南阳牛IGF2基因第2外显子多态性及其与生长发育相关性研究

以126头纯种南阳黄牛为研究材料，利用PCR-RFLPs技术对胰岛素样生长因子2（IGF2）第2外显子的多态性及其与生长发育的相关性进行了分析。结果表明：南阳牛在该位点的遗传多态性丰富。检测到2种等位基因A和B，频率分别为0．6865和0．3135，A等位基因在群体中是优势等位基因；BB型个体的6、12、18、24月龄体斜长和胸围，12、18和24月龄的坐骨端宽，初生、6月龄和24月龄体重等体征性状显著地优于AA型；6月龄体斜长、12月龄的胸围、18月龄和24月龄坐骨端宽也显著优于杂合型。初步推断JGF2基因是非常有价值的辅助选择标记，可为南阳牛肉用型方向选择提供理论依据。     

Transthoracic echocardiographic measurement of patent ductus arteriosus in dogs

BACKGROUND: Patent ductus arteriosus (PDA) size and morphology influence the selection of the kind and the size of the embolization device used to effect shunt closure. HYPOTHESIS: That echocardiographic measurement of PDA in dogs is accurate. ANIMALS: Forty-five client-owned dogs with PDA. METHODS: Prospective observational study. Echocardiographic and angiographic data were compared. RESULTS: Measurement of the ductus in color Doppler echocardiography (CD-E) and 2-dimensional echocardiography (2D-E) was achieved from left parasternal views in 43 of 45 unsedated dogs (96%). In these 43 dogs, the angiographic minimal PDA diameter was 3.72 +/- 1.59 mm, and the diameter of the PDA ampulla was 8.46 +/- 3.01 mm. The CD-E minimal PDA diameter ranged from 2.3 to 9.5 mm (median, 4.0 mm). There was a significant mean difference to the angiographic measurements (1.15 +/- 0.95 mm; P < .0001). An agreement in a 1-mm range was found in 21 of 43 dogs (48%). The 2D-E minimal PDA diameter was 3.73 +/- 1.78 mm, and the mean difference to the angiographic measurements was not significant (0.00 +/- 0.72 mm; P = .98). An agreement in a 1-mm range was found in 31 of 43 dogs (72%). The 2D-E measurement of the PDA ampulla revealed a significant mean difference to the angiographic data (1.95 +/- 2.43 mm, P < .0001). An agreement in a 2-mm range was found in 21 of 43 dogs (49%). CONCLUSIONS AND CLINICAL IMPORTANCE: The 2D-E from the left cranial parasternal view is an excellent noninvasive method to estimate the PDA minimal diameter before doing catheter intervention.     

Identification of polymorphisms and association analysis with meat quality traits in the porcine KIAA1717 and HUMMLC2B genes

Skeletal muscle genes are potential candidates for production and meat quality. Screening a subtracted cDNA library constructed with mRNA obtained from longissimus dorsi muscles of F1 hybrids Landrace × Yorkshire and their female parents Yorkshire, we isolated two partial sequences coding for the H3-K4-specific methyltransferase (KIAA1717) and skeletal muscle myosin regulatory light chain (HUMMLC2B) genes. Database search revealed KIAA1717 and HUMMLC2B encoded proteins with SET domain and EF-hand calcium binding motif, respectively. In the present work we identified their partial polymorphisms and two SNPs, one (C1354T) at the 3′ untranslated region (UTR) of KIAA1717 and one (A345G) at the SINE (PRE-1) element of HUMMLC2B, both created/disrupted a restriction site for endonuclease Msp I. The selected pigs were genotyped at the KIAA1717 C1354T and HUMMLC2B A345G sites by means of a PCR-RFLP protocol. Significant associations were observed for the KIAA1717 C1354T polymorphic site with meat marbling (longissimus doris (p < 0.05), biceps femoris (p < 0.01)) and intramuscular fat (p < 0.01). HUMMLC2B A345G were significantly associated with meat pH (longissimus doris (p < 0.05), biceps femoris (p < 0.01)), drip loss (p < 0.01), water holding capacity (p < 0.01) and meat color value (longissimus doris (p < 0.01), biceps femoris (p < 0.05)). Further studies are needed to confirm these preliminary results.     

鸡传染性法氏囊病毒VP2蛋白B细胞抗原表位预测

以鸡传染性法氏囊病毒VP2蛋白的基因组序列为基础,采用Garnier-Robson方法、Chou-Fasman方法和Karplus-Schultz方法预测VP2蛋白质的二级结构;用Kyte-Doolittle方案预测蛋白质的亲水性;用Emini方案预测蛋白质的表面可能性;用Jameson-Wolf方案预测氨基酸的抗原性指数。综合分析,预测VP2蛋白的抗原表位。通过以上几种方法预测IBDV病毒VP2蛋白的B细胞表位位于VP2蛋白N端3-10、30-45、77-84、150-157、197-206、211-222、278-288、298-303、315-325、376-381、386-394、403-411、415-425区段。     

饲料中添加2%麦饭石对猪生产性能的影响

试验结果显示:生产母猪饲料中添加2%麦饭石,母猪产仔成活率提高21.82%;猪育肥增重试验,断奶仔猪增重提高20.08%,提高饲料报酬34.21%:4月龄育肥猪增重提高18.38%,提高饲料报酬25.58%。     

