Hepatic Ethoxy‐, Methoxy‐ and Pentoxyresorufin O‐Dealkylase Activities in Landrace and Duroc Pigs Stimulated with hCG

The effect of human chorionic gonadotropin (hCG) stimulation on the activities of ethoxyresorufin O‐deethylase (EROD), methoxyresorufin O‐demethylase (MROD) and pentoxyresorufin O‐depentylase (PROD) was studied in intact male pigs of purebred Landrace and Duroc breeds. Pigs were divided into four groups: two control groups of each breed, without hCG stimulation (n = 20 for each breed), and two experimental groups (n = 18 for each breed), with hCG stimulation (Pregnyl^®; N.V. Organon, Oss, The Netherlands, 30 IU/kg live weight). Pigs were slaughtered 3 days after hCG stimulation and enzyme activities were measured in hepatic microsomes using two approaches. First, only one substrate concentration was used for the analysis of each enzyme activity. We found that EROD activity was suppressed by hCG‐stimulation in Landrace (p = 0.004), but not Duroc pigs (p > 0.05). Generally, EROD activity was higher in Duroc pigs compared with Landrace (p = 0.017). Methoxyresorufin O‐demethylase and PROD activities did not differ between groups (p > 0.05). To further characterize EROD, MROD and PROD, enzyme kinetic studies were performed. V_max values for EROD and MROD in both breeds were lower after hCG stimuation (p < 0.001 for Landrace and p < 0.05 for Duroc). Additionally, V_max values for EROD significantly differed between Landrace and Duroc pigs being higher in Duroc pigs (p < 0.05). We concluded that both hCG stimulation and breed differences may be important in the regulation of EROD and MROD activities. This study provides the first data on the effect of hCG stimulation and thus high testicular steroids, on EROD, MROD and PROD activities. Further studies are needed to investigate individual CYP450 enzymes and their regulation in porcine tissues.     

Effects of hCG Stimulation on Hepatic Activities of Cytochromes P4502E1 and P4502A in Pubertal Male Pigs

The effects of human chorionic gonadotropin (hCG) stimulation on fat skatole concentrations and hepatic activities of cytochromes P4502E1 (CYP2E1) and P4502A (CYP2A) were studied in Landrace and Duroc breeds of entire male pigs. Pigs were divided into four groups: two control groups of each breed, without hCG stimulation (n = 20 for each breed), and two experimental groups of each breed, with hCG stimulation (n = 18 for each breed). Pigs were slaughtered 3 days after hCG stimulation and activities of CYP2E1 and CYP2A were measured in liver homogenate. Activities of both CYP2E1 and CYP2A were lower in hCG‐stimulated pigs than control pigs for both Landrace (p = 0.005 for CYP2E1, p = 0.016 for CYP2A) and Duroc breeds (p = 0.003 for CYP2E1, p = 0.001 for CYP2A), and skatole concentrations in fat were higher in the hCG‐stimulated pigs of both breeds (p < 0.01). For both control and hCG‐stimulated groups, Duroc pigs had lower skatole concentrations than Landrace pigs (p = 0.001 for both groups). The activity of CYP2E1 did not differ significantly between breeds in either the control group or the experimental group (p = 0.233 for control pigs and p = 0.210 for experimental pigs). However, whereas CYP2A activity did not differ significantly between breeds in the control groups (p = 0.181 for CYP2A), in the hCG‐stimulated groups, CYP2A activity was lower in Duroc pigs than in Landrace (p = 0.011). Based on these findings, we conclude that hCG stimulation can suppress hepatic CYP2E1 and CYP2A activities, probably through an increase in the levels of testicular steroids. Between‐breed variations in skatole levels in fat were not related to the activities of CYP2E1 and CYP2A.     

