Comparative genomics of the eukaryotes

A comparative analysis of the genomes of Drosophila melanogaster, Caenorhabditis elegans, and Saccharomyces cerevisiae-and the proteins they are predicted to encode-was undertaken in the context of cellular, developmental, and evolutionary processes. The nonredundant protein sets of flies and worms are similar in size and are only twice that of yeast, but different gene families are expanded in each genome, and the multidomain proteins and signaling pathways of the fly and worm are far more complex than those of yeast. The fly has orthologs to 177 of the 289 human disease genes examined and provides the foundation for rapid analysis of some of the basic processes involved in human disease.     

功能基因组学研究的有力工具 --比较基因组学

比较基因组学在后基因组时代是一门重要的工具学科。通过不同物种间的基因组序列比较,可以发现生物体中蕴涵的大量生物学信息,其在功能基因组学的研究中将发挥重要作用。文章对比较基因组学的基本理论、应用策略、主要分析步骤及有关分析工具进行了概述。     

Comparative genomics provide a rapid detection of Fusarium oxysporum f. sp. conglutinans

Fusarium oxysporum f.sp.conglutinans(Foc)is the causal agent of Fusarium wilt disease of Brassica oleracea.A rapid,accurate,and reliable method to detect and identify plant pathogens is vitally important to integrated disease management.In this study,using a comparative genome analysis among Fusarium oxysporum(Fo),we developed a Foc-specific primer set(Focs-1/Focs-2)and established a multiplex-PCR assay.In the assay,the Focs-1/Focs-2 and universal primers for Fusarium species(W106R/F106S)could be used to detect Foc isolates in a single PCR reaction.With the optimized PCR parameters,the multiplex-PCR assay showed a high specificity for detecting Foc and was very sensitive to detect as little as100 pg of pure Foc genomic DNA or 1 000 spores in 1 g of twice-autoclaved soil.We also demonstrated that Foc isolates were easily detected from infected plant tissues,as well as from natural field soils,using the multiplex-PCR assay.To our knowledge,this is a first report on detection Fo by comparative qenomic method.     

原生动物起源的模糊性问题及其解决途径

原生动物起源是动物学、生物进化论研究的重要内容之一,原生动物的元祖生物的起源与演化等诸多问题尚不清楚．根据古生物学和现代生物进化论研究的成就,就原生动物起源中起源形成动物、起源生物及其不确定原因进行分析,提出几种理论假设及解决途径．     

Metabolic deficiencies in protozoa induced by thalidomide

Thalidomide inhibits growth of some protozoa. This inhibition was counteracted by nicotinic acid, nicotinamide, nicotinamide adenine dinucleotide, and vitamin K(1). The mechanism of toxicity may be an interference of cellular oxidation. A protozoan test system is useful for studying the potential "side actions" of drugs in higher animals and man.     

Interspecific morphogens regulating prey-predator relationships in protozoa

The ciliate Euplotes octocarinatus and some close relatives of it are triggered by predator-released substances to undergo morphogenetic changes that inhibit their engulfment. The changes occur within a few hours and do not require cell division. They are perpetuated during reproduction so long as the concentration of the morphogen is maintained. The ability of Euplotes to respond to predator-produced signals by a defensive change in cell architecture probably provides an effective mechanism for damping population oscillations ofboth prey and predators andfosters coexistence. The signal-induced cell transformation merits study for its own sake because of its developmental implications.     

Reverse vaccinology and genomics

The genomic revolution has had a dramatic effect on our ability to find new vaccine targets and develop effective vaccines.     

Heterotrophic bacteria and bacterivorous protozoa in oceanic macroaggregates

Oceanic macroaggregates (marine snow and Rhizosolenia mats) sampled from the Sargasso Sea are associated with bacterial and protozoan populations up to four orders of magnitude greater than those present in samples from the surrounding water. Filamentous, curved, and spiral bacteria constituted a higher proportion of the bacteria associated with the particles than were found among bacteria in the surrounding water. Protozoan populations were dominated numerically by heterotrophic microflagellates, but ciliates and amoebas were also observed. Macroaggregates are highly enriched heterotrophic microenvironments in the oceans and may be significant for the cycling of particulate organic matter in planktonic food chains.     

Legionella effectors that promote nonlytic release from protozoa

Legionella pneumophila, the bacterial agent of legionnaires' disease, replicates intracellularly within a specialized vacuole of mammalian and protozoan host cells. Little is known about the specialized vacuole except that the Icm/Dot type IV secretion system is essential for its formation and maintenance. The Legionella genome database contains two open reading frames encoding polypeptides (LepA and LepB) with predicted coiled-coil regions and weak homology to SNAREs; these are delivered to host cells by an Icm/Dot-dependent mechanism. Analysis of mutant strains suggests that the Lep proteins may enable the Legionella to commandeer a protozoan exocytic pathway for dissemination of the pathogen.