Association of polymorphism in the alpha (1,2) fucosyltransferase gene with growth performance in two Western pig breeds in Taiwan

The mutation at 307 bp (M307) of the alpha (1,2) fucosyltransferase gene has been proposed as being a marker for selection of E. coli F18 adhesion-resistant pigs. Nonetheless, exactly how this mutation affects pigs' growth performance remains unclear. This study investigated genotypic frequencies and the effect of M307 and the ryanodine receptor (RYR1) on the growth performance of two major Western pig breeds in Taiwan. In total, 1510 (1024 Duroc and 486 Landrace) boars were performance tested using segregated early weaning entrance. The genotypes of M307 and RYR1 were determined by polymerase chain reaction-based restriction fragment length polymorphism. The performance traits included average daily gain, the feed conversion ratio, backfat thickness, and age at 110 kg of body weight. The statistical model included starting age, test season, genotype of M307, genotype of RYR1, and two- and three-way interactions. The data were analyzed within breeds. Consequently, the genotypic frequencies of the AA genotype in M307 were 0.06 and 0.06, and of the GG genotype were 0.53 and 0.64 in Duroc and Landrace pigs, respectively. The genotypic frequencies of the NN genotype in RYR1 were 0.75 and 0.99, and of the nn genotype were 0.01 and 0.00 in Duroc and Landrace pigs, respectively. There was no significant effect of the M307 genotype on the growth performance in either Duroc or Landrace breeds. However, the RYR1 significantly influenced the average daily gain and age at 110 kg of body weight of Duroc pigs. The results suggest that selection of the favorable AA genotype at M307 for E. coli F18 adhesion resistance may not affect the growth performance traits in Duroc and Landrace pigs. However, the effect of the RYR1 on growth performance should be monitored during selection.     

苏太仔猪FUT1基因M307位点多态性与F18大肠杆菌抗病相关性的体外鉴定

采用PCR-RFLP方法检测了江苏苏太断奶仔猪FUT1基因M307位点等位基因多态性分布,在所检的49头仔猪中,GG基因型个体16头,AG基因型19头,AA基因型14头。在此基础上,制备上述不同基因型个体仔猪小肠上皮细胞,分别与表达F18ab菌毛的野生型大肠杆菌、表达F18ac菌毛含fed操纵子全基因的重组大肠杆菌和V型系统表面分泌表达F18abFedF亚单位的重组大肠杆菌进行体外黏附试验和黏附抑制试验。研究结果表明:FUT1基因M307位点中GG型和AG型仔猪小肠上皮细胞均能黏附上述3种大肠杆菌,而AA型个体小肠上皮细胞则不能黏附。将上述3种大肠杆菌分别与抗F18ab菌毛高免血清、F18ac菌毛高免血清及抗F18abFedF亚单位单因子血清作用后,则失去黏附仔猪肠上皮细胞能力。上述结果对苏太猪从体外试验上证明了FUT1基因M307位点多态性与断奶仔猪腹泻和水肿病存在着直接的相关性。     

苏太猪FUT1基因M307位点多态性及其对部分免疫指标的遗传效应分析

本研究旨在分析苏太猪抗F18大肠杆菌病育种基础群FUT1基因M307位点对部分免疫指标的遗传效应,为下一步苏太猪抗病育种工作提供一定的理论依据。采用PCR-RFLP方法对苏太猪抗F18大肠杆菌病育种基础群FUT1基因M307多态性进行分析,并探讨其与部分免疫指标的关系。结果表明,基础群中576个个体FUT1基因M307位点经Hin6Ⅰ酶切后,产生AA、AG和GG3种基因型,基因型频率分别为0.235、0.609和0.156,抗性基因A为优势等位基因,频率为0.540;群体显著偏离了Hardy-Weinberg平衡状态(P0.01)。AA基因型个体的血红蛋白(HGB)和白细胞计数(WTBC)显著高于AG和GG型个体(P0.05),AG和GG型个体间差异不显著(P0.05);AA基因型个体的异嗜性粒细胞与淋巴细胞比率(H/L值)显著低于AG和GG型个体(P0.05),AG和GG型个体间差异不显著(P0.05);AA基因型个体与AG和GG型个体间SRBC抗体滴度差异不显著(P0.05)。本试验结果初步说明苏太猪F18抗性型群体具有抗逆性强的优良特性,AA基因型不仅对仔猪断奶后水肿病和腹泻病具有抗性,而且具有较高的一般抗病力。     