Gender-related differences in cytochrome P450 in porcine liver--implication for activity, expression and inhibition by testicular steroids

In pigs, the hepatic cytochrome P450 (CYP) 1A2, 2A and 2E1 activity is important in the regulation of skatole accumulation in adipose tissue. This study investigated gender-related differences in CYP1A2, 2A and 2E1 dependent activity, protein and mRNA expression. This study also investigated the gonadal steroid dependent inhibition of CYP activity in relation to gender and dietary composition. Microsomes were prepared from the liver of female and entire male pigs (Landrace × Yorkshire sire and Duroc boars) reared under similar conditions and slaughtered at an age of 164 days. A group of entire male pigs fed dried chicory root for 16 days prior to slaughter were included in the study. CYP activities were assessed by the use of probe substrates, whilst mRNA and protein expression were analysed by RT-PCR and Western blotting. Furthermore inhibition of CYP dependent activity by gonadal steroids was assessed in vitro. Microsomes from female pigs had greater CYP1A2 and 2A activity, as well as mRNA expression compared to entire male pigs. The antibodies used did not detected differences in protein expression. In vitro inhibition by 17β-oestradiol, oestrone, androstenone and 3β-OH androstenol of CYP2E1 activity in microsomes from entire male pigs as well as inhibition of CYP1A activity in chicory fed entire male pigs was observed. Apart from that no effect of steroids was shown. In conclusion, female pigs show greater CYP activity and mRNA expression. Including chicory in the diet for 16 days changed the gonadal steroid dependent inhibition of CYP activity in entire male pigs.     

Screening 52 single nucleotide polymorphisms for extreme value of glycolytic potential and drip loss in pigs

Low heritability of meat quality traits and the lack of their systematic registration in breeding programs have encouraged the search for single nucleotide polymorphisms (SNPs) located within genes coding the proteins involved in muscle and fat metabolism. In this report, a panel of 52 SNPs was used to find which alleles and genotypes are more/less frequent in groups of pigs differentiated by extreme value of glycolytic potential (GP) and drip loss (DL). The analysis was carried out in 52 fatteners (chosen from 246 pigs), of which 28 were Landrace and 27 Landrace × Yorkshire. Two designs were performed: I, fatteners were divided into two groups showing extreme value of GP (<125 versus >145), II, fatteners were divided into two groups showing extreme value of DL (<6.0 versus >6.0). Allele frequency differences between the phenotypic groups of extreme GL or DL were not influenced by the breed. The frequency of 52 SNPs alleles for each of group was calculated and a chi‐squared test was used to estimate the significance of differences in allele frequencies between alternative groups in each experimental design. Three SNPs (DECR1, PPARGC1, MC4R) and another two (CYP21, SFRS1) showed significant differences between groups of extreme GP and DL, respectively. To exemplify and validate potential associations of candidate SNPs for GP and DL, 293 fatteners representing three commercial breeds/crosses (95 Landrace, 66 Landrace × Yorkshire and 132 Landrace × Yorkshire × Duroc were genotyped for DECR1 and CYP21 by PCR‐RFLP assays. DECR1 showed significant associations with GP in Landrace and Landrace × Yorkshire × Duroc fatteners. CYP21 showed significant associations with DL in all breeds/crosses. Interestingly, the CYP21 polymorphism revealed adverse associations trend in Landrace × Yorkshire × Duroc pigs in comparison to Landrace and Landrace × Yorkshire fatteners.     

In Vitro Cytochrome P450 2E1 and 2A Activities in the Presence of Testicular Steroids

