Initial sequencing and comparative analysis of the mouse genome

The sequence of the mouse genome is a key informational tool for understanding the contents of the human genome and a key experimental tool for biomedical research. Here, we report the results of an international collaboration to produce a high-quality draft sequence of the mouse genome. We also present an initial comparative analysis of the mouse and human genomes, describing some of the insights that can be gleaned from the two sequences. We discuss topics including the analysis of the evolutionary forces shaping the size, structure and sequence of the genomes; the conservation of large-scale synteny across most of the genomes; the much lower extent of sequence orthology covering less than half of the genomes; the proportions of the genomes under selection; the number of protein-coding genes; the expansion of gene families related to reproduction and immunity; the evolution of proteins; and the identification of intraspecies polymorphism.     

A map of human genome sequence variation containing 1.42 million single nucleotide polymorphisms

We describe a map of 1.42 million single nucleotide polymorphisms (SNPs) distributed throughout the human genome, providing an average density on available sequence of one SNP every 1.9 kilobases. These SNPs were primarily discovered by two projects: The SNP Consortium and the analysis of clone overlaps by the International Human Genome Sequencing Consortium. The map integrates all publicly available SNPs with described genes and other genomic features. We estimate that 60,000 SNPs fall within exon (coding and untranslated regions), and 85% of exons are within 5 kb of the nearest SNP. Nucleotide diversity varies greatly across the genome, in a manner broadly consistent with a standard population genetic model of human history. This high-density SNP map provides a public resource for defining haplotype variation across the genome, and should help to identify biomedically important genes for diagnosis and therapy.     

断陷盆地构造枢纽部位油气富集规律

以十屋断陷为例,根据其构造演化、主要断层特征及油气成藏条件分析,揭示多旋回断陷盆地构造枢纽带与油气富集关系.结果表明:十屋断陷枢纽部位经历了断陷期、断拗过渡期、拗陷期、萎缩隆升期等复杂的构造演化,多期差异构造变形及断裂活动导致了小宽枢纽带南段和北段具有相似性及差异性,后期构造反转发育部位多为早期断层发育部位,且主要集中在主干断层上,构造运动产生位移被断裂和褶皱吸收;不同阶段的隆起部位相叠加,使枢纽部位与构造高点相对位置发生变化,枢纽部位相对位置由原来的古隆起演变为斜坡部位;枢纽部位早期为油气的有利指向区,晚期具有良好的保存条件,同时发育多类型圈闭、有利沉积相组合及生储盖组合,围绕枢纽带可形成复式油气聚集带.     

A common sequence of calcium and pH signals in the mitogenic stimulation of eukaryotic cells

When normal quiescent (G0) cells are stimulated by mitogens to enter the cell cycle, the metabolic derepression which occurs is similar in a variety of cells. The mechanisms initiating these responses and their relationship to subsequent progression through G1 to DNA synthesis in S phase, however, are generally undefined. The clearest evidence has been obtained in sea urchin eggs, where fertilization by sperm causes a rapid, transient increase in the concentration of free cytoplasmic Ca2+ [(Ca]i), followed by a sustained increase in cytoplasmic pH (pHi). It has been demonstrated clearly that these ionic responses are obligatory for progression to DNA synthesis by the normal pathway after fertilization, although the Ca2+ signal can be bypassed by parthenogenetic agents which elevate directly pHi (for example, NH+4 ions). These observations raise the questions of whether other eukaryotic cells show the same sequence of ionic responses when stimulated by mitogens and whether such signals are an obligatory component of their mitogenic pathways. We show here that a common sequence of [Ca]i and pHi responses occurs in both quiescent mouse thymocytes and Swiss 3T3 fibroblasts stimulated by appropriate mitogens. Furthermore, 'opportunistic' mitogens (those that do not act on the cells in vivo, such as concanavalin A (Con A), the Ca2+ ionophore A23187 and 12-o-tetradecanoyl phorbol 13-acetate CTPA] that are mitogenic for both mouse thymocytes and 3T3 fibroblast, each produce characteristic ionic responses that are the same in both types of cell.