A 57‐bp deletion in the ovine KAP6‐1 gene affects wool fibre diameter

High glycine–tyrosine keratin‐associated proteins (HGT‐KAPs) are predominantly present in the orthocortex of wool fibres. They vary in abundance in different wools and have been implicated in regulating wool fibre properties, but little is known about the functional roles of these proteins in the fibre matrix. In this study, we used polymerase chain reaction – single‐strand conformational polymorphism (PCR‐SSCP) analysis to screen for variation in a gene encoding the ovine HGT‐KAP6‐1 protein. We identified three gene variants (A, B and C). Variants A and B were similar to each other, with only three nucleotide differences occurring downstream of the coding sequence. However, variant C had a 57‐bp deletion that would notionally result in a loss of 19 amino acids in the protein. The presence of C was found to be associated with an increase in mean fibre diameter (MFD), fibre diameter standard deviation (FDSD), coefficient of variation of fibre diameter (CVFD) and prickle factor (percentage of fibres over 30 microns; PF). Sheep of genotype BC produced wool of greater MFD, FDSD and PF than sheep of genotypes AA, AB and BB. The CVFD was greater in the BC sheep than the AB sheep. The results suggest that variation in ovine KRTAP6‐1 affects wool fibre diameter‐associated traits and that the 57‐bp deletion in this gene would lead to coarser wool with greater FDSD, CVFD and PF.     

Measurements of hypoxia ([18F]‐FMISO, [18F]‐EF5) with positron emission tomography (PET) and perfusion using PET ([15O]‐H2O) and power Doppler ultrasonography in feline fibrosarcomas*

The aim of this study was to evaluate if hypoxia in feline fibrosarcomas can be detected. This was done using positron emission tomography (PET), two hypoxia tracers and polarographic pO₂ measurements. Of the seven cats included, five received [¹⁸F]‐fluoromisonidazole and two 2‐(2‐nitro‐1H‐imidazol‐1‐yl)‐N‐(2,2,3,3,3‐pentafluoropropyl) acetamide. Perfusion was evaluated with [¹⁵O]‐H₂O (n = 4) and with contrast‐enhanced power Doppler ultrasonography (n = 5). Hypoxia was detected in three cats. Polarographic pO₂ measurements did not confirm PET results. In the ultrasonographic evaluation, low vascularity and low perfusion were seen with a peripheral vascular pattern and no perfusion in the centre of the tumour. This was in contrast to the [¹⁵O]‐H₂O scans, where central perfusion of the tumour was also found. In conclusion, it appears that hypoxia exists in this tumour type. The presence of tumour necrosis and heterogeneous hypoxia patterns in these tumours may explain the found discrepancies between the applied techniques.     

Distribution of alpha‐neoendorphin,ACTH (18–39) and beta‐endorphin (1–27) in the alpaca brainstem

Using an immunocytochemical technique, we have studied in the alpaca brainstem the distribution of immunoreactive structures containing prodynorphin (alpha‐neoendorphin)‐ and pro‐opiomelanocortin (adrenocorticotrophin hormone (18–39) (ACTH), beta‐endorphin (1–27))‐derived peptides. No peptidergic‐immunoreactive cell body was observed. Immunoreactive fibres were widely distributed, although in most of the brainstem nuclei the density of the peptidergic fibres was low or very low. In general, the distribution of the immunoreactive fibres containing the peptides studied was very similar. A close anatomical relationship occurred among the fibres containing alpha‐neoendorphin, ACTH or beta‐endorphin (1–27), suggesting a functional interaction among the three peptides in many of the brainstem nuclei. The number of fibres belonging to the prodynorphin system was higher than that of the pro‐opiomelanocortin system. A moderate/low density of immunoreactive fibres was observed in 65.11% (for alpha‐neoendorphin (1–27)), 18.18% (for ACTH) and 13.95% (for beta‐endorphin) of the brainstem nuclei/tracts. In the alpaca brainstem, a high density of immunoreactive fibres was not observed. The neuroanatomical distribution of the immunoreactive fibres suggests that the peptides studied are involved in auditory, motor, gastric, feeding, vigilance, stress, respiratory and cardiovascular mechanisms, taste response, sleep‐waking cycle and the control of pain transmission.     

