草木樨状黄芪抗甲硫氨酸变异系的离体筛选及鉴定

通过组织培养体系进行了草木樨状黄芪(Astragalus melilotoides Pall.)抗甲硫氨酸变异系的筛选。无菌苗幼茎切段诱导的愈伤组织经NaN_3诱变后,经过筛选获得了抗14mmol/L甲硫氨酸的变异细胞系,并分化出大量植株。再生植株已经在大田中开花结实。经分析表明:抗性细胞系脱离选择压6个月后,放在含15mmol/L甲硫氨酸的培养基上培养25天后,其相对增长率是对照的10.2倍。抗性系再生植株游离甲硫氨酸是对照的2.12倍,并且天冬族氨基酸都有明显增加。SDS-PAGE及过氧化物酶同工酶分析表明:在蛋白质及同工酶酶谱上抗性系再生植株均出现与对照不同的差异。     

马尾松毛虫蛋白质、核酸酶和羧酸酯酶与耐药性的关系

马尾松毛虫(Dendrolimus Punctatus Walder)幼虫蛋白质含量,羧酸酮酶和多酚氧化酶活力与虫龄大小成正相关;氰戊菊酯处理后,兴奋期的蛋白质含量和羧酸酯酶活力上升,到抑制期均降低到正常虫体的水平,而多酚氧化酶的变动不大。正常虫体中脱氧核糖核酸酶(Dnase)和核糖核酸酶(Rnase)的活力存在差异：Dnase从3-5龄幼虫随虫体增大而上升,到6龄时明显降低;Rnase与虫龄大小成负相关;氰戊菊酯处理后,Dnase便开始下降并低于正常虫体的水平,而Rnase在兴奋期上升,到抑制期下降亦低于正常虫体水平。结果说明,除多酚氧化酶外,蛋白质、核酸酶和羧酸酯酶均与耐药性存在一定的相关性,研制酶的抑制剂具有实用意义。根据毒力测定结果,马尾松毛虫幼虫随虫龄增大而耐药力增加,氰戊菊酯对5龄幼虫是3龄的2.8倍,6龄是4龄的2.3倍。因此,掌握在4龄前进行药物防治是合理的。     

Polyadenylation site-specific differences in the activity of the neuronal βCstF-64 protein in PC-12 cells

Recent genome-wide analyses have implicated alternative polyadenylation — the process of regulated mRNA 3′ end formation — as a critical mechanism that influences multiple steps of mRNA metabolism in addition to increasing the protein-coding capacity of the genome. Although the functional consequences of alternative polyadenylation are well known, protein factors that regulate this process are poorly characterized. Previously, we described an evolutionarily conserved family of neuronal splice variants of the CstF-64 mRNA, βCstF-64, that we hypothesized to function in alternative polyadenylation in the nervous system. In the present study, we show that βCstF-64 mRNA and protein expression increase in response to nerve growth factor (NGF), concomitant with differentiation of adrenal PC-12 cells into a neuronal phenotype, suggesting a role for βCstF-64 in neuronal gene expression. Using PC-12 cells as model, we show that βCstF-64 is a bona fide polyadenylation protein, as evidenced by its association with the CstF complex, and by its ability to stimulate polyadenylation of luciferase reporter mRNA. Using luciferase assays, we show that βCstF-64 stimulates polyadenylation equivalently at the two weak poly(A) sites of the β-adducin mRNA. Notably, we demonstrate that the activity of βCstF-64 is less than CstF-64 on a strong polyadenylation signal, suggesting polyadenylation site-specific differences in the activity of the βCstF-64 protein. Our data address the polyadenylation functions of βCstF-64 for the first time, and provide initial insights into the mechanism of alternative poly(A) site selection in the nervous system.     