Cytochrome P450 2E1 (CYP2E1) and 2A (CYP2A) are the main enzymes involved in the metabolism of skatole in pigs. In this study, physiological concentrations of androstenone, 17β‐oestradiol and testosterone were tested for their ability to regulate CYP2E1 and CYP2A activity in liver microsomes isolated from entire male and female pigs as well as in microsomes from Saccharomyces cerevisiae expressing either human recombinant CYP2E1 or CYP2A6. We found that physiological concentrations of androstenone and oestradiol had the ability to inhibit CYP2E1 activity. The magnitude of this inhibition (approximately 30%) was similar in recombinant human CYP2E1 and microsomes from entire male pigs. This inhibition was only seen when adding the steroid to the assay 15 min before the substrate. Interestingly, CYP2E1 activity in the microsomes from female pigs was not affected. None of the investigated steroids modified the activity of recombinant human CYP2A6. However, CYP2A activity was slightly increased in the microsomes from female pigs in the presence of oestradiol, but the magnitude of this increase was very low (below 10%) and probably irrelevant. Overall, these results indicate that physiological concentrations of androstenone and oestradiol have a potential to inhibit CYP2E1 activities in vitro, and that this inhibition is gender‐specific. Further studies are needed to investigate the biochemical mechanisms underlying those differences between the genders.     

Osteochondrosis in six breeds of slaughter pigs

Summary

The severity and extent of osteochondral lesions have been examined, macroscopically, radiographically as well as histopathologically, in six different breeds of pigs (Belgian Landrace (B), Duroc (D), Dutch Landrace (N), Dutch Yorkshire (G), Hampshire (H) and Piétrain (P)). In these pigs three different levels of feeding were used.

Duroc pigs had significantly more severe lesions in the fore limbs than Dutch Landrace (N), Dutch Yorkshire (G), Hampshire (H) and Piétrain (P) pigs, while Belgian Landrace pigs (B) had significant more severe lesions than Dutch Yorkshire (G) pigs. The differences between breeds related more to the degree of severity of the lesions in the articular surfaces of the distal humerus and proximal radius‐ulna and in the distal ulnar growth plate than to the presence of the lesions per se. In the hind limbs Belgian Landrace pigs (B) had significantly more severe osteochondral lesions than all other breeds, while Dutch Landrace pigs (N) had significantly more severe lesions than Duroc (D), Dutch Yorkshire (G), Hampshire (H) and Piétran (P) pigs.

Pigs with the highest growth rate showed sginificantly more severe osteochondral lesions in the distal ulnar growth plate and in the medial fe,moral condyle than pigs with a more restricted growth rate.     

Effect of Polymorphisms in Four Candidate Genes for Fertility on Litter Size in a German Pig Line

We carried out an SNP discovery project in pigs for candidate genes playing potentially important roles in embryonic development. Using eight pigs one each from eight breeds (Meishan, Mangalitza, Duroc, Pietrain, German Landrace, Hampshire, Husum Red Pied, German Large White), 36 SNPs were identified in intronic sequences of 21 porcine candidate genes based on sequencing of PCR products. The primer pairs were designed using porcine EST sequences allowing amplification of introns. These SNPs were tested for their association with the number of piglets born alive in German Large White sows using a discordant approach. Significant effects (p < 0.001 and p < 0.05, respectively) of intronic SNPs on litter size were found for four genes: mitogen‐activated protein kinase kinase kinase 3 (MAP3K3), vascular endothelial growth factor receptor (KDR), erbb2 interacting protein (ERBB2IP) and peroxisome proliferator‐activated receptor delta (PPARD). These SNPs can be further tested in upcoming association studies for their influence on litter size in different breeds using larger sample sizes.     

