Axonal and neuronal amyloid precursor protein immunoreactivity in the brains of guinea pigs given tunicamycin

Amyloid precursor protein (APP) immunocytochemistry was used to study axonal and neuronal changes in guinea pig brains exposed to tunicamycin. Substantial axonal injury was found in ischemic-hypoxic foci and more generally, but this injury was not readily appreciable in conventionally stained sections. Neuronal perikaryal APP expression was also widely distributed, possibly as an acute phase response to this neurotoxin.     

Estimation of the additive and dominance variances in SA Duroc pigs

The objective of this study was to estimate dominance variance for number born alive (NBA), 21-day litter weight (LWT21) and interval between parities (FI) in South African Duroc pigs. A total of 10,703 NBA, 6883 LWT 21 and 6881 FI records were analysed. Bayesian analysis via Gibbs sampling was used to estimate variance components and genetic parameters. Estimates of additive genetic variance were 0.554, 16.84 and 4.535 for NBA, FI and LWT21, respectively. Corresponding estimates of dominance variance were 0.246, 9.572 and 0.661 respectively. Dominance effects were statistically not significant for all traits studied. Further research utilizing a larger data set is necessary to make concrete conclusions on the importance of dominance genetic effects for the traits studied.     

梅山猪与杜洛克猪中等卵泡差异表达基因的鉴定

本试验采用抑制性消减杂交技术构建了卵泡期第4天梅山猪和杜洛克猪中等卵泡M2组织差异表达的消减cDNA文库,从中筛选差异表达的基因,并通过实时荧光定量PCR对其进行验证,利用DAVID软件对差异表达的基因进行聚类分析。结果表明,从梅山猪和杜洛克猪M2卵泡消减文库中筛选得到了148和75个差异表达的ESTs,分别含有125和60个已知的基因。实时荧光定量PCR验证结果与筛选结果相符。GO功能分类注释到调控代谢、细胞循环、生物合成、胞内转运、类固醇雌激素受体和刺激等生物学过程。KEGG Pathway分析表明有6个基因参与TGF-beta信号通路,5个基因参与卵母细胞减数分裂信号通路,7个基因参与类固醇雌激素受体信号通路,推测TGF-beta信号通路中的基因可能调控猪卵泡的发育。研究结果为深入探讨卵泡发育机理和对繁殖性状影响的遗传机理奠定了基础。     

Comparative Study of the Lifetime Productivity and Performance Characteristics of Meishan and Duroc Cross-bred Pigs

The objective of this study was to examine the potential of Meishan genotypes to improve production efficiency through increased reproductive performance and sow longevity. Sows of White composite, with either 1/4 Meishan, 1/4 Duroc or 1/8 Duroc were kept for up to six parities and reproductive performance and lifetime productivity of each sow breed was recorded. Progeny from these sows were analysed for growth and carcass characteristics. It was noted that Meishan genotype sows were more prolific (+1 pig/litter -1 ; P <0.05) and had greater longevity in the herd than either of the Duroc genotypes. The growth rate of slaughter pigs from 1/4 Meishan sows was slower than that of either 1/8 or 1/4 Duroc (893, 976 and 931 g day -1 , respectively; P <0.05) and they had poorer carcass lean content (56, 59 and 58%, respectively; P <0.05). The study would suggest that 1/4 Meishan sows may be useful for systems with low costs of production, small penalties for fat carcasses and where gilt replacement costs are high.     

Identification of Differentially Expressed Genes in Medium-sized Ovarian Follicles between Meishan and Duroc Sows

To reveal the molecular mechanism involved in different number of ovulation between hyperprolific and ordinary sows, forward and reverse subtracted cDNA libraries were constructed to screen differentially expressed genes in medium ovarian follicles at 4th day during follicular phase of estrous cycle between Meishan and Duroc sows. The differentially expressed genes selected were demonstrated by Real-time PCR and cluster analysis was performed through DAVID. The results showed that a total of 148 and 75 non-redundant ESTs were isolated from the SSH library of Meishan and Duroc sows M2 follicles, including 125 and 60 known genes, respectively. The results of Real-time PCR were consistent with the screening results. GO analysis indicated that these genes were involved in regulation of metabolic process, cell cycle, biosynthetic process, intracellular transport, steroid hormone receptor and stimulus. KEGG pathway analysis defined 6 genes involved in TGF-beta signaling pathway, 5 genes in oocyte meiosis pathway, 7 genes in steroid hormone receptor signaling pathway. Genes controlling TGF-beta signaling pathway were considered to play an important role in regulating follicle development. The research would be helpful for further studying the follicular development and the genetic mechanism on reproductive traits.     

