Functional promoter variants of highly conserved inducible hsp70 genes significantly affect stress response

Polymorphism of 16s rRNA Gene: Any Effect on the Biomolecular Quantitation of the Honey Bee (Apis mellifera L., 1758) Pathogen Nosema ceranae?

The microsporidian Nosema ceranae is a severe threat to the western honey bee Apis mellifera, as it is responsible for nosemosis type C, which leads the colonies to dwindle and collapse. Infection quantification is essential to clinical and research aims. Assessment is made often with molecular assays based on rRNA genes, which are present in the N. ceranae genome as multiple and polymorphic copies. This study aims to compare two different methods of Real-Time PCR (qPCR), respectively relying on the 16S rRNA and Hsp70 genes, the first of which is described as a multiple and polymorphic gene. Young worker bees, hatched in the laboratory and artificially inoculated with N. ceranae spores, were incubated at 33 °C and subject to different treatment regimens. Samples were taken post-infection and analyzed with both qPCR methods. Compared to Hsp70, the 16S rRNA method systematically detected higher abundance. Straightforward conversion between the two methods is made impossible by erratic 16s rRNA/Hsp70 ratios. The 16s rRNA polymorphism showed an increase around the inoculated dose, where a higher prevalence of ungerminated spores was expected due to the treatment effects. The possible genetic background of that irregular distribution is discussed in detail. The polymorphic nature of 16S rRNA showed to be a limit in the infection quantification. More reliably, the N. ceranae abundance can be assessed in honey bee samples with methods based on the single-copy gene Hsp70.

Association Analysis of Polymorphisms in the 5' Flanking Region of the HSP70 Gene with Blood Biochemical Parameters of Lactating Holstein Cows under Heat and Cold Stress

Thermal stress (heat and cold) has large economic and welfare implications for the worldwide dairy industry. Therefore, it is paramount to understand the genetic background of coping mechanism related to thermal stress for the implementation of effective genetic selection schemes in dairy cattle. We performed an association study between 11 single nucleotide polymorphisms having minor allelic frequency (MAF > 0.05) in the HSP70 gene with blood biochemical parameters. The concentrations of growth hormone (GH), lactate (LA), prolactin (PRL), and superoxide dismutase (SOD) in blood were significantly higher (p < 0.05), while the concentrations of blood urea nitrogen (BUN), c-reactive protein (CRP), potassium (K+), lactate dehydrogenase (LDH), lipid peroxide (LPO), and norepinephrine (NE) were significantly lower (p < 0.05) in heat-stressed animals as compared to the control group. A significant (p < 0.05) increase in the concentrations of cortisol (COR), corticosterone (CORT), and potassium (K+) was observed (p < 0.05), while the concentrations of adrenocorticotrophic hormone (ACTH), dopamine (DA), GH, LDH, NE, PRL, and SOD were significantly lower in cold-stressed animals as compared to the control group (p < 0.05). Furthermore, SNP A-12G and C181T were significantly associated with LA (p < 0.05), while A72G was linked with LPO (p < 0.05) in heat-stressed animals. Moreover, the SNPs A-12G and SNP C131G were significantly associated (p < 0.05) with DA and SOD under cold stress condition, respectively. These SNPs markers significantly associated with fluctuations in blood biochemical parameters under thermal stress provide a better insight into the genetic mechanisms underlying climatic resilience in Holstein cattle.