不同猪种5-羟色胺受体基因的表达及其与肉质的相关性分析

为研究5-羟色胺（5-HT）受体基因在不同猪种的表达及其与肉质的关系,试验选取淳安花猪与杜长大三元猪各12头,同时饲喂,达上市体重时分别屠宰,测定胴体、肉质性状及肌肉、脂肪中的5-HT受体基因表达量。结果表明：淳安花猪、杜长大三元猪的平均屠宰体重分别为88.1、102.4kg;淳安花猪的板油率、背膘厚、肌内脂肪等指标均显著高于杜长大三元猪（P〈0.05）;屠宰率、眼肌面积杜长大三元猪显著高于淳安花猪（P〈0.05）。5-HT2A、5-HT7受体基因在2个猪种脂肪组织中的表达量均显著高于肌肉组织（P〈0.05）,杜长大三元猪的肌肉中5-HT2A、5-HT7表达量显著低于淳安花猪（P〈0.05）,而脂肪中表达量两猪种间差异不显著。5-HT2A、5-HT7受体基因表达量与屠宰肉质指标之间基本呈负相关,尤其是肌肉中的5-HT2A表达量,呈较强负相关（杜长大三元猪）或显著负相关（淳安花猪）。研究初步认为,5-HT受体基因在中外猪种之间存在表达差异,并与屠宰肉质性状具有相关性。     

Expression of 3beta-hydroxysteroid dehydrogenase, cytochrome P450-c17, and sulfotransferase 2B1 proteins in liver and testis of pigs of two breeds: relationship with adipose tissue androstenone concentration

An excessive accumulation of androstenone in pig adipose tissue is a major contributor to the phenomenon of boar taint. Androstenone deposition is dependent on the rate of androstenone biosynthesis in testis and androstenone degradation in liver. The aim of the current study was to examine the possibility of the existence of breed-specific mechanisms controlling androstenone accumulation in pig adipose tissue. The specific objective was to investigate the expression of some of the key enzymes involved in testicular and hepatic androstenone metabolism in pigs of 2 breeds by using animals with high and low androstenone concentrations within each breed. The study was conducted with Norwegian Landrace (N. Landrace) and Duroc boars. The mean androstenone values for the low- and high-androstenone groups were 0.1 +/- 0.01 microg/g and 7.58 +/- 0.68 microg/g for N. Landrace boars, and 0.22 +/- 0.04 microg/g and 13.55 +/- 1.14 microg/g for Duroc boars. The enzymes investigated were 3beta-hydroxysteroid dehydrogenase (3beta-HSD), cytochrome P450-c17, and sulfotransferase 2B1 (SULT2B1). Expression of cytochrome P450-c17 in liver and testis did not differ between animals with high and low androstenone concentrations in either the N. Landrace or Duroc breed. Expression of hepatic 3beta-HSD, which catalyzes the first stage of androstenone degradation, was decreased in high-androstenone N. Landrace boars (P < 0.01), but not in high-androstenone Duroc boars. In contrast, the expression of hepatic SULT2B1, which catalyzes the second stage of steroid catabolism, was decreased in high-androstenone Duroc animals (P < 0.05), but not in high-androstenone N. Landrace animals. Sulfotransferase 2B1 was also inhibited in testis of high-androstenone pigs of both breeds compared with low-androstenone animals. We report breed differences in expression of the androstenone-metabolizing enzymes 3beta-HSD and SULT2B1 in the liver of high- and low-androstenone pigs. It is suggested that accumulation of androstenone in adipose tissue of N. Landrace boars might be related to a low rate of hepatic androstenone degradation in metabolic stage I, whereas the high androstenone concentration in Duroc boars might be related to a low rate of androstenone metabolism in metabolic stage II.     

品种、季节、胎次、采精月龄及采精间隔对猪精液品质的影响

【目的】探究品种、公猪出生胎次、公猪同窝仔猪数、公猪乳头数、采精季节、采精月龄和采精间隔对猪精液品质的影响,以及不同品种对精液质量稳定性的影响。【方法】选取909头杜洛克、长白、大白种公猪为试验群体,收集2021年4月至2022年4月27 408条精液测定记录,采用混合线性分析模型和方差分析探究品种、公猪出生胎次、公猪同窝仔猪数、公猪乳头数、采精季节、采精月龄和采精间隔对精液体积、精液密度、精子活力、直线前进运动精子比例、精子畸形率、总精子数及各精液性状稳定性的影响。【结果】从不同品种对精液品质的影响来看,长白猪精液体积和总精子数均显著高于大白猪、杜洛克猪(P<0.05),杜洛克猪精液密度显著高于大白猪和长白猪(P<0.05),杜洛克猪、大白猪精子活力均显著高于长白猪(P<0.05),大白猪直线前进运动精子比例显著高于长白猪和杜洛克猪(P<0.05),长白猪和大白猪精子畸形率均显著低于杜洛克猪(P<0.05);从不同公猪出生胎次对精液品质的影响来看,1～3胎出生的公猪具有较高的精液品质;从不同采精季节对精液品质的影响来看,精液密度、精子活力和总精子数秋、冬...     

