The Biogenesis of Mitochondria in Neurospora A Summary of Present Findings

Abstract

In the 75 years since the publication of Altmann’s “bioblast theory” the question of how mitochondria are formed by growing cells has been a continuing point of active speculation and discussion. During this period all possible mechanisms for mitochondrial biogenesis have been advanced, but in recent years greater attention has been given in speculations as well as in experimental work to the possibility that new mitochondria are derived through growth and division of pre-existing organelles. The observation that mitochondria contain a DNA of distinct base composition [6, 9] has provided an additional support for such a mechanism, and for some biologists it is now “established” that mitochondria are “self replicating” cell organs, just like Altmann’s bioblasts. The term “self replication” does not properly describe our current understanding of the problem: it fails to acknowledge some important uncertainties concerning mitochondrial biogenesis, and if applied in its strictest sense, it is incorrect.

This work has been supported by a grant from the National Science Foundation.