Deoxynivalenol triggers the expression of IL-8-related signaling cascades and decreases protein biosynthesis in primary monocyte-derived cells.

Humans and their immune system are confronted with mold-contaminated food and/or mold-contaminated air in daily life and indoor activities. This results in metabolic stress and unspecific disease symptoms. Other studies provided evidence that exposure to mold is associated with the etiology of allergies. Deoxynivalenol (DON) is of great concern due to its frequent occurrence in toxically relevant concentrations. The exposure to this toxin is a permanent health risk for both humans and farm animals because DON cannot be significantly removed during standard milling and processing procedures. However, the direct effect on immunity or hematology is poorly defined because most investigations could not separate the effect of DON-contaminated feed intake. Due to the widespread distribution of DON after rapid absorption, it is not surprising that DON is known to affect the immune system. The immune system of the organism has one important function, to defend against the invasion of unknown substances/organisms. This study shows for the first time a synergistic effect of both-low physiological DON-doses in combination with low LPS-doses with the focus on the IL-8 expression on protein and RNA level. Both doses were found in vivo. IL-8 together with other anorectic cytokines like IL-1ß can affect the food intake and anorexia. We could also show that a calcium-response is not involved in the increased IL-8 production after acute DON stimulation with high or low concentrations.

SNP discovery and association study for growth, fatness and meat quality traits in Iberian crossbred pigs.

Iberian pigs and its crosses are produced to obtain high-quality meat products. The objective of this work was to evaluate a wide panel of DNA markers, selected by biological and functional criteria, for association with traits related to muscle growth, fatness, meat quality and metabolism. We used 18 crossbred Iberian pigs with divergent postnatal growth patterns for whole genome sequencing and SNP discovery, with over 13 million variants being detected. We selected 1023 missense SNPs located on annotated genes and showing different allele frequencies between pigs with makerdly different growth patterns. We complemented this panel with 192 candidate SNPs obtained from literature mining and from muscle RNAseq data. The selected markers were genotyped in 480 Iberian × Duroc pigs from a commercial population, in which phenotypes were obtained, and an association study was performed for the 1005 successfully genotyped SNPs showing segregation. The results confirmed the effects of several known SNPs in candidate genes (such as LEPR, ACACA, FTO, LIPE or SCD on fatness, growth and fatty acid composition) and also disclosed interesting effects of new SNPs in less known genes such as LRIG3, DENND1B, SOWAHB, EPHX1 or NFE2L2 affecting body weight, average daily gain and adiposity at different ages, or KRT10, NLE1, KCNH2 or AHNAK affecting fatness and FA composition. The results provide a valuable basis for future implementation of marker-assisted selection strategies in swine and contribute to a better understanding of the genetic architecture of relevant traits.

Genome-wide SNP analysis clearly distinguished the Belarusian Red cattle from other European cattle breeds.

Local breeds can serve as an important source of genetic variability in domestic animal species. This study aimed to assess the genetic diversity and population structure of Belarusian Red cattle and their differentiation from other European cattle populations based on genome-wide SNP genotypes. Twenty pedigree-recorded non-closely related cows of Belarusian Red cattle were genotyped using the Illumina BovineHD BeadChip. Genotypes of 22 other European cattle breeds were included in the study for comparison. A total of 28 562 SNPs passed through the quality control checks and were selected for analysis. The Belarusian Red cattle displayed a moderate level of genetic variability (U HE  = 0.341, HO  = 0.368), and the highest heterozygote excess (U FIS  = -0.066), among the studied breeds; this reflects the contribution of multiple breeds to their formation. The principal component analysis, FST -based Neighbor-Net tree and Admixture clustering, clearly distinguished the Belarusian Red cattle from the other European cattle breeds. Moreover, the presence of ancestral genomic components of Danish Red and Brown Swiss breeds were clearly visible, which agrees with the breed's history and its recent development. Our study highlights the importance of maintaining the specific genomic components, which makes a significant contribution to the global genetic diversity in the modern population of Belarusian Red cattle, allowing us to consider them a valuable national genetic resource. Our research results will be useful for the development of conservation programs for this local cattle breed.

