The polymorphism in the beta4-defensin gene and its association with production and somatic cell count in Holstein-Friesian cows

Analysis of the effect of polymorphisms within the CATHL7 gene on dairy performance parameters

Introduction

Antimicrobial peptides, including cathelicidins, play a significant role in farm animals, influencing animal welfare, immunity, and thus the quality of animal products.

Material and Methods

The study used amplification-created restriction site and PCR-restriction fragment length polymorphism to analyse single nucleotide polymorphisms of the CATHL7 gene encoding the BMAP-34 protein in cattle, at positions 2,383 G > C and 2,468 G > C. The material was collected from 279 Polish Black-and-White Holstein-Friesian dairy cows.

Results

There were statistically significant differences between milk performance parameters in cows with the CATHL7/HhaI and CATHL7/HinfI genotypes. In the case of the CATHL7/HhaI polymorphism, the highest milk yield and protein and lactose content and the lowest somatic cell count in milk were observed for the CC genotype, while the fat content was the highest in milk from cows with the GG genotype. In the case of the CATHL7/HinfI polymorphism, the highest protein and lactose content in milk was observed for the CC genotype.

Conclusion

The results were statistically significant, which suggests that the search for relationships can be continued, and that the results can be used to improve selection programmes supporting dairy farming.

Analysis of amplification and association polymorphisms in the bovine beta-defensin 129 (BBD129) gene revealed its function in bull fertility

β-defensins are adsorbable on the sperm surface in the male reproductive tract (MRT) and enhance sperm functional characteristics. The beta-defensin 129 (DEFB129) antimicrobial peptide is involved in sperm maturation, motility, and fertilization. However, its role in bovine fertility has not been well investigated. This study examines the relationship between the bovine BBD129 gene and Bos indicus x Bos taurus bull fertility. The complete coding sequence of BBD129 mRNA was identified by RNA Ligase Mediated-Rapid Amplification of cDNA End (RLM-RACE) and Sanger sequencing methodologies. It consisted of 582 nucleotides (nts) including 5' untranslated region (UTR) (46nts) and 3'UTR (23nts). It conserves all beta-defensin-like features. The expression level of BBD129 was checked by RT-qPCR and maximal expression was detected in the corpus-epididymis region compared to other parts of MRT. Polymorphism in BBD129 was also confirmed by Sanger sequencing of 254 clones from 5 high fertile (HF) and 6 low fertile (LF) bulls at two positions, 169 T > G and 329A > G, which change the S57A and N110S in the protein sequence respectively. These two mutations give rise to four types of BBD129 haplotypes. The non-mutated TA-BBD129 (169 T/329A) haplotype was substantially more prevalent among high-fertile bulls (P < 0.005), while the double-site mutated GG-BBD129 (169 T > G/329A > G) haplotype was significantly more prevalent among low-fertile bulls (P < 0.005). The in silico analysis confirmed that the polymorphism in BBD129 results in changes in mRNA secondary structure, protein conformations, protein stability, extracellular-surface availability, post-translational modifications (O-glycosylation and phosphorylation), and affects antibacterial and immunomodulatory capabilities. In conclusion, the mRNA expression of BBD129 in the MRT indicates its region-specific dynamics in sperm maturation. BBD129 polymorphisms were identified as the deciding elements accountable for the changed proteins with impaired functionality, contributing to cross-bred bulls' poor fertility.