不同猪种ESR基因多态性的PCR-RFLP分析

运用PCR-RFLP方法,检测了杜洛克、约克夏、长白猪、皮特兰、梅山猪、二花脸猪、枫泾猪、荣昌猪、苏太猪等9个国内外猪种的ESR基因PvuⅡ位点多态性。结果表明,在约克夏猪、二花脸猪、枫泾猪和苏太猪中检测到了AA、AB、BB 3种基因型,在杜洛克猪、皮特兰猪中检测到AB、BB 2种基因型,在长白猪、梅山猪、荣昌猪中只检测到了AB基因型。在本研究中不同品种的A、B基因频率差异显著,总体上在国外猪群体中A等位基因为优势等位基因,而地方猪种中B等位基因为优势等位基因。     

Adjustment of pig or litter weights to a 21-day basis in Duroc, Landrace, and crossbred swine

A total of 457 Duroc, 137 Landrace, 131 Duroc x Landrace, and 110 three-and four-breed crossbred pigs were used to estimate multiplicative adjustment factors. Sixty-one Duroc, 24 Landrace, 18 Duroc x Landrace, and 16 three- and four-breed crossbred litters were weighed every 3 or 4 d from 13 to 30 d of age. Prediction equations for estimating pig weights from birth to 30 d and from 13 to 30 d of age are presented. Multiplicative adjustment factors for adjusting pig or litter weights to a 21-d basis for pigs or litters that are weighed between 13 and 30 d of age for different breeds and crossbred combinations are listed. Breed, litters within breed, and pigs within litter x breed effects adjusted for age at weighing were different (P less than .01). Quadratic regression coefficients of weight on age of pig from 13 to 30 d of age did not differ (P greater than .10) from zero for Landrace and three- and four-breed crossbred pigs but were significant for Duroc and Duroc x Landrace pigs.     

In vitro fermentative capacity of swine large intestine: comparison between native Lantang and commercial Duroc breeds

Native Lantang and commercial Duroc pigs were used as animal models to evaluate the differences existing in dietary fiber utilization ability between breeds. Animals were fed the same diet from weaning (4 weeks) to 4 months of age. Neutral detergent fiber (NDF) from wheat bran (as substrate) and fecal samples from the two breeds (as inoculum) were used in an in vitro gas production trial. Results showed that cumulative and maximum gas productions were higher in inocula from Lantang than those from the Duroc breed (P < 0.05). The degradation capacity of NDF for microbiome from Lantang fecal samples were significantly higher compared to Duroc (P < 0.01). The total quantity of short‐chain fatty acids and its constituents from the fermentation liquors were different between breeds, suggesting that the dynamic characteristics of fermentation differed between the two breeds. The PCR denaturing gradient gel electrophoresis fingerprint and cluster analysis demonstrated that microbial communities of the two breeds were separated into two clusters and the bacterial community structure of large intestine among the two breed of pigs was different. Our results concluded that Lantang had higher dietary fiber degradation capacity than Duroc pigs, and the higher degradation capacity for the former breed was due to differences in the inherent microbial community in their respective large intestines.     