Genome-wide association study of body morphological traits in Sudanese goats.

Long-term selection of goats for a certain production system and/or different environmental conditions will be reflected in the body morphology of the animals under selection. To investigate the variation contributing to different morphological traits and to identify genomic regions that are associated with body morphological traits in Sudanese goats, we genotyped 96 females belonging to four Sudanese goat breeds with the SNP52 BeadChip. After quality control of the data, the genome-wide association study was performed using 95 goats and 24 027 informative single nucleotide polymorphisms (SNPs). Bicoastal diameter was significantly associated (LOD = 6.32) with snp10185-scaffold1365-620922 on chromosome 2. The minor allele has an additive effect, increasing the bicoastal diameter by 2.6 cm. A second significant association was found between body length and snp56482-scaffold89-467312 on chromosome 3 (LOD = 5.65). The minor allele is associated with increased body length. Additionally, five regions were suggestive for cannon bone, head width, rump length and withers height (LOD > 5). Only one gene (CNTNAP5) is located within the 1-Mb region surrounding the significant SNP for bicoastal diameter on chromosome 2. The body length QTL on chromosome 3 harbors 49 genes. Further research is required to validate the observed associations and to prioritize candidate genes.

Temperature alterations during embryogenesis have a sex-dependent influence on growth properties and muscle metabolism of day-old chicks and 35-day-old broilers.

Broiler eggs were either incubated at 37.8°C during the whole incubation period (control), or at higher (38.8°C, group H) and lower temperatures (36.8°C, group L) from embryonic day (ED) 7 up to ED 10 (ED 7 to 10) or from ED 10 up to ED 13 (ED 10 to 13). Before and after this temperature treatment the eggs were incubated at 37.8°C. The day-old chicks were weighted, sexed and fed up to day 35. On days 1 and 35 samples were taken from the breast and leg muscles for analyzing of the mitochondrial respiratory activity (MRA) and from the breast muscles for analysis of the cross-sectional areas (CSA) and the glycogen phosphorylase (GP), phosphofructokinase (PFK), lactate dehydrogenase (LDH), citrate synthase (CS) and cytochrome oxidase (COX) activities. Statistical analysis showed that treatment (control, group H, group L), sex and their interaction, but not the treatment period (ED 7 to 10; ED 10 to 13), significantly influenced the results. Group H chicks had lower (P⩽0.05) body and heart weights but higher (P⩽0.05) liver weights, CSA values, leg MRA as well as PFK, LDH, CS, GP and COX activities compared with the group L chicks. The results of the control chicks differ (P⩽0.05) from those of the group H (body, heart weight, COX), the group L chicks (liver weight, PFK, LDH, CS, GP) or the birds of both other groups (CSA). The group H broiler had higher (P⩽0.05) body and leg weights as well as LDH, CS, COX and GP activities than the group L broilers. The BWs and the LDH and GP results of the control broiler differ (P⩽0.05) from those of both other groups or from the results of the group H (CS) and group L broiler (COX). Female broilers had lower (P⩽0.05) body, breast and leg weights, but higher (P⩽0.05) CSA, LDH, CS and GP activities than the male animals. Analysis of treatment×sex interaction showed that group H hens had higher (P⩽0.05) body and breast weights, LDH and GP activities compared with the group L hens, whereas in the male broiler no effect of the interaction could be found, except for the lower (P⩽0.05) CSA values in the group H than group L cocks. The treatment effects are probably due to altered embryonic activity and related molecular mechanisms. The sex-related differences in the broiler indicate that these alterations already occur in the embryos and chicks, but become significant with the sexual dimorphism after hatch.

MicroRNA expression profiling of porcine mammary epithelial cells after challenge with Escherichia coli in vitro.

