In Science this week, researchers from the University of Texas at Austin describe a study they conducted in humans and the yeast Saccharomyces cerevisiae indicating that orthologous genes from the two species that diverged about a billion years ago can retain their ancestral functions for just as long. The investigators replaced 414 essential S. cerevisiae genes with their human equivalents and discovered that about 47 percent of the yeast genes could be swapped out without any significant functional differences. Notably, genes located in the same signaling pathways and complexes appeared to retain their ancestral functions for the longest time.
Also in Science, a group of US and Chinese researchers report on the discovery of a gene, dubbed Nix, that plays a role in determining the sex of dengue- and yellow fever-spreading Aedes aegypti mosquitoes, of which only the females feed on human blood and transmit disease. After analyzing the male mosquito genome and identifying a candidate gene that is highly expressed during the insect's embryonic development, the scientists manipulated its expression using the gene-editing technology CRISPR. When the gene's expression was completely eliminated, many male mosquitos lost key features of their genitalia. When expressed on different parts of the genome, many female mosquitos became masculinized. The results could lead to new strategies to control mosquito-transmitted disease, the researchers say.