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11.
A candidate gene family for the mouse t complex responder (Tcr) locus responsible for haploid effects on sperm function 总被引:4,自引:0,他引:4
The mouse t complex responder (Tcr) locus plays a central haploid-specific role in the transmission ratio distortion phenotype expressed during germ cell differentiation in t-carrying males. The accumulated data map Tcr to a region of less than 500 kb. Over 400 kb of this region has been cloned and consists entirely of sequences associated with a clustered family of large cross-hybridizing elements of 30 kb to 70 kb in size. We have characterized a gene family within this region that is expressed uniquely in male germ cells with a complex pattern of RNA processing. Antibodies produced against a product of the putative open reading frame recognize a testes-specific polypeptide. Genetic data support the hypothesis that this polypeptide(s) functions to effect the Tcr phenotype. 相似文献
12.
A J Marcus L B Safier H L Ullman N Islam M J Broekman J R Falck S Fischer C von Schacky 《The Journal of biological chemistry》1988,263(5):2223-2229
In the course of a cell-cell interaction, 12-HETE (12-hydroxy-5,8,10,14-eicosatetraenoic acid), the arachidonic acid lipoxygenase product released from stimulated platelets, is metabolized by a cytochrome P-450 enzyme system in unstimulated neutrophils to 12,20-DiHETE (12,20-dihydroxy-5,8,10,14-eicosatetraenoic acid). This report describes time-dependent formation of a new eicosanoid by unstimulated neutrophils exposed to 12-HETE, which is more polar than 12,20-DiHETE (reversed-phase high performance liquid chromatography). Time course studies indicated that the precursor compound of this new eicosanoid was 12,20-DiHETE. This was determined by incubation of purified 12,20-DiHETE with neutrophils, which resulted in a progressive decrease in 12,20-DiHETE as formation of the polar metabolite increased. In the absence of neutrophils, 12,20-DiHETE was quantitatively unchanged. The new metabolite of 12,20-DiHETE was identified as 12-hydroxyeicosatetraen-1,20-dioic acid, based upon its UV spectrum, co-chromatography with a chemically synthesized standard in both high performance liquid chromatography and thin layer chromatography systems, and gas chromatography-mass spectrometry. Formation of 12-HETE-1,20-dioic acid was partially inhibited by 20-hydroxy-LTB4. This indicated that the neutrophil dehydrogenase responsible for further metabolism of 12,20-DiHETE may also be involved in conversion of 20-hydroxy-LTB4 to 20-carboxy-LTB4. The 12,20-DiHETE dehydrogenase enzyme system specifically requires NAD as cofactor and has subcellular components in both cytosolic and microsomal fractions which are synergistic in their activity. These results provide additional evidence for the occurrence of multicellular metabolic events during hemostasis, thrombosis, and the inflammatory response. 相似文献
13.
Alia Islam Obaid Ullah Beg Bengt Persson Zafar H. Zaidi Hans Jörnvall 《The protein journal》1988,7(5):561-569
The structure of the hernoglobin α-chain of Rose-ringed Parakeet was determined by sequence degradations of the intact subunit, the CNBr fragments, and peptides obtained by digestion with staphylococcal Glu-specific protease and trypsin. Using this analysis, the complete α-chain structure of 21 avian species is known, permitting comparisons of the protein structure and of avian relationships. The structure exhibits differences from previously established avian α-chains at a total of 61 positions, five of which have residues unique to those of the parakeet (Ser-12, Gly-65, Ser-67, Ala-121, and Leu-134). The analysis defines hemoglobin variation within an additional avian order (Psittaciformes), demonstrates distant patterns for evaluation of relationships within other avian orders, and lends support to taxonomic conclusions from molecular data. 相似文献
14.