Behavior and pituitary-adrenal function in large white and Meishan pigs

Six-wk-old piglets of both sexes from European Large White (LW, n = 36) and Chinese Meishan (MS, n = 24) breeds were individually exposed to a novel environment, a stressful stimulation. Behavioral and pituitary-adrenal reactivity were investigated. When compared with LW, MS pigs displayed low locomotion (18.5 ± 2.2 vs. 41.0 ± 3.8 squares crossed/10 min; P < 0.0001), and defecation scores (0.58 ± 0.15 vs. 4.86 ± 0.37 fecal boli; P < 0.0001). Basal concentrations of cortisol were higher in MS (96.1 ± 1.1 vs. 44.9 ± 1.1 ng/ml; P < 0.0001), although no differences between breeds were found in basal concentrations of adrenocorticotropic hormone (ACTH). In response to novel environment exposure, the ACTH increase was greater in LW than in MS, but the cortisol response was not different on a log scale. To further investigate the pituitary-adrenal differences between the two breeds, the 24-hr profile of ACTH and cortisol plasma concentrations, a corticotropin-releasing factor (CRF) and a coupled dexamethasone-ACTH test were studied. Five castrated male 9-wk-old piglets from each breed were fitted surgically with a jugular vein catheter. A classic marked circadian rhythm of cortisol and a weak nycthemeral variation of ACTH were found. Cortisol concentrations were approximately twice higher in MS exclusively during the early light phase (from 0800–1200 hr) of the cycle, but no significant interbreed difference was found in the circadian rhythm of ACTH. Administration of CRF (1 μg/kg iv) induced the same significant increase in plasma ACTH and cortisol concentrations in both breeds. Administration of ACTH (10 μg/kg iv) increased significantly cortisol concentrations and revealed no difference in plasma cortisol response to ACTH. These data suggest that the hypercortisolism of MS pigs is of adrenal origin, and related to extrapituitary factors that control the adrenal sensitivity during the light phase of the diurnal cycle.     

胆囊收缩素(CCK)与动物摄食

Ivy和O ldberg在1928年最先从狗的胃肠粘膜发现了胆囊收缩素(C CK),后来M un和Jorpes于1971年从猪小肠上段分离纯化了CCK,并阐明它是由33个氨基酸组成的多肽。1976年,M un又发现了CC K-39是CC K-33向N-端延伸了6个氨基酸残基的多肽分子。而实际上,他们仅仅是发现了CC K的一种分     

Alzheimer type II astrocytes in the brains of pigs with salt poisoning (water deprivation/intoxication)

The finding of Alzheimer type II astrocytes, in addition to the pathognomonic combination of laminar cerebrocortical necrosis and eosinophil infiltration, in the brains of pigs is reported for the first time in cases of indirect salt poisoning following water deprivation.     

梅山与杜洛克母猪发情前期卵巢组织差异表达基因的分离与鉴定

为了探讨梅山与杜洛克母猪卵巢差异表达基因对猪排卵与繁殖性状的影响,应用mRNA差异显示技术研究梅山猪与杜洛克猪卵巢中基因表达的差异性,分离9条在纯种梅山猪与纯种杜洛克猪卵巢中差异表达的表达序列标签(ESTs),并用半定量RT-PCR鉴定。通过BLAST比对发现,其中有3条EST与GenBank序列同源性较高。组织表达谱分析揭示了这些ESTs在梅山猪心脏、肝脏、肺脏、肾脏、肌肉、脂肪、小肠、大脑、卵巢、子宫、脾脏、输卵管等各个组织中的表达有不同程度的差异。研究结果表明,梅山猪和杜洛克猪卵巢之间的不同基因差异表达的方向存在差异,这些差异表达的基因可能在某种程度上导致猪繁殖力的差异,进而为研究影响猪排卵数的分子机理调控网络打下基础。     

