棕点湍蛙皮肤分泌液中促胰岛素释放肽的分离纯化、基因克隆及活性分析

通过分离纯化棕点湍蛙(Amolops loloensis)皮肤分泌液中的生物活性物质,得到有促胰岛素释放活性的分离峰,并鉴定其结构.采用葡聚糖Sephadex G-50凝胶层析和反相高效液相(RP-HPLC)等手段对棕点湍蛙皮肤分泌液进行分离纯化,利用胰岛素释放实验进行活性检测,Edman降解法测定活性峰的氨基酸序列,反转录法构建cDNA文库并克隆其基因.得到一个具有显著的促胰岛素释放活性的十六肽,测得其氨基酸序列为:FMPIvGKsMSGLSGKL-NH2,命名为amolopin-1.由cDNA(开放阅读框为192bp)推导的氨基酸一级结构显示,其前体由64个氨基酸残基(aa)组成,包括高度保守的信号肽(22aa),酸性肽以及成熟肽.经过数据库序列比对,从棕点湍蛙皮肤中得到一个新的促胰岛素释放肽,进一步分析其作用机理和药代动力学,极有可能得到一个新的治疗糖尿病的降糖药物.     

Distribution and ultrastructure of Merkel cell of the fishing bat (Myotis ricketti)

The distribution and ultrastructure of Merkel cells were described in detail in piscivorous bats through immunohistochemistry and transmission electron microscopy techniques. The findings indicated that Merkel cells are commonly found in raised-domes,hair follicles and in the basal epidermis of the skin from their back,abdomen,intercrural membranes,wing membranes and footpads. However,the density of Merkel cells is significantly higher in the footpad than in other places. These results suggested that there ...     

北京房山大足鼠耳蝠食鱼性及回声定位信号

大足鼠耳蝠 (Myotisricketti)具有食鱼蝙蝠的形态特征 ,但食鱼习性待考。以北京房山种群为对象 ,夜间在洞口悬挂雾网 ,捕获取食返洞大足鼠耳蝠共 18只 ,胃检发现 7例全为鱼类 (宽鳍 ,鲫鱼和洛氏 ) ,10例以鱼类为主 ,仅 1例全为昆虫。室内实验观察到捕鱼行为 2 5 6次 ,成功率 12 5 %。如此 ,该种具食鱼习性的猜测得到证实。回声定位信号属调频型 ,扫频范围从 6 7 4 0kHz到 2 3 6 3kHz ,主频 (38 2 1± 1 18)kHz ,声信号时程 (2 5 8± 0 34)ms。这些特征具有一定的物种特异性     

大足鼠耳蝠的分布

首次报道北京、成都和广东发现大足鼠耳蝠,并结合文献对其形态特征及其在我国现有分布区进行了描述。     

A novel algesic peptide derived from skin secretions of the frog Amolops loloensis.

Several algesic agents including bradykinin and tachykinin have been identified from skin secretions of amphibians. They may act in defensive roles against aggressors. In this study, a novel peptide named Amolos with an amino acid sequence of FLPIVGAKL and isolated from skin secretion of the frog Amolops loloensis, is shown to strengthen nociceptive responses induced by inflammatory factors and strongly inhibit the contraction of isolated ileum. A synthetic peptide based on the sequence obtained showed characterization data identical to those of the isolated material, confirming its structure. These two types of responses seem to be a part of the defensive functions against predators or aggressors. The current results suggest that pharmacological molecules in amphibian skins not only act as innate defense mechanisms against microorganisms but also exert other defensive physiological functions against other aggressors.     

