甘蓝型油菜矮化突变体的茎秆发育转录组分析

甘蓝型油菜矮化突变体"NDF-1"是从高秆油菜"3529"理化诱变群体中分离的矮化突变体,它的株高只有高秆亲本的1/3,是一个优良的甘蓝型油菜矮化资源.本文应用RNA-Seq测序技术分析了"NDF-1"茎开始伸长的抽薹期和花期转录组,为深入了解油菜茎秆发育机理提供基因组层面的参考.抽薹期和花期的测序数据通过筛选得到了4.55亿条质量合格的clean reads.经过对高质量序列的组装注释,筛选得到"NDF-1"和"3529"间的2147条差异表达基因(DEGs).选择其中的20个差异表达基因进行了荧光定量PCR验证.通过GO和KEGG分析,发现"NDF-1"的矮化与赤霉素、生长素和油菜素内酯相关,细胞伸长异常和细胞壁的不正常形成也影响"NDF-1"的茎秆发育.从差异基因中筛选出与植物矮化性状相关的基因,为利用矮化基因改善性状和矮化机理的研究和提供了更多信息.     

Further morphological and molecular studies of driftwood hoppers (Crustacea: Amphipoda: Talitridae) from Mediterranean/north-east Atlantic coastlines

An unknown talitrid was discovered in 2011 in the Swale, UK, living in driftwood. Sequencing of multiple mitochondrial and nuclear genes (cytochrome oxidase I, 18S rDNA and 28S rDNA) confirms that the unknown taxon was close to Orchestia mediterranea A. Costa 1857. The driftwood in which it was found was of Douglas fir (Pseudotsuga menziesii), probably imported from North America. Relative growth methods allow us to reject the null hypothesis that the unknown taxon was a juvenile Orchestia mediterranea. This is because the unknown taxon initiates sexual maturation at an earlier moult number (neoteny) and is predicted to reach terminal moult stages at a much smaller size (dwarfism) than its closest relative O. mediterranea. Both molecular and morphological data confirm that the unknown taxon from the Swale, UK, is a new driftwood specialist taxon, distantly related to the driftwood specialist genus Macarorchestia. Additional data for body length and sex ratios are presented for Macarorchestia. In addition, relative growth methods have shown that the driftwood species Orchestia microphtalma Amanieu and Salvat 1964 is closer to the genus Macarorchestia rather than to the wrack generalist one, Orchestia. This evidence is in line with the molecular results that do not cluster morphologically defined species of Orchestia monophyletically.     

Body size variability and water balance: A comparison between mainland and island populations ofMastomys huberti (Rodentia: Muridae) in Senegal

Generally rodents are found to be larger on islands than on the mainland. However, there are some exceptions to this rule, and the aim of this paper is to examine one of them. On the mainland of Senegal,Mastomys huberti occupies humid habitats. However, it occurs also on dry and sandy islands (Saloum delta), where its representatives are dwarf. Since water availability appeared to be the limiting factor in these islands when compared to the mainland, we studied water turnover characteristics in relation to body size, in mainland and island populations at the end of the dry season, under both field and laboratory conditions. All populations were found to be water balanced in their natural habitats. They presented similar rates of water turnover, even though island animals were subjected to stronger constraints than mainland ones. Laboratory experiments suggested that the physiological plasticity of one of the island populations may be reduced. Island populations have a higher kidney size to body weight ratio than those from the mainland. We propose that smaller size in the islands allows the maintenance of water balance with a smaller amount of water, and that a higher ratio of kidney filtration surface to body size may helpMastomys huberti to survive in dry islands. We discuss the factors responsible for body size variability and variation in water exchange characteristics and conclude that different factors could explain body size variation among island populations, depending on the species considered and the ecological constraints met within the islands.