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衰老和长寿基因方面的研究多以线虫 (如C .elegans)、酵母、果蝇、小鼠为模型 ,目前已鉴定了数十种衰老相关基因 ,改变某些基因的活性会延长寿命或促进衰老。最早引起人们兴趣的“老年基因”是DAF 16 ,但其机制至今未明。daf 16编码转录因子DAF 16 ,后者是一种调节其它基因活性的蛋白。DAF 16是C .elegans寿命的重要调节因子 ,它的作用可被某种激素信号途径 (例如由类似于哺乳类胰岛素和胰岛素样生长因子的蛋白激活的信号途径 )所阻断 ,减弱这一信号途径的活动能使成年C .elegans的寿命明显延长 ,对果蝇和小鼠也如此。因此要想完全阐明… 相似文献
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通过重组cDNA表达文库的血清学分析(SEREX)获得来自斑马鱼的cDNA序列,提取斑马鱼总RNA通过RT-PCR得到该基因全长共5171 bp编码1574个氨基酸,运用生物信息学研究工具进行分析显示该基因为一新基因,命名为KLP,在斑马鱼胚胎各个发育时期用RT-PCR检测该基因的表达情况发现:在斑马鱼早期胚胎发育的几个重要时期该基因都有高表达。该基因含有8个锌指结构,其中3个KAISO蛋白特征性的C2H2锌指结构,且此区域在多个物种内高度保守,提示其在胚胎发育早期过程中具有非常重要的作用。 相似文献
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Spin蛋白家族是具有Spin/Ssty保守结构域并在配子发生过程中发挥关键作用的一类分子。研究利用简并引物PCR,从斑马鱼成熟卵母细胞SMART cDNA文库中筛选到260 bp的DrSpin-1和DrSpin-2部分序列,经序列同源性比对,斑马鱼DrSpin-1的部分氨基酸序列与银鲫CagSpin一致性高达81%。利用RACEPCR从该cDNA文库中获得斑马鱼DrSpin-1的全长cDNA序列。序列分析表明,DrSpin-1全长cDNA为1082 bp,开放阅读框771 bp,编码257个氨基酸,具有三个Spin/Ssty保守域,8个可能的磷酸化位点,初步确定斑马鱼DrSpin-1是Spin基因家族成员。斑马鱼DrSpin-1蛋白与已报道的鱼类Spin蛋白多重序列比对表明,DrSpin-1蛋白与银鲫CagSpin蛋白同源性最高。可以推测克隆得到的斑马鱼DrSpin-1与已知功能的银鲫CagSpin具有相近的表达谱和生物学功能,可能在配子发生和受精过程中发挥重要作用。 相似文献
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gpr98基因突变与多种疾病相关,该基因在人类和斑马鱼中高度保守。建立斑马鱼gpr98基因突变体稳定系,可为阐释gpr98基因功能提供良好的动物模型和研究基础。本文利用CRISPR/Cas9基因敲除技术在斑马鱼gpr98基因2号外显子上选取两个相距42bp的靶位点,分别体外合成sgRNA,并与Cas9 mRNA一起共注射至斑马鱼胚胎单细胞期的胚胎内。随机挑选发育72h胚胎提取基因组DNA进行PCR分析,结果表明:除了有野生型DNA带外,部分胚胎有一条比野生型DNA小的带;进一步将F0代阳性个体与野生型的斑马鱼杂交,对杂交后代进行基因型分析,并成功筛选到缺失48bp(Δ48bp)的稳定遗传突变的gpr98基因敲除斑马鱼模型。该试验模型的构建为研究gpr98基因在心血管以及骨骼等组织器官的发育及相关疾病发生中的作用奠定了重要基础。 相似文献
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斑马鱼作为一种优良的动物模型已被广泛应用于人类相关疾病机理及药物筛选的研究。由于斑马鱼骨骼发育过程和调控机制与哺乳动物高度保守,目前已成功构建斑马鱼骨骼疾病模型。本文首先介绍斑马鱼骨骼发育过程和分子调控机制,并对斑马鱼模型骨骼研究的基本方法及在骨骼药物筛选中的研究现状进行分析和总结,以期对斑马鱼作为骨骼疾病模型进行药物筛选或基础研究提供参考。 相似文献
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The aquaporins are integral membrane proteins from a larger family of major intrinsic protein (MIP) that form pores in the membrane of cells. These proteins selectively transport water and other small uncharged solutes across cell plasma membranes. The organization of water within cells and tissues is fundamental to life, and the aquaporins play an important role in serving as the plumbing system for cells. As many as thirteen mammalian AQPs have been characterized, which have been shown to be vital for the regulation of water homeostasis in most tissues, such as renal water balance and brain-fluid homeostasis. However, complete expression patterns of most of the aquaporins in lower vertebrate at embryo stages has not been elucidated. Currently, we systematically described the temporal-spatial expression pattern of nine zebrafish aquaporins, using whole amount in situ hybridization. The results of whole mount in situ hybridization revealed that members of aquaporins family displayed diverse expression pattern, each of aquaporins has its unique distribution in different cell types and tissues, suggesting that they might play distinct roles in the embryonic development. Overall, current study will provide new insight into the expression of vertebrate quaporins and an important basis for the functional analysis of aquaporins in zebrafish development. 相似文献
