Gene family expansions and contractions are associated with host range in plant pathogens of the genus Colletotrichum

Background: Many species belonging to the genus Colletotrichum cause anthracnose disease on a wide range of plant species. In addition to their economic impact, the genus Colletotrichum is a useful model for the study of the evolution of host specificity, speciation and reproductive behaviors. Genome projects of Colletotrichum species have already opened a new era for studying the evolution of pathogenesis in fungi. Results: We sequenced and annotated the genomes of four strains in the Colletotrichum acutatum species complex (CAsc), a clade of broad host range pathogens within the genus. The four CAsc proteomes and secretomes along with those representing an additional 13 species (six Colletotrichum spp. and seven other Sordariomycetes) were classified into protein families using a variety of tools. Hierarchical clustering of gene family and functional domain assignments, and phylogenetic analyses revealed lineage specific losses of carbohydrate-active enzymes (CAZymes) and proteases encoding genes in Colletotrichum species that have narrow host range as well as duplications of these families in the CAsc. We also found a lineage specific expansion of necrosis and ethylene-inducing peptide 1 (Nep1)-like protein (NLPs) families within the CAsc. Conclusions: This study illustrates the plasticity of Colletotrichum genomes, and shows that major changes in host range are associated with relatively recent changes in gene content

Does the band cell survive the 21st century?

Item does not contain fulltextOBJECTIVES: The differentiation of white blood cells is a worldwide-accepted method to obtain medical information. The conventional microscopic differential, however, is a laborious and expensive test with a low statistical value. Especially for band cell identification there is a wide range of variance. In this report we describe the intervariability of band cell enumeration. METHODS: From a septic patient, an EDTA anti-coagulated blood sample was obtained and a smear was made and stained (May-Grunwald Giemsa). A PowerPoint presentation was made twice of 100 random cells and sent to 157 different hospital laboratories in the Netherlands for a leukocyte differential. In the first survey neutrophils were differentiated in segmented and band neutrophils whereas in the second survey no discrimination was made between segmented and band neutrophils. RESULTS: The first survey was responded by 68% of the laboratories (756 individuals) and the second survey by 73% of the laboratories (637 individuals). The laboratory mean values of the segmented neutrophils were 42.9% (SD: 7.8, range 22-64%) and 69.9% (SD: 1.4, range 62-72%) for the first and second survey respectively. For the individual technicians the values of the segmented neutrophils were 43.9% (SD: 11.2, range 15-72%) and 70.0% (SD: 2.0, range 59-77%) for the first and second survey respectively. CONCLUSIONS: Because of the enormous variation of band cell counting we recommend to cease quantitative reporting of band cells, especially since the results only have a clinical relevance in a limited number of pathological circumstances