排序方式: 共有164条查询结果,搜索用时 31 毫秒
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Alemeh Rafaee Anahita Mohseni Meybodi Parichehreh Yaghmaei Seyedeh Hanieh Hosseini Marjan Sabbaghian 《Molecular reproduction and development》2020,87(2):251-259
SEPT12 is a testis‐specific gene involved in the terminal differentiation of male germ cells. SEPT12 protein is required for sperm head‐tail formation and acts as a fundamental constituent of sperm tail annulus. In this study, we screened genetic variations in exons 5, 6, 7 of the SEPT12 and assessed the annulus status in teratozoospermic, globozoospermic, and patients with immotile short tail sperm. DNA sequencing was performed for 90 teratozoospermic and 30 normozoospermic individuals. Immunocytochemistry, transmission electron microscopy and western blotting were conducted to evaluate annulus status and the expression level of SEPT12 in patients with a distinct exonic variation (c.474G>A), respectively. Five polymorphisms identified within the desired regions of the SEPT12, among them c.474G>A had the potential to induce aberrant splicing results in the expression of a truncated protein. The annulus was detected in most of the spermatozoa from teratozoospermic and normozoospermic men with c.474G>A. In contrast, in the patient with short tail sperm defect carrying c.474G>A, 99% of spermatozoa were devoid of the annulus. Based on our findings there would be no association between exons 5, 6, 7 polymorphisms of the SEPT12 gene and the occurrence of mentioned disease but c.474G>A would be a predisposing factor in male infertility. 相似文献
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Mahboudi Somayeh Moosavi-Nasab Marzieh Kazemi Bahram Rahimpour Azam Eskandari Mohammad Hadi Mohammadian Omid Shams Forough 《Molecular biology reports》2021,48(5):4405-4412
Molecular Biology Reports - Monoclonal antibodies (mAbs) are widely employed as invaluable therapeutics for a vast number of human disorders. Several approaches have been introduced for the... 相似文献
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Mohammad Hashemi Abdolkarim Moazeni-roodi Farshid Arbabi Aliakbar Fazaeli Ebrahim Eskandari Nasab Mohsen Taheri 《Nucleosides, nucleotides & nucleic acids》2013,32(5):401-410
Several studies have focused on the RAGE genetic background and have demonstrated that its polymorphisms affect the receptor's activity, expression, and downstream signaling. However, there is only little information regarding RAGE polymorphism in breast cancer. In the present study, the authors studied RAGE polymorphisms in 71 patients with breast cancer and 93 healthy women. RAGE –374T/A, –429T/C, and 63 bp Ins/del polymorphisms were analyzed using a hexaprimer amplification refractory mutation system PCR (H-ARMS-PCR). The results showed that RAGE polymorphisms are not associated with breast cancer in the current study population. Larger studies are required to confirm these data in other populations. 相似文献
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Alexander Woglar Anahita Daryabeigi Adele Adamo Cornelia Habacher Thomas Machacek Adriana La Volpe Verena Jantsch 《PLoS genetics》2013,9(3)
Faithful chromosome segregation during meiosis I depends on the establishment of a crossover between homologous chromosomes. This requires induction of DNA double-strand breaks (DSBs), alignment of homologs, homolog association by synapsis, and repair of DSBs via homologous recombination. The success of these events requires coordination between chromosomal events and meiotic progression. The conserved SUN/KASH nuclear envelope bridge establishes transient linkages between chromosome ends and cytoskeletal forces during meiosis. In Caenorhabditis elegans, this bridge is essential for bringing homologs together and preventing nonhomologous synapsis. Chromosome movement takes place during synapsis and recombination. Concomitant with the onset of chromosome movement, SUN-1 clusters at chromosome ends associated with the nuclear envelope, and it is phosphorylated in a chk-2- and plk-2-dependent manner. Identification of all SUN-1 phosphomodifications at its nuclear N terminus allowed us to address their role in prophase I. Failures in recombination and synapsis led to persistent phosphorylations, which are required to elicit a delay in progression. Unfinished meiotic tasks elicited sustained recruitment of PLK-2 to chromosome ends in a SUN-1 phosphorylation–dependent manner that is required for continued chromosome movement and characteristic of a zygotene arrest. Furthermore, SUN-1 phosphorylation supported efficient synapsis. We propose that signals emanating from a failure to successfully finish meiotic tasks are integrated at the nuclear periphery to regulate chromosome end–led movement and meiotic progression. The single unsynapsed X chromosome in male meiosis is precluded from inducing a progression delay, and we found it was devoid of a population of phosphorylated SUN-1. This suggests that SUN-1 phosphorylation is critical to delaying meiosis in response to perturbed synapsis. SUN-1 may be an integral part of a checkpoint system to monitor establishment of the obligate crossover, inducible only in leptotene/zygotene. Unrepaired DSBs and unsynapsed chromosomes maintain this checkpoint, but a crossover intermediate is necessary to shut it down. 相似文献