Associations between Bovine β-Defensin 4 Genotypes and Production Traits of Polish Holstein-Friesian Dairy Cattle

Simple Summary

Mastitis negatively affects dairy cattle, causing inferior milk quality and premature animal culling, which leads to economic losses. Therefore, selection based on genetic markers (i.g., marker-assisted selection) should also include functional traits with low heritability, such as resistance to udder inflammation. Single nucleotide polymorphisms (SNPs) identified in genes involved in the immune system, such as defensins with antibacterial properties, could be valuable markers. We chose two SNPs within the bovine neutrophil beta-defensin 4 (BNBD4) gene analyzed in a previous study related to milk production and udder health. Since these SNPs are located very close to each other in the gene intron, it is useful to analyze their association with production traits as a combined genotype. The results showed that these genotypes are indeed associated with productivity, as well as functional traits (milk, fat, and protein yields, fat, protein, lactose, and dry matter contents, and somatic cell count). The differences between the results based on the phenotypic data and the breeding values of studied traits may confirm the results of simulation studies that indicate a high rate of false-positives in genome-wide association study (GWAS) based on classically calculated estimated breeding values (EBVs) using best linear unbiased prediction (BLUP) methodology.

Abstract

This study analyzed the associations between two single-nucleotide polymorphisms (C2239T and A1674C), used together as a genotype located in BNBD4, and milk traits and breeding values of productivity traits of Polish Holstein-Friesian dairy cows. The research was carried out on 322 cows, with 7070 milk parameter and somatic cell count records in daily milking, as well as 897 records covering data on whole lactations, and 2209 breeding value records for productivity traits. The DMU statistical package with a one-trait repeatability test-day animal model was used to estimate the associations. The differences between the genotype effects were analyzed using Duncan’s post-hoc tests. The CC/AA and CT/AC genotypes had the highest frequencies (0.62 and 0.23, respectively). For use in marker-assisted selection, the CC/AC genotype is the most promising as an indicator of high-yielding cows potentially resistant to mastitis, because it was associated with the lowest somatic cell count (SCC), highest milk, fat, and protein yields in daily milking, as well as with milk yield in the whole lactation. The studied genotypes were also related to the breeding values of all the investigated production traits. However, some simulation studies have indicated a high rate of false-positives in GWAS based on classically calculated EBVs.

β-Defensins: Farming the Microbiome for Homeostasis and Health

Diverse commensal populations are now regarded as key to physiological homeostasis and protection against disease. Although bacteria are the most abundant component of microbiomes, and the most intensively studied, the microbiome also consists of viral, fungal, archael, and protozoan communities, about which comparatively little is known. Host-defense peptides (HDPs), originally described as antimicrobial, now have renewed significance as curators of the pervasive microbial loads required to maintain homeostasis and manage microbiome diversity. Harnessing HDP biology to transition away from non-selective, antibiotic-mediated treatments for clearance of microbes is a new paradigm, particularly in veterinary medicine. One family of evolutionarily conserved HDPs, β-defensins which are produced in diverse combinations by epithelial and immune cell populations, are multifunctional cationic peptides which manage the cross-talk between host and microbes and maintain a healthy yet dynamic equilibrium across mucosal systems. They are therefore key gatekeepers to the oral, respiratory, reproductive and enteric tissues, preventing pathogen-associated inflammation and disease and maintaining physiological normality. Expansions in the number of genes encoding these natural antibiotics have been described in the genomes of some species, the functional significance of which has only recently being appreciated. β-defensin expression has been documented pre-birth and disruptions in their regulation may play a role in maladaptive neonatal immune programming, thereby contributing to subsequent disease susceptibility. Here we review recent evidence supporting a critical role for β-defensins as farmers of the pervasive and complex prokaryotic ecosystems that occupy all body surfaces and cavities. We also share some new perspectives on the role of β-defensins as sensors of homeostasis and the immune vanguard particularly at sites of immunological privilege where inflammation is attenuated.

