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51.
52.
Summary One new genus and two new species of the Lernaeopodidae (Copepoda: Siphonostomatoida), parasitic onTriakis maculata off the coast of Chile, are described and illustrated. The new genus,Pseudolernaeopoda, parasitizes the cloaca of its host. Its type-species,P. caudocapta, can be distinguished fromLernaeopoda by the absence of modified uropods. A new species ofLernaeopoda, L. tenuis, was found on the gills of the same host. In absence of the male, the generic affinities of this species must be considered only tentative. ac]19850409 相似文献
53.
54.
Human alveolar macrophage fibronectin: synthesis, secretion, and ultrastructural localization during gelatin-coated latex particle binding 总被引:14,自引:4,他引:10
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Human pulmonary alveolar macrophages synthesized and secreted several characteristic high molecular weight proteins for at least 7 d in vitro. Immunoprecipitates of medium and cell lysates from metabolically labeled cultures with specific anti-human plasma fibronectin IgG contained one major labeled polypeptide of molecular weight 440,000 (unreduced) or 220,000 (reduced). An identical polypeptide in conditioned medium from radiolabeled macrophages bound specifically to gelatin-Sepharose, demonstrating that alveolar macrophages synthesized and secreted a molecule immunologically and functionally similar to fibronectin. Fibronectin was the major newly synthesized and secreted polypeptide of freshly harvested alveolar macrophages. Pulse-chase experiments revealed that newly synthesized fibronectin was rapidly secreted into medium, approximately 50 percent appearing by 1 h and 80 percent by 8 h. Immunoperoxidase staining using antifibronectin F(ab’)(2)-peroxidase conjugates revealed the majority of immunoreactive fibronectin to be intracellular, localized to endoplasmic reticulum and Golgi apparatus. No extracellular matrix fibronectin was visualized, and cell surface staining was rarely seen, usually appearing only at sites where cells were closely apposed and not at sites of macrophage-substrate attachment. Similar immunostaining of fibroblast cultures revealed cell surface-associated fibrillar fibronectin. Ultrastructural localization of fibronectin during binding and phagocytosis of gelatin-coated and plain latex particles revealed fibronectin only on gelatin-latex beads and at their cell binding sites. Neigher plain latex beads nor their cell membrane binding sites stained for fibronectin. These results demonstrate that fibronectin is a major product of human alveolar macrophages, is rapidly secreted, and is localized at cell membrane binding sites for gelatin-coated particles. In view of the known binding properties of fibronectin, it may serve as an endogenous opsonic factor promoting the binding of staphylococcus, denatured collagen, fibrin, or other macromolecules to macrophages in the lower respiratory tract. 相似文献
55.
On the phospholipids of Bacillus megaterium 总被引:12,自引:0,他引:12
56.
57.
Biodegradation of softwood ( Pinus radiata ) by the ascomycete Chrysonilia sitophila was dependent on the nitrogen and glucose concentrations in the culture medium. Optimization studies of the delignification process, in which the nitrogen (0–50mmol/l NH+ 4 ) and glucose (0–2%) concentrations were varied, showed a maximal value of 17·8% for sawdust degradation in cultures containing 10 mmol/l NH4 + and 1·0% glucose. Solubility of the decayed sawdust in 1% NaOH at maximal delignification conditions showed a threefold increase and changes in the thermogravimetric pattern were also observed. Biodegraded wood chips showed significant decreases of the 280 and 310 nm characteristic lignin bands in the u.v. reflectance spectra. 相似文献
58.
Pseudocharopinoides myliobatidos n. g., n. sp. (Lernaepodidae) is described. Although similar to Pseudocharopinus Kabata, 1964, it differs from this genus in the ventral position of its posterior processes and by its non prehensile second antenna. The similarity indicates that it belongs to the Charopinus-branch of the Lernaeopodidae. In addition, Brianella corniger Wilson, 1915 is recorded on Sympterigia brevicaudata and is redescribed. ac]19861103 相似文献
59.
Phylogenetic screening of the human genome: identification of differentially hybridizing repetitive sequence families 总被引:1,自引:0,他引:1
The phi-screen, a method of phylogenetic screening, can be employed to
detect repetitive sequence families that differentially hybridize between
closely related species. Such differences may involve sequence divergence
or variations in copy number, including total presence versus absence of a
family of repeated DNA. We present the results of a phi-screen comparing
the human genome to that of the prosimian, Galago crassicaudatus. Three
human repetitive families that are divergent or not present in galago have
been detected. One of these families is described in detail; it is similar
among the anthropoids but is present in a lower copy number and/or
divergent form in prosimians. The family is clearly related to the
transposon-like human element (THE) described by Paulson et al. (1985).
THEs have long terminal repeats reminiscent of retroviruses but are unique
in that they have no sequence similarity to known mammalian retroviruses.
The sequence of a solo long terminal repeat, found unassociated with THE
internal sequence, is presented. This family member, THE p2, is bordered by
a 5-bp target-site repeat and is interrupted by the insertion of an Alu
element. A solo THE element sequenced by Wiginton et al. (1986) contains an
insertion of Alu at precisely the same position as does THE p2.
相似文献
60.
The alcohol dehydrogenase (Adh) region from five planitibia subgroup
species of Hawaiian picture-wing Drosophila has been cloned. A total of 15
kb of DNA in and around the Adh gene has been compared among the five
species. Genetic distances were calculated to determine evolutionary
relationships. These distances agree with previous distances determined by
protein polymorphism and DNA hybridization techniques and can be
interpreted in terms of specific island colonization and speciation
(founder) events over the past 5 Myr. Examination of the restriction maps
of the cloned Adh region from the five species shows many instances of
small deletions, insertion of a transposable element in D. heteroneura, and
the existence of a highly variable region on the 3' side of the Adh gene.
Clustering relationships and rates of DNA change are calculated and
compared with the relationship found for other species of Drosophila.
相似文献