Association analyses of single nucleotide polymorphisms in the <i>leptin</i>and <i>leptin receptor</i>genes on milk and morphological traits in Holstein cows

To date, only a few SNP in the leptin receptor gene have been detected and analyzed while the leptin gene has been extensively characterized and several polymorphisms were detected and associated to functional and productive traits in cattle. In this work, for the first time, the bovine leptin receptor gene was fully characterized by sequencing the whole coding region and part of the 5’ flanking region. A group of 95 Holstein cows was genotyped in order to search for SNP at both the LEPR and LEP genes, and to associate them with milk and morphological traits. Nine novel SNP in the leptin receptor gene and one novel SNP in the leptin gene were detected. Four SNP of the leptin receptor gene and one SNP of leptin gene showed a significant effect on one or more analyzed traits, and, in all cases, the greatest effect was observed on fat content. This study provided knowledge of the existence of further polymorphisms in the leptin receptor and leptin genes that have an influence on some important economic traits.

Telomere shortening as genetic risk factor of liver cirrhosis

Cirrhosis is the main complication of chronic liver disease, leads to progressive liver function impairment and is the main risk factor for the development of liver cancer. Liver failure at endstage cirrhosis is associated with increased mortality with liver transplantation as the only possible treatment at this stage. The pathogenesis of liver cirrhosis is not completely elucidated. Although the common factors leading to liver injury, such as viral hepatitis, alcohol consume or fatty liver disease can be identified in the majority of patients a small percentage of patients have no apparent risk factors. Moreover given the same risk factors, some patients progress to cirrhosis whereas others have a benign course, the reason remains unclear. In order to developnew diagnostic and therapeutic tools, it is s essential to understand the pathogenesis of cirrhosis. The identification of genetic risk factors associated with cirrhosis is one of the possible approach to achieve these goal. In the past years several studies have supported the role of telomere shortening and cirrhosis. In the recent year several studies on the relation between several single nucleotide polymorphism(SNPs) and cirrhosis have been published; it has been proposed also a cirrhosis risk score based on seven SNPs. Also epidemiological studies on identical twins and in different ethnic groups have been supporting the importance of the role of genetic risk factors. Finally in the very recent years it has been suggested that telomere shortening may represent a genetic risk factor for the development of cirrhosis.

蛋白依赖性激酶抑制剂2单核苷酸多态性与冠心病的关联性研究

冠心病是由遗传变异和环境因素共同影响的一种复杂多因素疾病,近年来的研究热点集中于9p21染色体SNPS方面。文章以9号染色体p21细胞周期蛋白依赖性激酶抑制剂2(cyclin dependent kinase inhibitor,CDKN2)基因为着眼点,对其与冠心病相关性的研究进展进行综述。

Why cuckoos should parasitize parrotbills by laying eggs randomly rather than laying eggs matching the egg appearance of parrotbill hosts?

The coevolutionary interaction between cuckoos and their hosts has been studied for a long time, but to date some puzzles still remain unsolved. Whether cuckoos parasitize their hosts by laying eggs randomly or matching the egg morphs of their hosts is one of the mysteries of the cuckoo problem. Scientists tend to believe that cuckoos lay eggs matching the appearance of host eggs due to selection caused by the ability of the hosts to recognize their own eggs.In this paper, we first review previous empirical studies to test this mystery and found no studies have provided direct evidence of cuckoos choosing to parasitize host nests where egg color and pattern match. We then present examples of unmatched cuckoo eggs in host nests and key life history traits of cuckoos, e.g. secretive behavior and rapid egg-laying and link them to cuckoo egg laying behavior. Finally we develop a conceptual model to demonstrate the egg laying behaviour of cuckoos and propose an empirical test that can provide direct evidence of the egg-laying properties of female cuckoos. We speculate that the degree of egg matching between cuckoo eggs and those of the host as detected by humans is caused by the ability of the hosts to recognize their own eggs, rather than the selection of matching host eggs by cuckoos. The case of Common Cuckoos(Cuculus canorus) and their parrotbill hosts(Paradoxornis alphonsianus), where it has been shown that both have evolved polymorphic eggs(mainly blue and white), was used to develop a conceptual model to demonstrate why cuckoos should utilize parrotbill hosts by laying eggs randomly rather than laying eggs matching the appearance of host eggs.In conclusion, we found no evidence for the hypothesis that cuckoos lay eggs based on own egg color matching that of the parrotbill-cuckoo system. We argue theoretically that laying eggs matching those of the hosts in this system violates a key trait of the life history of cuckoos and therefore should be maladaptive.

An Enhanced Automated Signature Generation Algorithm for Polymorphic Malware Detection

Polymorphic malware is a secure menace for application of computer network systems because hacker can evade detection and launch stealthy attacks. In this paper, a novel enhanced automated signature generation （EASG） algorithm to detect polymorphic malware is proposed. The EASG algorithm is composed of enhanced-expectation maximum algorithm and enhanced K-means clustering algorithm. In EASG algorithm, the fixed threshold value is replaced by the decision threshold of interval area. The false positive ratio can be controlled at low level, and the iterative operations and the execution time are effectively reduced. Moreover, the centroid updating is realized by application of similarity metric of Mahalanobis distance and incremental learning. Different malware group families are partitioned by the centroid updating.

CDKN2基因SNP与冠心病发生的关联研究

目的:探讨CDKN2基因邻近的rs10757278、rs10811656和rs1333047这3个位点的变异和冠心病(CAD)发生的关系。方法:选择359例无血缘关系的CAD患者,398例性别、年龄相匹配的健康者作为对照组。利用聚合酶连反应(PCR)扩增其功能区的外显子片段,双脱氧末端终止法测序。家系调查资料包括临床表现、体格检查、心脏超声和心电图。结果:CDKN2基因邻近的rs10757278的GG基因型、rs10811656的T等位基因和rs1333047的TT基因型与CAD发病风险相关联。GG基因型增加CAD发病风险1.91倍(95%CI:1.35～2.68),T等位基因增加CAD发病风险1.67倍(95%CI:1.26～2.23),TT基因型增加CAD发病风险1.57倍(95%CI:1.15～2.06)。结论:CDKN2基因邻近的3个位点变异和CAD发病风险增加相关联。