[Protista] No macronuclear regeneration

paul earl pearl at dsi.uanl.mx
Mon Oct 9 11:11:05 EST 2006


It is long known that the process of macronuclear regeneration in 
Paramecium aurelia is a mistake. Misreading the sequence of stages in 
stained slides caused this error. See Sonneborn (Adv Gen 1: 263-358, 
1947), and the most excellent modern view of macronuclear (MA) 
development by M Nowacki et al (Curr Biol15:1616–1628, 2005.). Both 
green fluorencent protein and FISH are very much underused in ciliate 
studies.

When the MA starts to break down, a signal has gone through saying, 
"wrong genotype for the old MA." If "same genotype" is the signal, the 
old genotype can stay and thereby compete with any other MA anlagen. 
Resorption of the old MA without fragmentation is possible, yet seems 
unlikely. When MA fragments appear only in exconjugants the wrong 
genotype signal might have come from the synkarion. All this is 
speculation just as MA regeneration is.

Paul R Earl




More information about the Protista mailing list