Spatial Distribution of Flavonoid Conjugates in Relation to Glucosyltransferase and Sulfotransferase Activities in Flaveria bidentis 总被引:2,自引:2,他引:0 下载免费PDF全文
The spatial distribution of sulfated and glucosylated flavonols as well as of the enzymes involved in the later steps of their biosynthesis, sulfotransferase and glucosyltransferase, were investigated in the shoots of Flaveria bidentis. The highest amounts of both types of flavonoid conjugates (as micromole per gram fresh weight) and the highest activities of their enzymes (as picokat per milligram) were detected in the terminal bud and the first pair of leaves. Sulfotransferase activity was also highest in the upper stem segments and in the basal section of the leaves. Western blot analysis of protein extracts showed that variations in sulfotransferase activity in different tissues correlate well with the amounts of immunodetected enzyme protein. These results were discussed in relation to the possible role of conjugated flavonoids in plant growth. 相似文献
15.
16.
K S Islam 《Journal of helminthology》1986,60(4):301-306
The development of Trichobilharzia australis Blair & Islam, 1983 in the intermediate host, Lymnaea lessoni Deshayes and in experimental definitive hosts, Muscovy ducks is described. 24 hours after entry into the snail, miracidia had lost their cilia, epidermal plates and lateral processes and became young mother sporocysts. They were located in the tissues of the head-foot organ of the snail and were oval in cross section but still retained the shape of a miracidium, and measured 0.058-0.066 X 0.041-0.049 mm. From the seventh day onward young mother sporocysts were tubular, thin-walled, irregular in shape and were in the tissues of the lung and kidney of the snail. On the 24th day mature mother sporocysts and young daughter sporocysts were found in the digestive gland. Between the 24th and 29th day mature daughter sporocysts with fully developed cercariae ready to emerge, or already emerged, could be seen in the digestive gland of the snail. Cercariae emerged from the snail from the 29th to 46th day after exposure at 25 degrees +/- 1 degree C. The prepatent period of T. australis in the Muscovy ducks was 22 to 42 days after the beginning of exposure to cercariae. 相似文献
17.
New isolates of spore-forming bacilli from larvae and pupae of 3 species of mosquitoes are recorded in central Iraq.Bacillus sphaericus Meyer and Neide was isolated fromCulex pipiens (L.) larva.Bacillus carotarum Koch andBacillus cereus Frankland & Frankland were isolated fromTheobaldia longiareolata (Macquart) pupae.Bacillus laterosporus Laubach andBacillus thuringiensis (H 18) were isolated fromAedes caspius (Pallas) larvae. In addition, unidentifiedBacillus spp. were isolated fromCx. pipiens, T. longiareolata andAe. caspius larvae. Examination of soil samples collected from mosquito natural breeding habitats revealed isolates ofB. cereus, Bacillus thuringiensis H4a 4b; H 12 and H 16 and an unidentifiedBacillus sp.
Résumé Des souches bactériennes sporogènes sont isolées de moustiques qui se trouvent dans la région centrale de l'Irak. Les résultats obtenus sont les suivants:Bacillus sphaericus Meyer & Neide [Culex pipiens (L.), larve],Bacillus carotarum Koch etBacillus cereus Frankland & Frankland [Theobaldia longiareolata (Macquart), nymphe],Bacillus laterosporus Laubach etBacillus thuringiensis (H 18) [Aedes caspius (Pallas), larvel]. L'examen des larves deCulex pipiens. T. longiareolata etAe. caspius, ainsi que l'analyse des échantillons du sol prélevés dans la région montrent la présence deBacillus cereus, Bacillus thuringiensis H4a 4b; H12 plus H16 et d'autresBacillus non identifiés.相似文献
18.
