 35 QTLs, located on 16 Ovis aries autosomes (OARs), were significantly associated with either of the four semen traits in this study. A total of 89, 95, 33, and 73 candidate genes were identified, via modified Bonferroni, within the QTLs significantly associated with volume, gross motility, concentration, and percent post-thaw motility, respectively. Among the candidate genes identified, SORD, SH2B1, and NT5E have been previously described to significantly influence spermatogenesis, spermatozoal motility, and high percent post-thaw motility, respectively. Several candidate genes identified could potentially influence ram semen traits based on existing evidence in the literature. As such, validation of these putative candidates may offer the potential to develop future strategies to improve sheep reproductive efficiency. Furthermore, Merino ram semen traits are lowly heritable (0.071-0.139), and thus may be improved by selective breeding.

MAPK family genes' influences on myogenesis in cattle: Genome-wide analysis and identification.

The mitogen-activated protein kinase (MAPK) family is highly conserved in mammals, and is involved in a variety of physiological phenomena like regeneration, development, cell proliferation, and differentiation. In this study, 13 MAPK genes were identified in cattle and their corresponding protein properties were characterized using genome-wide identification and analysis. Phylogenetic analysis showed that the 13 BtMAPKs were cluster grouped into eight major evolutionary branches, which were segmented into three large subfamilies: ERK, p38 and JNK MAPK. BtMAPKs from the same subfamily had similar protein motif compositions, but considerably different exon-intron patterns. The heatmap analysis of transcriptome sequencing data showed that the expression of BtMAPKs was tissue-specific, with BtMAPK6 and BtMAPK12 highly expressed in muscle tissues. Furthermore, knockdown of BtMAPK6 and BtMAPK12 revealed that BtMAPK6 had no effect on myogenic cell proliferation, but negatively affected the differentiation of myogenic cells. In contrast, BtMAPK12 improved both the cell proliferation and differentiation. Taken together, these results provide novel insights into the functions of MAPK families in cattle, which could serve as a basis for further studies on the specific mechanisms of the genes in myogenesis.

miR-33a Inhibits the Differentiation of Bovine Preadipocytes through the IRS2-Akt Pathway.

Several microRNAs (miRNAs) are known to participate in adipogenesis. However, their role in this process, especially in the differentiation of bovine preadipocytes, remains to be elucidated. This study was intended to clarify the effect of microRNA-33a (miR-33a) on the differentiation of bovine preadipocytes by cell culture, real-time fluorescent quantitative PCR (qPCR), Oil Red staining, BODIPY staining, and Western blotting. The results indicate that overexpression of miR-33a significantly inhibited lipid droplet accumulation and decreased the mRNA and protein expression of adipocyte differentiation marker genes such as peroxisome proliferator-activated receptor gamma (PPARγ), sterol regulatory element-binding protein 1 (SREBP1), and fatty acid-binding protein 4 (FABP4). In contrast, the interference expression of miR-33a promoted lipid droplet accumulation and increased the expression of marker genes. Additionally, miR-33a directly targeted insulin receptor substrate 2 (IRS2) and regulated the phosphorylation level of serine/threonine kinase (Akt). Furthermore, miR-33a inhibition could rescue defects in the differentiation of bovine preadipocytes and the Akt phosphorylation level caused by small interfering IRS2 (si-IRS2). Collectively, these results indicate that miR-33a could inhibit the differentiation of bovine preadipocytes, possibly through the IRS2-Akt pathway. These findings might help develop practical means to improve the quality of beef.

Effect of Tea Saponins on Rumen Microbiota and Rumen Function in Qinchuan Beef Cattle.