Novel polymorphism of HSP70 gene affected caprine physiological vital parameters

The synthesis of heat shock protein 70 (HSP70) is temperature-dependent and its response is considered as a cellular thermometer in response to thermal stress. The variation in HSP70 gene expression has been positively correlated with thermo-tolerance. Three different goat populations (Black Bengal, Ganjam and Raighar) which differ in body size, coat color and production performance were assessed for effect of thermal stress at different temperature humidity index (THI). The physiological vital parameters like rectal temperature (RT), skin temperature (ST), heart rate (HR) and respiration rate (RR) which are related to thermal stress susceptibility were recorded. The genetic variation of HSP70 gene in the three goat populations and its effect on physiological vital parameters related to thermal stress was assessed. A novel polymorphism (C241T) in the exonic region of HSP70 gene with significant (p < .05) statistical association with the physiological vital parameters like RT, ST and RR was identified indicating its role in thermo-tolerance.HighlightsThe HSP70 gene was found to be polymorphic in Indian goats.The non-synonymous nucleotide change (C241T) resulted change in amino acid Arginine 241 Cysteine in mature polypeptide which were not reported earlier.The constructed phylogenetic tree showed that Ganjam and Raighar goats are more close to each other.

Prospects of HSP70 as a genetic marker for thermo-tolerance and immuno-modulation in animals under climate change scenario

Heat stress induced by long periods of high ambient temperature decreases animal productivity, leading to heavy economic losses. This devastating situation for livestock production is even becoming worse under the present climate change scenario. Strategies focused to breed animals with better thermo-tolerance and climatic resilience are keenly sought these days to mitigate impacts of heat stress especially in high input livestock production systems. The 70-kDa heat shock proteins (HSP70) are a protein family known for its potential role in thermo-tolerance and widely considered as cellular thermometers. HSP70 function as molecular chaperons and have major roles in cellular thermotolerance, apoptosis, immune-modulation and heat stress. Expression of HSP70 is controlled by various factors such as, intracellular pH, cyclic adenosine monophosphate (cyclic AMP), protein kinase C and intracellular free calcium, etc. Over expression of HSP70 has been observed under oxidative stress leading to scavenging of mitochondrial reactive oxygen species and protection of pulmonary endothelial barrier against bacterial toxins. Polymorphisms in flanking and promoter regions in HSP70 gene have shown association with heat tolerance, weaning weight, milk production, fertility and disease susceptibility in livestock. This review provides insight into pivotal roles of HSP70 which make it an ideal candidate genetic marker for selection of animals with better climate resilience, immune response and superior performance.

Characterizing binding sites of heat responsive microRNAs and their expression pattern in heat stressed PBMCs of native cattle, exotic cattle and riverine buffaloes

It is generally believed that due to evolutionary differences and adaptation to tropical conditions, Indian native cattle has superior heat tolerant ability than Bos taurus cattle. In the present study, 3'-UTR of two most important heat responsive genes i.e., heat shock protein 70.1 (HSP70.1) and heat shock factor- 1 (HSF-1) were sequence characterized in different breeds of Indian native cattle to identify the variations and miRNA binding sites. In addition, the impact of heat stress was assessed in a total of 57 PBMCs samples of native Sahiwal cows (Bos indicus), exotic Holstein cows (Bos taurus) and Murrah buffaloes (Bubalus bubalis) using various cellular parameters like cell viability, cytotoxicity and apoptosis. Further, expression profile of 12 heat responsive miRNAs were also evaluated in unstressed and stressed PBMCs to understand post transcriptional changes in native cows, exotic cows and Murrah buffaloes. The sequence data showed 3'-UTR of HSP70.1 gene of Indian cattle to be exactly similar to Bos taurus with no miRNA binding site. Whereas, sequencing of 3'-UTR of HSF-1 gene revealed 3 SNPs at positions G1762T; C1811T and C1983T with 7 well conserved miRNA binding sites. The impact of heat stress on various cellular parameters in terms of cell viability, cytotoxicity and apoptosis was highest in PBMCs of Holstein cows followed by Murrah buffaloes and Sahiwal cows. Further, in contrast to Holstein Frisian cows and Murrah buffaloes, the expression pattern of 12 heat responsive miRNAs, in heat stressed PBMCs of Sahiwal cows were quite distinct. There was a significant (p < 0.05) induction in expression of most of the miRNAs after heat stress in PBMCs of Sahiwal cows followed by a rapid decline. The distinct cellular response and pattern of miRNA expression across cattle types and buffaloes might be influencing their PBMCs tolerance level to heat stress.

