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1.
High level of divergence of male-reproductive-tract proteins, between Drosophila melanogaster and its sibling species, D. simulans 总被引:1,自引:0,他引:1
We compared male-reproductive-tract polypeptides of Drosophila melanogaster
and D. simulans by using two-dimensional gel electrophoresis. Approximately
64% of male-reproductive-tract polypeptides were identical between two
randomly chosen isofemale lines from these two species, compared with 83%
identity for third-instar imaginal wing-disc polypeptides. Qualitatively
similar differences were found between reproductive tracts and imaginal
discs when D. sechellia was compared with D. melanogaster and with D.
simulans. When genic polymorphism was taken into account, approximately 10%
of male- reproductive-tract polypeptides were apparently fixed for
different alleles between D. melanogaster and D. simulans; this proportion
is the same as that found for soluble enzymes by one-dimensional gel
electrophoresis. Strikingly, approximately 20% of male-reproductive- tract
polypeptides of either D. melanogaster or D. simulans had no detectable
homologue in the other species. We propose that proteins of the Drosophila
male reproductive tract may have diverged more extensively between species
than have other types of proteins and that much of this divergence may
involve large changes in levels of polypeptide expression.
相似文献
2.
3.
A new method specific for the determination of subpicomole quantities of tryptophan has been developed by elaboration of the Pictet-Spengler reaction. It permitted reproducible quantitation of tryptophan in less than 1 μl of plasma ultrafiltrate or 1 mg of brain tissue. Samples deproteinized by trichloroacetic acid were boiled for 15 min with formaldehyde and potassium ferricyanide at controlled acidity, where tryptophan was converted to a single new product identified as 9-hydroxymethyl-β-carboline. It was quantitated by either direct spectrofluorometry or a reversed-phase HPLC system developed for β-carbolines. Under our conditions, peptides containing N-terminal tryptophan such as Trp-Leu and delta sleep-inducing peptide gave N-(9-hydroxymethyl-β-carboline-3-carbonyl) peptides which retained all amino acid residues except tryptophan. 相似文献
4.
G. K. Haines G. D. Ghadge S. Becker M. Kies H. Pelzer B. Thimmappaya J. A. Radosevich 《Virchows Archiv. B, Cell pathology including molecular pathology》1993,63(1):289-295
p68 is an inducible protein kinase which is believed to be an important factor in the regulation of both viral and cellular
protein synthesis. We have produced a monoclonal antibody (TJ4C4) which specifically detects p68, and which can be used to
detect this antigen in formalin-fixed, paraffin-embedded tissues. Because p68 plays an important role in cellular protein
synthesis, we hypothesized that it may correlate with normal and neoplastic cellular differentiation. One hundred and seventy-seven
head and neck squamous cell carcinoma specimens, representing 82 patients, were studied. The relative amount, frequency, and
distribution of p68 expression were determined by microscopic evaluation of ABC immunoperoxidase-stained specimens. A spectrum
of immunoreactivity was detected in 156 of 177 tumors, as well as within the normal squamous epithelium. Normal, actively
proliferating cells, such as the basal layer of squamous epithelium, expressed comparatively little p68. Increased p68 expression
was noted to parallel the morphologic features of cellular differentiation. In neoplastic tissue, p68 expression also increased
with the degree of cellular differentiation. These data demonstrate that the expression of p68 parallels the degree of cellular
differentiation in squamous cell carcinoma of the head and neck region, as well as within normal squamous mucosa. Therefore,
p68 may provide an objective biologic measure of cellular differentiation which does not depend on morphologic features. 相似文献
5.
G. D. Ghadge A. M. Bodhe S. T. Dhume M. V. Rele H. G. Vartak 《Journal of biosciences》1984,6(1):135-145
A simple apparatus for vertical.,in situ, polyacrylamide or agarose gel casting as well as for the subsequent electrophoresis is described. The apparatus is completely
leakproof and does not require any special device like clamps, O-rings, gaskets, grease etc. for sealing. Slab gels of various
thickness (0.04 to 1.0 cm) can be made and the apparatus can be used for analytical or preparative purposes. Gel rods can
also be cast and run in the device. Forward as well as reverse polarity electrophoresis of a sample can be run simultaneously
in the apparatus.
