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1.
A total of 901 cumulus-oocyte complexes (COCs) were collected from bovine ovaries obtained at a local abattoir. COCs randomly assigned to Treatment I (n = 451), were cultured in TCM-199 + 10% fetal bovine serum (FBS) and hormones, while oocytes in Treatment II (n = 450) were cultured in TCM-199 + 20% estrous cow serum (ECS). Assessment of maturation revealed that 91.3% (42/46) of oocytes in Treatment I had reached metaphase II of meiosis, which was greater (P less than 0.05) than the 73.3% (33/45) in Treatment II. Following in vitro fertilization, 203 oocytes from Treatment I were co-cultured on bovine granulosa cells (Treatment IA) while the remaining 202 oocytes were co-cultured on bovine oviductal cells (Treatment IB). Similarly, 203 oocytes from Treatment II were co-cultured on granulosa cells (Treatment IIA) or oviductal cells (Treatment IIB, n = 202). Co-culture was maintained for 8 days. The proportion of cleaved zygotes was higher (P less than 0.05) in Treatment IB (86.6%) compared to Treatments IA (78.8%), IIA (58.1%), and IIB (64.8%). The proportion of cleaved zygotes that progressed beyond the 16-cell stage was also greater (P less than 0.001) in Treatment IB (71.4%) compared to Treatments IA (50.0%), IIA (35.4%) and IIB (55.8%). Treatment IB also produced the highest proportion of blastocysts (P less than 0.0001) (41.1%) versus 24.6% (IA), 11.3% (IIA) and 18.3% (IIB). The proportion of day 6 morulae that progressed to form day 8 blastocysts was similar for both co-culture treatments (IA, 70.1%; IB 70.2%; IIA, 51.5%; IIB 50.8%) and varied only between in vitro maturation groups.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

2.
Type IIA and type IIB topoisomerases each possess the ability to pass one DNA duplex through another in an ATP-dependent manner. The role of ATP in the strand passage reaction is poorly understood, particularly for the type IIB (topoisomerase VI) family. We have solved the structure of the ATP-binding subunit of topoisomerase VI (topoVI-B) in two states: an unliganded monomer and a nucleotide-bound dimer. We find that topoVI-B is highly structurally homologous to the entire 40-43 kDa ATPase region of type IIA topoisomerases and MutL proteins. Nucleotide binding to topoVI-B leads to dimerization of the protein and causes dramatic conformational changes within each protomer. Our data demonstrate that type IIA and type IIB topoisomerases have descended from a common ancestor and reveal how ATP turnover generates structural signals in the reactions of both type II topoisomerase families. When combined with the structure of the A subunit to create a picture of the intact topoisomerase VI holoenzyme, the ATP-driven motions of topoVI-B reveal a simple mechanism for strand passage by the type IIB topoisomerases.  相似文献   

3.
Rat liver mitochondria and cytosol contain two types of 3-ketothiolases, namely 3-ketothiolases IA and IB, which cleave 3-ketoacyl-coenzyme A (CoA) esters containing four or more carbons and 3-ketothiolases IIA and IIB, which cleave 3-ketoacyl-CoA esters containing four carbons, i.e. acetoacetyl-CoA (Aragon, J.J., and Lowenstein, J.M. (1983) J. Biol. Chem. 258, 4725-4733). We now report that rat liver peroxisomes also contain 3-ketothiolases IA and IB and show that incubation of hepatocytes with 2-chloro-6-phenylhexanoate causes the selective inactivation of peroxisomal and cytosolic 3-ketothiolase IB, while mitochondrial 3-ketothiolases are not appreciably affected. The basis of the selectivity of the inhibitor for peroxisomal and cytosolic 3-ketothiolases can be accounted for in terms of the specificities of the enzymes in the different pathways of beta-oxidation. Evidence is presented that 2-chloro-6-phenylhexanoate is metabolized to 2-chloro-3-keto-6-phenylhexanoyl-CoA, which then alkylates 3-ketothiolase and thereby inactivates the enzyme. Evidence is presented which suggests that cytosolic 3-ketothiolases IA and IB are not artifacts of homogenization and organelle preparation.  相似文献   