Detection of functional polymorphisms in the hsp70 gene and association with cold stress response in Inner-Mongolia Sanhe cattle

The genetic mechanisms underlying the cattle resilience to severe cold temperatures are still unknown. In this study, we observed that four blood biochemical parameters were significantly altered, i.e., blood adrenocorticotropic hormone (ACTH), triiodothyronine (T3), thyroxine (T4), and potassium (K+) after expose to - 32 °C for 3 h. This was observed using 105 healthy Sanhe heifers with similar weight (398.17 ± 34.06 kg) and age (19.30 ± 4.91 months). A total of 20 single nucleotide polymorphisms (SNPs) were identified in 5'-flanking region of the hsp70 gene in Sanhe cattle, while only 10 SNPs were segregating when comparing genetic variations between Sanhe cattle and 285 Chinese Holstein samples. Statistically significant associations between the genomic markers SNP-42-, SNP-105+, SNP-181+, and SNP-205+ with blood T3 and between SNP-105+ and blood T4 were observed by applying the general linear model procedure and Bonferroni t test. Furthermore, we demonstrated that the T alleles of SNP-42- and SNP-205+ in the GC box and Kozak sequence of the hsp70 gene, respectively, significantly decreased the green fluorescent proteins activity in vitro GFP reporter assays. These findings suggest that these two SNPs are causative polymorphisms involved in the regulation of hsp70 promoter activity and might contribute to the observed association between the hsp70 gene and T3 and T4 levels in Sanhe cattle. Thus, hsp70 gene is a promising candidate gene to be validated in independent cattle populations and functional studies related to cold stress resilience in cattle.

The polymorphisms in the promoter of HSP90 gene and their association with heat tolerance of bay scallop

The heat shock protein 90 (HSP90) is a highly abundant and ubiquitous molecular chaperone which plays essential roles in many cellular processes. In the present study, the messenger RNA (mRNA) expressions of HSP90 after acute heat stress were investigated in two bay scallop populations (Argopecten irradians irradians and Argopecten irradians concentricus). The heat-resistant scallop A. i. concentricus, which is distributed in Zhanjiang, China, exhibited significantly higher induction of HSP90 compared with that of the heat-sensitive scallop A. i. irradians, which is distributed in Qinhuangdao, China. The promoter sequence of HSP90 gene from bay scallop (AiHSP90) was cloned, and the polymorphisms within this region were investigated by sequencing to analyze their association with heat tolerance. A total of six single nucleotide polymorphisms (SNPs), including -1167 T-C, -1023 A-C, -799 C-T, -774 A-G, -686 C-T, and -682 A-C, were identified in the amplified promoter region, and most of them affected the putative transcription factor binding sites except for locus -1167. All the six SNP sites were found to be associated with heat tolerance after Hardy-Weinberg equilibrium (HWE) and association analysis. Moreover, haplotypes CACACC and TCTATC were also found to be associated with heat tolerance based on the result of linkage disequilibrium and association analysis. The results provided insights into the molecular mechanisms underlying the thermal adaptation of different congener endemic bay scallops, which suggested that the increased heat tolerance of A. i. concentricus (compared with A. i. irradians) was associated with the higher expression of AiHSP90. Meanwhile, the six genotypes (-1167 TT, -1023 CC, -799 TT, -774 GG, -686 CC, and -682 AA) and two haplotypes (CACACC and TCTATC) could be used as potential markers for scallop selection breeding with higher heat tolerance.

The polymorphism in the promoter of HSP70 gene is associated with heat tolerance of two congener endemic bay scallops (Argopecten irradians irradians and A. i. concentricus)

Background

The heat shock protein 70 (HSP70) is one kind of molecular chaperones, which plays a key role in protein metabolism under normal and stress conditions.

