The economics of genes
Why do mitochondria and chloroplast still have some genes?
Mitochondria and chloroplast are the key energy factories of eukaryotes. If you don’t know who are eukaryotes, it’s you, me, and almost every living creature that you see around you. Except for the bacteria, which we generally can't see with the naked eye. But long back mitochondria and chloroplast were independent bacteria. In the course of evolution, they got internalized into other organisms leading to the evolution of eukaryotes. And such parts of eukaryotic cells are called organelles. These organisms became specialized factories focused on one particular task, either photosynthesis or respiration.
How did this happen is still a mystery, but one thing is for sure, these organisms had their own proper genome with hundreds or thousands of genes before they got engulfed. But now, after over a billion years, they have only a handful of genes, hardly about 5% of the original number of genes. Many of the lost genes have vanished while many others migrated to the nucleus.
But the question remains, why do they still have some genes? Why not all or none? A recent publication by Steven kelly analyzes this possibility.
Like all of us, cells also manage their budget. And for cells, the currency is ATP, a molecule that is used in many biological processes as a source of energy.
