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1.
Cladistic analysis of the subfamilies within the Tubificidae (Oligochaeta)   总被引:2,自引:0,他引:2  
A hypothesis of phylogenetic relationships within the family Tubificidae is presented, based on a Wagner analysis of morphological characters in the different subfamilies. Two major lincages are recognized. One, including the subfamilies Tubificinae, Telmatodrilinae and Limnodriloidinae, is supported by a synapomorphic ability to form slender spermatozeugmata in the spermathecae; the other, including Rhyacodrilinae (paraphyletic), Phallodrilinae, and the (present family) Naididae, is supported by two synapomorphics, the possession of modified penial setae and numerous coelomocytes (the latter secondarily lost in the Phallodrilinae). Some implications for the classification of the Tubificidae are discussed.  相似文献   
2.
A taxonomic and morphological account of a collection of Phallodrilinae from coralline sands at Heron Island in Australia's Great Barrier Reef is given. Ten new forms are described: Jamiesoniella athecata gen. et sp.n. Phallodrilus rectisetosus heronensis subsp.n. P. geniculatus sp.n. P. filithecatus sp.n. P. clavatus sp.n. (latter three all devoid of an alimentary canal), Bathydrilus superiovasatus sp.n. Coralliodrilus atriobifidus sp.n. C. oviatriatus sp.n. C. parvigenitalis sp.n. and the gutless C. avisceralis sp.n. Morphological notes are given for Phallodrilus albidus Jamieson, 1977 and Bathydrilus rohdei (Jamieson, 1977). The new meiobenthic genus Jamiesoniella is characterized by having simple atria with only one pair of prostate glands, which are attached to ectal parts of atria, and by lacking spermathecae and penial setae, The genus is probably related to Aktedrilus Knöllner and Bacescuella Hrabě. A gutless species, Phallodrilus comorensis sp.n. is described from the Comoro Islands in the Mozambique Channel (W Indian Ocean).  相似文献   
3.
A quaternary amine, Aliquat 336, inhibits the growth of the green alga Chlorella emersonii, 14C-fixation of the alga is also inhibited. The effect and the site of action of the compound was studied by using isolated spinach chloroplasts. The carbon dioxide dependent oxygen evolution of the chloroplasts is inhibited directly upon the addition of the amine and the oxygen evolution is replaced by an oxygen uptake. By investigating some electron transport reactions in the chloroplasts we were able to show that Aliquat 336 affects the electron transport on the level of photophosphorylation. The results from the in vivo and the in vitro experiments thus show that the quaternary amine affects the photosynthetic process. Aliquat 336 is a solvent extractant used in several industrial processes for extraction of metals from aqueous solutions. Aliquat 336 could be considered a presumptive water pollutant as the compound could enter a recipient water body and thus affect photosynthesis.  相似文献   
4.
The taxonomy and morphology of Aktedrilus Knöllner, 1935 and Bacescuella Hrabe' 1973 (subfamily Phallodrilinae), both common genera of the marine, littoral meiofauna, were studied on the basis of material from various geographical areas. A. monospermathecus Knöllner, 1935 is redescribed from France and Scotland. A. magnus sp.n., A. hrevis sp.n., A. curvipenis sp.n. and A. floridensis sp.n. are described from Italy, Brazil, France and Florida, respectively. Two very closely related forms are described from the Pacific: A. locyi sp.n. (California) and A. parviprostatus sp.n. (Great Barrier Reef). B. mediterranea sp.n. is described from Italy, and new European records are given forB. arclica Erséus, 1978 andfi. parvithecata Erséus, 1978. Both genera are characterized by having two pairs of prostate glands, well developed penes, and unpaired, mid-dorsal spermatheca (if present). The species of Bacescuella transfer their sperm by means of external spermatophores, structures that are not developed in Aktedrilus. The eight species of Aktedrilus are largely distinguished by means of the morphology of the spermatheca, penes and prostates. The four species of Bacescuella differ principally from each other in the length of the vasa deferentia, and in the morphology of the prostates and copulatory organs. Most Bacescuella species lack spermatheca.  相似文献   
5.
ATP-binding cassette (ABC) transporters are involved in the transport of multiple substrates across cellular membranes, including metabolites, proteins, and drugs. Employing a functional fluorochrome export assay, we found that UVB irradiation strongly inhibits the activity of ABC transporters. Specific inhibitors of poly(ADP-ribose) polymerase-1 (PARP-1) restored the function of ABC transporters in UVB-irradiated cells, and PARP-1-deficient cells did not undergo UVB-induced membrane transport inhibition. These data suggest that PARP-1 activation is necessary for ABC transporter functional downregulation. The hydrolysis of poly(ADP-ribose) by poly(ADP-ribose) glycohydrolase (PARG) was also required, since specific PARG inhibitors, which limit the production of ADP-ribose molecules, restored the function of ABC transporters. Furthermore, ADP-ribose molecules potently inhibited the activity of the ABC transporter P-glycoprotein. Hence, poly(ADP-ribose) metabolism appears to play a novel role in the regulation of ABC transporters.  相似文献   
6.
