共查询到20条相似文献,搜索用时 15 毫秒
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S H Bernstein S M Kharbanda M L Sherman V P Sukhatme D W Kufe 《Cell growth & differentiation》1991,2(6):273-278
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Julien Falk Jovana Drinjakovic Kin Mei Leung Asha Dwivedy Aoife G Regan Michael Piper Christine E Holt 《BMC developmental biology》2007,7(1):107
Background
Blastomere injection of mRNA or antisense oligonucleotides has proven effective in analyzing early gene function in Xenopus. However, functional analysis of genes involved in neuronal differentiation and axon pathfinding by this method is often hampered by earlier function of these genes during development. Therefore, fine spatio-temporal control of over-expression or knock-down approaches is required to specifically address the role of a given gene in these processes. 相似文献3.
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Amaury Herpin Detlev Schindler Anita Kraiss Ute Hornung Christoph Winkler Manfred Schartl 《BMC developmental biology》2007,7(1):99
Background
Dmrt1 is a highly conserved gene involved in the determination and early differentiation phase of the primordial gonad in vertebrates. In the fish medaka dmrt1bY, a functional duplicate of the autosomal dmrt1a gene on the Y-chromosome, has been shown to be the master regulator of male gonadal development, comparable to Sry in mammals. In males mRNA and protein expression was observed before morphological sex differentiation in the somatic cells surrounding primordial germ cells (PGCs) of the gonadal anlage and later on exclusively in Sertoli cells. This suggested a role for dmrt1bY during male gonad and germ cell development. 相似文献7.
Nami Akiba Sunna Jo Yosuke Akiba Harriet Baker John W. Cave 《Journal of molecular histology》2009,40(2):151-155
In the adrenal medulla, binding of the immediate early gene (IEG) proteins, EGR-1 (ZIF-268/KROX-24/NGFI-A) and AP-1, to the
tyrosine hydroxylase (Th) proximal promoter mediate inducible Th expression. The current study investigated the potential role of EGR-1 in inducible Th expression in the olfactory bulb (OB) since IEGs bound to the AP-1 site in the Th proximal promoter are also necessary for activity-dependent OB TH expression. Immunohistochemical analysis of a naris-occluded
mouse model of odor deprivation revealed weak EGR-1 expression levels in the OB glomerular layer that were activity-dependent.
Immunofluorescence analysis indicated that a majority of glomerular cells expressing EGR-1 also co-expressed TH, but only
small subset of TH-expressing cells contained EGR-1. By contrast, granule cells, which lack TH, exhibited EGR-1 expression
levels that were unchanged by naris closure. Together, these finding suggest that EGR-1 mediates activity-dependent TH expression
in a subset of OB dopaminergic neurons, and that there is differential regulation of EGR-1 in periglomerular and granule cells. 相似文献
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Jo?o V Neves Jonathan M Wilson Heiner Kuhl Richard Reinhardt L Filipe C Castro Pedro NS Rodrigues 《BMC evolutionary biology》2011,11(1):106
Background
The SLC11A1/Nramp1 and SLC11A2/Nramp2 genes belong to the SLC11/Nramp family of transmembrane divalent metal transporters, with SLC11A1 being associated with resistance to pathogens and SLC11A2 involved in intestinal iron uptake and transferrin-bound iron transport. Both members of the SLC11 gene family have been clearly identified in tetrapods; however SLC11A1 has never been documented in teleost fish and is believed to have been lost in this lineage during early vertebrate evolution. In the present work we characterized the SLC11 genes in teleosts and evaluated if the roles attributed to mammalian SLC11 genes are assured by other fish specific SLC11 gene members. 相似文献10.