Methodology

In the present study, the mRNA expressions of HSP70 under normal physiological condition and after acute heat stress were investigated in gills of two bay scallop populations (Argopecten irradians irradians and A. i. concentricus). The heat resistant scallops A. i. concentricus showed significantly lower basal level and higher induction of HSP70 compared with that of the heat sensitive scallops A. i. irradians. The promoter sequence of HSP70 gene from bay scallop (AiHSP70) was cloned and the polymorphisms within this region were investigated to analyze their association with heat tolerance. Totally 11 single nucleotide polymorphisms (SNPs) were identified, and four of them (−967, −480, −408 and −83) were associated with heat tolerance after HWE analysis and association analysis. Based on the result of linkage disequilibrium analysis, the in vitro transcriptional activities of AiHSP70 promoters with different genotype were further determined, and the results showed that promoter from A. i. concentricus exhibited higher transcriptional activity than that from A. i. irradians (P<0.05).

Conclusions

The results provided insights into the molecular mechanisms underlying the thermal adaptation of different congener endemic bay scallops, which suggested that the increased heat tolerance of A. i. concentricus (compared with A. i. irradians) was associated with the higher expression of AiHSP70. Meanwhile, the −967 GG, −480 AA, −408 TT and −83 AG genotypes could be potential markers for scallop selection breeding with higher heat tolerance.

Association analysis of HSP70A1A haplotypes with heat tolerance in Chinese Holstein cattle

Single-nucleotide polymorphisms (SNPs) in the coding and untranslated regions of heat shock 70 kDa protein 1A (HSP70A1A), an inducible molecular chaperone that is responsible for cellular protection against heat stress, have been reported as being associated with heat tolerance. A fragment of the HSP70A1A gene was amplified in Chinese Holstein cattle and eight novel mutations were found. We performed comprehensive linkage disequilibrium (LD) and haplotype analyses of the eight SNPs of the HSP70A1A gene and examined their involvement in heat resistance in 600 Chinese Holstein cattle. Our results revealed the presence of significant differences between individuals carrying haplotype 1 and those without haplotype 1 for most of the heat-tolerance traits. Haplotype 1 increased the risk of heat stress; however, association analysis of its combination with haplotype 2 showed the lowest rectal temperature and red blood cell K(+) level, moderate respiratory rate, and the highest red blood cell NKA level, suggesting a heterozygote advantage in the penetration of the phenotype. Protein expression levels in white blood cells among haplotype combinations further confirmed the hypothesis that heterozygotes for haplotypes 1 and 2 are more sensitive to heat stress. We presume that these mutations may be useful in the future as molecular genetic markers to assist selection for heat tolerance in cattle.

Promoter variants at AP2 box region of Hsp70.1 affect thermal stress response and milk production traits in Frieswal cross bred cattle

Heat shock proteins (Hsp) are known to play major role in protection of cells from thermal stress. Nucleotide polymorphisms within the promoter of Hsp affect degree of expression and inducibility of Hsp mRNA. The present study aimed to investigate the effect of polymorphism within promoter region on the cellular expression of Hsp70.1 mRNA and association of identified polymorphisms with the physiological parameters during summer stress and milk production traits in dairy cattle. Two hundred Frieswal cows were genotyped using double PCR-RFLP to identify deletion of cytosine within the Hsp70.1 promoter AP2 box at base position 895. Homozygous wild type genotypes (CC) were found in lower frequency (39.29, n=78) than heterozygous cytosine deletion mutant genotypes (C-) (60.71, n=122). In the observed physiological parameters (rectal temperature, respiration rate and heat tolerance coefficient), cows that were homozygous wild types had better significant (P<0.05) summer tolerance than the heterozygous deletion genotypes. Cytosine deletion mutation in the promoter region negatively affected (P<0.01) the expression of Hsp70.1 mRNA in peripheral bovine mononuclear cells (PBMC) subjected to in vitro heat stress. Further association of observed polymorphism with the milk production traits was significant as the heterozygous cytosine deletion cows had lower total milk yield, peak yield, yield at 300 days, protein% (P<0.01) and fat% (P<0.05) than the native wild type promoter cows. The results from the present study suggest that the promoter region of bovine hsp70.1 gene is polymorphic and may be useful in selection of dairy cows for relatively better thermotolerance and higher milk production.

