2.A mutant, TS-N-121 was obtained by mutation and plate screening from a parent strain Mycobacterium fortuitum MF2 , which could transform sterol into androstanedione as the main product.
2.Most modern eukaryotes rely on fat-like compounds called sterols, such as cholesterol, to build cell membranes and carry out other cellular functions.
5.One possibility is that eukaryotes that make more-modern sterols gained a selective advantage between one billion and 800 million years ago, eventually displacing their protosterol-making counterparts.
6.Because sterols are found throughout the eukaryotic family tree, they are thought to have been present in the last common ancestor of all modern eukaryotes.
7.Benjamin Nettersheim, a geobiologist at the University of Bremen in Germany, Jochen Brocks, a palaeobiogeochemist at the Australian National University in Canberra, and their colleagues decided to focus on short-lived molecules that modern eukaryotes make while synthesizing sterols.