TOSHIYA NISHIMURA AND MINORU TANAKADeletion of foxl3 in female Japanese rice fish, or medaka, enables the production of viable sperm in the animal’s ovaries, researchers from the National Institute for Basic Biology in Okazaki, Japan, and their colleagues reported in Science this week (June 11).
“This is exciting because it is absolutely unexpected,” said Manfred Schartl of the University of Würzburg in Germany who was not involved in the work. “That these germ cells have genetically determined sexual fate is new.”
“This shows how plastic the sexual fate of these germ cells is in this species,” said Josephine Bowles of the University of Queensland in Australia who also was not involved in the study.
Whether similar genetic control of germ cells occurs in other species remains to be seen.
WIKIMEDIA, DATABASE CENTER FOR LIFE SCIENCESBuilding upon a previous sequencing effort to identify disease-causing de novo mutations in children, investigators from Radboud University Medical Center in the Netherlands and their colleagues set out to estimate the frequency of somatic mosaic mutations in people. Somatic mosaicism, they found, may be responsible for more genomic variation within humans than previously recognized. The team’s results appeared in The American Journal of Human Genetics last week (June 5).
“Given the limitations of current sequencing technologies, this [frequency of mosaic mutations] may be just touching ...