Apoptosis and phagocytosis of apoptotic cells are crucial processes. At best the phagocytic machinery detects and swallows all apoptotic cells in a way that progression to secondary necrosis is avoided. Otherwise, inflammation and autoimmune diseases may occur. Most apoptotic cells are phagocytosed instantaneously in a silent fashion; however, some dying cells escape their clearance. If the cells are not cleared early, they lose membranes due to extensive shedding of membrane surrounded vesicles (blebbing) and shrink. It is unclear how apoptotic cells compensate their massive loss of plasma membrane. Here, we demonstrate that endoplasmic reticulum- (ER) resident proteins (calnexin, the KDEL receptor and a dysfunctional immunoglobulin heavy chain) were exposed at the surfaces of shrunken late apoptotic cells. Additionally, these cells showed an increased binding of lectins, which recognize sugar structures predominantly found as moieties of incompletely processed proteins in ER and Golgi. In addition the ER resident lipophilic ER-Tracker Blue-White DPX, and internal GM1 were observed to translocate to the cell surfaces during late apoptosis. We conclude that during blebbing of apoptotic cells the surface membrane loss is substituted by immature membranes from internal stores. This mechanism explains the simultaneous appearance of preformed recognition structures for several adaptor proteins known to be involved in clearance of dead cells.  相似文献   
7.
8.
The oxygen exchange obtained when isolated chloroplasts of wheat are irradiated, without the addition of a Hill oxidant, has been investigated. Depending on the wavelength, two types of oxygen exchange are obtained. In light absorbed by both photosystems an oxygen gush appears directly upon irradiation. This oxygen evolving reaction is soon replaced by an oxygen uptake which is present until the end of the irradiation period. In light absorbed mainly in photosystem I, no oxygen gush can be observed, instead an oxygen uptake appears directly upon irradiation. An oxygen evolving process can also be observed in irradiations performed with photo-system I light, but this process appears after 10–15 seconds of irradiation. The influence of various external factors on the oxygen gush and the oxygen uptake, e.g. different wavelengths, light intensity, length of the dark periods between irradiations, was studied. The results show that the oxygen evolving reaction appearing upon irradiation with light absorbed by photosystem II and I, reflect the reduction of an oxidant, probably plasto-quinone, in the electron transport chain between the two photosystems. The reoxidation of this oxidant can be brought about after irradiating with light absorbed in photosystem I, or by prolonging the dark period between irradiations, or through some unknown process connected to photosystem II. The oxygen uptake which consists of two components, one appearing directly upon irradiation and the other one appearing after about 10 seconds of irradiation, confirms earlier observations that oxygen can be reduced in photosystem I. The electrons for the oxygen uptake appearing directly upon irradiation, are obtained from the reduced intermediates in the electron transport chain between the two photosystems. The electrons for the other oxygen uptake process are obtained from a reductant in the chloroplasts with access to the carrier chain between the photosystems. Whether the two oxygen uptake reactions reflect two sites of interaction of oxygen with the electron transport chain or only one site is discussed.  相似文献   
9.
Tectidrilus probus sp.n. and Tectidrilus profusus sp.n. are described from offshore localities in southern California. Both species appear closely related to T. diversus Ersëus, 1982, which occurs in the same area, but they differ from the latter by possessing small oesophageal diverticula; T. probus differs also by its very small spermathecal vestibules. Tectidrilus profusus is a highly apomorphic form with elaborate, partly muscular, male ducts and spermathecae. Monophyly of Tectidrilus is supported by the short clitellum and the unisetal 'bundles' in postclitellar segments. Patterns of apomorphic character states within the genus are analyzed under the principle of Camin-Sokal parsimony (irreversibility of character states), giving three equally parsimonious cladograms. In the strict consensus tree of these cladograms, eight of the twelve members of Tectidrilus form an apomorphic group defined by the papillated body wall, but the individual species within this group cannot be unequivocally resolved from each other.  相似文献   
10.
A total of 28 species of marine Oligochaeta (belonging to the families Naididae, Tubificidae and Enchytraeidae) are reported from eulittoral and sublittoral sediment samples taken in the Koster area on the Swedish West Coast. Lumbricillus algensis sp.n. and Grania ovitheca sp.n. are described and their morphological and taxonomical relations to other enchytraeids are discussed. L. algensis is characterized mainly by its spermathecae, which project into segment VI, and by its very large penial bulbs. G. ovitheca possesses no dorsal setae, the ventral setae being present posterior to the clitellum only, and its spermathecae consist of a narrow duct and a large egg-shaped to oval ampulla, filling most of the coelom of segment V. Four sublittoral species, Limnodriloides barnardi (Tubificidae), Lumbricillus semifuscus, Marionina sublitoralis and Grania roscoffensis (all Enchytraeidae) are reported as new to the Swedish fauna.  相似文献   
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