顶复门原虫电子转移链代谢及Ⅱ型NADH脱氢酶研究进展

顶复门原虫是包括刚地弓形虫、疟原虫及球虫等在内的一大类寄生性原虫的总称,可引起重要的人畜寄生虫病.抗顶复门原虫药物的长期使用,甚至是滥用,使得这类寄生虫对现有药物产生了明显的抗药性,急需开发新型药物.Ⅱ型NAD(P)H脱氢酶是电子转移链途径中的关键酶,由于其仅存在于某些植物、细菌、真菌和寄生原虫等一些低等生物体内,而在高等动物体内缺失,是研发新型抗感染性药物的重要靶标.笔者主要针对顶复门原虫线粒体电子转移链代谢途径以及Ⅱ型NAD(P)H脱氢酶的研究概况进行综述.     

Ⅱ型犬腺病毒自然弱毒YCA18株的实验免疫研究

应用YCA18株第8代细胞培养物（YCA18－8）经口鼻和静脉接种犬腺(CAV)SN本＜1：2的易感犬作安全试验，结果未见任何CAV临床症状与病理解剖学改变；用不同剂量的YCA18－8分组免疫CAV易感犬，经SN抗体测定与用CAV强毒攻击试验，结果SN抗体达1：16以上的犬95％以上可获得免疫保护，最低免疫量为10^4TCID50；应用YCA18－8分别免疫母源抗体达1：4和1：8的两组试验犬，第一次免疫14d后SN抗体均未有升高，追加2－3次免疫后SN抗体才逐渐上升至1：16以上的免疫保护水平；用CAV易感犬和MDCK分别将YCA18连续传8代和20代，结果对犬仍然安全，对犬的免疫原性未见下降，最低免疫量仍为10^4TCID50；与CDV和CPV弱毒作免疫互扰试验，结果与各弱毒的单独免疫结果未见差异；将YCA18－8冰冻保存于一30℃，6个月内TCID50仍不低于10^-4/0.1ml，经加明胶－蔗糖低温真空冻干后，4℃和－30℃保存1年，TCID50均仍维持在10^-4/0.1ml以上，经YCA18－20 3次免疫的试验犬，1年后SN抗体仍在最低抗体保护值1：16以上。     

Repeat tuberculin skin testing leads to desensitisation in naturally infected tuberculous cattle which is associated with elevated interleukin-10 and decreased interleukin-1 beta responses

The principal surveillance tool used to control bovine tuberculosis in cattle is the removal of animals that provide a positive response to the tuberculin skin-test. In this study we performed a longitudinal investigation of the immunological and diagnostic consequences of repeated short-interval skin-tests in cattle naturally infected with Mycobacterium bovis. Tuberculin skin-test positive cattle were subjected to up to four further intradermal comparative cervical skin-tests at approximately 60-day intervals. A significant progressive reduction in the strength of the skin-test was observed after successive tests. In contrast, the magnitude of interferon-γ (IFN-γ) responses was not influenced by repeat skin-testing either transiently around the time of each skin-test or longitudinally following repeated tests. A significant boost in blood interleukin-10 (IL-10) production was observed within 3 days following each skin-test although the magnitude of this boosted response returned to lower levels by day 10 post-test. The application of a novel multiplex assay to simultaneously measure seven cytokines and chemokines also identified that skin-testing resulted in a significant and progressive reduction in antigen specific interleukin-1β (IL-1β) whilst confirming stable IFN-γ and elevated IL-10 responses in the blood. Therefore, we have demonstrated that in cattle naturally infected with M. bovis, repeat short-interval skin-testing can lead to a progressive reduction in skin-test responsiveness which has potential negative consequences for the detection of infected animals with marginal or inconclusive skin-test responses. The desensitising effect is associated with decreased IL-1β and elevated IL-10 responses, but importantly, does not influence antigen specific IFN-γ responses.     

Evaluation of a recombinant measles virus expressing hepatitis C virus envelope proteins by infection of human PBL-NOD/Scid/Jak3null mouse

In this study, we infected NOD/Scid/Jak3null mice engrafted human peripheral blood leukocytes (hu-PBL-NOJ) with measles virus Edmonston B strain (MV-Edm) expressing hepatitis C virus (HCV) envelope proteins (rMV-E1E2) to evaluate the immunogenicity as a vaccine candidate. Although human leukocytes could be isolated from the spleen of mock-infected mice during the 2-weeks experiment, the proportion of engrafted human leukocytes in mice infected with MV (10³–10⁵ pfu) or rMV-E1E2 (10⁴ pfu) was decreased. Viral infection of the splenocytes was confirmed by the development of cytopathic effects (CPEs) in co-cultures of splenocytes and B95a cells and verified using RT-PCR. Finally, human antibodies against MV were more frequently observed than E2-specific antibodies in serum from mice infected with a low dose of virus (MV, 10⁰–10¹ pfu, and rMV-E1E2, 10¹–10² pfu). These results showed the possibility of hu-PBL-NOJ mice for the evaluation of the immunogenicity of viral proteins.