一项研究发现,本地的熊蜂为了觅食而长距离地寻找物种丰富的花丛,而且提示这些蜂的觅食距离取决于花丛的多样性而非密度。Shalene Jha 和Claire Kremen使用一种种群遗传学方法研究了Bombus vosnesenskii这种熊蜂的觅食模式,这是一种濒危的本地授粉者。这组作者对加州8个研究区域的工蜂进行了取样,并根据它们的DNA的13个微卫星位点确定了这些个体所属的蜂群。然后这组作者根据Bombus vosnesenskii在一个地理区域的姐妹配对的相对频率并且通过计算所有的姐妹配对相互距离多远以及与中心蜂群的假定位置的距离从而估计了这些蜂的最大觅食距离。在被研究的地区,对这些蜂的最大觅食距离的估计从82米到2783米不等,蜂群同伴的平均觅食距离从13米到600米之间,这表明觅食距离比此前认为的差异要大很多。在花丛与花丛之间相对同质的花覆盖区域,蜂为了觅食而远距离地寻找物种丰富性大的花丛。这组作者说,这些结果可能用于指导自然地形和人类改变的地形的管理,从而增加本地蜂筑巢和长距离觅食。(生物谷Bioon.com)
doi:10.1038/ng.2505
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Genome-wide association analyses in east Asians identify new susceptibility loci for colorectal cancer
Wei-Hua Jia,1, 16 Ben Zhang,2, 16 Keitaro Matsuo,3 Aesun Shin,4 Yong-Bing Xiang,5 Sun Ha Jee,6 Dong-Hyun Kim,7 Zefang Ren,1 Qiuyin Cai,2 Jirong Long,2 Jiajun Shi,2 Wanqing Wen,2 Gong Yang,2 Ryan J Delahanty,2 Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO), Colon Cancer Family Registry (CCFR), Bu-Tian Ji,9 Zhi-Zhong Pan,1 Fumihiko Matsuda,10 Yu-Tang Gao,5 Jae Hwan Oh,11 Yoon-Ok Ahn,12 Eun Jung Park,6 Hong-Lan Li,5 Ji Won Park,11 Jaeseong Jo,6 Jin-Young Jeong,7 Satoyo Hosono,3 Graham Casey,13 Ulrike Peters,14, 15 Xiao-Ou Shu,2 Yi-Xin Zeng1, 17 & Wei Zheng2, 17
To identify new genetic factors for colorectal cancer (CRC), we conducted a genome-wide association study in east Asians. By analyzing genome-wide data in 2,098 cases and 5,749 controls, we selected 64 promising SNPs for replication in an independent set of samples, including up to 5,358 cases and 5,922 controls. We identified four SNPs with association P values of 8.58 × 10−7 to 3.77 × 10−10 in the combined analysis of all east Asian samples. Three of the four were replicated in a study conducted in 26,060 individuals of European descent, with combined P values of 1.22 × 10−10 for rs647161 (5q31.1), 6.64 × 10−9 for rs2423279 (20p12.3) and 3.06 × 10−8 for rs10774214 (12p13.32 near the CCND2 gene), derived from meta-analysis of data from both east Asian and European-ancestry populations. This study identified three new CRC susceptibility loci and provides additional insight into the genetics and biology of CRC.