金丝桃素体外抗H9N2亚型禽流感病毒活性研究

研究金丝桃素体外抗H9N2亚型禽流感病毒的活性。用MTT法观察金丝桃素预防、治疗、以及体外直接作用15 min 4种给药方式对感染H9N2亚型禽流感病毒的细胞的保护效果,以及用荧光酶标法测定金丝桃素对禽流感病毒神经氨酸酶的抑制活性。结果表明,金丝桃素的4种给药方式在体外对感染禽流感病毒的细胞的的保护率分别为6.43%、5.31%、39.89%、69.04%。金丝桃素对禽流感病毒神经氨酸酶活性的抑制,IC50为0.58 mg/mL。表明金丝桃素对感染H9N2亚型禽流感病毒的细胞有一定保护的作用,且对神经氨酸酶的活性有较显著的抑制作用。     

Reduced expression of voltage-gated chloride channel genes in Caenorhabditis elegans: Implications for the mode of action of chloride channel-directed nematicides

Caenorhabditis elegans nematodes (fourth-stage larvae) were exposed for 24 h to long (4 μg/μl) or short (5 μg/μl) double-stranded RNA (dsRNA) of two voltage-gated chloride channel (VGCC) genes, ceclc-1 and ceclc-2, coding for two VGCC proteins, CeClC-1 and CeClC-2. The treatments reduced expression of these genes in F₁ progeny in a time- and concentration-dependent manner. Progeny with reduced expression of ceclc-2 (but not ceclc-1) showed significant phenotypic effects, such as increased pharyngeal contractions and decreased locomotion, which were maximal in 48 h old worms. Generally, there was little effect on the worms when expression of ceclc-1 alone was reduced. F₁ progeny with reduced expression of both ceclc-1 and ceclc-2 had a higher percentage showing affected locomotion than were present with reduced expression of ceclc-2 alone, whereas the increase in frequency of pharyngeal contractions was not different from that obtained with reduced expression of ceclc-2 alone. These phenotypic effects were consistent with the known expression patterns of ceclc-1 and ceclc-2 in C. elegans tissues. A strong negative correlation was observed between in vitro concentration of long dsRNA and ceclc-2 expression level, as well as between ceclc-2 expression level and corresponding phenotypic effects. The effects of dsRNA exposure are similar to previous studies in which 24-h incubation in 50 ppm of anion transporter (AT) blockers DIDS, 9-AC, IAA-94, or NPPB increased pharyngeal contractions and the proportion of nematodes exhibiting impaired locomotion. These findings confirm that the principal mechanism of nematicidal activity of AT blockers may arise from the inhibition of CeClC-2.     

柳窿桉9号引种栽培适应性研究

在福建霞浦、仙游、永泰、南平延平区、邵武市、永安市和上杭县开展柳窿桉9号引种适应性试验研究,结果表明:柳窿桉9号适应性和速生性较强,在一般立地条件下造林(Ⅲ类地)成活率可达95%以上,中龄林保存率达85%左右。其速生性虽略比尾巨桉DH32-29差,但1年生平均树高可达2.0 m以上,2年生树高、胸径分别可达5.0 m、5.0 cm以上,尤其在低海拔山地不受冻或轻微受冻的情况下,其速生性较为明显;柳窿桉9号树干通直、径粗,抗风、抗旱和抗病虫害能力均较强。但柳窿桉9号对低温极为敏感,耐寒性有限,只可耐-2.0~-2.5℃的低温,在闽西北地区受冻几率大,在闽东南地区海拔300 m以下的山地种植受冻较轻,可以恢复正常生长。该无性系在福建中亚热带极端低温不低于-3℃的区域低海拔山地有种植前景,尤其适合闽东南沿海海拔300 m以下的山地栽培。     

猪流感病毒H9N2亚型济南株HA、NA基因的克隆与序列分析

根据GenBank中流感病毒H9N2亚型HA基因与NA基因序列,分别设计扩增HA基因与NA基因的特异性引物,用RT-PCR方法扩增猪流感病毒H9N2济南株(SW/SD/JT/07)HA基因和NA基因,分别将RT-PCR扩增产物克隆入pMD18-T载体,进行测序分析。结果表明,SW/SD/JT/07 HA基因长度为1701bp,编码566个氨基酸,HA0切割位点序列为R-S-S-R-G,属非高致病性毒株;HA蛋白有8个糖基化位点,与参考毒株糖基化位点数一致;HA蛋白有5个受体结合位点,其中在190位氨基酸与其余参考毒株存在差异。SW/SD/JT/07 NA基因长度为1413bp,编码470个氨基酸,NA蛋白基质结合部与参考毒株一致,高度保守;NA蛋白有5个抗原位点,在325位为D其余参考毒株均为N,SW/SD/JT/07与DC/HB/W1/04,CK/GS/2/99在398位为E,其余参考毒株为D或N;SW/SD/JT/07 NA蛋白与CK/SH/F/98,DC/HB/W1/04,CK/GS/2/99,SW/GD/WXL/04,SW/SD/W4/03,SW/YN/Simao2/07一样在茎区63,64,65位发生氨基酸缺失。SW/SD/JT/07 HA基因与参考毒株的同源性82.5%～98.6%,NA基因与参考毒株的同源性82.2%～99.1%。SW/SD/JT/07 HA基因与NA基因系统发生树分析表明,SW/SD/JT/07与AIV H9N2亚型亲缘关系密切。     