The mast cells of the mammalian central nervous system. IX. Development of the mast cells in the brain of the young rat 总被引:1,自引:0,他引:1
M Z Ibrahim 《Acta anatomica》1985,124(3-4):149-158
There are four potentially granular or frankly granular cells within the connective tissue compartment of the mammalian central nervous system, whether this is part of the surface leptomeninges or the leptomeningeal sleeves around parenchymal blood vessels larger than capillaries. These are: Cells that behave like macrophages, part of the mononuclear phagocyte system of the body; they are granular to varying degrees (containing lysosomes). Brown-pigmented granular cells which are mainly located on the surface but are also seen for varying distances along blood vessels as they pass inside the CNS of pigmented animals. Mast cells (MCs) which are granular and located especially prominently in surface leptomeninges of young mammals, and, in adults, are restricted to special parts of the CNS. Granular cells, referred to by me as neurolipomastocytoid cells (NLMs), are numerous, ubiquitously distributed, and seem to have morphological features in common with those of both MCs and macrophages. The exact identity of these NLMs still needs to established. One approach was to study the development of all three non-pigmented cells in the immature brain of the albino rat, especially at the ultrastructural level. This communication represents the findings regarding the MCs. The MCs appear to arise from a small mononuclear cell and to go through maturation stages identical to those described by others for MCs outside the CNS. The greatly flattened adjacent leptomeningeal cells are an easily identifiable entity especially due to their peculiar glycogen content in the young. 相似文献
19.
Austin K. Mircheff Dennis J. Ahnen Anisul Islam Nilda A. Santiago Gary M. Gray 《The Journal of membrane biology》1985,83(1-2):95-107
Summary Current procedures for isolating intestinal epithelial cell surface and intracellular membranes are based on the assumption that each organelle is marked by some unique constitutent. This assumption seemed inconsistent with the dynamic picture of subcellular organization emerging from studies of membrane turnover and recycling. Therefore, we have designed an alternative fractionation which is independent ofa priori marker assignments. We subjected mucosal homogenates to a sequence of separations based on sedimentation coefficient, equilibrium density, and partitioning in aqueous polymer twophase systems. The resulting distributions of protein and enzymatic markers define a total of 17 physically and biochemically distinct membrane populations. Among these are: basal-lateral membranes, with Na,K-ATPase enriched 21-fold; brush-border membranes, with alkaline phosphatase enriched as much as 38-fold; two populations apparently derived from the endoplasmic reticulum; a series of five populations believed to have been derived from the Golgi complex; and a series of five acid phosphatase-rich populations which we cannot identify unequivocally. Each of the five enzymatic markers we have followed is associated with a multiplicity of membrane populations. Basallateral, endoplasmic reticulum, and Golgi membranes contain alkaline phosphatase at the same specific activity as the initial homogenate. Similarly, Na,K-ATPase appears to be associated branes at specific activities two-to seven-fold that of the initial homogenate. 相似文献
20.
K. E. Ibrahim M. W. Couch C. M. Williams M. J. Fregly J. M. Midgley 《Journal of neurochemistry》1985,44(6):1862-1867
The development of a radiochemical enzyme assay for p-octopamine in 1969 led to its identification in a large number of invertebrate nerve systems and in mammalian sympathetic nerves. The original method by which p-octopamine was measured has now been found to be nonspecific; however, modifications of this procedure can determine both m- and p-octopamine. We recently developed a new specific method for the unequivocal identification and quantitative determination in tissue of the six octopamine and synephrine isomers. With this method--negative chemical ionization gas chromatography-mass spectrometry--the more physiologically active m-octopamine has been found in association with p-octopamine in 10 organs of the rat. m-Octopamine is present in concentrations equal to those of p-octopamine in heart, spleen, and liver and in concentrations from 30 to 60% of p-octopamine in adrenals, vas deferens, brain, kidney, large intestine, bladder, and lungs. In vivo inhibition of monoamine oxidase markedly increased the concentrations of both m- and p-octopamine in all organs examined. Both amines were virtually absent from all organs except the adrenals following chemical sympathectomy with 6-hydroxydopamine, thereby establishing that m- and p-octopamine are localized within sympathetic nerve endings. 相似文献