NCL Communication No.: 3077. 相似文献
6.
RS Fisher 《The Journal of general physiology》1977,69(5):571-604
When the outer surface of short-circuited frog skin was penetrated with microelectrodes, stable negative potentials that averaged near -100 mV were recorded consistently, confirming the results of Nagel (W. Nagel. 1975. Abstracts of the 5th International Biophysics Congress, Copenhagen. P-147.). The appearance of these stable potentials, V(O), concurrent with the observations that (a) a high resistance outer barrier R(O) accounting for approximately 75 percent or more of the transcellular resistance of control skins had been penetrated and that (b) 10(-5) M amiloride and reduced [Na] outside caused the values of V(O) to increase towards means value near -130 mV while the values of percent R(O) increased to more than 90 percent. It was of relationships were the same as the values of E(1) observed in studies of the current-voltage relationships were the same as the values of E’(1) defined as the values of voltage at the inner barrier when the V(O) of the outer barrier was reduced to zero by voltage clamping of the skins. Accordingly, these data are interpreted to mean that the values of E(1), approximately 130 mV, represent the E(Na) of the sodium pump at the inner barrier. 2,4-DNP was observed to decrease the values of transepithelial voltage less than E(1) the V(O) was negative. These data can be interpreted with a simple electrical equivalent circuit of the active sodium transport pathway of the frog skin that includes the idea that the outer membrane behaves as an electrical rectifier for ion transport. 相似文献
7.
Sarah E. Antinone Ghanashyam D. Ghadge Tukiet T. Lam Lijun Wang Raymond P. Roos William N. Green 《The Journal of biological chemistry》2013,288(30):21606-21617
Mutations in Cu,Zn-superoxide dismutase (mtSOD1) cause familial amyotrophic lateral sclerosis (FALS), a neurodegenerative disease resulting from motor neuron degeneration. Here, we demonstrate that wild type SOD1 (wtSOD1) undergoes palmitoylation, a reversible post-translational modification that can regulate protein structure, function, and localization. SOD1 palmitoylation was confirmed by multiple techniques, including acyl-biotin exchange, click chemistry, cysteine mutagenesis, and mass spectrometry. Mass spectrometry and cysteine mutagenesis demonstrated that cysteine residue 6 was the primary site of palmitoylation. The palmitoylation of FALS-linked mtSOD1s (A4V and G93A) was significantly increased relative to that of wtSOD1 expressed in HEK cells and a motor neuron cell line. The palmitoylation of FALS-linked mtSOD1s (G93A and G85R) was also increased relative to that of wtSOD1 when assayed from transgenic mouse spinal cords. We found that the level of SOD1 palmitoylation correlated with the level of membrane-associated SOD1, suggesting a role for palmitoylation in targeting SOD1 to membranes. We further observed that palmitoylation occurred predominantly on disulfide-reduced as opposed to disulfide-bonded SOD1, suggesting that immature SOD1 is the primarily palmitoylated species. Increases in SOD1 disulfide bonding and maturation with increased copper chaperone for SOD1 expression caused a decrease in wtSOD1 palmitoylation. Copper chaperone for SOD1 overexpression decreased A4V palmitoylation less than wtSOD1 and had little effect on G93A mtSOD1 palmitoylation. These findings suggest that SOD1 palmitoylation occurs prior to disulfide bonding during SOD1 maturation and that palmitoylation is increased when disulfide bonding is delayed or decreased as observed for several mtSOD1s. 相似文献
8.