4.
Type II DNA topoisomerases are divided into two families, IIA and IIB. Types IIA and IIB enzymes share homologous B subunits encompassing the ATP-binding site, but have non-homologous A subunits catalyzing DNA cleavage. Type IIA topoisomerases are ubiquitous in Bacteria and Eukarya, whereas members of the IIB family are mostly present in Archaea and plants. Here, we report the detection of genes encoding type IIB enzymes in which the A and B subunits are fused into a single polypeptide. These proteins are encoded in several bacterial genomes, two bacterial plasmids and one archaeal plasmid. They form a monophyletic group that is very divergent from archaeal and eukaryotic type IIB enzymes (DNA topoisomerase VI). We propose to classify them into a new subfamily, denoted DNA topoisomerase VIII. Bacterial genes encoding a topoisomerase VIII are present within integrated mobile elements, most likely derived from conjugative plasmids. Purified topoisomerase VIII encoded by the plasmid pPPM1a from Paenibacillus polymyxa M1 had ATP-dependent relaxation and decatenation activities. In contrast, the enzyme encoded by mobile elements integrated into the genome of Ammonifex degensii exhibited DNA cleavage activity producing a full-length linear plasmid and that from Microscilla marina exhibited ATP-independent relaxation activity. Topoisomerases VIII, the smallest known type IIB enzymes, could be new promising models for structural and mechanistic studies.  相似文献   

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7.
Both genomic and cDNA clones encoding a precursor for a pregnancy-specific beta 1-glycoprotein (PS beta G) belonging to the CEA family, expressed in a human promyelocytic leukemia cell line, HL-60, have been isolated and the entire primary structure of the precursor is deduced. The 335-AA precursor has a 34-AA signal peptide followed by domains of N, IIA, IIB and C, which are encoded by separate exons. The genomic sequence contains extra exons IA and IB between exons N and IIA. Apparently, exon IA is excluded from the mRNA by alternative splicing while IB is a pseudo-exon having a stop codon formed by a deletion of dinucleotide in the middle of the sequence. This provides another mechanism to render exon IB abortive and is different from that we reported for another PS beta G (Biochem. Biophys. Res. Comm. (1988) 156, 68-77).  相似文献   

8.
Phenotypic and genetic characterization indicated that Hup+ bean rhizobial strains are type IIA and type IIB Rhizobium tropici. The Hup+ strain USDA 2840, which did not cluster with either of the two types of R. tropici in a restriction fragment length polymorphism analysis, had electrophoretic patterns of PCR products generated with primers for repetitive extragenic palindromic and enterobacterial repetitive intergeneric consensus sequences similar to those of three reference strains of R. tropici type IIA. The Hup+ strain USDA 2738, which clustered with the reference strain of R. tropici IIB in a restriction fragment length polymorphism analysis, had electrophoretic patterns of PCR products generated with primers for repetitive extragenic palindromic and enterobacterial repetitive intergeneric consensus sequences more closely resembling those of the reference strains of R. tropici type IIA than those of type IIB. DNA amplification with the Y1 and Y2 primers to generate a portion of the 16S rDNA operon was useful to distinguish R. tropici type IIA strains from other bean rhizobial strains. The phylogenetic position of the type IIA strain of R. tropici USDA 2840, determined from the partial 16S rDNA sequence, indicated a more distant relationship with the type IIB strain of R. tropici CIAT899 than with the as yet unnamed rhizobial species of Leucaena leucocephala, TAL 1145. Therefore, we suggest that it may be appropriate either to separate R. tropici types IIA and IIB into two different species or to identify TAL 1145 to the species level as a third type of R. tropici.  相似文献   