The effect of M‐phase stage‐dependent kinase inhibitors on inositol 1,4,5‐trisphosphate receptor 1 (IP3R1) expression and localization in pig oocytes

At fertilization, inositol 1,4,5‐trisphosphate receptor type 1 (IP₃R1) has a crucial role in Ca²⁺ release in mammals. Expression levels, localization and phosphorylation of IP₃R1 are important for its function, but it still remains unclear which molecule(s) regulates IP₃R1 behavior in pig oocytes. We examined whether there was a difference in localization of IP₃R1 after in vitro or in vivo maturation of pig oocytes. In mouse oocytes, large clusters of IP₃R1 were formed in the cortex of the oocyte except in a ring‐shaped band of cortex adjacent to the spindle. However, no such clusters of IP₃R1 were observed in pig oocytes and there was no difference in its localization between in vitro and in vivo matured oocytes. We next tried to clarify which factor(s) regulates IP₃R1 localization, phosphorylation and expression using M‐phase stage‐dependent kinase inhibitors. Our results show that treatments with roscovitine (p34^cdc2 kinase inhibitor) or U0126 (mitogen‐activated protein kinase inhibitor) did not affect IP₃R1 expression or localization in pig oocytes, although the latter strongly inhibited phosphorylation. However, treatment with BI‐2536, an inhibitor of polo‐like kinase 1 (Plk1), dramatically decreased the expression level of IP₃R1 in pig oocytes in a dose‐dependent manner. From these results, it is suggested that Plk1 is involved in the regulation of IP₃R1 expression in pig oocytes.     

Influences of protein ingestion on glucagon‐like peptide (GLP)‐1‐immunoreactive endocrine cells in the chicken ileum

Influences of a specific dietary nutrient on glucagon‐like peptide (GLP)‐1‐containing cells in the chicken intestine are not yet clear. Significance of dietary protein level on GLP‐1‐containing cells in the chicken ileum was investigated. Chickens fed control or experimental diets of varying protein levels were examined using immunohistochemical and morphometrical techniques. We show that the protein ingestion had an impact on the activities of GLP‐1‐immunoreactive cells in the chicken ileum. Weight gains declined with decreasing dietary crude protein (CP) levels, but no significant differences were detected in the daily feed intake and villous height. GLP‐1‐immunoreactive cells with a round or oval shape were frequently observed in the lower CP level groups (4.5% and 0%). Frequencies of occurrence of GLP‐1‐immunoreactive cells were 41.1 ± 4.1, 38.5 ± 4, 34.8 ± 3.1 and 34.3 ± 3.7 (cells/mm², mean ± SD) for dietary CP level of 18%, 9%, 4.5% and 0% groups, respectively and significant differences were recognized between the control and lower CP level groups (P < 0.05). Multiple regression analysis indicated a significant correlation between the daily protein intake and frequencies of occurrence of GLP‐1‐immunoreactive cells. The protein ingestion is one of the signals that influence GLP‐1‐containing cells in the chicken small intestine.     

