Since Trichomonas is a rather primitive flagellate, my guess is that
short or no G1 is primitive, and that most cell cycle regulation in
these organisms is at the G2->M transition. Many amebae have a
similar cell cycle. The "advantage" of a G1, which presumably evolved
later, then would be the ability to not synthesize DNA unless the
cell is destined to divide soon.
> Dear Biosci Netters:
> We are working on a parasitic protozoa (Trichomonas vaginalis) with a
> dominant G2 phase and a very short G1 phase (less than an hour).
> Traditional G1 phase blockers do not have any effect on this protozoa.
> Do you have any idea about the advantages of having such a short G1
> phase and the possible biochemical differences between mammalian cell
> division cycle.
> Thanks in advance.
> Petrus Tang, Ph.D. (+H!P! ), Assistant Professor,
> Dept. of Parasitology, College of Medicine,
> Chang Gung University
> 259 Wenhwa 1st Road, Kweishan, Taoyuan 333, Taiwan.
> TEL: +886-3-3283016 Ext-5136
> FAX: +886-3-3283031
> E-mail: petang at cguaplo.cgu.edu.tw>>>>