Distribution patterns of mast cells in the uterus of pregnant Meishan pigs

The present study was performed to investigate the numerical distribution of mast cells (MCs) in the uteri of pregnant Meishan pigs to explore the functions of MCs in pig pregnancy. The uterine samples from pregnant (on days 15, 26 and 50 of gestation) pigs were obtained respectively and stained with toluidine blue. The results were as follows: MCs were constitutively located in the uterus of the Meishan pig, with the distribution varying with gestational stages. On days 15 and 26 of gestation, MCs were mainly distributed around the blood vessels and uterine glands within the endometrium. On day 50 of gestation, MCs were mostly distributed in the myometrium. These results indicated that uterine MCs possibly have versatile functions in pig pregnancy.     

Gastric zygomycosis (mucormycosis) in 4 suckling pigs

Acute gastric zygomycosis (mucormycosis) was diagnosed in four 6- to 7-day-old pigs with large venous infarcts in the gastric fundus. Two pigs were from one farm where several dams had developed fever at parturition and most of their litters had died. The other 2 pigs, from separate farms, had diarrhea that was unresponsive to broad-spectrum antibiotic therapy. Histologically there was severe hemorrhagic, ulcerative gastritis associated with numerous transmurally invading, mucoraceous fungi. The discussion includes speculation on the pathogenesis of this lesion in neonatal pigs.     

Genetic variations of randomly amplified polymorphic DNA polymorphisms in Taoyuan and Duroc pigs

The purposes of this study were to assess the genetic variability between Taoyuan (T) and Duroc (D) pigs using randomly amplified polymorphic DNA (RAPD) fingerprints and to evaluate the genetic relationship to a commercial synthetic line-Taiwan Black (TB) pig (75% D, 25% T). To assess the genetic variability between T and D, 71 random primers (Operon) were used for RAPD fingerprinting by polymerase chain reaction (PCR). The evaluation of the genetic relationship was based on band sharing frequency and band frequency. Thirty-five of the 71 primers (49%) could generate polymorphisms in RAPD fingerprints of T or D pigs. Twenty-two primers produced polymorphic bands from only T genomic DNA, and 14 primers could produce polymorphic bands from only D genomic DNA. These results indicated that there was some genetic difference between T and D pigs. The within-population genetic similarity (WGS) for T, D, and TB populations were 0.742, 0.747, and 0.745, respectively, the between-population genetic similarity (BGS) was 0.946 between T and TB; 0.953 between D and TB; and 0.934 between D and T. The parameters of genetic distance between T and TB; D and TB, T and D were 0.080, 0.064, and 0.096, respectively. When the values of genetic similarity and genetic distance between populations estimated as frequency of occurrence of bands showed lower genetic similarities between pig populations, but indicted similar relationship. TB was genetically more related to D than to T. It provided evidence of the usefulness of the RAPD technique to determine genetic relatedness among T, D, and TB.     

Cloning of Porcine SKP1 Gene and it's Expression Studies between Meishan and Duroc Pigs with Follicle

To detect the expression pattern of S-phase kinase association protein 1 (SKP1) gene in during porcine follicle development.The coding sequence (CDS) of SKP1 gene was cloned from porcine follicular tissue.To analyze the tissue expression profiling of SKP1 gene and its expression level in follicles with different diameter (S,M1,M2,L) from Duroc and Meishan pigs were investigated by Real-time fluorescence quantitative PCR.The results showed that the length of CDS of porcine SKP1 was 492 bp,and it's similarity with that of Ovis aries,Homo sapiens,Pan troglodytes,Bos taurus and Rattus were 93.10%,92.90%,92.29%,91.89% and 89.86%,respectively.SKP1 mRNA was expressed in all tested tissues (muscle,fat,heart,liver,spleen,lung,kidney,stomach,duodenum,ovarian,tubal,uterine,uterine horn,pituitary,corpus luteum,brain,hypothalamus),and especially high in uterine,spleen and tubal.Both in Meishan pig.The expression of SKP1 mRNA in S,M1 and M2 follicles were higher than Duroc pig.Especially,the expression in Meishan pig M1 and M2 follicles were significantly higher than Duroc pig (P<0.01),respectively 2.39,2.82 times,and the expression of L follicle in Duroc pig was higher than Meishan pig,which suggested that SKP1 gene might be involved in the process of procine's follicular development.     