Population structure of pigs determined by single nucleotide polymorphisms observed in assembled expressed sequence tags

We have collected more than 190 000 porcine expressed sequence tags (ESTs) from full‐length complementary DNA (cDNA) libraries and identified more than 2800 single nucleotide polymorphisms (SNPs). In this study, we tentatively chose 222 SNPs observed in assembled ESTs to study pigs of different breeds; 104 were selected by comparing the cDNA sequences of a Meishan pig and samples of three‐way cross pigs (Landrace, Large White, and Duroc: LWD), and 118 were selected from LWD samples. To evaluate the genetic variation between the chosen SNPs from pig breeds, we determined the genotypes for 192 pig samples (11 pig groups) from our DNA reference panel with matrix‐assisted laser desorption ionization time‐of‐flight mass spectrometry. Of the 222 reference SNPs, 186 were successfully genotyped. A neighbor‐joining tree showed that the pig groups were classified into two large clusters, namely, Euro‐American and East Asian pig populations. F‐statistics and the analysis of molecular variance of Euro‐American pig groups revealed that approximately 25% of the genetic variations occurred because of intergroup differences. As the F_IS values were less than the F_ST values_, the clustering, based on the Bayesian inference, implied that there was strong genetic differentiation among pig groups and less divergence within the groups in our samples.     

Evidence of breed-dependent differences in susceptibility to porcine circovirus type-2-associated disease and lesions

Porcine circovirus type 2 (PCV2) has been confirmed as the primary cause of postweaning multisystemic wasting syndrome (PMWS). However, in the field, PMWS is seen only in a small percentage of pigs infected with PCV2. The overall objective of the study reported here was to determine whether host genetic differences in the susceptibility to PCV2-associated disease exist among selected breeds of pigs. This study included Duroc (n = 23), Landrace (n = 19), and Large White (n = 21) pigs. The pigs were infected intranasally and intramuscularly at 5-7 weeks of age with PCV2. A portion of the pigs (31/63; 30.2%) had low passively acquired PCV2 antibodies at the time of infection. There were no differences in mean weight gain, rectal temperature, or respiratory score. Clinical disease compatible with PMWS was observed only in the Landrace pigs. Most of the PCV2-infected pigs had enlarged lymph nodes, and individual Duroc and Landrace pigs had mottled tan lungs. PCV2-associated lymphoid depletion and granulomatous inflammation were observed in pigs of all breeds. Three of 19 Landrace pigs and none of the Duroc or Large White pigs developed severe lymphoid lesions associated with large amounts of intralesional PCV2 antigen typical of PMWS. Compared with seronegative Landrace pigs, Landrace pigs that had low maternal antibodies at the time of PCV2 inoculation had significantly (P < 0.05) less-severe PCV2-associated lesions. The results suggest a predisposition of the Landrace pigs of this study to PCV2-induced disease and lesions, and that low levels of passively acquired antibodies are protective.     

Simultaneous identification of two MspI polymorphisms of the porcine myogenin gene in Hungarian breeds

Simultaneous analysis of two myogenin (MYOG) loci has been carried out using polymerase chain reaction‐restriction fragment length polymorphism (PCR‐RFLP) tests in DNA isolated from blood samples collected from four different pig breeds (Hungarian Large White, Duroc, Mangalica and Hungarian Landrace). The following MYOG^A frequency values have been obtained: Hungarian Large White 0.2416; Duroc 0.0900; Mangalica 0.6617; Hungarian Landrace 0.2361. The MYOG² allele was found in Duroc and Mangalica breeds only. This test allows the analysis of two loci of the MYOG gene in parallel, which might be used in marker assisted selection programmes in the near future. Ongoing studies on the possible effects of the MYOG types on carcass and growth traits are outlined.     

