Sirna Therapeutics said this week that R Scott Greer has been named chairman of the company's board of directors.
Greer, currently a member of Sirna's board, is also chairman of the boards of Abgenix, a company he founded, and Acologix.
He is also managing director of Numenor Ventures.
Sirna also said this week that Lutz Lingnau has joined the company's board.
Lingnau was a member of the executive board of Schering, and was also president and CEO of Berlex Laboratories, Schering's US drugs group. Sirna President and CEO Howard Robin was previously corporate vice president and general manager at Berlex.
Invitrogen said this week that James Glynn will retire as director of the company at its annual stockholders meeting on April 21 after seven years in the role.
Glynn joined Invitrogen's board of directors in 1998, and has held various positions at the company including CFO and interim CEO.
Upon his retirement, Invitrogen's board will be reduced in size from 10 directors to nine.
Rich Schifreen, vice president of research products at Mirus, has been appointed to the board of Platypus Technologies, a developer of nanotechnologies for the life sciences.