Association of polymorphisms of the β-defensin 1 gene with nematode and protozoan infection traits in goat

This study's purpose was to identify polymorphisms (SNP) in the goat β-defensin 1 gene and to associate these SNPs with traits related to nematodean and protozoan infections in Anglo-Nubian goats from semiarid region of Brazil. A total of 184 animals were used for DNA extraction, PCR and DNA automatic sequencing. The association analyses included the fixed effects of animal age, bloodline and genotype of the SNP marker in the statistical model. The means of genotypes were compared by the Fisher test (P < 0.05). Twelve polymorphism genotypes were found: two in intron 1, seven in exon 2 and three in 3' untranslated region. The SNPs of exon 2 were responsible for amino acid substitutions in six genetic codes, and the changes in the 25th and 33rd codes affected the protein function. The SNP 1937 was significantly associated with number of protozoan oocysts, whereas SNP 2001 was associated with degree of anaemia (Famacha©). Polymorphism 2046, in turn, showed a significant association with Famacha© degree and number of protozoan oocysts. SNP 2140 associated with maximum EPG of the animal. Results from this study suggest that the β-defensin 1 gene can be used as a molecular marker for selection of goats regarding the susceptibility to endoparasites infections.

Association of SNP and STR polymorphisms of insulin-like growth factor 2 receptor (IGF2R) gene with milk traits in Holstein-Friesian cows

The objective of the study reported in this Research Communication was to investigate the association of polymorphisms in the insulin-like growth factor receptor 2 (IGF2R) gene with milk traits in 283 Polish Holstein-Friesian (PHF) cows from the IGAB PAS farm in Jastrzębiec. IGF2R regulates the availability of biologically active IGF2 which is considered as a genetic marker for milk or meat production in farm animals. Two novel genetic polymorphisms were identified in the bovine IGF2R gene: a polymorphic TG-repeat in intron 23 (g.72389 (TG)15-67), and a g.72479 G > A SNP RFLP-StyI in exon 24. The following milk traits were investigated: milk yield, protein and fat yield, SCC and lactose content. To determine the influence of the IGF2R STR and SNP genotypes on the milk traits, we used the AI-REML (average information restricted maximum likelihood) method with repeatability, multi-trait animal model based on test-day information using DMU package. Statistical analysis revealed that the G/A genotype (P ≤ 0·01) was associated with milk and protein yield, lactose content and somatic cell count (SCC) in Polish HF cows. TGn (29/22, 28/29, 28/22, 28/28) genotypes were associated with high values for milk, (28/22, 28/23) with protein and fat yield, (25/20) with lactose content, and (29/33, 28/28) with low SCC. We suggest that the IGF2R gene polymorphisms could be useful genetic markers for dairy production traits in cattle.

β-defensins: An innate defense for bovine mastitis

Immune challenges are inevitable for livestock that are exposed to a varied range of adverse conditions ranging from environmental to pathogenic stresses. The β-defensins are antimicrobial peptides, belonging to “defensin” family and therefore acts as the first line of defense against the major infections occurring in dairy cattle including intramammary infections. The better resistance to mastitis displayed by Bos indicus is implicit in the fact that they have better adapted and also has more sequence variation with rare allele conserved due to lesser artificial selection pressure than that of Bos taurus. Among the 58 in silico predicted β-defensins, only a few have been studied in the aspect of intramammary infections. The data on polymorphisms occurring in various β-defensin genes is limited in B. indicus, indicating toward higher possibilities for exploring marker for mastitis resistance. The following review shall focus on concisely summarizing the up-to-date research on β-defensins in B. taurus and discuss the possible scope for research in B. indicus.

Identification of a Novel Single Nucleotide Polymorphism in Porcine Beta-Defensin-1 Gene

