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1.
3.5牛基因组遗传连锁图最近版本牛基因组遗传图报告的标记位点为1250个,其中有1236个多态DNA标记,14个红细胞抗体基因(EA)和血清蛋白多态。连锁图总长度2990cM,常染色体区内标记间平均间距为2.5cM。这个牛的第二代遗传连锁图为通过基因组扫描检测QTL提供了有效的标记密度(Kappes等,1997)。CSIRO的中等密度牛基因组遗传连锁图中DNA多态标记为746个,其中601个微卫星标记,31个连锁群(28个常染色体,2个性染色体),连锁图总长度分别为:常染色体加平均性别3532c…  相似文献   

2.
本研究利用微卫星标记技术,分析了4个微卫星座位多态性与皖系长毛兔1岁时的产毛量之间关系。结果表明:皖系长毛兔4个微卫星座位上平均检测到4.5(3~6)个等位基因,平均杂合度为0.680(0.630~0.721),平均多态信息含量为0.642(0.559~0.705)。Sol33微卫星座位与1岁时产毛量呈显著相关(P<0.05),其中基因型为AD和BD个体1岁时产毛量与其他3种基因型个体间均存在显著差异(P<0.05)。其他座位Sat4、Sat13和Sol44与皖系长毛兔1岁时产毛量相关不显著(P>0.05)。  相似文献   

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牛基因组研究进展(上)   总被引:2,自引:0,他引:2  
本文主要对牛基因组遗传连锁图,物理图以及牛基因组图与人类和其它畜种比较作图进展进行了综述。在过去近10年中,牛基因组图的研究随着作图技术,特别是DNA微卫星等多态标记和标定物理图的ZOO-FISH及RH图等方法的迅速发展,取得了很大进展。  相似文献   

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长期以来,荷斯坦牛一直是美国的主要牛种。在全国的1.01千万头产奶牛中,荷斯坦牛占了大约95%。由全国综合奶牛场改良方案(NCDHIP)组织进行的生产性能测验包括了国内48%的奶牛,其中的32%是官方测验。只有那些列入NCDHIP官方测验计划并且父亲明确有记录的母牛方可用于进行遗传评定。这些奶牛的大多数(58%)没有注册登记(等级牛)。虽然在评定中有记录的等级牛也许是纯种,但是它们的系谱不能列入协会登记品种中。大约76%的等级牛由于父亲  相似文献   

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本研究选取了绵羊1号和3号染色体上的十五个微卫星位点,对超细型细毛羊的六个父系半同胞的232个后代的遗传多样性进行了检测。计算了各位点的等位基因频率(P)、杂合度(H)、多态信息含量(PIC)和有效等位基因数(N)。结果表明:十五个微卫星位点中有七个未检测到多态,另外八个在超细型细毛羊中表现出较好的多态性。在这八个多态性标记中,微卫星MAF64位点的多态信息含量最高(PIC=0.8399),微卫星BL-4位点的多态信息含量最低(PIC=0.4201)。多态性标记在群体中的平均等位基因数为5.6个,平均多态信息含量PIC=0.64,平均杂合度H=0.67,平均有效等位基因数N=3.7。经分析,超细型细毛羊群体中的遗传杂合度较高,表明其遗传背景复杂,遗传多样性较为丰富。同时这八个多态性微卫星位点也可用于超细型细毛羊羊毛各性状的进一步研究。  相似文献   

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利用微卫星标记分析新疆天山马鹿3个群体的遗传多样性   总被引:2,自引:0,他引:2  
本文利用5个微卫星标记对新疆天山马鹿遗传多样性进行了检测分析。统计了天山马鹿三个群体的等位基因组成、平均有效等位基因数(E)和平均基因纯合率(Rh),利用等位基因频率计算出各群体的平均遗传杂合度(h)、多态信息含量(PIC)。结果表明5个微卫星位点在哈密1、04团和151团天山马鹿三个群体的平均多态信息含量分别为0.5462、0.5477、0.5895,除微卫星位点BM5004外均为高度多态,可作为有效的遗传标记用于天山马鹿遗传多样性分析;天山马鹿三个群体总平均PIC、h、Rh和E分别为:0.5611、0.5902、0.5826和2.9。分析认为天山马鹿遗传变异度相对较高,遗传多样性较为丰富。  相似文献   