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Erik Ziegler Ariane Foret Laura Mascetti Vincenzo Muto Anahita Le Bourdiec-Shaffii Johan Stender Evelyne Balteau Vinciane Dideberg Vincent Bours Pierre Maquet Christophe Phillips 《PloS one》2013,8(7)
Brain-derived neurotrophic factor (BDNF) modulates the pruning of synaptically silent axonal arbors. The Met allele of the BDNF gene is associated with a reduction in the neurotrophin''s activity-dependent release. We used diffusion-weighted imaging to construct structural brain networks for 36 healthy subjects with known BDNF genotypes. Through permutation testing we discovered clear differences in connection strength between subjects carrying the Met allele and those homozygotic for the Val allele. We trained a Gaussian process classifier capable of identifying the subjects'' allelic group with 86% accuracy and high predictive value. In Met carriers structural connectivity was greatly increased throughout the forebrain, particularly in connections corresponding to the anterior and superior corona radiata as well as corticothalamic and corticospinal projections from the sensorimotor, premotor, and prefrontal portions of the internal capsule. Interhemispheric connectivity was also increased via the corpus callosum and anterior commissure, and extremely high connectivity values were found between inferior medial frontal polar regions via the anterior forceps. We propose that the decreased availability of BDNF leads to deficits in axonal maintenance in carriers of the Met allele, and that this produces mesoscale changes in white matter architecture. 相似文献
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This study compares the relative influences of physiography and anthropogenic pressures on river biota at catchment, riparian corridor, and reach scales. Environmental data, catchment and riparian corridor land use, anthropogenic modifications and biological data were compiled for 301 French sites sampled from 2005 to 2008. First, relationships between anthropogenic pressures and fish and macroinvertebrate assemblages were analysed using redundancy analysis. Second, the influences of physiography and the three scales of human pressures on biological assemblages were measured using variance partitioning. Distributions of fish and macroinvertebrate taxa along the pressure gradients agreed with bio-ecological knowledge. At the reach scale, assemblage variability among the 301 French sites was related to the presence of an impoundment and to poor water quality, while at larger scales it was linked to a gradient from forest to agricultural covers. In addition, a large proportion of the explained variability in assemblage composition was related to complex interactions among factors (~40%) and to physiographic variables (~30%). Furthermore, our results highlight that catchment land use better reflects local water quality impairments than hydromorphological degradations. Finally, this study supports the idea that human pressure effects on river communities are linked at several spatial scales and must be considered jointly. 相似文献
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Yves Pauchard Thomas Fitze Diego Browarnik Amiraslan Eskandari Irene Pauchard William Enns-Bray 《Computer methods in biomechanics and biomedical engineering》2016,19(16):1693-1703
In this study, we propose interactive graph cut image segmentation for fast creation of femur finite element (FE) models from clinical computed tomography scans for hip fracture prediction. Using a sample of N = 48 bone scans representing normal, osteopenic and osteoporotic subjects, the proximal femur was segmented using manual (gold standard) and graph cut segmentation. Segmentations were subsequently used to generate FE models to calculate overall stiffness and peak force in a sideways fall simulations. Results show that, comparable FE results can be obtained with the graph cut method, with a reduction from 20 to 2–5 min interaction time. Average differences between segmentation methods of 0.22 mm were not significantly correlated with differences in FE derived stiffness (R2 = 0.08, p = 0.05) and weakly correlated to differences in FE derived peak force (R2 = 0.16, p = 0.01). We further found that changes in automatically assigned boundary conditions as a consequence of small segmentation differences were significantly correlated with FE derived results. The proposed interactive graph cut segmentation software MITK-GEM is freely available online at https://simtk.org/home/mitk-gem. 相似文献
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Heat shock protein 90 (Hsp90) is a member of the heat shock family of molecular chaperones that regulate protein conformation and activity. Hsp90 regulates multiple cell signaling pathways by controlling the abundance and activity of several important protein kinases and cell cycle-related proteins. In this report, we show that inhibition of Hsp90 by geldanamycin or its derivative, 17-allylamino-17-desmethoxygeldamycin, leads to activation of the Rho GTPase and a dramatic increase in actin stress fiber formation in human tumor cell lines. Inactivation of Rho prevents geldanamycin-induced actin reorganization. Hsp90 inactivation does not alter the appearance of filopodia or lamellipodia and tubulin architecture is not visibly perturbed. Our observations suggest that Hsp90 has an important and specific role in regulating Rho activity and Rho-dependent actin cytoskeleton remodeling. 相似文献