title: Patterns in Saccharomyces cerevisiae yeast colonies via magnetic resonance imaging.
abstract: We report the use of high-resolution magnetic resonance imaging methods to observe pattern formation in colonies of Saccharomyces cerevisiae. Our results indicate substantial signal loss localized in specific regions of the colony rendering useful imaging contrast. This imaging contrast is recognizable as being due to discontinuities in magnetic susceptibility (χ) between different spatial regions. At the microscopic pixel level, the local variations in the magnetic susceptibility (Δχ) induce a loss in the NMR signal, which was quantified via T2and T2* maps, permitting estimation of Δχ values for different regions of the colony. Interestingly the typical petal/wrinkling patterns present in the colony have a high degree of correlation with the estimated susceptibility distribution. We conclude that the presence of magnetic susceptibility inclusions, together with their spatial arrangement within the colony, may be a potential cause of the susceptibility distribution and therefore the contrast observed on the images.
authors.affiliation: Centro Regional de Ciências Nucleares do Nordeste, Comissão Nacional de Energia Nuclear, Av. Prof. Luiz Freire, 200, Cidade Universitária, 50740-540, Recife, Pernambuco, Brazil. romuloptenorio@cnen.gov.br.
authors.forename: Rômulo P
authors.initials: RP
authors.lastname: Tenório
authors.affiliation: Departamento de Física, Universidade Federal de Pernambuco, Av. Prof. Luiz Freire, s/n, Cidade Universitária, 50670-901, Recife, Pernambuco, Brazil.
authors.forename: Wilson
authors.initials: W
authors.lastname: Barros
mesh_terms: D060328:Magnetic Phenomena; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000706:statistics & numerical data; D009172:Mycology / Q000379:methods; D010363:Pattern Recognition, Automated; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000254:growth & development