9.
The efficacy of cabergoline solely or combined with a PGF2alpha analogue in inducing abortion at different stages of pregnancy was investigated in 18 queens. The queens were assigned to two treatments: Group I ( n=10 )-cabergoline (15 microg/kg; daily, orally) and Group II ( n=8 )-cabergoline (15 microg/kg; daily, orally) combined with alfaprostol (10 microg/kg; every other day, subcutaneously). Each group was divided into two subgroups according to the duration of pregnancy when treatments started: Group IA ( n=8 ) included queens from Days 34 to 42 after mating. Group IB cats ( n=2 ) started treatments on Day 45 post-mating. Similarly, the combination of cabergoline and PGF2alpha analogue was first given to Group IIA ( n=6 ) from Days 25 to 40 of pregnancy and to Group IIB ( n=2 ) on Days 45 and 47, respectively. Termination of pregnancies was successful in all cats of Group IA, while treatments failed in both cats of Group IB, even though seven and eight treatments, respectively, were given. Mean (+/-S.D.) plasma progesterone concentrations before the start of treatments were 85.0+/-12.3 nmol/l and decreased within 3 days to 8 nmol/l and subsequently to basal values, when the queens aborted (Group IIA, n=6 ) or gave birth prematurely (Group IIB, n=2 ). When abortions failed (Group IB, n=2 ), progesterone concentrations remained elevated (16.9 and 9.8 nmol/l). Duration of combined therapy during late pregnancy in Group IIB ( n=2 ) lasted about 10 days. In both cases, premature birth occurred and the kittens died within 16 h after birth. Overall, treatments starting on Days 25-42 of pregnancy (Groups IA and IIA) had abortion rates of 100%. The average duration of treatments was 5.6+/-1.5 days (range, 3-8). Side effects seen were vomiting and occurred in 6 of the 109 (5.5%) treatments. In conclusion, pregnancies were successfully terminated in the second trimester of feline pregnancy by daily application of cabergoline solely or combined with the PGF2alpha analogue alfaprostol (given every other day). Cabergoline alone was ineffective in inducing abortion at later stages of pregnancy.  相似文献   

10.
Eight anionic disaccharide precursors of lipid A accumulate at 42 degrees C in 3-deoxy-D-manno-octulosonic acid-deficient temperature-sensitive mutants of Salmonella typhimurium. These compounds comprise a series of lipids based on the minimal structure, O-[2-amino-2-deoxy-N2,O3-bis(3-hydroxytetradecanoyl)-beta-D-glucopyranos yl] -(1----6)-2-amino-2-deoxy-N2, O3-bis(3-hydroxytetradecanoyl)-alpha-D-glucopyranose 1,4'- bisphosphate (designated lipid IVA) that differ from each other by the presence of an additional phosphoethanolamine moiety (IIIA), or an aminodeoxypentose moiety (IIA), or both (IA). A homologous set of metabolites is further derivatized with a palmitoyl function; these are designated IVB, IIIB, IIB, and IB (Raetz, C. R. H., Purcell, S., Meyer, M. V., Qureshi, N., and Takayama, K. (1985) J. Biol. Chem. 260, 16080-16088). The attachment of the palmitoyl moiety, known to be on the reducing terminal GlcN residue by mass spectrometry, was determined to be O-beta of the N2-linked beta-hydroxymyristoyl group of that residue of IVB by 13C NMR and two-dimensional 1H chemical shift correlation spectroscopy experiments. 31P NMR indicated the presence of diphosphodiester moieties in IIIA, IIIB, and IA and monophosphodiester moieties in IIA and IA. Selective 1H decoupling of the 31P spectrum of IIIA demonstrated that the O-diphosphoethanolamine moiety is attached to the O4' position in IIIA. On the basis of the observed 31P chemical shifts it was concluded that the aminodeoxypentose is located at position 1 in IIA and IA, while diphosphoethanolamine is most likely located at O-4' in IA and IIIB, as in IIIA.  相似文献   