Novel polymorphisms in UTR and coding region of inducible heat shock protein 70.1 gene in tropically adapted Indian zebu cattle (Bos indicus) and riverine buffalo (Bubalus bubalis)

Due to evolutionary divergence, cattle (taurine, and indicine) and buffalo are speculated to have different responses to heat stress condition. Variation in candidate genes associated with a heat-shock response may provide an insight into the dissimilarity and suggest targets for intervention. The present work was undertaken to characterize one of the inducible heat shock protein genes promoter and coding regions in diverse breeds of Indian zebu cattle and buffaloes. The genomic DNA from a panel of 117 unrelated animals representing 14 diversified native cattle breeds and 6 buffalo breeds were utilized to determine the complete sequence and gene diversity of HSP70.1 gene. The coding region of HSP70.1 gene in Indian zebu cattle, Bos taurus and buffalo was similar in length (1,926 bp) encoding a HSP70 protein of 641 amino acids with a calculated molecular weight (Mw) of 70.26 kDa. However buffalo had a longer 5' and 3' untranslated region (UTR) of 204 and 293 nucleotides respectively, in comparison to Indian zebu cattle and Bos taurus wherein length of 5' and 3'-UTR was 172 and 286 nucleotides, respectively. The increased length of buffalo HSP70.1 gene compared to indicine and taurine gene was due to two insertions each in 5' and 3'-UTR. Comparative sequence analysis of cattle (taurine and indicine) and buffalo HSP70.1 gene revealed a total of 54 gene variations (50 SNPs and 4 INDELs) among the three species in the HSP70.1 gene. The minor allele frequencies of these nucleotide variations varied from 0.03 to 0.5 with an average of 0.26. Among the 14 B. indicus cattle breeds studied, a total of 19 polymorphic sites were identified: 4 in the 5'-UTR and 15 in the coding region (of these 2 were non-synonymous). Analysis among buffalo breeds revealed 15 SNPs throughout the gene: 6 at the 5' flanking region and 9 in the coding region. In bubaline 5'-UTR, 2 additional putative transcription factor binding sites (Elk-1 and C-Re1) were identified, other than three common sites (CP2, HSE and Pax-4) observed across all the analyzed animals. No polymorphism was found within the 3'-UTR of Indian cattle or buffalo as it was found to be monomorphic. The promoter sequences generated in 117 individuals showed a rich array of sequence elements known to be involved in transcription regulation. A total of 11 nucleotide changes were observed in the promoter sequence across the analyzed species, 3 of these changes were located within the potential transcription factor binding domains. We also identified 4 microsatellite markers within the buffalo HSP70.1 gene and 3 microsatellites within bovine HSP70.1. The present study identified several distinct changes across indicine, taurine and bubaline HSP70.1 genes that could further be evaluated as molecular markers for thermotolerance.