Antibiotics can promote livestock growth but have side effects, so the search for safe and effective alternatives to antibiotics is urgent. This study aimed to evaluate the effect of supplementing cattle feed with tea saponins on ruminal bacteria and fungi. Sixteen Qinchuan beef cattle with a live body weight of 250 ± 10 kg were divided into four groups (four animals in each group) using a completely randomized experimental design. Four different levels of tea saponins were provided to the Qinchuan cattle as treatments, including 0 g/cattle per day control, CON), 10 g/cattle per day (low-level, LT), 20 g/cattle per day (medium-level, MT) and 30 g/cattle per day (high-level, HT). The pre-feeding period was 10 days and the official period was 80 days in this experiment. After 90 days of feeding, the rumen fluid from sixteen Qinchuan beef cattle was collected using an oral stomach tube for evaluating changes in ruminal microbiota and rumen fermentation parameters. Results indicate that the total VFAs and proportions of propionate in the LT group was significantly higher than that in the CON and HT groups (p < 0.05). For ruminal bacteria, results indicate that the Chao1 index of the MT group was significantly lower than the CON and HT groups (p < 0.05). The phyla Bacteroidetes and Firmicutes were found to be the most abundant in all treatment groups, with the LT group having significantly increased relative abundances of Proteobacteria, Actinobacteria and Ascomycota at the phylum level (p < 0.05). The relative abundance of Bacteroides was found to be relatively lower in the LT, MT and HT treatment groups compared with the CON treatment group at the genus level (p < 0.05). For ruminal fungi, the LT treatment group was found to have higher relative abundances of Saccharomyces and Aspergillus, and lower relative abundances of Succiniclasticum and Bacteroides at the at the phylum level (p < 0.05). Compared with the CON treatment group, a significant increase in the relative abundance of Saccharomyces and Aspergillus were observed in the LT treatment group at the genus level (p < 0.05). PICRUSt analyses identified pathways associated with Xenobiotic biodegradation and metabolism and glycolysisIII to be significantly enriched in the LT and HT treatment groups (p < 0.05). These findings could provide insights on how tea saponins may influence ruminal bacteria and fungi, providing a theoretical basis for replacing antibiotics with tea saponins for promoting growth in cattle.

Genetic variation in the OPN gene affects milk composition in Chinese Holstein cows.

The aim of this study was to investigate the association between genotypes and haplotypes of OPN, and milk composition in dairy cows. A total of 317 Chinese Holstein cows were genotyped via DNA sequencing in this study. Three single nucleotide polymorphisms (SNPs), g.2916G > A, g.58675C > T and g.58899C > A, and eight haplotypes were identified. Of the eight possible haplotypes, four haplotypes i.e., Hap2 (ACC; 55.30%), Hap6 (GCC, 15.6%), Hap1 (ACA, 13.6%) and Hap4 (ATC, 5.70%), were considered to be major with a cumulative estimated frequency of >90%. Single markers (g.2916G > A and g.58899C > A) and Haplotype Hap6/4 were found to be associated with an increase in butter-fat percentage (p < 0.05). Taken together, our results provided evidence that polymorphisms in OPN are associated with milk composition, and could potentially be used for marker-assisted selection in Chinese Holstein cows.

Heritability and Genetic Parameters for Semen Traits in Australian Sheep.

Semen characteristics including volume, gross motility, spermatozoal concentration, and percent post-thaw motility are routinely assessed to determine the quality and quantity of an ejaculate prior to use in artificial breeding programs. Currently, artificial breeding programs in sheep place relatively little emphasis on ram-side factors, such as the fertilising potential of an ejaculate, which may contribute to variability in conception outcomes. Estimating genetic parameters for ejaculate quality and quantity traits could provide insights into whether selective breeding can be used to improve such ram-side traits, improving ovine reproductive performance and farm profitability. Therefore, in this study, a total of 11,470 ejaculate records, including data for ejaculate volume, gross motility, spermatozoal concentration, and percent post-thaw motility, collected over a 20-year period was used to estimate genetic parameters in sheep. Univariate and bivariate mixed model analysis was performed including a variety of fixed effects such as breed, age at collection, centre of collection, collection number, season of collection, and method of collection; and the permanent environmental effects associated with each ram, stud and year of collection, and the breeding value of rams included as random effects. The heritability for ejaculate volume, gross motility, concentration, and percent post-thaw motility was estimated to be 0.161, 0.170, 0.089, and 0.081. Repeatability estimates were moderate, ranging between 0.4126 and 0.5265. Overall, results indicate that semen traits are lowly heritable and moderately repeatable, indicating that these traits are significantly influenced by environmental variables.

Temporal Changes in the Faecal Microbiota of Beef Cattle on Feedlot Placement.

The microbial communities that inhabit the intestinal tract play an important role in modulating health and productivity. Environmental stressors can impact microbial communities, which can significantly influence host physiology. Cattle are subjected to several environmental stressors when placed on feedlots, such as transportation stress, exposure to feedlot environments and change in diet and management. Exposure to these stressors could influence host gut microbiota, which in turn, could potentially influence host health and performance. The aim of the current study was to characterise the temporal changes that occur in intestinal microbiota as a consequence of feedlot placement by profiling 16s rRNA sequences in rectal faecal samples. When faecal microbiome profiles were compared in terms of relative abundances and alpha diversity metrics, the results showed significant, observable changes in profiles 2 days post-feedlot induction. Furthermore, beta-diversity analysis indicated that the phylogenetic similarity between samples significantly decreased on day 2 (PERMANOVA, p < 0.001). These trends were suggestive of a short-term reduction in microbial diversity coupled with decreased similarity between animals. These changes warrant further investigation and could provide opportunities for improved performance, health and even welfare of feedlot cattle in future.

