Yeast cell membrane visualized by some membrane proteins fused with RFP and GFP fluorescent markersWIKIMEDIA COMMONS, MASUR
Yeast cells are capable of synthesizing steroid molecules—the basic building blocks of the biological membranes that are essential to eukaryotic life—using only trace amounts of oxygen, according to a study published on the website of the Proceedings of the National Academy of Sciences this Monday (August 8).
Life began its 3.8-billion-year evolutionary journey when the Earth was largely devoid of oxygen. For eons, anaerobic organisms ruled the planet until photosynthetic, ancestral bacteria proliferated in the ancient seas and filled the atmosphere with the gas about 2.4 billion years ago, opening the door to aerobic life.
But fossils of ancestral yeast cells harboring ancient steroid molecules—of which oxygen is a key component—indicated that these aerobic organisms were around prior to this profusion of atmospheric oxygen. How ...
