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Monardes A Iribarren C Morin V Bustos P Puchi M Imschenetzky M 《Journal of cellular biochemistry》2005,96(2):235-241
Male pronucleus formation involves sperm nucleus decondensation and sperm chromatin remodeling. In sea urchins, male pronucleus decondensation was shown to be modulated by protein kinase C and a cdc2-like kinase sensitive to olomoucine in vitro assays. It was further demonstrated that olomoucine blocks SpH2B and SpH1 phosphorylation. These phosphorylations were postulated to participate in the initial steps of male chromatin remodeling during male pronucleus formation. At final steps of male chromatin remodeling, all sperm histones (SpH) disappear from male chromatin and are subsequently degraded by a cysteine protease. As a result of this remodeling, the SpH are replaced by maternal histone variants (CS). To define if sperm nucleus decondensation is coupled with sperm chromatin remodeling, we have followed the loss of SpH in zygotes treated with olomoucine. SpH degradation was followed with anti-SpH antibodies that had no cross-reactivity with CS histone variants. We found that olomoucine blocks SpH1 and SpH2B phosphorylation and inhibits male pronucleus decondensation in vivo. Interestingly, the normal schedule of SpH degradation remains unaltered in the presence of olomoucine. Taken together these results, it was concluded that male nucleus decondensation is uncoupled from the degradation of SpH associated to male chromatin remodeling. From these results, it also emerges that the phosphorylation of SpH2B and SpH1 is not required for the degradation of the SpH that is concurrent to male chromatin remodeling. 相似文献
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依赖ATP的染色质物理修饰 总被引:2,自引:0,他引:2
染色质重塑是基因表达调控过程中一个非常重要的环节 .染色质重塑主要包括 2种类型 :一种是依赖ATP的物理修饰 ,另一种是依赖共价结合反应的化学修饰 .依赖ATP的物理修饰主要是利用ATP水解释放的能量 ,使DNA超螺旋旋矩和旋相发生变化 ,使转录因子更易接近并结合核小体DNA ,从而调控基因的转录过程 相似文献
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This article is a report on finding a new species of Russia fauna, the low sea urchin Pseudocentrotus depressus (A. Agassiz), in the South Kuril Strait near Shikotan Island. 相似文献
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Unfertilized sea urchin eggs exposed to the sulfhydryl reagents Ag+ or N-ethylmaleimide either elevated fertilizationlike membranes, formed surface protrusions, developed a clear cortical layer devoid of organelles, or cytolysed. The relative fraction of each modification varied from batch to batch and was also dose and time dependent. With Ag+ and higher doses of N-EMI (10?3 M), the most common effect was the elevation of a membrane indicating cortical exocytosis, while at lower doses of N-EMI protrusions were predominant. Glutathione (GSH) protected eggs against these reagents also in a dose-dependent manner. Eggs exposed to equimolar amounts of N-EMI and GSH, which otherwise formed membranes, produced protrusions, while increasing GSH tenfold afforded complete protection. We suggest there are two targets for the sulfhydryl reagents–the first, SH groups on proteins that regulate the release of Ca2+ from the intracellular sequestering mechanism which subsequently triggers cortical exocytosis; the second, SH groups on the egg surface that may regulate cortical organization. 相似文献
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Tatsuo Harumi Masanori Kurita Norio Suzuki 《Development, growth & differentiation》1992,34(2):151-162
Creatine kinase and guanylate cyclase were purified from Hemicentrotus pulcherrimus spermatozoa. The molecular weight of the purified sperm tail creatine kinase was estimated to be 137,000 by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Sperm tail guanylate cyclase was purified by chromatography on a WGA-Sepharose column connected to a Concanavalin A-Sepharose column, and a Superose 12 HR column. The molecular weight of the tail guanylate cyclase was estimated to be 128,000 by SDS-PAGE. The specific activity of the purified enzyme was 8.25 μmol of cGMP formed/min/mg protein. Sperm-activating peptide I (SAP-I) causes an electrophoretic mobility shift of H. pulcherrimus sperm guanylate cyclase from 131 kDa to 128 kDa. The 131 kDa form of guanylate cyclase was co-purified with a 76 kDa protein, whose molecular mass is similar to that of a SAP-I receptor. The purified 131 kDa form of guanylate cyclase had higher activity than the 128 kDa form. The 131 kDa and 128 kDa forms of guanylate cyclase contained 23.83 ± 0.65 and 4.16 ± 0.45 moles of phosphate per mol protein (mean ± S.D.; n = 3), respectively. The activities of guanylate cyclase and creatine kinase increased during the testis development. During spermatogenesis, sperm tail creatine kinase was detected immunohistochemically only in mature spermatozoa. 相似文献
