中国荷斯坦牛PIN1基因对产奶性状的遗传效应分析

前期研究通过荷斯坦公牛全基因组重测序鉴定到17个奶牛产奶性状候选功能基因,其中,肽基脯氨酸顺反异构酶基因(PIN1)参与甘油三酯代谢、甘油磷脂代谢以及mTOR信号通路,且位于产奶量和乳蛋白量性状QTL区间.为进一步系统分析PIN1基因是否对奶牛产奶性状具有遗传效应,本实验基于40头公牛的基因组DNA混池,采用PCR产物...     

栗蚕幼虫酯酶同工酶酶谱多态性及应用于品种间亲缘关系的分析

栗蚕是珍稀的野蚕资源。采用聚丙烯酰胺凝胶电泳法,测定栗蚕幼虫不同发育时期、不同组织器官的酯酶同工酶酶谱,并依据酯酶同工酶酶谱的多态性分析纯黑、纯绿2个品种的亲缘关系。检测结果表明:栗蚕幼虫中肠的酯酶同工酶活性和酶带数随龄期而增加,且同一龄期以盛食期的酶表达量最高;幼虫中肠及脂肪体中的酯酶同工酶活性较强,并且酶带数较多;2个供试品种间的酯酶同工酶酶谱明显不同。根据酶谱差异分析2个品种的遗传相似系数为0.86,表现出较近的亲缘关系。研究结果提示:栗蚕幼虫酯酶同工酶的酶活性和酶带数与生长发育和组织功能有关,幼虫酯酶同工酶酶谱可以作为分析品种间亲缘关系的依据之一。     

Genetic and Environmental Correlations Among Female Fertility Traits,and Between the Ability to Show Oestrus and Milk Production in Dairy Cattle

Genetic and environmental correlations were estimated both between the ability to show oestrus and milk production, and among different fertility traits (heat-intensity score, number of days between consecutive inseminations, number of inseminations per service period, interval between calving and first or last insemination, and interval between first and last insemination). Milk production was measured as the average of the energy-corrected milk yield on second and third monthly test days. The number of records were approximately 450000, 350000, 180000 and 75000 in the heifer period, first, second and third lactations, respectively. A linear, trivariate model that included the effects of herd-year, year, month, age and cow's sire was applied. The results indicated that further selection for increased milk production is not expected to deteriorate heat intensity. The number of days between calving and first insemination, the number of inseminations and the heat intensity were complementary, and can be recommended for a selection index for fertility.     

Determination of Normal Values Using an Automated Coagulation Timer for Activated Coagulation Time and its Application in Dogs with Hemophilia

The present study was performed to determine normal values for the Medtronic HemoTec automated activated coagulation time (ACT) analyzer (Medtronic HemoTec Inc, Parker, CO, distributed in Switzerland by Convergenza AG, Vaduz, Liechtenstein), and to evaluate its ability to detect dogs with hemophilia. ACT was measured in 43 healthy dogs presented to the Companion Animal Hospital, University of Bern, Bern, Switzerland, with the Medtronic HemoTec ACT analyzer to determine normal values. The mean +/- 2 standard deviations (SDs) of the values obtained was defined as the normal range. ACT was measured 8-10 times on the same day in 6 dogs to determine repeatability. ACT also was measured in 11 dogs with hemophilia and compared with a conventional visual ACT measurement test and with the activated partial thromboplastin time (APTT). ACT values of the 43 dogs used to determine normal values ranged from 66.5 to 97.0 seconds (mean, 79.3 seconds; SD, 7.35 seconds; median, 78.5 seconds). A range of 64-95 seconds (mean +/- 2 SDs) was defined as the normal range for the tested device. Repeatability was poor (r = 0.256). ACT values measured with the automated device did not correlate with ACT values measured with a conventional visual test or with APTT Sensitivity of the test was 90.9%, specificity was 98.0%, and accuracy was 96.7%. Variability in the test results was large and may lead to incorrect results. The automated measurement device was not superior to the conventional visual method in evaluating dogs with hemophilia.     

Development of a Latex Agglutination Test Using The Major Epitope Domain of Glycoprotein E of Pseudorabies Virus Expressed in <Emphasis Type="Italic">E. coli</Emphasis> to Differentiate Between Immune Responses in Pigs Naturally Infected or Vaccinated with Pseudorabies Virus

A 0.8 kb DNA fragment encoding the major epitope domain of glycoprotein E (gE) of pseudorabies virus (PRV) was inserted downstream of the T7 promoter of an expression vector, pET-28b, to yield the recombinant plasmid pETgE804. After induction by isopropy1-β-D-thiogalactopyranoside (IPTG), a high level expression of fusion protein was obtained. SDS-PAGE and western immunoblotting analysis showed that the fusion protein was 38 kDa and could bind with antisera against PRV. The protein existed mainly in the form of the inclusion body. After being denatured and renatured, the protein was used to prepare the latex antigen. The concentration of antigen, temperature and time for sensitization were optimized. The latex agglutination test (LAT) was able to differentiate sera of PRV-infected pigs from those of gE-deletion vaccine-immunized pigs. The diagnostic specificity and sensitivity of the developed gE latex agglutination test (gE-LAT) were also evaluated by using sets of sera. The diagnostic specificity and diagnostic sensitivity of the gE-LAT were 96.77% and 95.76%, respectively. For comparison between gE-LAT and a commercial blocking enzyme-linked immunosorbent assays (ELISA), 260 serum samples were tested. The coincidence frequency of both assays was 96.94% (252/260). No significant difference was found between the two methods (p>0.05). For comparison between the abilities of gE-LAT and gE-ELISA to detect sera with low titres of gE-specific antibody, 66 sera from 22 pigs were tested. The data indicate that the gE-LAT is of similar sensitivity to gE-ELISA. These results indicate that gE-LAT using recombinant gE might be very useful as a routine screening method for the differential diagnosis of PRV infection.