BACKGROUND: Coliform mastitis is a symptom of postpartum dysgalactia syndrome (PDS), a multifactorial infectious disease of sows. Our previous study showed gene expression profile change after bacterial challenge of porcine mammary epithelial cells (PMECs). These mRNA expression changes may be regulated through microRNAs (miRNAs) which play critical roles in biological processes. Therefore, miRNA expression profile was investigated in PMECs. RESULTS: PMECs were isolated from three lactating sows and challenged with heat-inactivated potential mastitis-causing pathogen Escherichia coli (E. coli) for 3 h and 24 h, in vitro. At 3 h post-challenge with E. coli, target gene prediction identified a critical role of miRNAs in regulation of host immune responses and homeostasis of PMECs mediated by affecting pathways including cytokine binding (miR-202, miR-3277, miR-4903); IL-10/PPAR signaling (miR-3277, miR-4317, miR-548); and NF-ĸB/TNFR2 signaling (miR-202, miR-2262, miR-885-3p). Target genes of miRNAs in PMECs at 24 h were significantly enriched in pathways associated with interferon signaling (miR-210, miR-23a, miR-1736) and protein ubiquitination (miR-125, miR-128, miR-1280). CONCLUSIONS: This study provides first large-scale miRNA expression profiles and their predicted target genes in PMECs after contact with a potential mastitis-causing E. coli strain. Both, highly conserved miRNAs known from other species as well as novel miRNAs were identified in PMECs, representing candidate predictive biomarkers for PDS. Time-dependent pathogen clearance suggests an important role of PMECs in inflammatory response of the first cellular barrier of the porcine mammary gland.

TRIENNIAL GROWTH AND DEVELOPMENT SYMPOSIUM: Factors influencing bovine intramuscular adipose tissue development and cellularity.

Appearance, distribution, and amount of intramuscular fat (IMF), often referred to as marbling, are highly variable and depend on environmental and genetic factors. On the molecular level, the concerted action of several drivers, including hormones, receptors, transcription factors, etc., determines where clusters of adipocytes arise. Therefore, the aim of future studies remains to identify such factors as biological markers of IMF to increase the ability to identify animals that deposit IMF early in age to increase efficiency of high-quality meat production. In an attempt to unravel the cellular development of marbling, we investigated the abundance of markers for adipogenic differentiation during fattening of cattle and the transcriptome of muscle and dissected IMF. Markers of different stages of adipogenic differentiation are well known from cell culture experiments. They are usually transiently expressed, such as delta-like homolog 1 (DLK1) that is abundant in preadipocytes and absent during differentiation to mature adipocytes. It is even a greater challenge to detect those markers in live animals. Within skeletal muscles, hyperplasia and hypertrophy of adipocytes can be observed throughout life. Therefore, development of marbling requires, on the cellular level, recruitment, proliferation, and differentiation of adipogenic cells to store excess energy in the form of lipids in new cells. In a recent study, we investigated the localization and abundance of early markers of adipogenic differentiation, such as DLK1, in bovine muscle tissue. An inverse relationship between IMF content and number of DLK1-positive cells in bovine muscle was demonstrated. Considering the cellular environment of differentiating adipocytes in muscle and the secretory action of adipocytes and myocytes, it becomes obvious that cross talk between cells via adipokines and myokines may be important for IMF development. Secreted proteins can act on other cells, inhibiting or stimulating their function via autocrine and paracrine actions. Such factors with potential influence on IMF, among them, agouti signaling protein and thrombospondin 4, were identified in transcriptome analyses and further investigated. Furthermore, results from transcriptome analysis indicate involvement of genes that are not directly related to adipogenesis and lipid metabolism, providing new candidates for future research.

Detection of the important chromosomal regions determining production traits in meat-type chicken using entropy analysis.

1. The objective of this study was to indicate the most informative chromosomal regions and candidate genes connected to body weight at 36 d, body weight at 39 d, body weight changes between 39 and 46 d, feed intake between 39 and 46 d and feed conversion ratio of meat-type chicken based on genomic data using entropy analysis. 2. Data contained information about 862 genotyped individuals from a Cobb commercial line using 60K Illumina iSelect chicken array and information from 42 770 Single Nucleotide Polymorphisms (SNPs). Entropy analysis was employed to detect important chromosomal regions determining the target traits. Locations of genes within the designated regions on each chromosome and for each trait were verified using the Ensembl genome database. 3. The most informative SNPs were located on chromosomes 1, 2, 4, 8, 12 and Z, whereas clusters of the most informative pairs of SNPs connected to all recorded traits were located on chromosomes 1, 2, 3, 4, 6, 12, 20 and Z. The identified chromosomal localisations overlap with genes functionally connected to the nervous system and gastrointestinal tract.