Polymorphisms in the bovine hemoglobin‐beta gene provide evidence for gene‐flow between wild species of Bos (Bibos) and domestic cattle in Southeast Asia

The electrophoretic variation in bovine hemoglobin‐beta (HBB) is one of the most investigated genetic markers. The presence of a unique HBB variant, HBB^X, in Southeast Asian cattle has been reputed as a sign of gene‐flow from wild bovine species. In this study, we analyzed the DNA sequences of HBB genes in domestic and wild bovine species to verify this belief. Isoelectric focusing of HBB chain revealed that the HBB^X in domestic cattle had dimorphism and was separated into HBB^X1 and HBB^X2. The HBB^X1 had the same DNA sequence of the common HBB variant in gayal (Bos gaurus frontalis), while some of the HBB^X2 were identical with that of Cambodian banteng (Bos javanicus birmanicus). As a result, we confirmed that the bovine HBB variants can be a good indicator of introgression between wild and domestic cattle. The HBB^X1 was always predominant to HBB^X2 in the continental populations, suggesting that the gaur had contributed to the gene pool of domestic cattle in this region much more than the banteng. On the other hand, the mitochondrial DNA analysis could not detect gene‐flow from wild species. Autosomal markers that can trace the phylogeny between alleles are suitable for the assessment of bovine interspecific introgression.     

A possible solution to model nonlinearity in elimination and distributional clearances with α2‐adrenergic receptor agonists: Example of the intravenous detomidine and methadone combination in sedated horses

The alpha(α)₂‐agonist detomidine is used for equine sedation with opioids such as methadone. We retrieved the data from two randomized, crossover studies where detomidine and methadone were given intravenously alone or combined as boli (STUDY 1) (Gozalo‐Marcilla et al., 2017, Veterinary Anaesthesia and Analgesia, 2017, 44 , 1116) or as 2‐hr constant rate infusions (STUDY 2) (Gozalo‐Marcilla et al., 2019, Equine Veterinary Journal, 51 , 530). Plasma drug concentrations were measured with a validated tandem Mass Spectrometry assay. We used nonlinear mixed effect modelling and took pharmacokinetic (PK) data from both studies to fit simultaneously both drugs and explore their nonlinear kinetics. Two significant improvements over the classical mammillary two‐compartment model were identified. First, the inclusion of an effect of detomidine plasma concentration on the elimination clearances (Cls) of both drugs improved the fit of detomidine (Objective Function Value [OFV]: ?160) and methadone (OFV: ?132) submodels. Second, a detomidine concentration‐dependent reduction of distributional Cls of each drug further improved detomidine (OFV: ?60) and methadone (OFV: ?52) submodel fits. Using the PK data from both studies (a) helped exploring hypotheses on the nonlinearity of the elimination and distributional Cls and (b) allowed inclusion of dynamic effects of detomidine plasma concentration in the model which are compatible with the pharmacology of detomidine (vasoconstriction and reduction in cardiac output).     

Pharmacokinetics and bioavailability after intramuscular injection of the 5‐HT1A serotonin agonist R‐8‐hydroxy‐2‐(di‐n‐propylamino) tetralin (8‐OH‐DPAT) in domestic goats (Capra aegagrus hircus)

To determine the bioavailability and pharmacokinetic properties of the serotonin 5‐HT_1A receptor agonist R‐8‐OH‐DPAT in goats, and 0.1 mg kg^?1 R‐8‐OH‐DPAT hydrobromide was administered intramuscularly (i.m.) and intravenously (i.v.) to six goats in a two‐phase cross‐over design experiment. Venous blood samples were collected from the jugular vein 2, 5, 10, 15, 20, 30, 40 and 60 min following treatment and analysed by liquid chromatography tandem mass spectrometry. Bioavailability and pharmacokinetic parameters were determined by a one‐compartment analysis. Mean bioavailability of R‐8‐OH‐DPAT when injected i.m. was 66%. The mean volume of distribution in the central compartment was 1.47 L kg^?1. The mean plasma body clearance was 0.056 L kg^?1 min^?1. All goats injected i.v. and two of six goats injected i.m. showed signs of serotonin toxicity. In conclusion, R‐8‐OH‐DPAT is well absorbed following i.m. injection and the observed pharmacokinetics suggest that administration via dart is feasible. Administration of R‐8‐OH‐DPAT hydrobromide, at a dosage of 0.1 mg kg^?1, resulted in the observation of clinical signs of serotonin toxicity in the goats. It is suggested that dosages for the clinical use of the compound should be lower in order to achieve the desired clinical effect without causing serotonin toxicity.     

