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1.
In C. elegans, cell death can be readily studied at the cellular, genetic, and molecular levels. Two types of death have been characterized in this nematode: (1) programmed cell death, which occurs as a normal component in development; and (2) pathological cell death which occurs aberrantly as a consequence of mutation. Analysis of mutations that disrupt programmed cell death in various ways has defined a genetic pathway for programmed cell death which includes genes that perform such functions as the determination of which cells die, the execution of cell death, the engulfment of cell corpses, and the digestion of DNA from dead cells. Molecular analysis is providing insightinto the nature of the molecules that function in these aspects of programmed cell death. Characterization of some genes that mutate to induce abnormal cell death has defined a novel gene family called degenerins that encode putative membrane proteins. Dominant alleles of at least two degenerin genes, mec-4 and deg-1, can cause cellular swelling and late onset neurodegeneration of specific groups of cells. © 1992 John Wiley & Sons, Inc.  相似文献   
2.
We describe the development of DNA markers for the fungal pathogen of Eucalyptus, Cryphonectria cubensis. These markers originated from cloned intershort sequence repeat polymerase chain reactions, which enrich for medium to highly repetitive DNA sequences. In total, 10 markers were isolated, eight of which were polymorphic, and these can subsequently be applied to study populations of C. cubensis.  相似文献   
3.
Joseph Parker 《ZooKeys》2014,(373):57-66
A new genus and species of the large Neotropical pselaphine tribe Jubini is described from Manaus, Brazil, based on material preserved in the Natural History Museum, London. Morphogenia struhli gen. et sp. n. represents the possible sister taxon of the abundant and speciose genus Barrojuba Park, sharing with it the putatively derived condition of anterolaterally shifted vertexal foveae, producing a smoothly convex vertex devoid of fovea or sulci. However, unlike Barrojuba, Morphogenia retains a plesiomorphic antebasal sulcus on the pronotum in both sexes, and additionally lacks elaborate abdominal fovea-like pockets and teeth on the lateral margins of the pronotum that are typical of Barrojuba. The genus is also unusual among jubine genera in lacking the characteristic V- or Y-shaped gular carina. In contrast to the commonly-collected Barrojuba, specimens of Morphogenia are absent in extensive jubine collections housed in museums in the United States, indicating that the new taxon may be relatively scarce or localised.  相似文献   
4.
Two electrophoretically different forms of superoxide dismutase, one of them containing manganese-protein and the other iron-protein, were detected in eleven different strains of the genus Flavobacterium. The activities of the different strains were similar to those described for other bacteria. The two molecular forms of the enzyme differed clearly with regard to activity, electrophoretic behaviour, sensitivity to cyanide and peroxide, and NaCl requirement. Both molecular forms were isolated from Flavobacterium halmephilum. Molecular mass absorption spectra, metal content, optimum pH, heat-sensitivity and stability were described.  相似文献   
5.
本文记述采自云南澜沧江水系的鲤科(鱼丹)亚科鱼类一新属新种。新属裸(鱼丹)属Gymnodanio gen.nov.在侧线、臀鳍条数目等特征上近似于低线(?)属Barilius,但以其除侧线鳞外体裸露无鳞,具不完全之腹棱等而与其及(鱼丹)亚科现有各属相区别。新种命名为条纹裸(鱼丹)G.strigatus sp.nov.。  相似文献   
6.
7.
绕茧蜂属Ropalophorus Curtis,1837是茧蜂科中的一个小属,迄今世界上仅记载有2种。一种为R.clavicornis(Wesmael),1835,分布于欧州及日本,寄生于云杉八齿小蠹Ips typographus及I.amitinus成虫体内;另一种为R.wisconsinensis Shenefelt,1960,仅分布于美国,由于该种是用诱捕器捕到的,因此,其奇主不详,但有可能为I.pini(Shenefelt,1960)。  相似文献   
8.
云南蝗虫一新属新种:直翅目:斑腿蝗科   总被引:1,自引:0,他引:1  
本文记述采自云南省瑞丽地区蝗虫新属龙川蝗属Longchuanacris gen.nov.及新种巨尾片龙川蝗 L.macrofurculus sp.nov.该新属近似于 Pseudogerunda Bey-Bienko.主要区别为前胸背板侧片后缘极凹入;前翅到达第一腹节背板的后缘;后足股节下膝侧片顶刺状:后足附节第3节长度为第1、2节长度之和;雄性腹部末节背板具尾片。  相似文献   
9.
杯叶科是食鱼的爬行类、鸟类、哺乳类寄生的吸虫。本文修订了以往在福建报道的虫种,叙述了一个新属三个新种,取消了前此所定的一个属及种[Tangiella parovipara(Faust and Tang,1938)],认为是存疑的种。本文还报道了盖前冠吸虫 Prosostephanus Tubangu,1922的终末宿主河獭,从而作者(Tang,1941)完成了其生活史的研究。本文比较了从河獭所得的标本与从描、犬所获标本各器官的测量数据,发现由最佳的终末宿住所得标本,其个体及各器官和卵子的测量数据均较大。  相似文献   
10.
本文记述刺脉实蝇族Acanthinevrini一新属三新种,即墨实蝇属Cyaforma gen. nov., 神峨墨实蝇C.shenonica sp.nov., 西藏川实蝇 Ortalotrypeta tibeta sp.nov., 单鬃川实蝇 O.singula sp.nov。  相似文献   
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