In 1999, a dangerous new strain of the disease-causing fungus Cryptococcus gatti emerged on Vancouver Island, Canada. Several highly virulent strains have since emerged in the northwestern United States, causing serious illness and occasionally death. These outbreak strains are particularly menacing due to their unusual ability to survive and rapidly reproduce inside immune cells that engulf them (pictured). Now, researchers have demonstrated that the genes conferring such traits are easily passed to offspring when the two parent strains are closely related, but those genes are much less likely to be transmitted when the parent strains are distantly related. And although most organisms inherit mitochondrial DNA from one parent, researchers found that offspring of outbreak strains can inherit mitochondrial genes from both parents. This means the fungus can shuffle and recombine its mitochondrial genes as well as its nuclear genes, potentially making it easier to spontaneously develop disease-causing traits.
Written by
BPoD stands for Biomedical Picture of the Day. Managed by the MRC Laboratory of Medical Sciences until Jul 2023, it is now run independently by a dedicated team of scientists and writers. The website aims to engage everyone, young and old, in the wonders of biology, and its influence on medicine. The ever-growing archive of more than 4000 research images documents over a decade of progress. Explore the collection and see what you discover. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.
BPoD is also available in Catalan at www.bpod.cat with translations by the University of Valencia.