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近年来牛的人工繁育在英国取得了很大进展,在母牛发情后6—7天进行胚胎移植(授卵)将取代发情时的人工授精。这就提供了与母牛的遗传背景不同的产犊机会。在有些农场体系中,这一革新有着使农场主获取更大利润的潜力。在英国,据称用荷斯坦母牛授卵所生产的3/4肉犊牛每头的价值很可能要比传统的半血荷斯坦犊牛高70英磅。  相似文献   

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为揭示西门塔尔牛及其与夏洛来牛、海福特牛和安格斯牛的杂种幼牛的最适屠宰年龄,笔者在巴什基里亚自治共和国斯捷尔利塔马克区日丹诺光集体农庄严格按照通用法进行了专门的试验。所选出的各组母牛在年龄(产犊6~6次之后)、活重(460~500公斤)、品种性和体质类型方面相似。用相应品种公牛的冷冻精液分别给他们输精。  相似文献   

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目的 定位-个四代常染色体显性遗传先天性板层白内障家系的致病基因.方法 选取在北京同仁医院就诊的河北任丘先天性白内障家系,记录家系遗传史.该家系28例成员(12例患者,16例非患者)进入本研究,12例患者接受全身及眼部检查,以排除存在白内障以外的眼部及全身疾患,16例非患者仅接受眼部检查.28例研究对象均采集外周静脉血5ml,提取基因组DNA,选取在物理距离上与已知非综合征常染色体显性遗传性先天性白内障相关的18个致病基因紧密连锁的微卫星分子标记,基因组聚合酶链式反应(PCR)扩增后进行基因分型.以基因分型的结果为基础,利用等位基因共享分析和基因测序对已知候选基因进行排除定位.结果 该家系遗传特点符合常染色体显性遗传,临床表型为板层先天性白内障;与位于1、2、10、11、12、16、17、21、22染色体上的15个致病基因附近的微卫星位点均不存在等位基因共享,基因测序排除了微卫星杂合度较低(位于3、13,19号染色体)的基因座.结论 该家系存在新的致病基因,进一步确证了先天性白内障具有高度临床和遗传异质性.该家系致病位点的确定有待于进一步研究.  相似文献   

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肉牛的饲养     
全苏肉牛研究所饲养室的研究人员改进了肉用牛的饲养标准,并提出按22个标准指标进行全价平衡饲养的新体系。 考虑肉牛业经营特点、生产方向、管理工艺等因素,制订营养物质和能量标准,可充分利用牛生长速度的遗传潜力,在节省单位产品饲料消耗情况下,可使优质牛肉平均增产10%。 周年的问并标准根据活重、生理状况和管理工艺来确定。为获得有生活力的犊牛,在舍饲条件下,母牛产前S个月需1.9—2.2千克干物质,h3一  相似文献   

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Excitation functions of the reactions (nat)Sb((3)He,xn)(124,123,121)I were measured from their respective thresholds up to 35 MeV, with particular emphasis on data for the production of the medically important radionuclide (124)I. The conventional stacked-foil technique was used. From the experimental data the theoretical yields of the three investigated radionuclides were calculated. The yield of (124)I over the energy range E9(30He) = 35 --> 13 MeV amounts to 0.95 MBq/microA h. The radionuclidic impurities are discussed. A comparison of (3)He- and alpha-particle-induced reactions on antimony for production of (124)I is given. The alpha-particle-induced reaction on enriched (121)Sb and the (3)He-particle-induced reaction on enriched (123)Sb would lead to comparable (124)I yields, but the level of impurities in the latter case would be somewhat higher.  相似文献   

13.
体外循环对全身炎症反应的影响   总被引:3,自引:0,他引:3  
目的 探讨体外循环(CPB)对全身炎症反应(SIR)的影响.方法 选择健康杂种犬12只,随机分为自体肺组(利用杂种犬自体肺作为氧合器)和人工肺组(常规体外循环,利用鼓泡肺作为氧合器).两组采用相同的心肌保护、心脏停跳方法(冷晶体停跳液),CBP持续1小时,于CPB前、CPB开始30分钟、停机后5、60分钟、2、4小时取血标本,用ELSISA法测定血浆中白介素-6(IL-6)、白介素-8(IL-8)、TNF-α及白介素-10(IL-10)水平.所得数据用SAS6.14统计软件对数据进行相关分析.结果 转流后各组血浆中IL-6、IL-8及TNF-α水平均明显高于基础值(P<0.05),其中人工肺组在不同时点明显高于自体肺组(P<0.05);CPB开始后血浆中IL-10水平明显升高(P<0.05),人工肺组在不同时点低于自体肺组(P<0.05).结论 心脏手术CPB诱导了SIR及抗炎反应,自体CPB降低了血浆中促炎性细胞因子的水平,促使抗炎性细胞因子IL-10的生成,抑制炎症反应.  相似文献   

