龙眼体细胞胚发生中期的蛋白质组学研究

 【目的】了解龙眼体细胞胚发生中期（球形胚至子叶形胚）蛋白质组的变化,为进一步阐明植物体细胞胚发生的机制提供依据。【方法】进行龙眼体细胞胚发生中期的同步化调控,采用双向电泳和质谱对龙眼体细胞胚发生中期的蛋白质组变化进行分析。【结果】龙眼体细胞胚发生中期表达蛋白的种类随着体细胞胚的发育逐渐减少,但在鱼雷形胚阶段其种类数量有所回升,且增加的蛋白分子质量小于66.0 kD,pI主要集中在5.00—7.00。成功鉴定了35个差异蛋白,发现了多个与体细胞胚发生密切相关的蛋白。1/2以上的蛋白与代谢途径有关,多个蛋白与氧化胁迫有关。RAN2 和 GTPase ObgE在龙眼体细胞胚发生中期发生了活跃的变化。【结论】随着体细胞胚的发育,细胞不断分化,体细胞胚中表达的蛋白种类减少。氧化胁迫相关蛋白、RAN2 和 GTPase ObgE与龙眼体细胞胚发生的调控有关。     

芸薹属蔬菜遗传改良与种质创新研究进展

芸薹属植物是我国蔬菜的重要组成部分,其遗传资源的多样性直接关系到我国蔬菜产业的进一步发展和提升。本文综述了近年来通过远缘杂交、种间嫁接、体细胞杂交、分子育种等技术手段,在芸薹属蔬菜遗传改良和种质创新中取得的重要研究成果,并对芸薹属蔬菜种质改良方法以及亲本新资源的创制提出了展望。     

聚乙二醇细胞融合技术在牛手工体细胞克隆中的应用初探

本研究分3个实验。实验1对比了不同浓度的离子霉素对牛去透明带卵母细胞孤雌激活的效果;实验2比较了手工半卵切割法去核与显微半卵切割法去核的效果;实验3对聚乙二醇（PEG）细胞融合技术在牛手工体细胞克隆的应用进行了初步探讨。结果表明,对于去透明带牛卵母细胞孤雌激活,离子霉素浓度为2．0μmol／L组的激活效果最好,其囊胚发育率（29．4％）极显著地高于浓度为5．0μmol／L的对照组和0．5μmol／L组（囊胚率分别为8．3％和9．4％,P〈0．01）;采用半卵切割法去核,手工切割的半卵存活率（85．6％）与显微操作（90．3％）差异不大,切割速率（约100枚卵／h）相仿。对双半卵与体细胞进行同步融合处理时,应用50％浓度的PEG融合率（39．3％）极显著好于45％、55％和60％的PEG（融合率分别为0％、16．2％和5．3％,P〈0．01）。     

无角陶赛特羊与陶寒F2代羔羊生长发育对比简

为客观评价无角陶赛特羊产肉性能,及对小尾寒羊杂交改良的实际效果,于2012年7月～2012年11月对90日龄断奶纯种无角陶赛特羊和陶寒F2代羔羊（DHF2）的体重及体尺指标进行测定并进行差异性分析.结果表明：三月龄断奶陶寒F2代体重与纯种无角陶赛特羔羊差异不显著;陶赛特羊与陶寒F2代的公母羔体高、胸围均差异显著（P＜0.05）;公羔尻宽、胸深差异显著（P＜0.05）;母羔尻宽、胸深差异不显著（P＞0.05）;公羔体长差异不显著（P＞0.05）,母羔体长差异极显著（P＜0.01）;管围公母羔差异均不显著（P＞0.05）.可见从杂交育种到羔羊肉生产方面,杂交效果明显.     

大豆有性杂交技术初探

有性杂交是大豆育种工作中不可缺少的一个重要环节,它具有目标性、方向性强的特点,也是我国育成品种最多的育种方法。经过多年的杂交研究工作,总结出一些实用的杂交方法,以供参考。     

皱纹盘鲍与盘鲍杂交效果分析

从杂种优势的角度对皱纹盘鲍♀与盘鲍♂杂交子一代的经济性状进行分析。结果表明,4月龄杂交鲍子一代(F1)活体重比皱纹盘鲍增加36.87%,软体部干重增加33.21%,总干重增加29.20%,其它性状也显著优于皱纹盘鲍。杂交鲍F1的壳长、壳宽、活体重、软体部干重和总干重等主要性状的变异系数为12.94%~44.51%,其中软体部干重的变异系数最大,壳长的变异系数最小;且杂交鲍各性状的变异系数均大于皱纹盘鲍。杂交鲍子一代的变异有助于定向选择,提高杂交育种的效果。     

A comparison of the effect of short-acting and long-acting cloxacillin-based dry-cow therapy on somatic cell counts after calving in cows also given internal teat sealants

AIM: To compare, in cows treated with an internal teat sealant, the effect of short-acting and long-acting cloxacillin-based dry-cow therapy on somatic cell counts (SCC) after calving.