Exploring the physiological roles of circular RNAs in livestock animals.

Circular RNAs (circRNAs) are a recently identified class of RNAs produced via back-splicing and covalent linkage between RNA ends, resulting in a circularized RNA molecule. Physiologically, circRNAs are known to influence a variety of biological pathways, and can also regulate transcription, post-transcription, RNA splicing, or interaction with other proteins or microRNAs (miRNAs). Functionally, circRNAs are known to competitively bind to various other RNA molecules including miRNAs and other competing endogenous RNA such as long noncoding RNA, thereby significantly influencing gene expression. Since gene expression is a crucial factor that underlies economically important livestock traits, it is likely that circRNAs significantly influence livestock traits like growth, milk production, reproduction, meat quality, hair follicle growth, and gametogenesis. Thousands of circRNAs have been recognized in different species of animals, and some of these circRNAs have also been shown to regulate stress responses that may be crucial for animal welfare. Therefore, in this review, we aim to highlight the biogenesis of circRNAs, along with its potential implications for livestock. The presented summary would offer a fundamental understanding of the molecular machinery that underlies circRNAs and associated biological phenomena and emphasize the need for further explorations into the role of circRNAs in the other productive, reproductive, and physiological attributes in animals.

Krüppel-like factors family regulation of adipogenic markers genes in bovine cattle adipogenesis.

Intramuscular fat (IMF) content is a crucial determinant of meat quality traits in livestock. A network of transcription factors act in concert to regulate adipocyte formation and differentiation, which in turn influences intramuscular fat. Several genes and associated transcription factors have been reported to influence lipogenesis and adipogenesis during fetal and subsequent growth stage. Specifically in cattle, Krüppel-like factors (KLFs), which represents a family of transcription factors, have been reported to be involved in adipogenic differentiation and development. KLFs are a relatively large group of zinc-finger transcription factors that have a variety of functions in addition to adipogenesis. In mammals, the participation of KLFs in cell development and differentiation is well known. Specifically in the context of adipogenesis, KLFs function either as positive (KLF4, KLF5, KLF6, KLF8, KLF9, KLF10, KLF11, KLF12, KLF13, KLF14 and KLF15) or negative organizers (KLF2, KLF3 and KLF7), by a variety of different mechanisms such as crosstalk with C/EBP and PPARγ. In this review, we aim to summarize the potential functions of KLFs in regulating adipogenesis and associated pathways in cattle. Furthermore, the function of known bovine adipogenic marker genes, and associated transcription factors that regulate the expression of these marker genes is also summarized. Overall, this review will provide an overview of marker genes known to influence bovine adipogenesis and regulation of expression of these genes, to provide insights into leveraging these genes and transcription factors to enhance breeding programs, especially in the context of IMF deposition and meat quality.

Potentials, prospects and applications of genome editing technologies in livestock production.

In recent years, significant progress has been achieved in genome editing applications using new programmable DNA nucleases such as zinc finger nucleases (ZFNs), transcription activator-like endonucleases (TALENs) and the clustered regularly interspaced short palindromic repeats/Cas9 system (CRISPR/Cas9). These genome editing tools are capable of nicking DNA precisely by targeting specific sequences, and enable the addition, removal or substitution of nucleotides via double-stranded breakage at specific genomic loci. CRISPR/Cas system, one of the most recent genome editing tools, affords the ability to efficiently generate multiple genomic nicks in single experiment. Moreover, CRISPR/Cas systems are relatively easy and cost effective when compared to other genome editing technologies. This is in part because CRISPR/Cas systems rely on RNA-DNA binding, unlike other genome editing tools that rely on protein-DNA interactions, which affords CRISPR/Cas systems higher flexibility and more fidelity. Genome editing tools have significantly contributed to different aspects of livestock production such as disease resistance, improved performance, alterations of milk composition, animal welfare and biomedicine. However, despite these contributions and future potential, genome editing technologies also have inherent risks, and therefore, ethics and social acceptance are crucial factors associated with implementation of these technologies. This review emphasizes the impact of genome editing technologies in development of livestock breeding and production in numerous species such as cattle, pigs, sheep and goats. This review also discusses the mechanisms behind genome editing technologies, their potential applications, risks and associated ethics that should be considered in the context of livestock.

RNA-Seq reveals the potential molecular mechanisms of bovine KLF6 gene in the regulation of adipogenesis.