Antibiotic effects on cytochromes P450 content and mixed-function oxygenase (MFO) activities in the American alligator,Alligator mississippiensis

There are no Food and Drug Administration (FDA)-approved antimicrobial agents for use in cultured American alligators (Alligator mississippiensis) destined for human consumption yet some producers administer antibiotics for prophylaxis. The cytochromes P450-dependent mixed-function oxygenases (MFO) catalyze the oxidation of xenobiotic compounds such as drugs, pesticides and polycyclic aromatic hydrocarbons. Herein, we describe the effects of oxytetracycline, ceftazidime and enrofloxacin on the MFO system of the American alligator, Alligator mississippiensis. Juvenile alligators (4 animals/treatment) were administered these antibiotics intraperitoneally in an effort to induce hepatic microsomal cytochromes P450. Alligators treated with enrofloxacin exhibited emesis and convulsive spasms within 5 min of the initial injection. Total hepatic cytochromes P450 contents were significantly decreased in oxytetracycline-and enrofloxacin-pretreated alligators. In vitro hepatic microsomal benzyloxyresorufin O-dealkylase (BROD) activity was significantly decreased by enrofloxacin pretreatment. Western blots of proteins from antibiotic-pretreated alligator hepatic microsomes incubated with several mammalian and fish cytochromes P450 (CYP) antibodies exhibited little or no induction of CYP1A1, 2B, 2C and 2E1. In vitro incubation with enrofloxacin and oxytetracycline caused a concentration-dependent decrease in alkyl-substituted phenoxazone dealkylase activities catalyzed by phenobarbital- and 3-methylcholanthrene-induced alligator hepatic microsomes.     

The effects of fenbendazole, flubendazole and mebendazole on activities of hepatic cytochromes P450 in pig

Fenbendazole (FBZ), flubendazole (FLBZ) and mebendazole (MBZ) are benzimidazole anthelmintics widely used in veterinary medicine. The effects of these drugs on cytochromes P450 (CYP) were investigated in primary cultures of swine (Sus scrofa f. domestica) hepatocytes. After 48-h incubation of hepatocytes with benzimidazoles (0.1-2.5 microm), ethoxyresorufin O-deethylation (EROD), benzoxyresorufin O-dearylation (BROD), testosterone hydroxylase (6beta-TOH) and testosterone oxidase (17-TO) activities were measured and the CYP1A and 3A protein levels were determined by Western blotting. FBZ produced a significant, concentration-dependent increase of CYP1A activity (EROD) and protein level. No enhancement of CYP1A was observed after exposure to FLBZ and MBZ. All benzimidazoles tested did not cause any induction of CYP3A (BROD, 6beta-TOH, 17-TO activities and protein content). On the other hand, MBZ produced a significant, concentration-dependent decrease of CYP3A (BROD, 6beta-TOH and 17-TO) activities. Pharmacological and toxicological consequences of CYP1A induction and CYP3A inhibition should be taken into account in treatment of pigs with FBZ and MBZ.     

猪SLA-DRA基因外显子2多态性及其与仔猪腹泻的关联分析

为探索SLA-DRA基因作为猪抗病育种分子标记的可能性,本研究采用PCR-SSCP和克隆测序方法对大白、长白和杜洛克共216头猪的SLA-DRA基因外显子2进行了多态性研究,分析了该基因与仔猪腹泻的关联性。结果,在SLA-DRA外显子2上检出了3个等位基因和6种基因型;6种基因型(AA、AB、BB、AC、BC和CC)在大白猪和长白猪中都存在,而在杜洛克猪中只检出4种基因型(AA、BB、AB和BC)。杜洛克猪与大白猪和长白猪间基因型分布均差异极显著(P<0.01);3个品种的基因型分布均处于Hardy-Weinberg平衡状态(P>0.05)。最小二乘法分析表明,品种和性别对仔猪腹泻影响不显著(P>0.05),基因型与仔猪腹泻显著相关(P<0.05);AA和BB基因型个体腹泻评分的最小二乘均值均显著高于AC和CC基因型个体(P<0.05)。本研究表明,SLA-DRA基因不同基因型对仔猪腹泻有着重要的影响,可作为猪抗病育种应用中的一个潜在遗传标记。