Methylating micronutrient supplementation during pregnancy influences foetal hepatic gene expression and IGF signalling and increases foetal weight.

PURPOSE: Maternal diet during pregnancy impacts foetal growth and development. In particular, dietary levels of methylating micronutrients (methionine, folate, choline, vitamins B6, and B12) interfere with the availability and allocation of methyl groups for methylation reactions, thereby influencing normal transcription. However, the currently recommended methylating micronutrient supplementation regimen is haphazard and arbitrary at best. METHODS: To investigate the effects of a methylating micronutrient-rich maternal diet, pregnant Pietrain sows were fed either a standard diet (CON) or a diet supplemented with methionine, folate, choline, B6, B12, and zinc (MET). Foetal liver and muscle (M. longissimus dorsi) tissues were collected at 35, 63, and 91 days post-conception. Transcriptional responses to diet were assessed in foetal liver. Altered insulin-like growth factor (IGF) signalling in transcriptome analyses prompted investigation of IGF-2 and insulin-like growth factor binding proteins (IGFBPs) levels in muscle and liver. RESULTS: Maternal diet enriched with methylating micronutrients was associated with increased foetal weight in late gestation. Hepatic transcriptional patterns also revealed differences in vitamin B6 and folate metabolism between the two diets, suggesting that supplementation was effective. Additionally, shifts in growth-supporting metabolic routes of the lipid and energy metabolism, including IGF signalling, and of cell cycle-related pathways were found to occur in liver tissue in supplemented individuals. Weight differences and modulated IGF pathways were also reflected in the muscle content of IGF-2 (increased in MET) and IGFBP-2 (decreased in MET). CONCLUSIONS: Maternal dietary challenges provoke stage-dependent and tissue-specific transcriptomic modulations in the liver pointing to molecular routes contributing to the organismal adaptation. Subtle effects on late foetal growth are associated with changes in the IGF signalling mainly in skeletal muscle tissue that is less resilient to dietary stimuli than liver.

Genetic Association of the Porcine C9 Complement Component with Hemolytic Complement Activity.

The complement system is a part of the natural immune regulation mechanism against invading pathogens. Complement activation from three different pathways (classical, lectin, and alternative) leads to the formation of C5-convertase, an enzyme for cleavage of C5 into C5a and C5b, followed by C6, C7, C8, and C9 in membrane attack complex. The C9 is the last complement component of the terminal lytic pathway, which plays an important role in lysis of the target cells depending on its self-polymerization to form transmembrane channels. To address the association of C9 with traits related to disease resistance, the complete porcine C9 cDNA was comparatively sequenced to detect single nucleotide polymorphisms (SNPs) in pigs of the breeds Hampshire (HS), Duroc (DU), Berlin miniature pig (BMP), German Landrace (LR), Pietrain (PIE), and Muong Khuong (Vietnamese potbelly pig). Genotyping was performed in 417 F2 animals of a resource population (DUMI: DU×BMP) that were vaccinated with Mycoplasma hyopneumoniae, Aujeszky diseases virus and porcine respiratory and reproductive syndrome virus at 6, 14 and 16 weeks of age, respectively. Two SNPs were detected within the third exon. One of them has an amino acid substitution. The European porcine breeds (LR and PIE) show higher allele frequency of these SNPs than Vietnamese porcine breed (MK). Association of the substitution SNP with hemolytic complement activity indicated statistically significant differences between genotypes in the classical pathway but not in the alternative pathway. The interactions between eight time points of measurement of complement activity before and after vaccinations and genotypes were significantly different. The difference in hemolytic complement activity in the both pathways depends on genotype, kind of vaccine, age and the interaction to the other complement components. These results promote the porcine C9 (pC9) as a candidate gene to improve general animal health in the future.

Analysis of non-synonymous SNPs of the porcine SERPINA6 gene as potential causal variants for a QTL affecting plasma cortisol levels on SSC7.