Rno‐miR‐425‐5p targets the DLST and SLC16A1 genes to reduce liver damage caused by excessive energy mobilization under cold stress

MicroRNAs (miRNAs) are a class of single‐stranded non‐coding small RNA molecules, which participate in the regulation of many physiological processes, and play a crucial role in cancer, metabolism and other processes. Rno‐miR‐425‐5p has been shown to play a role in the response to cold stress. To explore the mechanism by which rno‐miR‐425‐5p regulates the response to cold stress, we analysed the candidate target genes of rno‐miR‐425‐5p. After verification in rat hepatocyte BRL cells and in rat liver tissue, we identified several target genes that were altered in expression in response to cold stress. In rat liver tissue, the expression of rno‐miR‐425‐5p was significantly increased and the expression levels of target genes DLST and SLC16A1 were decreased under cold stress. The miRNA and mRNA levels were analysed by quantitative real‐time PCR and the protein levels were detected by Western blot analysis. Combined with the results of bioinformatic analysis, we concluded that rno‐miR‐425‐5p reduced the expression of DLST and SLC16A1, inhibiting energy release from the tricarboxylic acid cycle and preventing the liver from being injured by excessive energy mobilization.     

Potential role of ALDH3A2 on the lipid and glucose metabolism regulated by (‐)‐hydroxycitric acid in chicken embryos

This study aimed to investigate the effect of (‐)‐hydroxycitric acid ((‐)‐HCA) on lipid and glucose metabolism, and further analyzed these actions whether associated with modulation of aldehyde dehydrogenase 3 family member A2 (ALDH3A2) expression in chicken embryos. Results showed that (‐)‐HCA decreased triglyceride content and lipid droplet counts, while these effects induced by (‐)‐HCA were reversed in chicken embryos pre‐transfected with sh4‐ALDH3A2. (‐)‐HCA decreased malic enzyme, acetyl‐CoA carboxylase, fatty acid synthase, and sterol regulatory element binding protein‐1c mRNA level, while increased carnitine palmitoyl transferase 1A (CPT1A) and peroxisome proliferators‐activated receptor α (PPARα) mRNA level; and the action of (‐)‐HCA on lipid metabolism factors had completely eliminated in embryos pre‐transfected with sh4‐ALDH3A2. Chicken embryos pre‐transfected with sh4‐ALDH3A2 had eliminated the increasing of serum glucose and hepatic glycogen content induced by (‐)‐HCA. (‐)‐HCA decreased phosphofructokinase‐1 and increased G6P, fructose‐1,6‐bisphosphatase, phosphoenolpyruvate carboxykinase (PEPCK), and pyruvate carboxylase mRNA level in chicken embryos. Similarly, the effect of (‐)‐HCA on these key enzyme mRNA level was reversed in embryos pre‐transfected with sh4‐ALDH3A2. Furthermore, (‐)‐HCA increased PPAR‐γ‐coactivator‐1α (PGC‐1α), PPARα, hepatic nuclear factor‐4A, PEPCK, and CPT1A protein level, and these actions of (‐)‐HCA disappeared in embryos pre‐transfected with sh4‐ALDH3A2. These results indicated that (‐)‐HCA reduced fat accumulation and accelerated gluconeogenesis via activation of PGC‐1α signaling pathway, and these effects of (‐)‐HCA might associate with the increasing of ALDH3A2 expression level in chicken embryos.     

