Comparative analysis of chimpanzee and human Y chromosomes unveils complex evolutionary pathway

The mammalian Y chromosome has unique characteristics compared with the autosomes or X chromosomes. Here we report the finished sequence of the chimpanzee Y chromosome (PTRY), including 271 kb of the Y-specific pseudoautosomal region 1 and 12.7 Mb of the male-specific region of the Y chromosome. Greater sequence divergence between the human Y chromosome (HSAY) and PTRY (1.78%) than between their respective whole genomes (1.23%) confirmed the accelerated evolutionary rate of the Y chromosome. Each of the 19 PTRY protein-coding genes analyzed had at least one nonsynonymous substitution, and 11 genes had higher nonsynonymous substitution rates than synonymous ones, suggesting relaxation of selective constraint, positive selection or both. We also identified lineage-specific changes, including deletion of a 200-kb fragment from the pericentromeric region of HSAY, expansion of young Alu families in HSAY and accumulation of young L1 elements and long terminal repeat retrotransposons in PTRY. Reconstruction of the common ancestral Y chromosome reflects the dynamic changes in our genomes in the 5-6 million years since speciation.     

Chronic quercetin exposure affects fatty acid catabolism in rat lung

Dietary quercetin intake is suggested to be health promoting, but this assumption is mainly based on mechanistic studies performed in vitro. Previously, we identified rat lung as a quercetin target tissue. To assess relevant in vivo health effects of quercetin, we analyzed mechanisms of effect in rat lungs of a chronic (41 weeks) 1% quercetin diet using whole genome microarrays. We show here that fatty acid catabolism pathways, like beta-oxidation and ketogenesis, are up-regulated by the long-term quercetin intervention. Up-regulation of genes (Hmgcs2, Ech1, Acox1, Pcca, Lpl and Acaa2) was verified and confirmed by quantitative real time PCR. In addition, free fatty acid levels were decreased in rats fed the quercetin diet, confirming that quercetin affects fatty acid catabolism. This in vivo study demonstrates for the first time that fatty acid catabolism is a relevant process that is affected in rats by chronic dietary quercetin. Received 6 July 2006; received after revision 29 August 2006; accepted 28 September 2006     

吉林市的雾淞与秋沙鸭

吉林市位于长白山脚下,由长白山天池瀑布形成的第二松花江弯弯地流过市区。距市区东南几十公里建有一座中型水电站——丰满水电站。由于吉林市和水电站的独特的地理和气象条件,在严寒的冬天,可以在吉林市区江湾路一带十多里的江岸堤边看到堤林路树万朵银花。当地人称曰“树挂”,美名曰“雾淞”。     

面向Deadline约束的网格QoS任务调度

根据调度算法中对QoS的匹配需求,提出了一种基于QoS优先级分组的网格任务调度思想,并且在此基础上引入任务的Deadline约束,综合考虑任务的可接受率以及系统的makespan性能,提出一种面向Dead-line约束的网格任务调度策略QD-Sufferage.实验表明,该算法在makespan、吞吐率等方面的综合性能较以往的算法有较大的提高.     

天文航海CAI软件的研制

通过对三维动画和天文航海中有关算法的研究，用Ｃ语言编制了天文航海ＣＡＩ软件，该软件的完成为天文航海的教学提供了一个有效的工具。     

SNP的检测方法及其在农作物遗传育种中的应用

SNP(单核苷酸多态性)在生物基因组中具有数量多、分布广等特点,是目前广泛应用的第3代分子标记,在现代生物研究方面具有重要的应用价值。本研究综述了SNP的检测方法及其在农作物遗传育种中的应用。     

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