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Using probes specific for several oncogenes/proto-oncogenes we have performed gel blot hybridization analyses of genomic DNA isolated from the sea urchinStrongylocentrotus droebachiensis. Probes prepared from v-erbB, v-myc, c-myb and v-fps were found to hybridize with discrete fragments of HindIII digested genomic DNA. In contrast, probes prepared from v-abl, v-fos, v-sis, v-src, and v-mos either hybridized with multiple fragments, indicating non-specific binding, or failed to hybridize at all above background levels. These results clearly demonstrate the presence of proto-oncogene homologous sequences in the sea urchin genome. 相似文献
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Fung ES Thurm C Reuille R Brede B Livingston BT 《Development, growth & differentiation》2005,47(7):461-470
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分子伴侣一词最初是指一类在细胞核内介导蛋白和核酸相互作用的生物分子.核质蛋白是第一个发现和命名的核内分子伴侣,它在体内以五聚体的形式存在,参与核小体的装配、染色质的重建以及细胞凋亡中染色质的聚缩等重要生命活动.其序列中富含的酸性氨基酸区带是核质蛋白行使功能的重要结构域,这些酸性区带通过屏蔽组蛋白中的正电荷,使得组蛋白能逐步有序地结合到DNA上装配成核小体.核质蛋白晶体结构的测定又将研究推向分子机制的深入探讨和作用模型的建立. 本文主要对核质蛋白的结构和生物学性质、核质蛋白的相关功能以及活性调节的研究进展作一综述. 相似文献
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Martin F. Brown Jacqueline S. Partin Christopher E. Killian William J. Lennarz 《Development, growth & differentiation》1995,37(1):69-78
When proteins isolated from spicules of Strongylocentrotus purpuratus embryos were examined by western blot analysis, a major protein of approximately 43 kDa was observed to react with the monoclonal antibody, mAb 1223. Previous studies have established that this antibody recognizes an asparagine-linked, anionic carbohydrate epitope on the cell surface glycoprotein, msp130. This protein has been shown to be specifically associated with the primary mesenchyme cells involved in assembly of the spicule. Moreover, several lines of evidence have implicated the carbohydrate epitope in Ca2+ deposition into the growing spicule. The 43 kDa, spicule matrix protein detected with mAb 1223 also reacted with a polyclonal antibody to a known spicule matrix protein, SM30. Further characterization experiments, including deglycosylation using PNGaseF, two-dimensional electrophoresis, and immunoprecipitation, verified that the 43 kDa spicule matrix protein had a pl of approximately 4.0, contained the carbohydrate epitope recognized by monoclonal antibody mAb 1223 and reacted with anti-SM30. Electron microscopy confirmed the presence of proteins within the demineralized spicule that reacted with mAb 1223 and anti-SM30. We conclude that the spicule matrix protein, SM30, is a glycoprotein containing carbohydrate chains similar or identical to those on the primary mesenchyme cell membrane glycoprotein, msp130. 相似文献
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Moritani K Tagashira H Shimotori T Sakamoto N Tanaka S Takata K Mitsunaga-Nakatsubo K Bojiiwa Y Yamamoto T Shimada H Akasaka K 《Development, growth & differentiation》2004,46(4):335-341
We report the identification and characterization of Unichrom, a gene encoding a new G-stretch-DNA-binding protein in the sea urchin embryo. The derived amino acid sequence of Unichrom contains plant homeodomain (PHD) finger and high mobility group (HMG) motifs as well as motifs required for cell-cycle-dependent degradation. The expression of a Unichrom-green fluorescent protein (GFP) fusion protein in sea urchin embryonic cells indicates that Unichrom protein accumulates in nuclei during interphase and disperses into the cytoplasm at mitosis. Overexpression of dominant negative Unichrom, which contains the DNA binding domain lacking the motif for cell-cycle-dependent degradation, causes impairment of chromosome segregation. These results suggest that Unichrom binds to genome DNA at G-stretch and that degradation of Unichrom is required for segregation of chromosomes. 相似文献
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An annual reproductive periodicity of Tripneustes gratilla in northern Taiwan is revealed by both the gonad development stages and the gonad index. The gonads of T. gratilla recovered from spawning in February—March, propagated gametocytes in April—June, came to prematurity in July—August, and matured in September—November. Spawning occurred in October—December. The breeding pattern of T. gratilla over a broad geographical area appears to be related to seasonal changes of sea temperatures. 相似文献
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Echinoderms have long served as model organisms for a variety of biological research, especially in the field of developmental biology. Although the genome of the purple sea urchin Strongylocentrotus purpuratus has been sequenced, it is the only echinoderm whose whole genome sequence has been reported. Nevertheless, data is rapidly accumulating on the chromosomes and genomic sequences of all five classes of echinoderms, including the mitochondrial genomes and Hox genes. This blossoming new data will be essential for estimating the phylogenetic relationships among echinoderms, and also to examine the underlying mechanisms by which the diverse morphologies of echinoderms have arisen. 相似文献