薜荔榕小蜂对薜荔和爱玉子雌花期榕果挥发物的行为反应

薜荔和爱玉子均属雌雄异株桑科榕属植物,两者互为原变种与变种的关系,分别与薜荔传粉小蜂和爱玉子传粉小蜂(二者互为隐存种)建立了专性共生关系,榕树榕果挥发物在维系传粉小蜂与其寄主的共生关系上起着重要作用。利用Y型嗅觉仪测定薜荔榕小蜂(薜荔和爱玉子的传粉小蜂)对薜荔和爱玉子雌花期榕果挥发物的行为反应。结果表明:(1)雌花期果型的大小对薜荔榕小蜂行为反应无显著影响,薜荔大、小果型雌花期雌(雄)榕果挥发物对其传粉小蜂均具有强烈的吸引作用;(2)榕果挥发物浓度影响薜荔榕小蜂行为反应,薜荔、爱玉子雌花期雌(雄)榕果挥发物对其传粉小蜂的吸引作用均可能存在阈值反应,即榕果挥发物浓度未超过阈值时,雌花期榕果挥发物对传粉小蜂的吸引作用与挥发物浓度成正相关关系,而一旦超过阈值,榕果挥发物对传粉蜂的吸引作用显著下降,表明寄主榕果挥发物浓度影响传粉小蜂的寄主定位;(3)薜荔传粉小蜂对低浓度爱玉子雌花期雌(雄)榕果挥发物、爱玉子传粉小蜂对低浓度薜荔雌花期雌(雄)榕果挥发物均既无趋向也无驱避行为;薜荔传粉小蜂对高浓度的爱玉子雌花期雌(雄)榕果挥发物表现为显著的驱避行为,而爱玉子传粉小蜂对高浓度薜荔雌(雄)雌花期榕果挥发物表现为显著的趋向行为,因此,薜荔传粉小蜂与爱玉子传粉小蜂存在寄主专一性不对称现象,爱玉子传粉小蜂进入薜荔雌(雄)果内传粉或产卵的可能性较大,而福州地区的薜荔传粉小蜂可能难以进入爱玉子雌(雄)果内传粉或产卵。本研究结果将为榕-蜂共生体系的化学生态学理论研究以及爱玉子栽培提供科学依据。     

斜纹夜蛾水通道蛋白1（AQP1）基因的克隆、分子特性和表达分析

水通道蛋白(aquaporin, AQP)是生物体中一种重要的跨膜通道蛋白, 它通过一些中性小分子化合物的运输, 从而参与了昆虫对食物中水分再吸收、抗寒和抗干燥等重要生理机制。为研究斜纹夜蛾中水通道蛋白的基因特征和时空表达特征, 本研究利用同源克隆和RACE技术获得了斜纹夜蛾水通道蛋白1（AQP1）基因的两个转录异构体, 并将其分别命名为SL-AQP1A （GenBank登录号： KC999953）和SL-AQP1B （GenBank登录号： KC999954）,其中SL-AQP1B比SL-AQP1A在推导的编码区5′端连续性缺失81个碱基, 而其他序列完全一致; 同源分析显示推导的SL-AQP1与家蚕为代表的水通道蛋白1具有较高的同源性。拓扑学和三级结构模拟显示其有经典的6个全跨膜结构域、2个半跨膜结构域、2个保守的NPA (asparagine-proline-alanine, 天冬氨酸-脯氨酸-丙氨酸)结构基序及选择性水孔构件ar/R （aromatic arginine, 芳香族精氨酸）。qRT-PCR结果显示, SL-AQP1整体时空表达差异性十分明显, 并且SL-AQP1B的表达量显著高于SL-AQP1A; SL-AQP1在卵期和预蛹期有较高的表达量, 在中肠、马氏管、血淋巴、消化腺中有相对较高的表达量, 暗示其在斜纹夜蛾中存在重要的渗透压调节作用。本文结果为进一步研究水通道蛋白在斜纹夜蛾中的作用提供了一定的分子基础。     

日本松干蚧性信息素光学异构体的引诱活性

对合成的日本松干蚧Matscoccus matsumurse(kuwana)性信息素4、6、10、12-四甲基-反2、反4-十三碳二烯-7-酮1所有四个光学活性异构体,进行了诱虫活性测定和林间诱捕试验。结果表明,只有6R、10R-4、6、10、12-四甲基-反2 反4-十三碳二烯-7-酮对日本松干蚧雄成虫具有强烈引诱活性,被确定为该虫天然性信息素的绝对构型。     