11.
目的:观察宫颈癌组织中Th1/Th2类细胞因子的漂移情况。方法:选以IL-2和IFN-γ代表Th1类细胞因子,IL-4和IL-6代表Th2类细胞因子,通过逆转录聚合酶链反应(RT-PCR)检测25例宫颈癌癌组织中Th1/Th2类细胞因子mRNA的表达。结果:IIIB期宫颈癌组织中,Th1型细胞因子的表达显著低于IB期、IIA期、IIB期,Th2型细胞因子的表达显著高于IB期、IIA期、IIB期,差异均有统计学意义(P0.05)。Ⅰ期和Ⅱ期宫颈癌以Th1型细胞因子表达为主。25例宫颈癌组织中,13例呈典型的Th1类细胞因子的强势表达,7例为Th2型,5例为Th0型,随着宫颈癌分期的增高,由Th1向Th2漂移(P0.05)。结论:IB期、IIA期、IIB期宫颈癌患者组织中细胞因子呈Th1状态,IIIA期呈Th0状态,IIIB期呈Th2状态,随着宫颈癌分期的增高,由Th1向Th2漂移。  相似文献   

12.
This study was designed to test whether Mucuna pruriens, a natural source of l-dihydroxyphenylalanine (l-DOPA, a dopamine precursor) feeding, can influence development and reproductive conditions in the high food value bird, Japanese quail, Coturnix coturnix japonica. Experiments were performed in both male and female Japanese quail. One-week-old quail chicks were divided into three groups of 36 birds each. Group I was provided with normal diet and served as control. Group II was provided with food mixed with l-DOPA (50 mg/15 g food) and Group III was provided with food mixed with M. pruriens seed powder (480 g/kg food). At the age of 3 weeks (when birds were sexually distinguished) Group I was divided into two sub-groups IA (male) and IB (female) of six birds each. Similarly, Groups II and III were sub-divided into IIA (male), IIB (female) and IIIA (male), IIIB (female), respectively, of six birds each. Observations were made up to the age of 5 weeks. Male experimental groups (IIA and IIIA) showed significantly increased testicular activity, cloacal gland volume, body weight (BW), plasma testosterone and LH level in comparison to control (IA). Similarly female experimental groups (IIB and IIIB) showed significantly greater weight of reproductive organs (uterus, ovary, oviduct and ovarian follicle), BW, egg weight and size and number of follicles. On the other hand, plasma prolactin level was significantly low in comparison to control (IB). Results suggest that M. pruriens is a rich natural source of l-DOPA and the development and reproduction in Japanese quail might be associated with the dopaminergic system of the brain.  相似文献   

13.
Three monoclonal antibodies, LM5, F2 and F39 raised to chicken fast skeletal muscle myosin, specific for myosin heavy chain (MHC) subunit, were used to study the composition and distribution of this protein in some vertebrate skeletal muscles. These antibodies in immunohistochemical investigations did not react with the majority of the type I fibres in most muscles. Antibodies LM5 and F39 stained all the type II fibres in all the adult chicken skeletal muscles studied. Antibody F2 also stained all the type II fibres in most chicken skeletal muscles tested except in gastrocnemius in which a proportion of both the type IIA and IIB fibres either did not stain or stained only weakly. Antibody F2 unlike LM5 and F39 stained most of the type IIIB fibres in anterior latissimus dorsi (ALD) and IB fibres in red strip of chicken Pectoralis muscle. Antibodies LM5 and F2 in the rat diaphragm reacted with all the type IIA and IIB fibres, while antibody F39 stained only the type IIB fibres darkly with most IIA fibres being either not stained or only weakly stained. In the rat extensor digitorum longus (EDL) and tibialis anterior (TA) muscles, antibody LM5 stained all the IIA and IIB fibres. Antibody F2 in these muscles stained all the type IIA fibres but only a proportion of the IIB fibres. The remaining IIB fibres were either unstained or only weakly positive. Antibody F39 in rat EDL and TA muscles did not only distinguish subgroups of IIB fibres (dark, intermediate and negative or very weak) but also of the IIA fibres. These three antibodies used together therefore detected a great deal of heterogeneity in the myosin heavy chain composition and muscle fibre types of several skeletal muscles.  相似文献   

