172 resultados para Caceres (MT)
em Chinese Academy of Sciences Institutional Repositories Grid Portal
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植物种子萌发、开花结实和衰老等一系列生长发育过程,都受到植物激素的影响。细胞分裂素作为重要的生长调节物质,对其传统生物化学和生理学特性的研究已积累子大量资料。随着分子生物学的发展,对植物激素的研究又进一步从单纯的生物学描述阶段深入到分子水平研究的阶段。尤其是近年来对来自病原微生物植物激素相关基因的研究,为揭示细胞分裂素的作用机理和细胸分裂素的水平调节机制的阐明开辟了新的途径。 根瘤农杆菌T-DNA上ipt、iaaM和iaaH基因和发根农杆菌的rol基因表达产物与植物激素的代谢有关。rolC基因是位于发根农杆菌T-DNA区的12号开放读框,编码细胞分裂素-β-葡萄糖苷酶,水解结合态细胞分裂素为自由态细胞分裂素。ipt基因编码异戊烯基转移酶,是细胞分裂素合成过程中的关键酶。 本文用PCR方法从发根农杆菌(Agrobacterium rhizogenes)1601质粒中扩增 rolC基因,并构建CaMV 35S启动子驱动下的双元表达载体。以农杆菌介导的叶盘法,分别对野生型烟草(Nicotiana tabacum L. cv. W38)和已转入异戊烯基转移酶基因(ipt)的3F1和3F2烟草进行转达化。Southern blot和Northern Dot Blot分析表明,rolC基因已导入烟草植株,并具有转录活性。转基因烟草的形态特征与细胞分裂素过量表达的植株表现出的特征一致。 用ELISA方法测定转基因烟草植株中激素的含量,结果显示,单独转rolC基因烟草和同时转入rolC和ipt两个基因的烟草,细胞分裂素的水平有不同程度的提高。转基因烟草表现多芽、节间缩短、叶色深绿等现象。同时,转基因烟草内部发生生理变化,如总自由氨基酸、脯氨酸在正常情况下较对照减少,气孔延迟关闭。在干旱胁迫下,转基因烟草随水势的降低、总自由氨基酸和脯氨酸的变化与对照不同。转基因烟草在开始干旱阶段较对照的总自由氨基酸和脯氨酸含量低,随着干旱胁迫的加深,植物中自由氨基酸的含量增加,但转基因植物自由氨基酸的含量高峰值出现时间较对照推迟。干旱胁迫48小时后,恢复给水,转基因植物较对照易恢复正常生长状态,表明转细胞分裂素基因植物抗旱能力增强。另外,叶片总蛋白SDS-PAGE电泳分析表明,转基因植物蛋白质含量高于对照,某些蛋白组分所占比例也明显提高。 综上所述,转rolC和ipt基因烟草的形态和生理变化,是细胞分裂素过量表达引起植物体内激素失衡的结果。
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从眼镜蛇毒中纯化出膜毒素MT-I,该毒素与磷脂酶A_(2)产生协同溶血效应,使小鸡颈二腹肌等标本产生进行性挛缩,对体外Hut-78细胞有杀伤作用,腹腔注射能引起家猫的心电图异常。
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本研究用10种限制性内切酶对蜂猴和树鼩肝脏线粒体DNA进行了分析. 蜂猴线粒体DNA, BglⅠHind Ⅲ、PstⅠ、SalⅠ和XhoⅠ均各只1个切点、EcoRⅠ、BglⅡ和Pvu Ⅱ各有2切点, BamHⅠ和 EcoRⅤ 分别有3个切点. 对于树鼩线粒体 DNA, BglⅡ、Hind Ⅲ、PstⅠ、SalⅠ和 XhoⅠ均只1个切点, BamHⅠBglⅠ和 PvuⅡ 分别有2个切点, EcoRⅠ 有3个切点, EcoRⅤ有4个切点. 根据单酶和双酶解片段的数目和分子量, 建立了蜂猴和树鼩线粒体 DNA 的物理图谱。
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鳃形目鱼类是一类在鱼类乃至脊椎动物进化史上占有很重要地位的古老濒 危鱼类,长期悬而未决的系统演化关系为世人瞩目.采用DNA测序技术首次测定了 包括中国特有鳃形目鱼类在内的12种鳃形目鱼类的mtDNA ND4L和ND4基因(703 by)的序列,并进行了分子系统学分析.从分子系统学的角度得出了如下结论:(1) 鲤属可以归并到鳃属;(2)达氏鳃与中华鳃的亲缘关系最近,很有可能为中华鳃的 一陆封类型;(3)环太平洋地区的鳃科鱼类可能有共同的起源;(4) ND4L和ND4基 因是进行鳃形目鱼类系统演化研究很好的遗传标记.