Recently, the SERPINA6 gene encoding corticosteroid-binding globulin (CBG) has been proposed as a candidate gene for a quantitative trait locus (QTL) affecting cortisol level on pig chromosome 7. The QTL was repeatedly detected in different lines, including a Piétrain × (German Landrace × German Large White) cross (PiF1) and purebred German Landrace (LR). In this study, we investigated whether the known non-synonymous polymorphisms c.44G>T, c.622C>T, c.770C>T, c.793G>A, c.832G>A and c.919G>A of SERPINA6 are sufficient to explain the QTL in these two populations. Our investigations revealed that SNPs c.44G>T, c.622C>T, c.793G>A and c.919G>A are associated with cortisol level in PiF1 (P < 0.01). Haplotype analysis showed that these associations are largely attributable to differences between a major haplotype carrying SNPs c.793G>A and c.919G>A and a haplotype carrying SNPs c.44G>T and c.622C>T. Furthermore, some SNPs, particularly c.44G>T and c.622C>T and the carrier haplotype, showed association with meat quality traits including pH and conductivity (P < 0.05). In LR, the non-synonymous SNPs segregate at very low frequency (<5%) and/or show only weak association with cortisol level (SNPs c.832G>A and c.919G>A; P < 0.05). These findings suggest that the non-synonymous SNPs are not sufficient to explain the QTL across different breeds. Therefore, we examined whether the expression of SERPINA6 is affected by cis-regulatory polymorphisms in liver, the major organ for CBG production. We found allelic expression imbalance of SERPINA6, which suggests that its expression is indeed affected by genetic variation in cis-acting elements. This represents candidate causal variation for future studies of the molecular background of the QTL.

Breed-specific transcriptome response of spleen from six to eight week old piglet after infection with Streptococcus suis type 2.

Different pig breeds have shown differential susceptibility to the pathogen infection; however, molecular mechanisms of the infection susceptibility are not fully understood. Streptococcus suis type 2 (SS2) is an important zoonotic pathogen. To identify the genes responsible for infection susceptibility, pigs from two different breeds (Enshi black and Landrace) were inoculated with SS2 and their spleen transcriptome profiles were investigated in the present study. The differentially expressed genes (DEGs) were analyzed from infected versus control pigs in each breed, and then compared between both pig breeds. Enshi black pig showed more DEGs than Landrace (830 vs. 611) and most of these were due to down-regulated genes (543 vs. 387). However some DEGs were uniquely expressed in one breed, some were expressed in opposite direction in both breeds. A number of candidate genes and pathways are identified which might be involved in susceptibility to SS2, for example, MMP9 and Resistin were only significantly expressed in Landrace. NPG3 and PMAP23 were up-regulated in Landrace whereas down-regulated in Enshi black. LENG8 in control Landrace have inherently higher expression than control Enshi black. IGKV6 is down-regulated in Landrace but up-regulated in Enshi black. Overall, the transcriptome profiles are consistent with the clinical signs, i.e. the Enshi black is more susceptible to SS2 infection than Landrace. This is the first study to identify differential gene expression between indigenous and modern commercial pigs after in vivo SS2 infection using RNA-seq. The significant DEGs in splenic profiles between two pig breeds suggested considerable involvement of genetic background in susceptibility to the SS2 infection in pigs.

Investigations on the pattern of linkage disequilibrium and selection signatures in the genomes of German Piétrain pigs.

The aim of this study was to study the population structure, to characterize the LD structure and to define core regions based on low recombination rates among SNP pairs in the genome of Piétrain pigs using data from the PorcineSNP60 BeadChip. This breed is a European sire line and was strongly selected for lean meat content during the last decades. The data were used to map signatures of selection using the REHH test. In the first step, selection signatures were searched genome-wide using only core haplotypes having a frequency above 0.25. In the second step, the results from the selection signature analysis were matched with the results from the recently conducted genome-wide association study for economical relevant traits to investigate putative overlaps of chromosomal regions. A small subdivision of the population with regard to the geographical origin of the individuals was observed. The extent of LD was determined genome-wide using r(2) values for SNP pairs with a distance ≤5 Mb and was on average 0.34. This comparable low r(2) value indicates a high genetic diversity in the Piétrain population. Six REHH values having a p-value < 0.001 were genome-wide detected. These were located on SSC1, 2, 6 and 17. Three positional candidate genes with potential biological roles were suggested, called LOC100626459, LOC100626014 and MIR1. The results imply that for genome-wide analysis especially in this population, a higher marker density and higher sample sizes are required. For a number of nine SNPs, which were successfully annotated to core regions, the REHH test was applied. However, no selection signatures were found for those regions (p-value < 0.1).