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PURPOSE: To assess the effect of changes in end-tidal partial pressure of O(2) (PETO(2)) on cerebrovascular reactivity (CVR) estimated from changes in blood oxygen level-dependent (BOLD) signal during cyclic changes in end-tidal partial pressure of CO(2) (PETCO(2)). MATERIALS AND METHODS: BOLD response to fixed cyclic step changes in PETCO(2) (range = 30.4-48.8 mmHg) and PETO(2) (range = 100.6-444.0 mmHg) was studied in four healthy volunteers. RESULTS: The BOLD reactivity to PETCO(2) and PETO(2) were 0.283 (0.188-0.379) (median, range) and 0.004 (0.003-0.006)%/mmHg, respectively, in the whole brain; 0.438 (0.382-0.614) vs. 0.006 (0.004-0.009)%/mmHg, respectively, in the gray matter; and 0.075 (0.065-0.093) vs. 0.002 (0.001-0.002)%/mmHg, respectively, in the white matter. CONCLUSION: The BOLD reactivity to PETO(2) was much smaller than that to PETCO(2). However, BOLD reactivity can be significantly distorted by CO(2)-induced changes in PETO(2). We conclude that PETO(2) should be carefully controlled during studies that use BOLD reactivity as an indicator of CVR.  相似文献   

19.
Excitation functions were measured by the stacked-foil technique for (nat)Rb(alpha,xn)(87m,87m+g,88)Y and (nat)Sr(alpha,xn)(86,88,89)Zr reactions from their respective thresholds up to 26 MeV. The samples for irradiation were prepared by sedimentation and pellet pressing techniques. The measured data were compared with those available in the literature. From the excitation functions, integral yields of the products were calculated. The suitable energy ranges for the production of (87)Y and (88)Y via (nat)Rb(alpha,xn) processes and of (89)Zr via the (nat)Sr(alpha,xn) process are E(alpha)=26-->20 MeV, E(alpha)=26-->5 MeV and E(alpha)=20-->8.5 MeV, respectively. The respective yields amount to 8.2, 0.08 and 0.9 MBq/microA h. Production of (88)Y is feasible if a waiting time of about 2 months is allowed to let the impurities decay out. Also, (87)Y can be produced with a relatively low impurity of (88)Y. The yields of both (88)Y and (87)Y via the present routes are, however, appreciably lower than those via the (nat)Sr(p,xn) processes. There is a possibility to produce (89)Zr via the alpha-particle irradiation of (nat)Sr. The yield is rather low but would be considerably increased if enriched (86)Sr would be used as target material. The radionuclidic impurity levels in all the three products are discussed.  相似文献   

20.

Purpose

To measure the potential impact on clinical MRI practice in the UK of the European Union (EU) Physical Agents Directive (PAD) on electromagnetic fields (EMF). There is evidence that the exposure limit values contained in the PAD will make it impossible for members of staff to stand close to the magnet during scanning; currently this is common practice in order to provide care and support for vulnerable patients. Interventional MR procedures will also be impossible.

Materials and Methods

Members of the British Association of MR Radiographers (BAMRR) were sent a questionnaire to assess the impact of the PAD and related safety issues.

Results

A total of 25% of responding sites have at least one sedation/general anesthesia (GA) session per week, while only 3% reported any interventional practice. A total of 29% of respondents reported that operators give a bolus injection by hand during contrast‐enhanced magnetic resonance angiography (CE‐MRA) scans. Overall it is estimated that 3% of all MR examinations in the UK are performed with a staff member in the magnet room. Some of these examinations would be impossible without staff in the room and it would be necessary for patients to have computed tomography (CT) instead of MRI. The additional radiation dose of substituting CT for MRI is estimated at 224 man‐sievert per year.

Conclusion

While the financial costs of implementing the PAD (EMF) are relatively low, the social costs are difficult to quantify but potentially more alarming. J. Magn. Reson. Imaging 2007;26:1303–1307. © 2007 Wiley‐Liss, Inc.  相似文献   

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