4
$\begingroup$

Some yeast cells have very low mitochondria copy number (see number of mitochondria in non budding cell, you can count mtDNA). This makes them susceptible to fluctuations, and one can conceive that some yeast cells might arise entirely without mitochondria. Would they survive? Could they reproduce?

Please, assume they have all the nutrients required, in particular excess glucose to ferment, so mitochondrial energy output is dispensable.

If you could point me to some references that would be awesome.

$\endgroup$
3
$\begingroup$

Basic answer: Yes, they can survive, but only if they do not need to undergo cellular respiration. I quote from Microbiological Research, Volume 169, Issue 2-3, p. 185-195:

Mitochondrial DNA (mtDNA) is a compulsory genetic component for encoding essential respiratory enzymes in all eukaryotic cells.

In other words, for cellular respiration to occur, the yeast must have the mtDNA. However, the article goes on to explain,

However, some yeast species (called rho positive) could survive without mtDNA under conditions of fermentation (a metabolic pathway alternative to respiration). In these species, partial or complete losses of mtDNA (spontaneous or induced by mutagenic factors) is associated with the formation of respiratory deficient mutants (rho− type or rho0 type) characterised by slow growth on fermentable carbon sources (e.g. glucose) and inability to grow on non-fermentable sources, such as glycerol or ethanol.

In other words, yeast can survive in the presence of correct conditions for fermentation to occur. In the absence of those conditions, the yeast must have the mitochondrial DNA, because in order for it to survive, it must perform cellular respiration.

$\endgroup$
0
$\begingroup$

No, yeast cannot survive without mitochondria. Petite positive yeast can survive on fermentable carbon sources without mitochondrial DNA, but they must have a mitochondrial compartment. Mitochondrial respiration can even be lost in human tissue culture cells, but they too must have mitochondrial compartments. Mitochondrial compartments are where Fe-S cluster assembly and other essential biochemical pathways occur, thus they are required for eucaryotic cells to either live for a long time or reproduce.

$\endgroup$
  • $\begingroup$ Can you add a reference? $\endgroup$ – inf3rno Oct 31 '17 at 0:17

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.