Tolerability and pharmacokinetic profile of a novel benzene‐poly‐carboxylic acids complex with cis‐diammineplatinum (II) dichloride in dogs with malignant mammary tumours

The pharmacokinetic profile, tolerability and efficacy of benzene‐poly‐carboxylic acids complex with cis‐diammineplatinum (II) dichloride (BP‐C1) were studied in dogs with mammary cancer. A three‐level response surface pathway designed trial was performed on seven dogs. At each level BP‐C1 was administered subcutaneously daily for 7 days followed by a 7‐day rest period in a dose escalating manner. Adverse events according to VCOG‐CTCAE, performance status and tumour progression were recorded. The pharmacokinetic profile followed a two‐compartment model with rapid absorption, short distribution, and a slow elimination phase. The overall elimination half‐life was 125 h. The maximum tolerated dose of BP‐C1 was estimated to be above 0.46 mg kg^?1. A significant reduction in VCOG‐CTCAE toxicity which correlated negatively with increasing dose was found. The dogs' general performance status remained unchanged. No decrease in total tumour burden was found, although temporary tumour reduction was seen in some target tumours.     

Influences of incorporating detoxified Jatropha curcas kernel meal in common carp (Cyprinus carpio L.) diet on the expression of growth hormone‐ and insulin‐like growth factor‐1‐encoding genes

Jatropha curcas is a drought‐resistant shrub or small tree widespread all over the tropics and subtropics. The use of J. curcas (L) kernel meal in fish feed is limited owing to the presence of toxic and antinutritional constituents. In this study, it was detoxified using heat treatment and organic solvent extraction method. The detoxification process was carried out for 60 min to obtain the detoxified meal. Cyprinus carpio L. fingerlings (n = 180; avg. wt. 3.2 ± 0.07 g) were randomly distributed in five treatment groups with four replicates and fed isonitrogenous diets (crude protein 38%) for 8 weeks. The inclusion levels of the detoxified Jatropha kernel meal (DJKM) and soybean meal (SBM) were as follows: control diet was prepared with fish meal (FM) and wheat meal, without any DJKM and SBM; diets S₅₀ and J₅₀: 50% of FM protein replaced by SBM and DJKM respectively; diets S₇₅ and J₇₅: 75% of FM protein replaced by SBM and DJKM respectively. Highest body mass gain and insulin‐like growth factor‐1 (IGF‐1) gene expression in brain, liver and muscle were observed for the control group, which were statistically similar to those for J₅₀ group and significantly (p < 0.05) higher than for all other groups, whereas growth hormone gene expression in brain, liver and muscle exhibited opposite trend. Insulin‐like growth factor‐1 concentration in plasma did not differ significantly among the five groups. Conclusively, growth performance was in parallel with IGF‐1 gene expression and exhibited negative trend with GH gene expression.     

Genetic association between GHSR1a 5′UTR‐microsatellite and nt‐7(C>A) loci and growth and carcass traits in Japanese Black cattle

We carried out a genetic association study between five nucleotide polymorphisms (5′UTR microsatellite ((TG)_n), nt‐7(C>A), L24V, DelR242 and Intron 1 microsatellite) of the GHSR1a gene and growth and carcass traits in 1285 steers sired by 117 Japanese Black bulls in a progeny testing program. We report herein, a significant association between the 5′UTR microsatellite and nt‐7(C>A) loci and growth and carcass traits. We also propose a translational hypothesis that the association is due to differences in the secondary structure of GHSR1b mRNA (the non‐spliced type with the 5′UTR microsatellite) among the GHSR1a gene haplotypes. Furthermore, we predicted the potential increase in profitability due to increased carcass weight in cow‐calf fattening enterprises through planned matings based on DNA testing of the 5′UTR microsatellite. Statistical analysis revealed that the 5′UTR microsatellite locus had a significant additive effect on carcass weight (CW) and average daily gain (ADG), but not on beef marbling score (BMS). One of the four major microsatellite alleles (19‐TG allele) with an allele frequency of 0.145, had a significantly (P < 0.0007) desirable effect on CW and ADG. We concluded that the 19‐TG allele could potentially be economically useful nucleotide markers for growth and carcass traits in Japanese Black cattle.     