猪SKP1基因的克隆及其在梅山猪与杜洛克猪卵泡中的表达研究

为探索SKP1(S-phase kinase association protein 1)基因在猪卵泡中的表达规律,本试验从猪卵泡组织中克隆了猪SKP1基因CDS区全长序列,采用Real-time PCR方法检测SKP1基因在不同组织中的表达谱,进一步分析了该基因在梅山猪和杜洛克猪S卵泡、M1卵泡、M2卵泡、L卵泡中的表达。结果表明,经克隆测序,得到了猪SKP1基因492 bp编码区全长序列,与羊、人、黑猩猩、牛、大鼠的同源性分别为93.10%、92.90%、92.29%、91.89%、89.86%。SKP1基因在各组织中均有不同程度的表达(肌肉、脂肪、心脏、肝脏、脾脏、肺脏、肾脏、胃、十二指肠、卵巢、输卵管、子宫、子宫角、垂体、黄体、大脑、下丘脑),其中在子宫、脾脏、输卵管中表达量较高。SKP1基因的表达量在梅山猪S卵泡、M1卵泡和M2卵泡中的表达量均高于杜洛克猪,特别是在梅山猪M1卵泡和M2卵泡中SKP1基因的表达量极显著高于杜洛克猪(P<0.01),分别达到了2.39、2.82倍,而在L卵泡中的表达量却是杜洛克猪高于梅山猪,结果提示SKP1基因可能参与猪卵泡发育过程。     

Age-related changes of reproductive hormones in young Meishan boars

Meishan pigs are known for their early sexual maturity. On the other hand, they grow slowly. There is no information currently available about the combination of these two characteristics in Meishan pigs. To study the developmental characteristics of Meishan pigs, the plasma concentrations of LH, FSH, inhibin, testosterone, estradiol-17beta, progesterone and insulin-like growth factor-I (IGF-I) in young Meishan boars were determined using RIA and ELISA. Inhibin decreased with age in weeks, while testosterone and estradiol-17 beta increased. Testosterone increased gradually, and an increase in estradiol-17beta occurred after sexual maturity. IGF-I increased before puberty and subsequently decreased just after puberty like a pubertal IGF-1 surge. FSH, LH and progesterone did not change with age. There was no significant correlation among the hormones. During the experimental period, the Meishan boars showed large individual differences. These differences may depend on the fact that Meishan boar reach maturity at 12 weeks of age and continue to grow thereafter.     

Association of swine vertnin (VRTN) gene with production traits in Duroc pigs improved using a closed nucleus breeding system

Vertnin (VRTN) is involved in the variation of vertebral number in pigs and it is located on Sus scrofa chromosome 7. Vertebral number is related to body size in pigs, and many reports have suggested presence of an association between body length (BL) and meat production traits. Therefore, we analyzed the relationship between the VRTN genotype and the production and body composition traits in purebred Duroc pigs. Intramuscular fat content (IMF) in the Longissimus muscle was significantly associated with the VRTN genotype. The mean IMF of individuals with the wild‐type genotype (Wt/Wt) (5.22%) was greater than that of individuals with the Wt/Q (4.99%) and Q/Q genotypes (4.79%). In addition, a best linear unbiased predictor of multiple traits animal model showed that the Wt allele had a positive effect on the IMF breeding value. No associations were observed between the VRTN genotype and other production traits. The VRTN genotype was related to BL. The Q/Q genotype individuals (100.0 cm) were longer than individuals with the Wt/Q (99.5 cm) and Wt/Wt genotypes (98.9 cm). These results suggest that in addition to the maintenance of an appropriate backfat thickness value, VRTN has the potential to act as a genetic marker of IMF.