METHODS: Cows from a spring-calving, pasture-based dairy farm in the Manawatu-Whanganui region of New Zealand were randomly allocated to receive either a short-acting cloxacillin and ampicillin dry-cow therapy and internal teat sealant (n=291) or a long-acting cloxacillin and ampicillin dry-cow therapy and internal teat sealant (n=288) at the end of lactation. Cows were managed on-farm with routine husbandry procedures through the dry period and following calving. A multivariable logistic regression model was used to determine the association between length of action of dry-cow therapy and the proportion of cows with a SCC >150,000?cells/mL at the first herd test after calving.

RESULTS: Age of cow, mean SCC for the preceding season and interval from calving to the first post-calving herd test were all associated with the proportion of cows with an individual SCC >150,000?cells/mL at the first herd test (p<0.001) Treatment with the short-acting dry-cow therapy was not associated with decreased odds of cows having a SCC >150,000?cells/mL at the first herd test compared with treatment with long-acting dry-cow therapy (OR=0.724; 95% CI=0.40–1.30).

CONCLUSIONS AND CLINICAL RELEVANCE: In this herd, which routinely used internal teat sealants, the use of short-acting cloxacillin-based dry-cow therapy did not result in an increased proportion of cows with elevated SSC post-calving. This was a single farm, single year study but indicates that in this herd, changing from a long-acting to a short-acting antimicrobial may have no impact on the prevalence of subclinical mastitis.     

奥利亚罗非鱼（♀）、鳜（♂）及其子代间遗传关系的研究

罗非鱼生长快、味道好,是人们喜爱的鱼类,现已是世界性养殖鱼类,但它不能忍受低温,因此影响其养殖业的进一步发展。鳜则是名贵性鱼类,但其终生摄食活的鱼虾,这也限制了其养殖的发展。奥利亚罗非鱼(Oreochromisaurea)属鲈形目、鲡鱼科,鳜(Sinipercachuatsi)属鲈形目、脂科,它们间的杂交为科间杂交。鱼类科间杂交成功率很低,种间杂交有时可获得具有双亲性状的杂种鱼,有时也可发生雌核发育[1]。本研究中奥利亚罗非鱼雌鱼性染色体为ZW,其卵子如能在鳜精子刺激下行雌核发育,则可在短时间获得奥利亚罗非鱼纯系。在本文中,利用RAPD标记,对…     

玉米转录因子基因ZmPTF1在转基因烟草中的表达

为了探讨转录因子基因ZmPTF1在玉米种子萌发中的作用,本研究根据GenBank中收录的玉米PTF1序列设计PCR引物,利用普通玉米自交系A318克隆得到ZmPTF1的全长cDNA序列.该序列开放阅读框包括1 446bp碱基,由481个氨基酸组成.本文构建植物表达载体PCAMBIA3301-ZmPTF1转化烟草W38,经过抗生素筛选和PCR鉴定得到转基因阳性烟草,对2株生长正常的T1转基因烟草进行southern杂交分析及RT-PCR检测,结果表明外源ZmPTF1已经整合进了烟草基因组中并且能正常转录并遗传.与对照相比,转基因烟草种子的发芽率、发芽势及萌发种子α-淀粉酶活性显着增高,表明ZmPTF1基因过表达会促进烟草种子提前解除休眠进入发芽阶段,提高烟草种子发芽势和发芽率.该研究结果为进一步研究ZmPTF1基因的功能提供理论依据.     

Cloned calves derived from somatic cell nuclear transfer embryos cultured in chemically defined medium or modified synthetic oviduct fluid

Somatic cell nuclear transfer (SCNT) is considered to be a critical tool for propagating valuable animals. To determine the productivity calves resulting from embryos derived with different culture media, enucleated oocytes matured in vitro were reconstructed with fetal fibroblasts, fused, and activated. The cloned embryos were cultured in modified synthetic oviduct fluid (mSOF) or a chemically defined medium (CDM) and developmental competence was monitored. After 7 days of culturing, the blastocysts were transferred into the uterine horn of estrus-synchronized recipients. SCNT embryos that were cultured in mSOF or CDM developed to the blastocysts stages at similar rates (26.6% vs. 22.5%, respectively). A total of 67 preimplantational stage embryos were transferred into 34 recipients and six cloned calves were born by caesarean section, or assisted or natural delivery. Survival of transferred blastocysts to live cloned calves in the mSOF and the CDM was 18.5% (to recipients), 9.6% (to blastocysts) and 42.9% (to recipients), 20.0% (to blastocysts), respectively. DNA analysis showed that all cloned calves were genetically identical to the donor cells. These results demonstrate that SCNT embryos cultured in CDM showed higher viability as judged by survival of the calves that came to term compared to blastocysts derived from mSOF cultures.