ORIGINAL ARTICLE: Intravenous injections of cobalt reduce fatty acid desaturation products in milk and blood of lactating cows

The objective of this study was to determine whether intravenous infusion of Co affects levels of fatty acid desaturation products in bovine milk. Six cows were assigned to two replicated 3 × 3 Latin squares with 14‐day periods. Treatment occurred on days 1 to 5 and depuration occurred on days 6–14. Two treatments were tested, the first consisting of per os supplementation of 3.5 g Co daily in the form of Co acetate and the second consisting of intravenous injection of 175 mg Co daily in the form of Co acetate diluted in saline solution. The third treatment was a control. Both Co treatments decreased cis‐9 18:1 levels from approximately 18 to 14 g/100 g fatty acids, and increased 18:0 levels from 11 to 17 g/100 g fatty acids in milk fat (p < 0.001). The proportions of cis‐9 10:1, cis‐9 12:1, cis‐9 14:1, cis‐9 16:1 and cis‐9 17:1 decreased (p < 0.001), whereas 17:0 and trans‐11 18:1 increased (p < 0.001). In blood plasma, levels of cis (6,9,12) 18:3 (p < 0.001) and cis (8,11,14,17) 20:4 (p = 0.008) decreased after both the Co treatments. It is concluded that intravenous supply of Co reduces levels of fatty acid desaturation products in both bovine milk and blood.     

抗逆转ABP9基因黑麦草和高羊茅植株的鉴定

选取黑麦草(Lolium perenne)barti和telstar品系以及高羊茅(Festuca elata)追寻者品系作为相应的受体材料,采用实验室克隆的玉米(Zea mays)抗逆相关转录因子ABP9通过农杆菌介导和基因枪轰击2种方法进行遗传转化,获得再生植株;并对再生植株进行PCR、Southern和Northern杂交分子检测以及抗逆性鉴定。试验结果表明,成功获得ABP9在基因组中整合并表达且抗逆性得到显著提高的转基因黑麦草和高羊茅植株。     

以rLaSota为骨架构建表达强毒株HN蛋白的嵌合体新城疫病毒

新城疫病毒(NDV)的HN蛋白是一个多功能蛋白,具有血凝素(HA)和神经氨酸酶(NA)两种活性,在病毒感染过程中扮演重要角色。本研究利用反向遗传操作技术,将NDV强毒株F48E9的HN基因替换弱毒株rLaSota的HN基因,获得嵌合病毒rL-F48E9HN。收获病毒尿囊液,提取基因组RNA,进行序列分析,结果显示嵌合病毒基因组的HN基因获得了正确替换。嵌合病毒在鸡胚内的生长特性与亲本株LaSota一致,与F48E9的生长特性相差甚远。嵌合病毒红细胞吸附性明显增强,较rLaSota株增加51%,而细胞融合作用无明显变化。rL-F48E9HN的鸡胚平均致死时间(MDT)为148 h,脑内致病指数(ICPI)为0.43,静脉接种致病指数(IVPI)为0,说明rL-F48E9HN的毒力仍然属于弱毒力范围,而没有达到中等毒力或者强毒力。     

丰产抗病西瓜新品种农科大9号的选育与评价

为了选育丰产性、抗病性更强的西瓜新品种,以高抗枯萎病母本Z10-1和优良父本J2-2杂交配制农科大9号。该品种中晚熟,露地栽培全生育期约100 d,保护地栽培全生育期120 d,果实发育期34 d。植株生长势强,坐果容易且整齐。果实椭圆形,果型指数1.4。果皮绿色,上覆深绿色中细条带。果肉红色,肉质脆,果实中心可溶性固形物含量95 mg/g、总糖85.3 mg/g、蛋白质11.1 mg/g、粗纤维0.71 mg/g、Vc 0.059 1mg/g。单瓜质量7.47 kg。区试产量66 073.5 kg/hm2,生产示范产量75 180 kg/hm2,分别比对照西农8号增产9.8%和16.2%。抗枯萎病性强于对照。     

马铃薯新品种郑薯9号的选育

郑薯9号是由早大白×豫马铃薯1号杂交后代选育而成的马铃薯新品种。早熟,生育期(出苗至收获)56d(天)左右。每667m2产量1200kg左右。薯块椭圆形,黄皮白肉,薯皮光滑,芽眼浅,商品薯率89.08%～100%。淀粉含量11.8%,VC252mg·kg-1,蛋白质2.52%,还原糖0.32%。田间调查较抗病毒病、晚疫病、环腐病。适宜二季作栽培及一季作早熟栽培。