Marbling influences the taste and tenderness of meat and is the main determinant of carcass quality in many countries. This study aims to investigate the influence of KLF6 (Kruppel Like Factor 6) and associated molecular mechanisms on lipid metabolism in bovine adipocytes. In the current study, KLF6 gene expression was down regulated via siRNA (small interfering RNA) in bovine adipocytes in vitro. Subsequently, adipogenic cells were collected from the culture media after 9 days, and subjected to fluorescent imaging and RNA sequencing. After confirming that KLF6 was down regulated in bovine adipocytes by siRNA, differential gene expression analysis was used to characterize the infuence of KLF6 on gene expression profiles in bovine adipocytes. A total of 10,812 genes were characterized as differentially expressed genes (DEGs) of which, 109 were up-regulated and 62 were down-regulated genes. KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analysis identified that the DEGs were associated with lipid metabolism, carbohydrate metabolism, cell growth and death, cancer, and the signaling pathways for calcium, AMPK (Adenosine Monophosphate-Activated Protein Kinase), PI3K-Akt (Phosphatidylinositol 3-kinase), PPAR (Peroxisome proliferator-activated receptors), MAPK (mitogen-activated protein kinase), cAMP (Cyclic adenosine monophosphate), and Wnt (Wingless-related integration site). Similarly, gene ontology analysis indicated that down-regulation of KLF6 gene significantly up regulated the genes that regulate adipogenesis, differentiation and regulation of adipocytes and homeostasis of bovine adipocytes, specifically regulating the cell-type specific apoptotic action, negative regulation of apoptotic pathways, programmed cell death, and growth. Results indicate that KLF6 has a role in regulating lipid metabolism in bovine adipocytes. These findings provide evidence that may inform further investigations into molecular mechanisms that underlie the role of bovine KLF6 gene in regulating adipogenesis.

Maternal Behavior in Beef Cattle: The Physiology, Assessment and Future Directions-A Review.

Bovine maternal behavior is known to be influenced by a variety of factors including hormonal mediation, breed, age, parity, host genetics and general management practices. Following centuries of varying levels of domestication processes, the behavior of the bovine cow has altered from that of her original wild ungulate ancestors, although many maternal instincts have remained unchanged. The influence of maternal behavior on calf health and performance is of interest to cow-calf beef production operations, as in most instances, the cow is solely responsible for rearing the calf until weaning. However, investigating the magnitude of this influence is challenging, in part because objective measurement of behavioral traits is difficult, particularly in extensive settings. In recent years, while a number of remote monitoring devices have been developed that afford opportunities for objective measurement of behavioral traits in livestock, characterization of physiological mechanisms that underlie superior maternal behavior, including identification of potential biomarkers remains elusive in cattle. Hormonal profiles during the periparturient period have been shown to influence behavioral patterns in both current and future generations in other mammalian species and may provide insights into the physiology of bovine maternal behavior. Therefore, the aim of this review is to describe general characteristics of bovine maternal behavior and the factors known to influence it, including hormonal drivers, through which cross-reference to other species is made. Current methods of measuring and assessing behavior that may also be applicable to most production settings have also been reviewed. At present, there is no known hormonal assay that can be used to measure and/or reliably predict bovine maternal behavior post-calving or across generations. Being able to objectively assess superior maternal behavior, whether that be through remote monitoring, hormonal profiling or indirectly through measuring calf performance will be beneficial to livestock industries in the future.

Screening and Identification of Muscle-Specific Candidate Genes via Mouse Microarray Data Analysis.

Muscle tissue is involved with every stage of life activities and has roles in biological processes. For example, the blood circulation system needs the heart muscle to transport blood to all parts, and the movement cannot be separated from the participation of skeletal muscle. However, the process of muscle development and the regulatory mechanisms of muscle development are not clear at present. In this study, we used bioinformatics techniques to identify differentially expressed genes specifically expressed in multiple muscle tissues of mice as potential candidate genes for studying the regulatory mechanisms of muscle development. Mouse tissue microarray data from 18 tissue samples was selected from the GEO database for analysis. Muscle tissue as the treatment group, and the other 17 tissues as the control group. Genes expressed in the muscle tissue were different to those in the other 17 tissues and identified 272 differential genes with highly specific expression in muscle tissue, including 260 up-regulated genes and 12 down regulated genes. is the genes were associated with the myofibril, contractile fibers, and sarcomere, cytoskeletal protein binding, and actin binding. KEGG pathway analysis showed that the differentially expressed genes in muscle tissue were mainly concentrated in pathways for AMPK signaling, cGMP PKG signaling calcium signaling, glycolysis, and, arginine and proline metabolism. A PPI protein interaction network was constructed for the selected differential genes, and the MCODE module used for modular analysis. Five modules with Score > 3.0 are selected. Then the Cytoscape software was used to analyze the tissue specificity of differential genes, and the genes with high degree scores collected, and some common genes selected for quantitative PCR verification. The conclusion is that we have screened the differentially expressed gene set specific to mouse muscle to provide potential candidate genes for the study of the important mechanisms of muscle development.