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Nel is a multimeric extracellular glycoprotein which predominantly expressed in the nervous system and play an important role in neural development and functions. There are three nel paralogues included nell2a, nell2b, and nell3 in zebrafish, while systematic expression analysis of the nel family is still lacking. In this study, we performed a phylogenetic analysis on 7 species, in different species the nell2a are highly conserved, as is nell2b. Then, the expression profiles of nell2a, nell2b and nell3 were detected by in situ hybridization in zebrafish embryo, and the result showed that nel genes highly enriched in the central nervous system, but distributed in different regions of the brain. In addition, nell2a is also expressed in the olfactory pit, spinal cord, otic vesicle and retina (ganglion cell layer), nell2b was detected to express in gill arches, olfactory epithelium, olfactory pit, spinal cord, photoreceptor and retina (ganglion cell layer), it should be noted that the expression of nell3 is special, was only detected at 96 hpf in the brain and spinal cord of zebrafish. Overall, our results indicate that nell2a and nell2b genes are expressed in the nervous system and eyes of zebrafish embryo, while nell3 is expressed in different regions in the nervous system. The phylogenetic analysis also shows that nell3 sequences are significantly different from nell2a and nell2b. This study provides new evidence to better understand the role of nel in zebrafish embryo development. 相似文献
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Radiographic analysis of zebrafish skeletal defects 总被引:6,自引:0,他引:6
Systematic identification of skeletal dysplasias in model vertebrates provides insight into the pathogenesis of human skeletal disorders and can aid in the identification of orthologous human genes. We are undertaking a mutagenesis screen for skeletal dysplasias in adult zebrafish, using radiography to detect abnormalities in skeletal anatomy and bone morphology. We have isolated chihuahua, a dominant mutation causing a general defect in bone growth. Heterozygous chihuahua fish have phenotypic similarities to human osteogenesis imperfecta, a skeletal dysplasia caused by mutations in the type I collagen genes. Mapping and molecular characterization of the chihuahua mutation indicates that the defect resides in the gene encoding the collagen I(alpha1) chain. Thus, chihuahua accurately models osteogenesis imperfecta at the biologic and molecular levels, and will prove an important resource for studies on the disease pathophysiology. Radiography is a practical screening tool to detect subtle skeletal abnormalities in the adult zebrafish. The identification of chihuahua demonstrates that mutant phenotypes analogous to human skeletal dysplasias will be discovered. 相似文献
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The vertebrate Hox genes have been shown to confer regional identity along the anteroposterior axis of the developing embryo, especially within
the central nervous system (CNS) and the paraxial mesoderm. The notochord has been shown to play vital roles in patterning
adjacent tissues along both the dorsoventral and mediolateral axes. However, the notochord’s role in imparting anteroposterior
information to adjacent structures is less well understood, especially as the notochord shows no morphological distinctions
along the anteroposterior axis and is not generally described as a segmental or compartmentalized structure. Here we report
that four zebrafish hox genes: hoxb1, hoxb5, hoxc6 and hoxc8 are regionally expressed along the anteroposterior extent of the developing notochord. Notochord expression for each gene
is transient, but maintains a definite, gene-specific anterior limit throughout its duration. The hox gene expression in the zebrafish notochord is spatially colinear with those genes lying most 3’ in the hox clusters having the most anterior limits. The expression patterns of these hox cluster genes in the zebrafish are the most direct molecular evidence for a system of anteroposterior regionalization of
the notochord in any vertebrate studied to date.