14.
Summary Three monoclonal antibodies, LM5, F2 and F39 raised to chicken fast skeletal muscle myosin, specific for myosin heavy chain (MHC) subunit, were used to study the composition and distribution of this protein in some vertebrate skeletal muscles. These antibodies in immunohistochemical investigations did not react with the majority of the type I fibres in most muscles. Antibodies LM5 and F39 stained all the type II fibres in all the adult chicken skeletal muscles studied. Antibody F2 also stained all the type II fibres in most chicken skeletal muscles tested except in gastrocnemius in which a proportion of both the type IIA and IIB fibres either did not stain or stained only weakly. Antibody F2 unlike LM5 and F39 stained most of the type IIIB fibres in anterior latissimus dorsi (ALD) and IB fibres in red strip of chicken Pectoralis muscle. Antibodies LM5 and F2 in the rat diaphragm reacted with all the type IIA and IIB fibres, while antibody F39 stained only the type IIB fibres darkly with most IIA fibres being either not stained or only weakly stained. In the rat extensor digitorum longus (EDL) and tibialis anterior (TA) muscles, antibody LM5 stained all the IIA and IIB fibres. Antibody F2 in these muscles stained all the type IIA fibres but only a proportion of the IIB fibres. The remaining IIB fibres were either unstained or only weakly positive. Antibody F39 in rat EDL and TA muscles did not only distinguish subgroups of IIB fibres (dark, intermediate and negative or very weak) but also of the IIA fibres. These three antibodies used together therefore detected a great deal of heterogeneity in the myosin heavy chain composition and muscle fibre types of several skeletal muscles.  相似文献   

15.
The aim of our study was to determine the in vitro developmental potential of porcine nuclear-transferred (NT) embryos that had been reconstructed with Tg(pWAPhGH-GFPBsd) transgene-expressing fibroblast cells. The gene construct was introduced into fibroblast cells by the novel method of nucleofection or standard lipofection. NT oocytes derived from foetal and adult dermal fibroblast cells were stimulated by either simultaneous fusion and electrical activation (Groups IA and IB) or sequential electrical and chemical activation (Groups IIA and IIB). The percentages of cloned embryos that reached the morula and blastocyst stages were 152/254 (59.8%) and 77/254 (30.3%) or 139/276 (50.4%) and 45/276 (16.3%) in Groups IA or IB, respectively. The rates of NT embryos that developed to the morula and blastocyst stages were 103/179 (57.5%) and 41/179 (22.9%) or 84/193 (43.5%) and 27/193 (14.0%) in Groups IIA and IIB, respectively. In conclusion, the in vitro developmental competences of porcine transgenic NT embryos that had been reconstructed with the Tg(pWAPhGH-GFPBsd) gene-transfected fibroblast cells were relatively high. Further, the nucleofection efficiency of all the porcine fibroblast cell lines as estimated by intra-vitam fluorescent evaluation based on the index of reporter eGFP transgene expression was nearly 100%. However, PCR analysis for transgene screening confirmed the absence of Tg(pWAPhGH-GFPBsd) fusion gene in some of the nucleofected cell lines. To our knowledge, the novel method of nucleofection is the first to transfect nuclear donor cells in the production of transgenic cloned embryos.  相似文献   

16.
The present study investigates the effect of particle size on compaction behavior of forms I and II of ranitidine hydrochloride. Compaction studies were performed using three particle size ranges [450–600 (A), 300–400 (B), and 150–180 (C) μm] of both the forms, using a fully instrumented rotary tableting machine. Compaction data were analyzed for out-of-die compressibility, tabletability, and compactibility profiles and in-die Heckel and Kawakita analysis. Tabletability of the studied size fractions followed the order; IB > IA > > IIC > IIB > IIA at all the compaction pressures. In both the polymorphs, decrease in particle size improved the tabletability. Form I showed greater tabletability over form II at a given compaction pressure and sized fraction. Compressibility plot and Heckel and Kawakita analysis revealed greater compressibility and deformation behavior of form II over form I at a given compaction pressure and sized fraction. Decrease in particle size increased the compressibility and plastic deformation of both the forms. For a given polymorph, improved tabletability of smaller sized particles was attributed to their increased compressibility. However, IA and IB, despite poor compressibility and deformation, showed increased tabletability over IIA, IIB, and IIC by virtue of their greater compactibility. Microtensile testing also revealed higher nominal fracture strength of form I particles over form II, thus, supporting greater compactibility of form I. Taken as a whole, though particle size exhibited a trend on tabletability of individual forms, better compactibility of form I over form II has an overwhelming impact on tabletability.  相似文献   