Genome-wide association analysis for growth, muscularity and meat quality in Piétrain pigs.

Improvement in growth and meat quality is one of the main objectives in sire line pig breeding programmes. Mapping quantitative trait loci for these traits using experimental crosses and a linkage-based approach has been performed frequently in the past. The Piétrain breed often was involved as a founder breed to establish the experimental crosses. This breed was selected for muscularity and leanness but shows relatively poor meat quality. It is frequently used as a sire line breed. With the advent of genome-wide and dense SNP chips in pig genomic research, it is possible to also conduct genome-wide association studies within the Piétrain breed. In this study, around 500 progeny-tested sires were genotyped with 60k SNPs. Data filtering showed that around 48k SNPs were useable in this sample. These SNPs were used to conduct a genome-wide association study for growth, muscularity and meat quality traits. Because it is known that a mutation in the RYR1 gene located on chromosome 6 shows a major effect on meat quality, this mutation was included in the models. Single-marker and multimarker association analyses were performed. The results revealed between zero and eight significant associations per trait with P < 5 × 10(-5) . Of special interest are SNPs located on SSC6, SSC10 and SSC15.

Hepatic expression patterns in psychosocially high-stressed pigs suggest mechanisms following allostatic principles.

Psychosocial challenges are known to introduce cellular and humoral adaptations in various tissues and organs, including parts of the sympatho-adrenal-medullary system and hypothalamic-pituitary-adrenal axis as well as other peripheral tissue being responsive to cortisol and catecholamines. The liver is of particular interest given its vital roles in maintaining homeostasis and health as well as regulating nutrient utilization and overall metabolism. We aimed to evaluate whether and how response to psychosocial stress is reflected by physiological molecular pathways in liver tissue. A pig mixing experiment was conducted to induce psychosocial stress culminating in skin lesions which reflect the involvement in aggressive behavior and fighting. At 27 weeks of age, animals prone to psychosocially low- and high-stress were assigned to mixing groups. Skin lesions were counted before mixing and after slaughter on the carcass. Individual liver samples (n=12) were taken. The isolated RNA was hybridized on Affymetrix GeneChip porcine Genome Arrays. Relative changes of mRNA abundances were estimated via variance analyses. Molecular routes related to tRNA charging, urea cycle, acute phase response, galactose utilization, and steroid receptor signaling were found to be increased in psychosocially high-stressed animals, whereas catecholamine degradation and cholesterol biosynthesis were found to be decreased. In particular, psychosocially high-stressed animals show decreased expression of catechol-O-methyltransferase (COMT) which has been linked to molecular mechanisms regulating aggressiveness and stress response. The expression patterns of high-stressed animals revealed metabolic alterations of key genes related to energy-mobilizing processes at the expense of energy consuming processes. Thus, the coping following psychosocial challenges involves transcriptional alterations in liver tissue which may be summarized with reference to the concept of allostasis, a strategy which is critical for survival.

High- and low-protein gestation diets do not provoke common transcriptional responses representing universal target-pathways in muscle and liver of porcine progeny.