Natalie Garrett Juan Viruel Nathaniel Klimpert Marybel Soto Gomez Vivienne K. Y. Lam Vincent S. F. T. Merckx Sean W. Graham 《American journal of botany》2023,110(4):e16141
Premise
Species in Thismiaceae can no longer photosynthesize and instead obtain carbon from soil fungi. Here we infer Thismiaceae phylogeny using plastid genome data and characterize the molecular evolution of this genome.Methods
We assembled five Thismiaceae plastid genomes from genome skimming data, adding to previously published data for phylogenomic inference. We investigated plastid-genome structural changes, considering locally colinear blocks (LCBs). We also characterized possible shifts in selection pressure in retained genes by considering changes in the ratio of nonsynonymous to synonymous changes (ω).Results
Thismiaceae experienced two major pulses of gene loss around the early diversification of the family, with subsequent scattered gene losses across descendent lineages. In addition to massive size reduction, Thismiaceae plastid genomes experienced occasional inversions, and there were likely two independent losses of the plastid inverted repeat (IR) region. Retained plastid genes remain under generally strong purifying selection (ω << 1), with significant and sporadic weakening or strengthening in several instances. The bifunctional trnE-UUC gene of Thismia huangii may retain a secondary role in heme biosynthesis, despite a probable loss of functionality in protein translation. Several cis-spliced group IIA introns have been retained, despite the loss of the plastid intron maturase, matK.Conclusions
We infer that most gene losses in Thismiaceae occurred early and rapidly, following the initial loss of photosynthesis in its stem lineage. As a species-rich, fully mycoheterotrophic lineage, Thismiaceae provide a model system for uncovering the unique and divergent ways in which plastid genomes evolve in heterotrophic plants. 相似文献11.
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Loyal A. Goff Jonathan Davila Mavis R. Swerdel Jennifer C. Moore Rick I. Cohen Hao Wu Yi E. Sun Ronald P. Hart 《PloS one》2009,4(9)
Background
MicroRNAs are required for maintenance of pluripotency as well as differentiation, but since more microRNAs have been computationally predicted in genome than have been found, there are likely to be undiscovered microRNAs expressed early in stem cell differentiation.Methodology/Principal Findings
SOLiD ultra-deep sequencing identified >107 unique small RNAs from human embryonic stem cells (hESC) and neural-restricted precursors that were fit to a model of microRNA biogenesis to computationally predict 818 new microRNA genes. These predicted genomic loci are associated with chromatin patterns of modified histones that are predictive of regulated gene expression. 146 of the predicted microRNAs were enriched in Ago2-containing complexes along with 609 known microRNAs, demonstrating association with a functional RISC complex. This Ago2 IP-selected subset was consistently expressed in four independent hESC lines and exhibited complex patterns of regulation over development similar to previously-known microRNAs, including pluripotency-specific expression in both hESC and iPS cells. More than 30% of the Ago2 IP-enriched predicted microRNAs are new members of existing families since they share seed sequences with known microRNAs.Conclusions/Significance
Extending the classic definition of microRNAs, this large number of new microRNA genes, the majority of which are less conserved than their canonical counterparts, likely represent evolutionarily recent regulators of early differentiation. The enrichment in Ago2 containing complexes, the presence of chromatin marks indicative of regulated gene expression, and differential expression over development all support the identification of 146 new microRNAs active during early hESC differentiation. 相似文献13.
Background
Less than 30% of malignant gliomas respond to adjuvant chemotherapy. Here, we have asked whether variations in the constitutive expression of early-growth response factor 1 (EGR-1) predicted acute cytotoxicity and clonogenic cell death in vitro, induced by six different chemotherapics. 相似文献14.
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Background
Granulocytes and monocytes/macrophages differentiate from common myeloid progenitor cells. Granulocyte colony-stimulating factor (G-CSF) and CD137 (4-1BB, TNFRSF9) are growth and differentiation factors that induce granulocyte and macrophage survival and differentiation, respectively. This study describes the influence of G-CSF and recombinant CD137-Fc protein on myelopoiesis.Methodology/Principal Findings
Both, G-CSF and CD137 protein support proliferation and survival of murine bone marrow cells. G-CSF enhances granulocyte numbers while CD137 protein enhances macrophage numbers. Both growth factors together give rise to more cells than each factor alone. Titration of G-CSF and CD137 protein dose-dependently changes the granulocyte/macrophage ratio in bone marrow cells. Both factors individually induce proliferation of hematopoietic progenitor cells (lin-, c-kit+) and differentiation to granulocytes and macrophages, respectively. The combination of G-CSF and CD137 protein further increases proliferation, and results in a higher number of macrophages than CD137 protein alone, and a lower number of granulocytes than G-CSF alone demonstrating that CD137 protein-induced monocytic differentiation is dominant over G-CSF-induced granulocytic differentiation. CD137 protein induces monocytic differentiation even in early hematopoietic progenitor cells, the common myeloid progenitors and the granulocyte macrophage progenitors.Conclusions/Significance
This study confirms earlier data on the regulation of myelopoiesis by CD137 receptor - ligand interaction, and extends them by demonstrating the restriction of this growth promoting influence to the monocytic lineage. 相似文献17.
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