Porcine beta-defensin-1 (PBD-1) gene plays an important role in the innate immunity of pigs. The peptide encoded by this gene is an antimicrobial peptide that has direct activity against a wide range of microbes. This peptide is involved in the co-creation of an antimicrobial barrier in the oral cavity of pigs. The objective of the present study was to detect polymorphisms, if any, in exon-1 and exon-2 regions of PBD-1 gene in Large White Yorkshire (LWY) and native Ankamali pigs of Kerala, India. Blood samples were collected from 100 pigs and genomic DNA was isolated using phenol chloroform method. The quantity of DNA was assessed in a spectrophotometer and quality by gel electrophoresis. Exon-1 and exon-2 regions of PBD-1 gene were amplified by polymerase chain reaction (PCR) and the products were subjected to single strand conformation polymorphism (SSCP) analysis. Subsequent silver staining of the polyacrylamide gels revealed three unique SSCP banding patterns in each of the two exons. The presence of single nucleotide polymorphisms (SNPs) was confirmed by nucleotide sequencing of the PCR products. A novel SNP was found in the 5'-UTR region of exon-1 and a SNP was detected in the mature peptide coding region of exon-2. In exon-1, the pooled population frequencies of GG, GT, and TT genotypes were 0.67, 0.30, and 0.03, respectively. GG genotype was predominant in both the breeds whereas TT genotype was not detected in LWY breed. Similarly, in exon-2, the pooled population frequencies of AA, AG, and GG genotypes were 0.50, 0.27, and 0.23, respectively. AA genotype was predominant in LWY pigs whereas GG genotype was predominant in native pigs. These results suggest that there exists a considerable genetic variation at PBD-1 locus and further association studies may help in development of a PCR based genotyping test to select pigs with better immunity.

Expression patterns of β-defensin and cathelicidin genes in parenchyma of bovine mammary gland infected with coagulase-positive or coagulase-negative Staphylococci

BACKGROUND

Mastitis is still considered to be the most economically important infectious disease in dairy cattle breeding. The immune response in mammary gland tissues could help in developing support strategies to combat this disease. The role of neutrophils and macrophages in the innate response of mammary gland is well known. However, the immune response in mammary gland tissues, including levels of antimicrobial peptide transcripts, has not been well recognized. Moreover, most studies are conducted in vitro, on cell cultures, or on artificially infected animals, with analysis being done within a several dozen hours after infection.The aim of the study was to examine the in vivo transcript levels of beta-defensin and cathelicidins genes in cow mammary gland secretory tissue (parenchyma) with the chronic, recurrent and incurable mammary gland inflammation induced by coagulase-positive or coagulase-negative Staphyloccoci vs. bacteria-free tissue.

RESULTS

The mRNA of DEFB1, BNBD4, BNBD5, BNBD10 and LAP genes, but not of TAP gene, were detected in all investigated samples regardless of the animals' age and microbiological status of the mammary gland, but at different levels. The expression of most of the beta-defensin genes was shown to be much higher in tissues derived from udders infected with bacteria (CoPS or CoNS) than from bacteria-free udders, regardless of parity. Cathelicidins (CATH4, CATH5 and CATH6) showed expression patterns contrasting those of β-defensins, with the highest expression in tissues derived from bacteria-free udders.

CONCLUSION

Increased expression of genes encoding β-defensins in the infected udder confirms their crucial role in the defense of the cow mammary gland against mastitis. On the other hand, the elevated cathelicidin transcripts in non-infected tissues indicate their role in the maintenance of healthy mammary tissues. The expression levels of investigated genes are likely to depend on the duration of the infection and type of bacteria.

Bovine β-defensin gene family: opportunities to improve animal health?

Recent analysis of the bovine genome revealed an expanded suite of β-defensin genes that encode what are referred to as antimicrobial or host defense peptides (HDPs). Whereas primate genomes also encode α- and θ-defensins, the bovine genome contains only the β-defensin subfamily of HDPs. β-Defensins perform diverse functions that are critical to protection against pathogens but also in regulation of the immune response and reproduction. As the most comprehensively studied subclass of HDPs, β-defensins possess the widest taxonomic distribution, found in invertebrates as well as plants, indicating an ancient point of origin. Cross-species comparison of the genomic arrangement of β-defensin gene repertoire revealed them to vary in number among species presumably due to differences in pathogenic selective pressures but also genetic drift. β-Defensin genes exist in a single cluster in birds, but four gene clusters exist in dog, rat, mouse, and cow. In humans and chimpanzees, one of these clusters is split in two as a result of a primate-specific pericentric inversion producing five gene clusters. A cluster of β-defensin genes on bovine chromosome 13 has been recently characterized, and full genome sequencing has identified extensive gene copy number variation on chromosome 27. As a result, cattle have the most diverse repertoire of β-defensin genes so far identified, where four clusters contain at least 57 genes. This expansion of β-defensin HDPs may hold significant potential for combating infectious diseases and provides opportunities to harness their immunological and reproductive functions in commercial cattle populations.