AIM: Maternal diets introduce transcriptional changes in the offspring, highlighting the concept of genetic and physiological plasticity. Our previous analyses investigated stage-dependent transcriptional responses to either maternal high or low protein/carbohydrate ratios in either muscle or liver. Foetal programming is proposed to be mediated by a small number of gatekeeper processes, such as cytoskeleton remodelling and cell-cycle regulation. Here, we conducted an overall analysis of a three-dimensional data set aiming to elucidate, whether there are universally targeted pathways of adaptive transcriptional response to different protein/carbohydrate ratios. METHODS: Microarray analyses were performed on liver and skeletal muscle tissue sampled at 94 days post-conception and 1, 28 and 188 days post-natum from offspring (n = 253) of German Landrace gilts that were fed isoenergetic diets containing low, high or adequate protein. RESULTS: Cluster analyses revealed a hierarchical influence of tissue, ontogenetic stage and diet on transcript levels. Considering results cumulatively over stages, liver showed only marginal transcriptional differences between the dietary groups, whereas considerable differences appeared in muscle. Considering results cumulatively over tissues, nutrition-responsive transcriptions were observed along ontogenesis. Pathway analyses revealed transcript differences in genes related to tissue remodelling, cell-cycle regulation and mitochondrial function. CONCLUSION: The factors tissue, stage and diet impact gene expression in a hierarchical order. Porcine liver appeared to be a tissue that was more resilient to nutritional modulation compared with skeletal muscle tissue. Differential modulation between tissues and dietary groups reveal that there are no universal target-pathways of adaptive transcriptional response to different protein diets.

A study based on records taken at time of hoof trimming reveals a strong association between the IQ motif-containing GTPase-activating protein 1 (IQGAP1) gene and sole hemorrhage in Holstein cattle.

Feet and leg problems have a major effect on the well-being and lifespan of the dairy cow and thus are economically important to the dairy farmer. Apart from approaches using genetic selection for classical traits from conformation scoring, attempts for genetic improvement can be based either on records of individual disease cases or on records of disorder status at time of hoof trimming. In this study, 1,962 first-lactation cows were subjected to hoof trimming with an assessment of disorder status for sole hemorrhage as a binary trait. Cows were from 7 large commercial herds in Mecklenburg-Western Pomerania (northeastern Germany) that had similar housing with cubicles, slatted flooring, little use of straw for bedding, and total mixed ration feeding. Cows were trimmed and assessed once, focusing on cows in the first half of the lactation. Herds were visited at intervals to enable recording of cohorts at a similar stage of lactation. Each cohort or herd-visit included between 31 and 165 cows. Additional measurements included body weight, back fat thickness, and body condition at time of trimming. Further data on dairy production, conformation scores, and reproductive performance were merged after collection of records had finished. The DNA extracted from blood of 1,183 cows was used for analysis with a custom-made array of 384 single nucleotide polymorphisms (SNP). The SNP were selected according to results from the literature for effects in classical conformation traits, from biochemical pathway analysis, and from comparative analysis of putative candidate genes in cattle, pigs, and sheep. Selection of cohorts of cows for SNP chip analysis was such that cohorts with extreme frequencies of disorders and cohorts with slightly deviating housing systems were excluded in this first step. The results from a mixed threshold model analysis with genotype included as a fixed effect and accounting for relationships among animals revealed that the intronic SNP rs29017173 (A/G) within the IQ motif-containing GTPase-activating protein 1 (IQGAP1, Bos taurus autosome 21) was significantly associated with disorder status. Back-transformed means of disorder status for the 3 genotypes were 0.37 (AA), 0.52 (AG), and 0.56 (GG). Using the full data set of 1,962 cows, including the less-suitable cohorts, gave back-transformed means of 0.51 (AA), 0.58 (AG), and 0.62 (GG). As SNP rs29017173 is included on the Illumina BovineSNP50 DNA Analysis BeadChip (Illumina Inc., San Diego, CA), a sample of 2,394 artificial insemination sires from the German calibration sample for genomic selection from birth years 1998 to 2003 was studied for possible correlated effects. The A/G polymorphism of SNP rs29017173 studied here was also associated with substantial effects for feet and leg traits from the classical conformation score system. Selection using this polymorphism will be facilitated by the fact that the same allele is favored for all traits with substantial effects.

Deoxynivalenol affects the composition of the basement membrane proteins and influences en route the migration of CD16(+) cells into the intestinal epithelium.

