Botrytis Cinerea mating types distribution and NEP1 protein sequence analysis

Mestrado em Engenharia Agronómica - Instituto Superior de AgronomiaBotrytis cinerea [teleomorph: Botryotinia fuckeliana] is a heterothallic filamentous plant pathogenic Ascomycete with over two hundred different hosts, and its control at the crop level is still very difficult to achieve. Sexual reproduction as an active part in the fungus dispersal and variability has been underestimated until recent years. Research leading to more insight into the MAT locus and the fundamental principles of the mating process can prompt new strategies for B. cinerea control. During the B. cinerea infection process, phytotoxic proteins such as NEP1 are produced. Their function is yet to be unraveled, but it was postulated that they might play a role in speciation in the genus Botrytis. This report describes a mating type screening of a population of 80 field isolates of B. cinerea. Findings indicate a typical 1:1 Mendelian distribution of the MAT loci, and one strain with both MAT genes is reported. A scan of the MAT locus suggests the absence of the MAT1-1 locus in dual mating strains. Furthermore, Southern blotting demonstrates for the first time the possible presence of a complete MAT1-1 locus in a dual mating strain, instead of the predicted incomplete MAT1-1 locus (dMAT1). Besides the MAT loci, genomic sequences of the BcNEP1 gene in 16 different B. cinerea strains are analyzed, and results demonstrate the existence of three haplotypes and two alleles. Purifying selection is accounted for evolutionary changes within the gene.Finally, four uORF independent knockout mutants were created. This predicted gene is located within the MAT1-1 locus, but its function is yet to be described

Characterisation of microbial attack on archaeological bone

As part of an EU funded project to investigate the factors influencing bone preservation in the archaeological record, more than 250 bones from 41 archaeological sites in five countries spanning four climatic regions were studied for diagenetic alteration. Sites were selected to cover a range of environmental conditions and archaeological contexts. Microscopic and physical (mercury intrusion porosimetry) analyses of these bones revealed that the majority (68%) had suffered microbial attack. Furthermore, significant differences were found between animal and human bone in both the state of preservation and the type of microbial attack present. These differences in preservation might result from differences in early taphonomy of the bones. © 2003 Elsevier Science Ltd. All rights reserved