Genetic variation in the ovine uncoupling protein 1 gene: association with carcass traits in New Zealand (NZ) Romney sheep,but no association with growth traits in either NZ Romney or NZ Suffolk sheep

The uncoupling protein 1 (UCP1) plays an important role in the regulation of lipolysis and thermogenesis in adipose tissues. Genetic variation within three regions (the promoter, intron 2 and exon 5) of the ovine UCP1 gene (UCP1) was investigated using polymerase chain reaction‐single‐strand conformational polymorphism (PCR‐SSCP) analyses. These revealed three promoter variants (designated A, B and C) and two intron 2 variants (a and b). The association of this genetic variation with variation in lamb carcass traits and postweaning growth was investigated in New Zealand (NZ) Romney and Suffolk sheep. The presence of B in a lamb's genotype was associated with decreased subcutaneous carcass fat depth (V‐GR) (p = 0.004) and proportion of total lean meat yield of loin meat (p = 0.005), and an increased proportion of total lean meat yield of hind‐leg meat (p = 0.018). In contrast, having two copies of C was associated with increased V‐GR (p < 0.001) and proportion of total lean meat yield of shoulder meat (p = 0.009), and a decreased hind‐leg yield (p = 0.032). No associations were found with postweaning growth. These results suggest that ovine UCP1 is a potential gene marker for carcass traits.     

A long‐term study of the effects of SLC12A1 homozygous mutation (g.62382825G>A,p.Pro372Leu) in Japanese Black cattle

Recessive missense mutation in the solute carrier family 12, member 1 (SLC12A1) gene (g.62382825G>A) is associated with hydrallantois, which is the accumulation of fluid in the allantoic cavity of a pregnant animal, and usually causes fetal death in Japanese Black cattle. However, the symptoms of a homozygote with this mutation that do not result in fetal death have not previously been tracked and evaluated. In the present study, we observed a homozygote with the SLC12A1 risk allele over a long‐term period. The calf did not show any obvious clinical symptoms, although it did exhibit a slight growth retardation that accompanied mild calciuria. At 28 months of age, the homozygote showed renal dysfunction, which in turn resulted in hydronephrosis. The time course of the symptoms was consistent with the phenotype of Bartter syndrome in humans. Additionally, the risk heterozygous genotype did not any effects on carcass traits, which indicates that eliminating the risk allele would not have any unfavorable effects. Therefore, we emphasize that both the fetal‐ and late‐stage symptoms associated with the SLC12A1 risk allele compromise animal welfare, and consequently may result in severe economic losses for individual farmers if the SLC12A1 risk allele is not eliminated from the population.     

Carrier rate of the c.235G>C mutation in the bovine isoleucyl-tRNA synthetase (IARS) gene of Japanese Black cows at Kagoshima prefecture, Japan,and analysis of the metabolic profiling and reproductive performance of heterozygous cows

Bovine isoleucyl-tRNA synthetase (IARS) disorder, a major cause of weak calf syndrome, is caused by a homozygous missense (c.235G>C) mutation in the bovine IARS gene of Japanese Black (JB) cattle, which was identified in 2013. However, the extent to which the carrier rate has changed at Kagoshima prefecture, Japan, and whether the carrier status is associated with any clinical or reproductive problems, have yet to be ascertained. In this study, using a real-time polymerase chain reaction-based genotyping assay, we determined the carrier rate in a regional JB cow population at Kagoshima prefecture. Comparative analyses were performed on the metabolic profile test (MPT) results and reproductive performance data obtained for heterozygous carrier and homozygous wild-type cows. In 2009 and 2018, DNA samples were collected from 130 and 462 clinically healthy JB cows, respectively, in Kagoshima prefecture. MPT results and reproductive performance data were evaluated for 62 cows, comprising four heterozygous carriers and 58 wild-type cows. Genotyping revealed that the carrier rate was 6.9% in 2009 and 1.5% in 2018, the difference of which was statistically significant (P<0.005). There were no statistically significant differences between the carrier and wild-type cows with respect to either MPT results or reproductive performance, indicating that the carrier cows have necessary IARS activity to maintain minimal health and reproductive potential.