Failure of respiratory defenses in the pathogenesis of bacterial pneumonia of cattle

The respiratory system is well defended against inhaled bacteria by a dynamic system of interacting layers, including mucociliary clearance, host defense factors including antimicrobial peptides in the epithelial lining fluid, proinflammatory responses of the respiratory epithelium, resident alveolar macrophages, and recruited neutrophils and monocytes. Nevertheless, these manifold defenses are susceptible to failure as a result of stress, glucocorticoids, viral infections, abrupt exposure to cold air, and poor air quality. When some of these defenses fail, the lung can be colonized by bacterial pathogens that are equipped to evade the remaining defenses, resulting in the development of pneumonia. This review considers the mechanisms by which these predisposing factors compromise the defenses of the lung, with a focus on the development of bacterial pneumonia in cattle and supplemented with advances based on mouse models and the study of human disease. Deepening our understanding of how the respiratory defenses fail is expected to lead to interventions that restore these dynamic immune responses and prevent disease.

Six novel single-nucleotide polymorphisms in SPAG11 gene and their association with sperm quality traits in Chinese Holstein bulls

Sperm-associated antigen 11 (SPAG11) is predominant in the male reproductive tract. Similar to β-defensin, aside from its antibacterial activity, SPAG11 also has an important role in male reproductive function. In the present study, the association of bovine SPAG11 gene polymorphism with sperm quality traits was examined, including ejaculate volume, sperm concentration, fresh sperm motility, post-thaw cryopreserved sperm motility, and deformity rate of bull semen. Six novel single nucleotide polymorphisms (SNPs) of the SPGA11 gene were investigated in 426 normal mature Chinese Holstein bulls using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP), PCR-restriction fragment length polymorphism (PCR-RFLP), created restriction site-PCR (CRS-PCR), and DNA sequencing methods. Linkage disequilibrium analysis showed that g.1306G>A and g.1454G>A (SNP-1), and g.16904G>T, g.16974C>T, and g.17000A>G (SNP-2) are completely linked, respectively. Correlation analysis showed the SNP-2 marker had a marked effect on fresh sperm motility and sperm concentration (P<0.05). SNP-3 g.22696T>C had a marked effect on post-thaw cryopreserved sperm motility (P<0.05) and deformity rate (P<0.01). However, the presence of SNP-1 was not correlated with the sperm production traits (P>0.05). Furthermore, association analyses of the 8 haplotypes constructed from the 17 combined haplotypes and reproductive traits showed that the bulls with the combined haplotype H5H6 (GGT/TTC) have the highest ejaculate volumes and the bulls with combined haplotypes H1H1 (AAT/TTT) and H1H6 (AGT/TTC) had the highest fresh and post-thaw sperm motilities, respectively. These results indicate that new molecular markers associated with sperm quality traits can be used in marker-assisted selection in bull breeding programs.

Short communication: influence of the muscle hypertrophy mutation of the myostatin gene on milk production traits and milk fatty acid composition in dual-purpose Belgian Blue dairy cattle