基于12S和16S rRNA序列的湍蛙属部分物种的系统发育关系

测定了湍蛙属 6个种共 10个种群 ,以及 4个外群种的线粒体 12S和 16SrRNA基因片段 ,比对后有94 0bp序列 ,发现 35 2个变异位点、 186个简约性位点。运用NJ法、MP法、ML法构建了系统关系树 ,各系统树一致表明内群为一单系群 ,分为两组 :第一组中 ,四川湍蛙两种群先聚合 ,再和棕点湍蛙聚为一支 ;第二组中 ,香港湍蛙和戴云湍蛙聚为一支 ,而香港大屿山离岛湍蛙种群首先与华南湍蛙相聚 ,再与武夷湍蛙构成姐妹支。研究结果表明 :香港地区增加 1种湍蛙分布 ;戴云湍蛙是一有效种 ;四川湍蛙的石棉和洪雅种群间遗传差异达到或超过其他种间的分歧水平。     

横断山区四种湍蛙的细胞遗传学研究

通过染色体组型分析,C带(BSG技术)分析及一种简便的Ag-NORs带分析,对四川湍蛙、理县湍蛙、棕点湍蛙和棘皮湍蛙的种间关系、染色体的演化及其性染色体等问题进行了初步探讨。结果表明:(1)四川湍蛙、理县湍蛙和棕点湍蛙之间的亲缘关系较近,而它们与棘皮湍蛙的亲缘关系较远;(2)在近缘种的分化中,染色体结构异染色质的变化和臂间倒位是重要的因素之一,这在小型染色体上表现得尤为突出;(三)四川湍蛙具有在形态上分化很明显的性染色体。C带分析表明,此性染色体主要由常染色质构成,但在其Y染色体的长臂上存在明显的中间C带,推测尚处于性染色体分化的初期阶段。     

云南景东地区四川湍蛙的核型,C—带和Ag—NORs的研究

本文报道了云南景东四川湍蛙的核型：２ｎ＝２６（２０Ｍ＋６ｓＭ），ＮＦ＝５２，５＋８模式，次缢痕以及Ａｇ－ＮＯＲｓ均位于６ｐｉｎｔｅｒ，Ｃ－带阳性分布于全部染色体的着丝点区域和８ｑｉｎｔｅｒ，但６ｐｉｎｔｅｒ１２ｐｔｅｒ和１３ｑｔｅｒ等处间或也显示Ｃ－带正染。没有发现与性别相关的异形染色体。与采自四川宝兴地区的居群作了比较，并讨论了细胞地理学问题。     

A new species of the genus Amolops (Anura: Ranidae) from high-altitude Sichuan,southwestern China,with a discussion on the taxonomic status of Amolops kangtingensis

A new species of the genus Amolops Cope,1865 is described from Xinduqiao,Kangding,Sichuan.It was previously identified as Amolops kangtingensis,which is synonymized to Amolops mantzorum in this study.The new species,Amolops xinduqiao sp.nov.,is distinguished from all other congeners by the following combination of characters:(1) medium body size,adult males SVL 41.2-47.5 mm (n=15,average 43.9 mm),adult females SVL 48.5-56.6 mm (n=15,average 52.5 mm);(2) head length equal to width or slightly wider than long;(3) tympanum small,but distinct;(4) vomerine teeth in two tiny rows,separated by a space about one vomerine teeth row;(5) bony projections on lower jaw absent;(6) dorsolateral folds usually absent;(7) tarsal folds or glands on tarsus absent;(8) circummarginal groove on disc of finger Ⅰ absent;(9) tibiotarsal articulation reaching nostril or beyond;(10) webs of toe Ⅳ reaching to distal articulation,other toes fully webbed to disc;and (11) vocal sac absent in males.     

景东湍蛙抗菌肽jindongenin-1d的分析和活性测定

新型抗菌肽研究有助于解决细菌对抗生素的耐药性问题。本研究用SMART技术构建了景东湍蛙Amolops jingdongensis皮肤的全长cDNA文库。通过单克隆和测序获得一个抗菌肽cDNA序列,序列比对结果表明其属于jindongenin-1家族,命名为jindongenin-1d。其cDNA序列全长321bp,编码含66个氨基酸残基的多肽。该多肽包括1个信号肽和1个前肽序列。成熟jindongenin-1d多肽包含24个氨基酸残基,理论分子量为2 709.38,等电点为9.24。对人工合成的jindongenin-1d蛋白进行了抗菌和溶血活性分析,结果表明jindongenin-1d对所选的革兰氏阴性菌、革兰氏阳性菌和真菌均有显著抑制作用,同时有弱溶血活性。本研究结果有助于进一步了解两栖动物皮肤分泌物活性物质的多态性和新型抗感染药物的设计。