Metabolic and hormonal acclimation to heat stress in domesticated ruminants

Environmentally induced periods of heat stress decrease productivity with devastating economic consequences to global animal agriculture. Heat stress can be defined as a physiological condition when the core body temperature of a given species exceeds its range specified for normal activity, which results from a total heat load (internal production and environment) exceeding the capacity for heat dissipation and this prompts physiological and behavioral responses to reduce the strain. The ability of ruminants to regulate body temperature is species- and breed-dependent. Dairy breeds are typically more sensitive to heat stress than meat breeds, and higher-producing animals are more susceptible to heat stress because they generate more metabolic heat. During heat stress, ruminants, like other homeothermic animals, increase avenues of heat loss and reduce heat production in an attempt to maintain euthermia. The immediate responses to heat load are increased respiration rates, decreased feed intake and increased water intake. Acclimatization is a process by which animals adapt to environmental conditions and engage behavioral, hormonal and metabolic changes that are characteristics of either acclimatory homeostasis or homeorhetic mechanisms used by the animals to survive in a new 'physiological state'. For example, alterations in the hormonal profile are mainly characterized by a decline and increase in anabolic and catabolic hormones, respectively. The response to heat load and the heat-induced change in homeorhetic modifiers alters post-absorptive energy, lipid and protein metabolism, impairs liver function, causes oxidative stress, jeopardizes the immune response and decreases reproductive performance. These physiological modifications alter nutrient partitioning and may prevent heat-stressed lactating cows from recruiting glucose-sparing mechanisms (despite the reduced nutrient intake). This might explain, in large part, why decreased feed intake only accounts for a minor portion of the reduced milk yield from environmentally induced hyperthermic cows. How these metabolic changes are initiated and regulated is not known. It also remains unclear how these changes differ between short-term v. long-term heat acclimation to impact animal productivity and well-being. A better understanding of the adaptations enlisted by ruminants during heat stress is necessary to enhance the likelihood of developing strategies to simultaneously improve heat tolerance and increase productivity.

Cellular thermotolerance is associated with heat shock protein 70.1 genetic polymorphisms in Holstein lactating cows

Heat shock proteins (Hsp) are known to protect cells from several stressors. Nucleotide changes in the flanking regions [5'- and 3'-untranslated region (UTR)] of Hsp gene might affect inducibility, degree of expression, or stability of Hsp70 mRNA. The present study aimed to investigate the association between inducible Hsp70.1 single nucleotide polymorphisms (SNPs) and heat shock (HS) response of peripheral blood mononuclear cells (PBMC) in dairy cows. Four hundred forty-six Italian Holstein cows were genotyped for four Hsp70.1 SNPs: g895 C/- and g1128 G/T in 5'-UTR, and g2154 G/A and g64 G/T in 3'-UTR. Genetic polymorphisms in 3'-UTR of bovine Hsp70.1 gene resulted monomorphic. Distribution of alleles of the nucleotide sequence polymorphism within the 5'-UTR of the bovine Hsp70.1 gene were 81.2% and 18.8% for C and -, respectively, and 77.8% and 22.2% for G and T, respectively. Among the 446 genotyped animals, a group of cows balanced for days in milk and parity was selected to be representative of the following genotypes: CC (n = 8), C- (n = 7), and -- (n = 7) and GG (n = 8), GT (n = 11), and TT (n = 3) in 5'-UTR. PBMC were isolated from blood samples and heated at 43°C in thermal bath for 1 h and then incubated at 39°C in atmosphere of 5% CO(2) for 1, 2, 4, 8, 16, and 24 h (recovery times). Cell viability was determined by XTT assay. Gene and protein expression of Hsp70.1 was determined by real-time reverse transcription-polymerase chain reaction and by ELISA assay, respectively. For the two SNPs detected, one allele was the most frequent (C, 66.8% and G, 56.8%). Genotypes -- and TG showed higher (P < 0.05) viability compared with CC and GG, respectively. Genotypes C- and TT had intermediate viability. Gene expression of Hsp70.1 showed higher (P < 0.001) levels in -- and TG genotype compared with their counterparts. Genotypes -- and TG showed the higher level of inducible Hsp70.1 protein in respect to C-, TT and CC, GG. In conclusion, exposure to HS differently affected cell viability and gene and protein expression of Hsp70.1 in the selected genotypes. These results indicate that the presence of SNPs (C/- and G/T) in the 5'-UTR region of inducible Hsp70.1 ameliorates HS response and tolerance to heat of bovine PBMC. These mutation sites may be useful as molecular genetic markers to assist selection for heat tolerance.