Paula H Suss Luiz Guilherme A Capriglione Fabiane Barchiki Lye Miyague Danielle Jackowski Letícia Fracaro Andressa V Schittini Alexandra C Senegaglia Carmen LK Rebelatto Márcia Olandoski Alejandro Correa Paulo RS Brofman 《Experimental biology and medicine (Maywood, N.J.)》2015,240(7):969-978
The development of new therapeutic strategies is necessary to reduce the worldwide social and economic impact of cardiovascular disease, which produces high rates of morbidity and mortality. A therapeutic option that has emerged in the last decade is cell therapy. The aim of this study was to compare the effect of transplanting human umbilical cord-derived stromal cells (UCSCs), human umbilical cord blood-derived endothelial cells (UCBECs) or a combination of these two cell types for the treatment of ischemic cardiomyopathy (IC) in a Wistar rat model. IC was induced by left coronary artery ligation, and baseline echocardiography was performed seven days later. Animals with a left ventricular ejection fraction (LVEF) of ≤40% were selected for the study. On the ninth day after IC was induced, the animals were randomized into the following experimental groups: UCSCs, UCBECs, UCSCs plus UCBECs, or vehicle (control). Thirty days after treatment, an echocardiographic analysis was performed, followed by euthanasia. The animals in all of the cell therapy groups, regardless of the cell type transplanted, had less collagen deposition in their heart tissue and demonstrated a significant improvement in myocardial function after IC. Furthermore, there was a trend of increasing numbers of blood vessels in the infarcted area. The median value of LVEF increased by 7.19% to 11.77%, whereas the control group decreased by 0.24%. These results suggest that UCSCs and UCBECs are promising cells for cellular cardiomyoplasty and can be an effective therapy for improving cardiac function following IC. 相似文献
9.
Patients with systemic autoimmune diseases usually produce high levels of antibodies to self-antigens (autoantigens). The
repertoire of common autoantigens is remarkably limited, yet no readily understandable shared thread links these apparently
diverse proteins. Using computer prediction algorithms, we have found that most nuclear systemic autoantigens are predicted
to contain long regions of extreme structural disorder. Such disordered regions would generally make poor B cell epitopes
and are predicted to be under-represented as potential T cell epitopes. Consideration of the potential role of protein disorder
may give novel insights into the possible role of molecular mimicry in the pathogenesis of autoimmunity. The recognition of
extreme autoantigen protein disorder has led us to an explicit model of epitope spreading that explains many of the paradoxical
aspects of autoimmunity – in particular, the difficulty in identifying autoantigen-specific helper T cells that might collaborate
with the B cells activated in systemic autoimmunity. The model also explains the experimentally observed breakdown of major
histocompatibility complex (MHC) class specificity in peptides associated with the MHC II proteins of activated autoimmune
B cells, and sheds light on the selection of particular T cell epitopes in autoimmunity. Finally, the model helps to rationalize
the relative rarity of clinically significant autoimmunity despite the prevalence of low specificity/low avidity autoantibodies
in normal individuals. 相似文献
10.
EFFECTS OF HUMAN ACTIVITIES ON STRUCTURE AND COMPOSITION OF WOODY SPECIES OF THE NOKREK BIOSPHERE RESERVE OF MEGHALAYA,NORTHEAST INDIA
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Aims Our study was conducted in the Nokrek Biosphere Reserve (NBR) in the Garo hills districts of Meghalaya, Northeast India. Our aim was to assess the effects of human activities on plant diversity,population structure and regeneration.Methods We selected a representative 1.2 hm2 stand in both the core and buffer zones of NBR. Structure and composition were determined by randomly sampling square quadrats, population structure was assessed by determining age structure, and regeneration was assessed by measuring densities of seedling, sapling and adult trees.Important findings More woody species were recorded from the core zone than the buffer zone (87 vs. 81 species), and there were a large number of tropical, temperate, and Sino-Himalayan, Burma-Malaysian and Malayan elements, primitive families and primitive genera. The trees were distributed in three distinct strata,canopy, subcanopy and sapling. Subcanopy and sapling layers had the highest species richness (81% -88% ). Lauraceae and Euphorbiaceae were the dominant families in terms of the number of species, and a large number of families were represented by single species. Most woody species (57 % - 79 % ) were contagiously distributed and had low frequency ( < 20% ). Although stand density was high in the buffer zone, its basal area was low compared to the stand in the core zone. Low similarity and high β-diversity indicate marked differences in species composition of the stands. Shannon diversity index was high in both the stands, while Simpson dominance index was low. The diameter-class distribution for dominant species revealed that the most had a large number of young individuals in their populations. Preponderance of tree seedlings, followed by a steep decline in population density of saplings and adult trees, indicated that the seedling to sapling stage was the most critical in the life cycle of the tree populations. Most species (42 % - 48 % ) had no regeneration,25 % - 35 % had good/fair regeneration, and the rest had poor regeneration or reoccurred as immigrants. 相似文献