Alternative Lengthening of Telomeres in Yeast: Old Questions and New Approaches.

Alternative lengthening of telomeres (ALT) is a homologous recombination-based pathway utilized by 10-15% of cancer cells that allows cells to maintain their telomeres in the absence of telomerase. This pathway was originally discovered in the yeast and, for decades, yeast has served as a robust model to study ALT. Using yeast as a model, two types of ALT (-dependent and -independent) have been described.

Meiotic, genomic and evolutionary properties of crossover distribution in Drosophila yakuba.

The number and location of crossovers across genomes are highly regulated during meiosis, yet the key components controlling them are fast evolving, hindering our understanding of the mechanistic causes and evolutionary consequences of changes in crossover rates. Drosophila melanogaster has been a model species to study meiosis for more than a century, with an available high-resolution crossover map that is, nonetheless, missing for closely related species, thus preventing evolutionary context. Here, we applied a novel and highly efficient approach to generate whole-genome high-resolution crossover maps in D.

A unified alternative telomere-lengthening pathway in yeast survivor cells.

Alternative lengthening of telomeres (ALT) is a recombination process that maintains telomeres in the absence of telomerase and helps cancer cells to survive. Yeast has been used as a robust model of ALT; however, the inability to determine the frequency and structure of ALT survivors hinders understanding of the ALT mechanism. Here, using population and molecular genetics approaches, we overcome these problems and demonstrate that contrary to the current view, both RAD51-dependent and RAD51-independent mechanisms are required for a unified ALT survivor pathway.

Support for the Dominance Theory in Transcriptomes.

Interactions among divergent elements of transcriptional networks from different species can lead to misexpression in hybrids through regulatory incompatibilities, some with the potential to generate sterility. While the possible contribution of faster-male evolution to this misexpression has been explored, the role of the hemizygous chromosome (, the dominance theory for transcriptomes) remains yet to be determined. Here, we study genome-wide patterns of gene expression in females and males of , and their hybrids.

Background selection as null hypothesis in population genomics: insights and challenges from studies.

The consequences of selection at linked sites are multiple and widespread across the genomes of most species. Here, I first review the main concepts behind models of selection and linkage in recombining genomes, present the difficulty in parametrizing these models simply as a reduction in effective population size () and discuss the predicted impact of recombination rates on levels of diversity across genomes. Arguments are then put forward in favour of using a model of selection and linkage with neutral and deleterious mutations (i.