The objective of this study was to estimate genetic effects for the muscle hypertrophy mutation (mh) of the myostatin gene for conventional milk production traits and for milk fatty acid composition in dual-purpose Belgian Blue dairy cows. For the present study, only cows from a single herd, in which genotype frequencies were as balanced as possible (0.266 for +/+, 0.523 for mh/+, and 0.211 for mh/mh), were chosen to avoid confounding between herd and genotype effects. A total of 109 cows with 3,190 test-day records for fat, protein, and milk yields and 1,064 test-day records for saturated and monounsaturated fatty acids were used for the calculations. Variance component and gene effect estimations were performed via expectation-maximization REML and BLUP methods, respectively, using a multi-trait mixed test-day model with an additional fixed regression on the muscle hypertrophy genotype. Results showed that one copy of the wild-type "+" allele led to a significant additive effect of 26.35 g/d for fat yield. Significant dominance effects of 23.22 g/d for protein yield and 30.28 g/d for fat yield were also observed. In contrast, a nonsignificant trend was observed in favor of lower saturated fatty acid contents in milk for one copy of the mutant "mh" allele. Concerning milk, fat, and protein yields, our results confirmed literature results indicating a superior effect of the "+" allele compared with the mutant allele. Therefore, the selection of the "+" allele has the potential to increase conventional milk production traits in the dual-purpose Belgian Blue breed. However, when focus is given to milk fatty acid profile, a possible antagonistic effect between the benefit of the "+" allele for higher milk production and the "mh" allele for reduced saturated fatty acid content in milk should be confirmed in further studies.

Identification of SNPs in interferon gamma, interleukin-22, and their receptors and associations with health and production-related traits in Canadian Holstein bulls

Genetic variants in a number of immunoregulatory genes have been previously associated with health and production traits in dairy cattle. Therefore, in the following study, the genes coding interferon gamma (IFNG), IFNG receptor 1 and 2 domains, interleukin-22 (IL22), and IL22 receptor alpha 1, were investigated for single nucleotide polymorphisms (SNPs) in Holstein bulls. These SNPs, along with SNPs previously identified in IL10, IL10 receptor, and transforming growth factor beta 1 (TGFB1) genes, were evaluated for statistical associations to estimated breeding values for milk somatic cell score (SCS), a trait highly correlated to mastitis incidence, and various production-related traits, including milk yield, protein yield, fat yield, and lactation persistency. While no significant associations were found between these SNPs and SCS, SNPs in IL10 receptor beta subunit showed a significant effect on protein yield and lactation persistency. While there is evidence that IL10 plays an important role during lactation, it is also likely that the effects of SNPs in IL10 receptor beta subunit on protein yield and lactation persistency are due to linkage disequilibrium with a neighboring QTL.

The spatial expression pattern of antimicrobial peptides across the healthy bovine udder

Antimicrobial peptides are key molecules in local host defense. With the aim to better understand the possible involvement of these peptides in the prevention of bovine mastitis, we determined, for the first time to our knowledge, the spatial pattern of constitutive expression of 5 bovine beta-defensins and bovine psoriasin (S100A7) across 5 localizations of the bovine mammary gland applying a quantitative real-time PCR approach. We observed 3 different expression patterns in the healthy udder: 1) constitutive expression of the lingual and tracheal antimicrobial peptides (LAP and TAP), as well that of bovine neutrophil beta-defensins 4 and 10 (BNBD4 and BNBD10), is essentially restricted to the mammary lymph node; 2) bovine beta-defensin 1 (DEFB1) is mainly expressed in the cisternal epithelium and the Rosette of Fürstenberg; 3) strong constitutive mRNA expression of the calcium-binding protein S100A7, which is also known as psoriasin and which has been reported to be highly active against Escherichia coli, was detected in the streak canal. These results indicate a crucial role of S100A7 in the early-stage prevention of coliform mastitis, and the analyzed beta-defensins might be regarded as inducible weapons against already invading pathogens.

Board-invited review: the biology and regulation of preadipocytes and adipocytes in meat animals

The quality and value of the carcass in domestic meat animals are reflected in its protein and fat content. Preadipocytes and adipocytes are important in establishing the overall fatness of a carcass, as well as being the main contributors to the marbling component needed for consumer preference of meat products. Although some fat accumulation is essential, any excess fat that is deposited into adipose depots other than the marbling fraction is energetically unfavorable and reduces efficiency of production. Hence, this review is focused on current knowledge about the biology and regulation of the important cells of adipose tissue: preadipocytes and adipocytes.