Dettman, Anderson, and Kohn recently published a paper in BMC Evolutionary Biology on reproductive experimental evolution in two Neurospora crassa populations evolved under different selective conditions. This is a great study that complements work published last year in Nature on experimental evolution in Saccharomyces cerevisiae populations. Neurospora populations were evolved under high salt and low temperature and were started from either high diversity (interspecific crosses, N. crassa vs N. intermedia) or low diversity (intraspecific cross, two N. crassa isolates D143 (Louisiana, USA)and D69 (Ivory Coast)) as described in Figure 1. The experimentally evolved populations were then tested for asexual and sexual fitness (they were taken through complete meiotic cycle throughout the experiment to avoid insure there was selection on the sexual reproduction pathway.
While many strains of S. cerevisiae are being sequenced, a single strain, YJM789, isolated from the lung of an AIDS patient was sequenced a few years ago at Stanford and published this summer. The genome was described in a paper entitled “Genome sequencing and comparative analysis of Saccharomyces cerevisiae strain YJM789”.
A paper in PLoS Biology from Sandy Johnson’s lab entitled “Interlocking Transcriptional Feedback Loops Control White-Opaque Switching in Candida albicans“ discusses phenotype switching in the human pathogenic fungus Candida albicans. Why is the important?
“White-opaque switching is an epigenetic phenomenon, where genetically identical cells can exist in two distinctive cell types, white and opaque. Each cell type is stably inherited for many generations, and switching between the two types of cells occurs stochastically and rarely—roughly one switch in 10^4 cell divisions”
There is also a review by Kira O’Day to discuss the implications of the findings. Understanding this sort of developmental and epigenetic signaling is important to better know how fungi adjust and interact with their environment. However, the authors do conclude that White-Opaque switching is exclusive to Candida albicans so aspects of this research only directly applicable to studies in this system. Phenotype switching is an active area of research for Candida biologists – some nice micrographs and SEM of the different cell morphologies can be seen at Prof. Joachim Morschhäuser’s page (and linked to the right).
I’m including a recapping as many of the talks as I remember. There were 6 concurrent sessions each afternoon so you have to miss a lot of talks. The conference was bursting at the seams as it was- at least 140 people had to be turned away beyond the 750 who attended.
If there was any theme in the conference it was “Hey we are all using these genome sequences we’ve been talking about getting”. I only found the overview talks that solely describe the genome solely a little dry as compared to those more focused on particular questions. I guess my genome palate is becoming refined.