Possible genetic sign of heat stress adaptation in Hungarian Grey Bos taurus breed

The synthesis of Heat Shock Protein 70.2 mRNA is also regulated by the Upper Promoter elements of the gene. This promoter region is polymorphic in cattle. These polymorphisms have a major effect on the activity of the mRNA transcription. In a comparison of quantity of transcribed mRNA from the wild type and AP2 mutant allele the wild type can produce 2-3-fold more transcripts.The Hungarian Grey Cattle (HG) and Norwegian Red (NFR) as control breed were genotyped with PCR-RFLP method. Our results showed that the frequencies of alleles in breeds (p(wt)HG = 0.859419, p(wt)NFR = 0.5) are different. The effective response to heat stress in the Norwegian Red seems to be less important than in the Hungarian Grey breed. The extensive keeping in hot and arid region during centuries could have been proved as selection pressure for the heat tolerance.Our results combined with the global climate forecasts emphasize the role of autochthonous, well adopted, heat tolerant breeds in the near future.

Heat shock protein 70 is upregulated in the intestine of intrauterine growth retardation piglets

The objective of this study is to investigate the expression and distribution of heat shock protein 70 (Hsp70) in the intestine of intrauterine growth retardation (IUGR) piglets. Samples from the duodenum, prejejunum, distal jejunum, ileum, and colon of IUGR and normal-body-weight (NBW) piglets were collected at birth. The results indicated that the body and intestine weight of IUGR piglets were significantly lower than NBW piglets. The villus height and villus/crypt ratio in jejunum and ileum of IUGR piglets were significantly reduced compared to NBW piglets. These results indicated that IUGR causes abnormal gastrointestinal morphologies and gastrointestinal dysfunction. The mRNA of hsp70 was increased in prejejunum (P < 0.05), distal jejunum (P < 0.05), and colon in IUGR piglets. However, the hsp70 mRNA in ileum of piglets with IUGR was decreased. Similar to hsp70 mRNA, the protein levels of Hsp70 in prejejunum (P < 0.05), distal jejunum, and colon (P < 0.05) in IUGR piglets were higher than those in NBW piglets. These results indicated that the expression of Hsp70 in the intestinal piglets was upregulated by IUGR, and different intestinal sites had different responses to stress. Meanwhile, the localization of Hsp70 in the epithelial cells of the whole villi and intestinal gland rather than in the lamina propria and myenteron suggested that Hsp70 has a cytoprotective role in epithelial cell function and structure.

The inducible form of heat shock protein 70 in the serum, colon and small intestine of the pig: Comparison to conventional stress markers

Modern rearing conditions may cause stress to pigs. At the cellular level all animals respond to stress by synthesizing heat shock proteins (HSP), which protect cells from injury. The objective of this study was to examine the concentrations of stress-inducible HSP72 in porcine small intestine and colon, known to be stress sensitive tissues, and to compare the findings with HSP72 concentrations in serum and with conventional markers of stress, namely blood lactate and serum cortisol, glucose, free fatty acids and acute phase proteins. HSP72 in the colon correlated with serum HSP72 but there was a negative correlation with carcass weight (growth). The results suggest that the colon may be a significant source of serum HSP72, the concentration of which may reflect changes in the permeability of intestinal epithelium due to stressors, such as transport and handling.

A 3'-UTR variant of the inducible porcine hsp70.2 gene affects mRNA stability

Large individual differences were observed in the abundance of transcripts from the hsp70.2 gene in primary fibroblast cultures sampled from 15 different pigs. While previously described functional promoter variants of this gene can partly account for the high variability of heat-induced increased abundance of transcripts, they are unrelated to the observed highly variable absolute amounts of hsp70.2 transcripts. Comparative sequence analysis revealed an alteration of the 3'-untranslated region (3'-UTR) sequences in these samples. The variant 3'-UTR allele proved to increase the half life of the hsp70.2 mRNA in reporter gene assays. It is suggested that the cellular stress response is significantly affected by the action and interaction of both promoter and 3'-UTR variants of the hsp70.2 gene.