诱发小麦花药愈伤组织及其再生植株抗盐性变异的研究

不同基因型小麦花药愈伤组织对化学诱变剂的敏感性不同。选用对诱变剂敏感的类型,经EMS(甲基磺酸乙酯)诱变可以产生耐盐变异。实验获得的耐盐变异株, 离开盐胁迫3代后,经盐池鉴定后代中有52.9%的品系达到一级耐盐,表现了一定的遗传稳定性。耐盐品系的结实率也逐渐得到恢复,达到92.4%。利用其高代材料进行耐盐性的遗传分析结果表明,小麦的耐盐性不仅受核基因的控制,也受细胞质因子的影响。经酸性聚丙烯酰胺凝胶电泳分析,发现耐盐突变体特有的Rf值为0.19的醇溶蛋白能稳定遗传。 Abstract:The study discovered that the sensibilities of anther calli in different wheat genetypes to chemical mutagenic agent were different.The mutation-sensitive type might generate salt-tolerant variation after mutagenizing with EMS.The fourth generation of salt-tolerant plants which were planted for three generations in usual soil expressed tolerance stability after planting in the salt pond of a 0.45% salt concentration,52.9% of the lines in the offspring belonged to first grade of salt-tolerance,showing that the salt-tolerant variant had a certain stability.The fertility of salt-tolerant lines was gradually recovered and reached 92.4%.The high generation materials were used for genetic analysis of the salt-tolerance.The results indicated that the wheat salt-tolerant trait is not only controlled by nuclear gene,but also effected by cytoplasmic factor.In addition,A-PAGE(Acid-Polyacrylamide gel electrophoresis)discovered that the salt-resistant mutant had a unique gliadin band with a Rf value of 0.19,and that this unique band was stable inherited.     

见于我国人群的一例St~a血型糖蛋白

在我国人群中筛查出一例疑似St~a血型糖蛋白(GP)变种。先证者为黎族男青年,属杂合子。家系调查表明,其遗传变异来自母亲。現借助限制性核酸內切酶图谱及一系列序列重叠的寡核苷酸探针,完成了其基因结构的鉴定,确证为見于我国的首例St~aGP变种。在其(δ-α)杂化基因的交叉点,δGP基因断裂于26号氨基酸残基附近,而αGP基因断裂则位于59号氨基酸残基附近。     

肝素酶基因可变剪接体的克隆及鉴定

目的:克隆肝素酶基因的可变剪接体并测序。方法:根据人肝素酶的cDNA序列设计引物,用RT-PCR方法从正常人外周血白细胞中扩增肝素酶基因的可变剪接体,构建至pGEM-T Easy载体中,转化大肠杆菌DH5α感受态细胞,筛选阳性克隆并进行序列测定。结果:获得了肝素酶基因的3种可变剪接体形式,即5号外显子缺失可变剪接体、6号外显子缺失可变剪接体、5和6号外显子缺失可变剪接体,其中后2种可变剪接体尚未报道。结论:克隆了肝素酶基因的3种可变剪接体,有助于研究各种肝素酶可变剪接体编码蛋白的结构和功能及其在肿瘤发生转移过程中的作用。     

Stem anatomy and development of inter- and intraxylary phloem in Leptadenia pyrotechnica (Forssk.) Decne. (Asclepiadaceae)

Modification of external morphology and internal structure of plants is a key feature of their successful survival in extreme habitats. They adapt to arid habitats not only by modifying their leaves, but also show several modifications in their conducting system. Therefore, the present study is aimed to investigate the pattern of secondary growth in Leptadenia pyrotechnica (Forssk.) Decne., (Asclepiadaceae), one such species growing in Kachchh district, an arid region of Gujarat State. A single ring of vascular cambium, responsible for radial growth, divided bidirectionally and formed the secondary xylem centripetally and the phloem centrifugally. After a short period of secondary xylem differentiation, small arcs of cambium began to form secondary phloem centripetally instead of secondary xylem. After a short duration of such secondary phloem formation, these segments of cambium resumed their normal function to produce secondary xylem internally. Thus, the phloem strands became embedded within the secondary xylem and formed interxylary phloem islands. Such a recurrent behavior of the vascular cambium resulted in the formation of several patches of interxylary phloem islands. In thick stems the earlier formed non-conducting interxylary phloem showed heavy accumulation of callose on the sieve plates followed by their crushing in response to the addition of new sieve elements. Development of intraxylary phloem is also observed from the cells situated on the pith margin. As secondary growth progresses further, small arcs of internal cambium get initiated between the protoxylem and intraxylary phloem. In the secondary xylem, some of the vessels are exceptionally thick-walled, which may be associated with dry habitats in order to protect the vessel from collapsing during the dryer part of the year. The inter- and intraxylary phloem may also be an adaptive feature to prevent the sieve elements to become non-conducting during summer when the temperature is much higher.