排序方式: 共有7条查询结果,搜索用时 15 毫秒
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神经突起生长导向因子(Netrin)蛋白家族是分泌型蛋白质,其通过与不同的受体相互作用,在神经发育过程中起轴突导向和细胞迁移中发挥着双重导向功能.本文分别对涉及到细胞相互作用的Netrin基因家族的起源与进化进行研究.以进化史不同阶段的代表物种作为研究对象,通过使用MEGA的邻接法和似释然法分别对Netrin基因家族构建系统发育树;使用PAML 4.7工具以核苷酸序列作为分析材料进行选择压分析,筛选出发生正选择作用的位点;使用DIVERGE3.0软件对Netrin氨基酸序列进行功能分化分析,筛选出Ⅰ型和Ⅱ型功能分化位点. 相似文献
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Karlsson EK Baranowska I Wade CM Salmon Hillbertz NH Zody MC Anderson N Biagi TM Patterson N Pielberg GR Kulbokas EJ Comstock KE Keller ET Mesirov JP von Euler H Kämpe O Hedhammar A Lander ES Andersson G Andersson L Lindblad-Toh K 《Nature genetics》2007,39(11):1321-1328
With several hundred genetic diseases and an advantageous genome structure, dogs are ideal for mapping genes that cause disease. Here we report the development of a genotyping array with approximately 27,000 SNPs and show that genome-wide association mapping of mendelian traits in dog breeds can be achieved with only approximately 20 dogs. Specifically, we map two traits with mendelian inheritance: the major white spotting (S) locus and the hair ridge in Rhodesian ridgebacks. For both traits, we map the loci to discrete regions of <1 Mb. Fine-mapping of the S locus in two breeds refines the localization to a region of approximately 100 kb contained within the pigmentation-related gene MITF. Complete sequencing of the white and solid haplotypes identifies candidate regulatory mutations in the melanocyte-specific promoter of MITF. Our results show that genome-wide association mapping within dog breeds, followed by fine-mapping across multiple breeds, will be highly efficient and generally applicable to trait mapping, providing insights into canine and human health. 相似文献
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Saal LH Gruvberger-Saal SK Persson C Lövgren K Jumppanen M Staaf J Jönsson G Pires MM Maurer M Holm K Koujak S Subramaniyam S Vallon-Christersson J Olsson H Su T Memeo L Ludwig T Ethier SP Krogh M Szabolcs M Murty VV Isola J Hibshoosh H Parsons R Borg A 《Nature genetics》2008,40(1):102-107
Basal-like breast cancer (BBC) is a subtype of breast cancer with poor prognosis. Inherited mutations of BRCA1, a cancer susceptibility gene involved in double-strand DNA break (DSB) repair, lead to breast cancers that are nearly always of the BBC subtype; however, the precise molecular lesions and oncogenic consequences of BRCA1 dysfunction are poorly understood. Here we show that heterozygous inactivation of the tumor suppressor gene Pten leads to the formation of basal-like mammary tumors in mice, and that loss of PTEN expression is significantly associated with the BBC subtype in human sporadic and BRCA1-associated hereditary breast cancers. In addition, we identify frequent gross PTEN mutations, involving intragenic chromosome breaks, inversions, deletions and micro copy number aberrations, specifically in BRCA1-deficient tumors. These data provide an example of a specific and recurrent oncogenic consequence of BRCA1-dependent dysfunction in DNA repair and provide insight into the pathogenesis of BBC with therapeutic implications. These findings also argue that obtaining an accurate census of genes mutated in cancer will require a systematic examination for gross gene rearrangements, particularly in tumors with deficient DSB repair. 相似文献
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Anna Rising Mona Widhe Jan Johansson My Hedhammar 《Cellular and molecular life sciences : CMLS》2011,68(2):169-184
Spider dragline silk is an outstanding material made up of unique proteins—spidroins. Analysis of the amino acid sequences
of full-length spidroins reveals a tripartite composition: an N-terminal non-repetitive domain, a highly repetitive central
part composed of approximately 100 polyalanine/glycine rich co-segments and a C-terminal non-repetitive domain. Recent molecular
data on the terminal domains suggest that these have different functions. The composite nature of spidroins allows for recombinant
production of individual and combined regions. Miniaturized spidroins designed by linking the terminal domains with a limited
number of repetitive segments recapitulate the properties of native spidroins to a surprisingly large extent, provided that
they are produced and isolated in a manner that retains water solubility until fibre formation is triggered. Biocompatibility
studies in cell culture or in vivo of native and recombinant spider silk indicate that they are surprisingly well tolerated,
suggesting that recombinant spider silk has potential for biomedical applications. 相似文献
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Most foot-propelled swimming birds sweep their webbed feet backwards in a curved path that lies in a plane aligned with the swimming direction. When the foot passes the most outward position, near the beginning of the power stroke, a tangent to the foot trajectory is parallel with the line of swimming and the foot web is perpendicular to it. But later in the stroke the foot takes an increasingly transverse direction, swinging towards the longitudinal axis of the body. Here we show that, early in the power stroke, propulsion is achieved mostly by hydrodynamic drag on the foot, whereas there is a gradual transition into lift-based propulsion later in the stroke. At the shift to lift mode, the attached vortices of the drag-based phase turn into a starting vortex, shed at the trailing edge, and into spiralling leading-edge vortices along the sides of the foot. Because of their delta shape, webbed feet can generate propulsive forces continuously through two successive modes, from drag at the beginning of the stroke, all the way through the transition to predominantly lift later in the stroke. 相似文献
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Salmon Hillbertz NH Isaksson M Karlsson EK Hellmén E Pielberg GR Savolainen P Wade CM von Euler H Gustafson U Hedhammar A Nilsson M Lindblad-Toh K Andersson L Andersson G 《Nature genetics》2007,39(11):1318-1320
The dorsal hair ridge in Rhodesian and Thai Ridgeback dogs is caused by a dominant mutation that also predisposes to the congenital developmental disorder dermoid sinus. Here we show that the causative mutation is a 133-kb duplication involving three fibroblast growth factor (FGF) genes. FGFs play a crucial role in development, suggesting that the ridge and dermoid sinus are caused by dysregulation of one or more of the three FGF genes during development. 相似文献
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