Received: 30 March 1998 / Accepted: 16 June 1998 相似文献
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Burket CT Montgomery JE Thummel R Kassen SC LaFave MC Langenau DM Zon LI Hyde DR 《Transgenic research》2008,17(2):265-279
Two commonly used promoters to ubiquitously express transgenes in zebrafish are the Xenopus laevis
elongation factor 1 α promoter (XlEef1a1) and the zebrafish histone variant H2A.F/Z (h2afv) promoter. Recently, transgenes utilizing these promoters were shown to be silenced in certain adult tissues, particularly
the central nervous system. To overcome this limitation, we cloned the promoters of four zebrafish genes that likely are transcribed
ubiquitously throughout development and into the adult. These four genes are the TATA box binding protein gene, the taube nuss-like gene, the eukaryotic elongation factor 1-gamma gene, and the beta-actin-1 gene. We PCR amplified approximately 2.5 kb upstream of the putative translational start site of each gene and cloned each
into a Tol2 expression vector that contains the EGFP reporter transgene. We used these four Tol2 vectors to independently
generate stable transgenic fish lines for analysis of transgene expression during development and in the adult. We demonstrated
that all four promoters drive a very broad pattern of EGFP expression throughout development and the adult. Using the retina
as a well-characterized component of the CNS, all four promoters appeared to drive EGFP expression in all neuronal and non-neuronal
cells of the adult retina. In contrast, the h2afv promoter failed to express EGFP in the adult retina. When we examined EGFP expression in the various cells of the blood cell
lineage, we observed that all four promoters exhibited a more heterogenous expression pattern than either the XlEef1a1 or h2afv promoters. While these four ubiquitous promoters did not express EGFP in all the adult blood cells, they did express EGFP
throughout the CNS and in broader expression patterns in the adult than either the XlEef1a1 or h2afv promoters. For these reasons, these four promoters will be valuable tools for expressing transgenes in adult zebrafish. 相似文献
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The presence of two sets of paired appendages is one of the defining features of jawed vertebrates. We are interested in identifying
genetic systems that could have been responsible for the origin of the first set of such appendages, for their subsequent
duplication at a different axial level, and/or for the generation of their distinct identities. It has been hypothesized that
four genes of the T-box gene family (Tbx2–Tbx5) played important roles in the course of vertebrate limb evolution. To test this idea, we characterized the orthologs of
tetrapod limb-expressed T-box genes from a teleost, Danio rerio. Here we report isolation of three of these genes, tbx2, tbx4, and tbx5. We found that their expression patterns are remarkably similar to those of their tetrapod counterparts. In particular, expression
of tbx5 and tbx4 is restricted to pectoral and pelvic fin buds, respectively, while tbx2 can be detected at the anterior and posterior margins of the outgrowing fin buds. This, in combination with conserved expression
patterns in other tissues, suggests that the last common ancestor of teleosts and tetrapods possessed all four of these limb-expressed
T-box genes (Tbx2–Tbx5), and that these genes had already acquired, and have subsequently maintained, their gene-specific functions. Furthermore,
this evidence provides molecular support for the notion that teleost pectoral and pelvic fins and tetrapod fore- and hindlimbs,
respectively, are homologous structures, as suggested by comparative morphological analyses.
Received: 14 July 1999 / Accepted: 4 September 1999 相似文献
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