BIOL 371 Lecture Notes - Lecture 7: Heterocyst, Claudian Letters, Nitrogen Fixation
Document Summary
Biol 371 lecture 7 mi(cid:272)ro(cid:271)ial gro(cid:449)th (cid:272)o(cid:374)t". Some prokaryotes display the basic principle of differentiation. Prior to endospore formation, the cell divides asymmetrically. The smaller cell develops into the endospore, which is surrounded by the larger mother cell. Once development is complete, the mother cell bursts, releasing the endospore. Endospore formation is controlled by 4 sigma factors. T(cid:449)o (cid:894) f a(cid:374)d g ) activate genes needed in the forespore (developing endospore) T(cid:449)o (cid:894) e a(cid:374)d k ) activate genes needed in the mother cell. Spoiie removes the phosphate from spoiiaa, and this triggers the latter to remove the anti-sigma factor spoiiab; this liberates the sig(cid:373)a fa(cid:272)tor f , a key step in the sporulation process. The sporulatio(cid:374) sig(cid:374)al, tra(cid:374)s(cid:373)itted (cid:448)ia po0a, a(cid:272)ti(cid:448)ates f i(cid:374) the forespore (cid:894) f is already present in forespore but inactive because it is bound by an anti-sigma factor.
