BACKGROUND & AIMS:
:Cartilaginous fish, primarily sharks, rays and skates (elasmobranchs), appeared 450 million years ago. They are the most primitive vertebrates, exhibiting jaws and teeth, adaptive immunity, a pressurized circulatory system, thymus, spleen, and a liver comparable to that of humans. The most used elasmobranch in biomedical research is the spiny dogfish shark, Squalus acanthias. Comparative genomic analysis of the dogfish shark, the little skate (Leucoraja erincea), and other elasmobranchs have yielded insights into conserved functional domains of genes associated with human liver function, multidrug resistance, cystic fibrosis, and other biomedically relevant processes. While genomic information from these animals is informative in an evolutionary framework, experimental verification of functions of genomic sequences depends heavily on cell culture approaches. We have derived the first multipassage, continuously proliferating cell line of a cartilaginous fish. The line was initiated from embryos of the spiny dogfish shark. The cells were maintained in a medium modified for fish species and supplemented with cell type-specific hormones, other proteins and sera, and plated on a collagen substrate. SAE cells have been cultured continuously for three years. These cells can be transfected by plasmids and have been cryopreserved. Expressed Sequence Tags generated from a normalized SAE cDNA library included a number of markers for cartilage and muscle, as well as proteins influencing tissue differentiation and development, suggesting that SAE cells may be of mesenchymal stem cell origin. Examination of SAE EST sequences also revealed a cartilaginous fish-specific repetitive sequence that may be evidence of an ancient mobile genetic element that most likely was introduced into the cartilaginous fish lineage after divergence from the lineage leading to teleosts.
背景与目标:
:fish鱼出现于4.5亿年前,主要是鲨鱼,rays鱼和溜冰鞋(弹bra)。它们是最原始的脊椎动物,具有下颚和牙齿,适应性免疫力,加压的循环系统,胸腺,脾脏和与人类相当的肝脏。在生物医学研究中最常用的弹性s是有刺的dog鱼鲨鱼,Squalus acanthias。对狗鱼鲨鱼,小溜冰鞋(Leucoraja erincea)和其他弹性分支进行的比较基因组分析已经深入了解了与人类肝脏功能,多药耐药性,囊性纤维化以及其他生物医学相关过程相关的保守基因功能域。尽管这些动物的基因组信息在进化框架中是有用的,但基因组序列功能的实验验证在很大程度上取决于细胞培养方法。我们已经获得了软骨鱼类的第一个多通道,连续增殖细胞系。该品系从多角鲨的鲨鱼的胚胎开始。将细胞维持在针对鱼类物种改良的培养基中,并补充了细胞类型特异性激素,其他蛋白质和血清,并铺在胶原蛋白底物上。 SAE细胞已经连续培养了三年。这些细胞可以被质粒转染,并且已经被冷冻保存。从标准化的SAE cDNA文库生成的表达序列标签包括许多软骨和肌肉的标志物以及影响组织分化和发育的蛋白质,这表明SAE细胞可能是间充质干细胞来源的。对SAE EST序列的检查还揭示了软骨鱼类特异的重复序列,这可能是古老的移动遗传元件的证据,该遗传基因很可能在与导致硬骨鱼类的血统背道而驰后才被引入到软骨鱼血统中。