Bidirectional reflectance distribution function measurements and analysis of retroreflective materials.

We compare the performance of various analytical retroreflecting bidirectional reflectance distribution function (BRDF) models to assess how they reproduce accurately measured data of retroreflecting materials. We introduce a new parametrization, the back vector parametrization, to analyze retroreflecting data, and we show that this parametrization better preserves the isotropy of data. Furthermore, we update existing BRDF models to improve the representation of retroreflective data.

Intron open reading frames as mobile elements and evolution of a group I intron.

Group I introns are proposed to have become mobile following the acquisition of open reading frames (ORFs) that encode highly specific DNA endonucleases. This proposal implies that intron ORFs could behave as autonomously mobile entities. This was supported by abundant circumstantial evidence but no experiment of ORF transfer from an ORF-containing intron to its ORF-less counterpart has been described.

Plasticity of the mitochondrial genome in Podospora. Polymorphism for 15 optional sequences: group-I, group-II introns, intronic ORFs and an intergenic region.

The mitochondrial chromosome of 15 Podospora anserina and one Podospora comata wild-type strains have been extensively examined for the presence of optional elements and for sequence divergence. Among the P. anserina strains, nine optional sequences were found.

Premature death in Podospora anserina: sporadic accumulation of the deleted mitochondrial genome, translational parameters and innocuity of the mating types.

The Podospora anserina premature death syndrome was described as early growth arrest caused by a site-specific deletion of the mitochondrial genome (mtDNA) and occurring in strains displaying the genotype AS1-4 mat-. The AS1-4 mutation lies in a gene encoding a cytosolic ribosomal protein, while mat- is one of the two forms (mat- and mat+) of the mating-type locus. Here we show that, depending on culture conditions, death due to the accumulation of the deleted mtDNA molecule can occur in the AS1-4 mat+ context and can be delayed in the AS1-4 mat- background.