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In the present study, we examined the effects of exposure to an extremely low-frequency magnetic field of 1 mT intensity on learning and memory in Lohmann brown domestic chicks using detour learning task. These results show that 20 h/day exposure to a low
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Human perception of speed declines with age. Much of the decline is probably mediated by changes in the middle temporal (MT) area, an extrastriate area whose neural activity is linked to the perception of speed. In the present study, we used random-dot pa
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2003年8月—2005年8月,对无量山大寨子5个黑长臂猿群体的结构和组成进行了观察。当一个群体在早晨鸣叫或依次通过树冠时,记录群体的结构和组成。每个群体都由1个成年雄性、2个成年雌性及其后代组成。2003年8月平均群体大小为6·2只;到2005年8月,平均群体大小发展为6·4只,其中有2个亚成年雄性从出生群迁出,且有3只幼猿出生。在3个群体(G1、G2和G3)中两个成年雌性都成功繁殖了后代。同一群体内两个成年雌性间无攻击或等级行为。2005年4月15日,当一只亚成年雌性进入G3的领域后,两只成年雌性对其进行追逐驱赶,并且干扰其与成年雄性配合进行二重唱,成年雄性没有直接驱赶流浪的亚成年雌性,10天后这只亚成年雌性离开了G3的领域。亚成年雄性经常与群体其他成员保持一定距离,并且在出生地通过独唱练习鸣叫。黑长臂猿可能通过亚成年雄性和雌性的迁出,及成年雌性对外来流浪雌性的驱赶维持这种一夫二妻的群体结构。
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We studied seasonal variation in the activity budget of a habituated group of Nomascus concolor jingdongensis at Mt. Wuliang, Central Yunnan, China from March 2005 to April 2006 via scan sampling at 5-min intervals. The study site is near the northern extreme of the distribution of hylobatids, at high altitude with extreme seasonality of temperature and rainfall. During the day, feeding manifested a bimodal pattern of high activity levels in mid-morning and mid-afternoon, whereas resting reached a peak at midday, with proportionally less time used for traveling. Annually, the group spent an average of 40.0% of the time resting, 35.1% feeding, 19.9% traveling, 2.6% singing, 1.2% playing, and 1.3% in other activities. The proportion of time allocated to activities showed significant monthly variations and was influenced by the diet and temperature. Gibbons increased traveling and playing time and decreased feeding time when they ate more fruit, and they decreased traveling, singing, and playing time and increased feeding time when they ate more leaves. Moreover, when the temperature was low, the gibbons decreased time traveling and increased time resting. In summary, black-crested gibbons employed high-effort activities when they ate more fruit and energy-conservation patterns when they ate more leaves and in low temperature. Behavioral data from the site are particularly useful in understanding gibbon behavioral adaptations to different sets of ecological conditions.
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Data on sleep-related behaviors were collected for a group of central Yunnan black crested gibbons (Nomascus concolor jingdongensis) at Mt. Wuliang, Yunnan, China from March 2005 to April 2006. Members of the group usually formed four sleeping units (adult male and juvenile, adult female with one semi-dependent black infant, adult female with one dependent yellow infant, and subadult male) spread over different sleeping trees. Individuals or units preferred specific areas to sleep; all sleeping sites were situated in primary forest, mostly (77%) between 2,200 and 2,400 m in elevation. They tended to sleep in the tallest and thickest trees with large crowns on steep slopes and near important food patches. Factors influencing sleeping site selection were (1) tree characteristics, (2) accessibility, and (3) easy escape. Few sleeping trees were used repeatedly by the same or other members of the group. The gibbons entered the sleeping trees on average 128 min before sunset and left the sleeping trees on average 33 min after sunrise. The lag between the first and last individual entering the trees was on average 17.8 min. We suggest that sleep-related behaviors are primarily adaptations to minimize the risk of being detected by predators. Sleeping trees may be chosen to make approach and attack difficult for the predator, and to provide an easy escape route in the dark. In response to cold temperatures in a higher habitat, gibbons usually sit and huddle together during the night, and in the cold season they tend to sleep on ferns and/or orchids.
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We used data on loud duetted and solo songs collected from one habituated polygynous group of black-crested gibbons (Nomascus concolor jingdongensis) on Mt. Wuliang, Yunnan, to test several hypotheses about the functions of these songs. The major function
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The diet of a habituated group of black crested gibbon (Nomascus concolor jingdongensis) was studied from March 2005 to April 2006 in the Wuliang Mountains, central Yunnan, China. Gibbons consumed 77 different plant species, one mammal-, two bird-, one li
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Predation on vertebrates is infrequent in gibbons. In a 14-month field study of the central Yunnan black crested gibbon (Nomascus concolor jingdongensis) at Mt. Wuliang, Yunnan, China, we observed gibbons attacking, killing and eating giant flying squirre
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We studied the altitudinal ranging of one habituated group of black-crested gibbons (Nomascus concolor) at Dazhaizi, Mt. Wuliang, Yunnan, China, between March 2005 and April 2006. The group ranged from 1,900 to 2,680 m above sea level. Food distribution was the driving force behind the altitudinal ranging patterns of the study group. They spent 83.2% of their time ranging between 2,100 and 2,400 m, where 75.8% of important food patches occurred. They avoided using the area above 2,500 m despite a lack of human disturbance there, apparently because there were few food resources. Temperature had a limited effect on seasonal altitudinal ranging but probably explained the diel altitudinal ranging of the group, which tended to use the lower zone in the cold morning and the higher zone in the warm afternoon. Grazing goats, the main disturbance, were limited to below 2,100 m, which was defined as the high-disturbance area (HDA). Gibbons spent less time in the HDA and, when ranging there, spent more time feeding and travelling and less time resting and singing. Human activities directly influenced gibbon behaviour, might cause forest degradation and create dispersal barriers between populations. Copyright (C) 2010 S. Karger AG, Basel