The numerous pores in the basement membrane (BM) of the intestinal villi are essential for the communication of enterocytes with cells in the lamina propria, an important mechanism for the induction of intestinal immune responses. The intestinal epithelial barrier is affected by the mycotoxin deoxynivalenol (DON) from both the apical (luminal) and basolateral (serosal) side. The pig is the most susceptible species to the anorectic and immune-modulating effects of DON, which is most prevalent in crops. We analysed in pigs the effect of DON-contaminated feed on the composition and perforation of the BM and the presence of CD16(+) cells or their dendrites in the epithelium. In addition to in vivo experiments, in vitro studies were carried out. Using microarray analyses, the effects of DON on IPEC-J2 cells were studied with the focus on the BM. Our in vivo results showed in the control pigs: (1) a significant increased pore number (p ≤ 0.001) in the jejunum in comparison to ileum, (2) no difference in the pore size, and (3) comparable frequency of intraepithelial CD16(+) cells/dendrites in the jejunum and ileum. There was a marked trend that DON feeding increases: (1) the pore number in jejunum, and (2) the number of CD16(+) cells/dendrites in the epithelium (Tukey-Kramer; p = 0.055 and p = 0.067, respectively). The in vivo results were extended with microarray analyses of epithelial cell (IPEC-J2 cells). The down-regulation of genes like syndecan, fibulin 6 and BM-40 was observed. These proteins are important factors in the BM composition and in formation of pores. Our results provide evidence that already low basolateral concentrations of DON (50 ng/mL) influence the production of the BM protein laminin by epithelial cells. Thus, DON affects the composition of the BM.

Transcriptional profiling and miRNA-dependent regulatory network analysis of longissimus dorsi muscle during prenatal and adult stages in two distinct pig breeds.

MicroRNAs (miRNAs) and mRNAs establish a complex regulatory network influencing diverse biological pathways including muscle development and growth. Elucidating miRNA-dependent regulatory networks involved in muscle development could provide additional insights into muscle traits largely predefined during prenatal development. The present study aimed to determine differentially expressed transcripts and functional miRNA-mRNA relationships associated with different stages of skeletal muscle development in two pig breeds, German Landrace and Pietrain, distinct in muscle characteristics. A comparative transcriptional profiling of longissimus dorsi muscle tissues from fetuses at 35, 63 and 91 days post-conception as well as adult pigs (180 days postnatum) was performed using the Affymetrix GeneChip porcine genome microarray. Differential expression patterns were identified to be associated with muscularly developmental stages and breed types. The integration of miRNA expression data and ingenuity pathways analysis (ipa) pathway analysis revealed several miRNA-dependent regulatory networks related to muscle growth and development. The present results provide insights into muscle biology for further improvement of porcine meat quality.

QTL region-specific microarrays reveal differential expression of positional candidate genes of signaling pathways associated with the liability for the inverted teat defect.

The inverted teat defect is the most common disorder of the mammary complex in pigs. It is characterized by the failure of teats to protrude from the udder surface, preventing normal milk flow and thus limiting the rearing capacity and increasing the risk of mastitis. The inverted teat defect is a liability trait with a complex mode of inheritance. We previously identified QTL for inverted teats. As a complementary approach that integrates map-based efforts to identify candidate genes for the inverted teat defect with function-driven expression analysis, application-specific microarrays were constructed that cover 1525 transcripts mapping in QTL regions on pig chromosomes 2, 3, 4, 6 and 11. About 950 transcripts were expressed in epithelial and mesenchymal teat tissue. The expression of three categories of teats was compared: normal teats of both non-affected and affected animals and inverted teats of affected animals. In epithelium and mesenchyme, 62 and 24 genes respectively were significantly differentially expressed (DE). The majority of biofunctions to which a significant number of DE genes were assigned are related to the following: (1) cell maintenance, proliferation, differentiation and replacement; (2) organismal, organ and tissue development; or (3) genetic information and nucleic acid processing. Moreover, the DE genes belong almost exclusively to canonical pathways related to signaling rather than metabolic pathways. This is in line with findings obtained by genome-wide catalogue microarrays. This study adds another piece to the puzzle of the etiology of inverted teats by indicating that causal genetic variation leading to the disorder is likely among the genes encoding for members of the signaling cascades of growth factors.