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We have purified and characterized a collagenase/gelatinase activity expressed during sea urchin embryonic development. The native molecular mass was determined to be 160 kDa, while gelatin substrate gel zymography revealed an active species of 41 kDa, suggesting that the native enzyme is a tetramer of active subunits. Incubation in the presence of EGTA resulted in nearly complete loss of activity and this effect could be reversed by calcium. Calcium-induced reactivation appeared to be cooperative and occurred with an apparent kd value of 3.7 mM. Two modes of calcium binding to the 41-kDa subunit were detected; up to 80 moles of calcium bound with a kd value of 0.5 mM, while an additional 120 moles bound with a kd value of 5 mM. Amino acid analysis revealed a carboxy plus carboxyamide content of 24.3 mol/100 mol, indicating the availability of substantial numbers of weak Ca2+-binding sites. Calcium binding did not result in either secondary or quaternary structural changes in the collagenase/gelatinase, suggesting that Ca2+ may facilitate activation through directly mediating the binding of substrate to the enzyme. The collagenase/gelatinase activity was detected in blastocoelic fluid and in the hyalin fraction dissociated from 1-h-old embryos. Immunolocalization studies revealed two storage compartments in the egg; cortical granules and small granules/vesicles dispersed throughout the cytoplasm. After fertilization, the antigen was detected in both the apical and basal extracellular matrices, the hyaline layer, and basal lamina, respectively. J. Cell. Biochem. 71:546–558, 1998. © 1998 Wiley-Liss, Inc. 相似文献
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Giovanni Giudice 《Development, growth & differentiation》1995,37(3):221-242
The main literature regarding gene structure and expression in sea urchin embryos is schematically reported and briefly commented upon. Although the subject has expanded particularly over the last 10 years, to which the review mostly refers, some historical reference is also given. More space is reserved to the regulation of the synthesis of histones and cytoskeletal actins, where the attention of various authors has been especially present; the regulation of such a synthesis is described both at a territorial level and a temporal level during the sea urchin development. 相似文献
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E.C. Tauchman 《Invertebrate reproduction & development.》2013,57(3):152-161
Lytechinus variegatus larvae were used to examine the effects of ecologically relevant short-term exposures of ultraviolet radiation (UVR) on larval morphology and settlement. A laboratory experiment tested the blastula, gastrula, and early pluteus stages of larval development for susceptibility to damage from exposure to UVR produced by an artificial light source. Larval post-oral arm length and percent settlement were measured to assess UVR effects. Larvae exposed at the blastula and gastrula stages had a reduction in larval post-oral arm length compared with non-exposure controls, while larvae exposed at the early pluteus stage were similar to controls. Larvae exposed in the gastrula stage had a significant reduction in percent settlement compared with controls. Negative consequences from ecologically relevant levels of UVR were differentially dependent on the larval stage at time of exposure suggesting time point in larval development at exposure will be important in interpreting effects on higher levels of biological organization. 相似文献
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The hyaline layer (HL) is an apically located extracellular matrix (ECM) which surrounds the sea urchin embryo from the time of fertilization until metamorphosis occurs. While gelatin-cleavage activities were absent from freshly prepared hyaline layers, a dynamic pattern of activities developed in layers incubated at 15 or 37 degrees C in Millipore-filtered sea water (MFSW). Cleavage activities at 90, 55, 41, and 32 kDa were evident following incubation at either temperature. The activation pathway leading to the appearance of these species was examined to determine the minimum salt conditions required for processing and to establish precursor-product relationships. In both qualitative and quantitative assays, the purified 55 kDa gelatinase activity was inhibited by 1,10-phenanthroline (a zinc-specific chelator) and ethylenebis (oxyethylenenitrilo) tetraacetic acid (EGTA). Calcium reconstituted the activity of the EGTA-inhibited enzyme with an apparent dissociation constant (calcium) of 1.2 mM. Developmental substrate gel analysis was performed using various stage embryos. The 55 and 32 kDa species comigrated with gelatin-cleavage activities present in sea urchin embryos. Collectively, the results reported here document a zymogen activation pathway which generates a 55 kDa, gelatin-cleaving activity within the extraembryonic HL. This species displayed characteristics of the matrix metalloproteinase class of ECM modifying enzymes. 相似文献