17.
Fiber type composition of the vastus lateralis muscle of young men and women.   总被引:11,自引:0,他引:11  
This study presents data collected over the past 10 years on the muscle fiber type composition of the vastus lateralis muscle of young men and women. Biopsies were taken from the vastus lateralis muscle of 55 women (21.2+/-2.2 yr) and 95 men (21.5+/-2.4 yr) who had volunteered to participate in various research projects. Six fiber types (I, IC, IIC, IIA, IIAB, and IIB) were classified using mATPase histochemistry, and cross-sectional area was measured for the major fiber types (I, IIA, and IIB). Myosin heavy chain (MHC) content was determined electrophoretically on all of the samples from the men and on 26 samples from the women. With the exception of fiber Type IC, no significant differences were found between men and women for muscle fiber type distribution. The vastus lateralis muscle of both the men and women contained approximately 41% I, 1% IC, 1% IIC, 31% IIA, 6% IIAB, and 20% IIB. However, the cross-sectional area of all three major fiber types was larger for the men compared to the women. In addition, the Type IIA fibers were the largest for the men, whereas the Type I fibers tended to be the largest for the women. Therefore, gender differences were found with regard to the area occupied by each specific fiber type: IIA>I>IIB for the men and I>IIA>IIB for the women. These data establish normative values for the mATPase-based fiber type distribution and sizes in untrained young men and women.  相似文献   

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The enzymatic and physiochemical properties of poly(A) polymerases IIA and IIB from cultured hamster fibroblasts were investigated. The enzymes show an absolute requirement for Mn2+ as the divalent ion. Although Mg2+ alone is inactive, maximum activity is observed in the presence of both Mn2+ and Mg2+. An optimal pH of approx. 8 is found for polymerases IIA and IIB. The enzymes, however, differ somewhat in the pH curves as well as in the Mn2+ and Mg2+ concentration curves. Poly(A) polymerases IIA and IIB have an isoelectric point of about 6 and a sedimentation coefficient of 3.5--4 S. The molecular weights, obtained by gel filtration chromatography, are 145 000 and 155 000 for enzymes IIA and IIB, respectively. Poly(A) polymerases IIA and IIB can utilize a variety of natural and synthetic RNAs as well as DNA as primers. Poly(A) polymerase IIA is saturated at much lower concentrations of primer than enzyme IIB. On the other hand, the chain length of the product synthesized by polymerase IIA is independent of the primer concentration, whereas, with polymerase IIB, the length of the product decreases when the concentration of RNA is increased.  相似文献   

20.
Type II topoisomerases help disentangle chromosomes to facilitate cell division. To advance understanding of the structure and dynamics of these essential enzymes, we have determined the crystal structure of an archaeal type IIB topoisomerase, topo VI, at 4.0-A resolution. The 220-kDa heterotetramer adopts a 'twin-gate' architecture, in which a pair of ATPase domains at one end of the enzyme is poised to coordinate DNA movements into the enzyme and through a set of DNA-cleaving domains at the other end. Small-angle X-ray scattering studies show that nucleotide binding elicits a major structural reorganization that is propagated to the enzyme's DNA-cleavage center, explaining how ATP is coupled to DNA capture and strand scission. These data afford important insights into the mechanisms of topo VI and related proteins, including type IIA topoisomerases and the Spo11 meiotic recombination endonuclease.  相似文献   

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