Mitochondrial vs Nuclear GenomeMitochondrial genome
1. Mitochondrial DNA or mt DNA is double stranded and circular.
2. Mitochondrial DNA is not enveloped by a membrane.
3. In Humans, the mitochondrial genome size is 16,569 DNA base pairs.
4. Each mitochondrion contains dozens of copies of mt DNA. Several mitochondria in a cell accounts for 1000 of copies of mt DNA per cell.
5. The mitochondrial genome contains 37 genes that encode 13 proteins, 22 tRNAs, and 2 rRNAs.
6. Mitochondrion is a semi-autonomous organelle as majority of proteins required are coded by nuclear genes.
7. Generally introns or non coding sequences are absent in mitochondrial DNA.
8. Some mitochondrial coding sequences (triplet codons) do not follow the universal codon
pattern, when they are translated into proteins.
Examples: In mitochondrion, AUA codes for methionine (not Isoleucine) and UGA codes for tryptophan (not a stop codon as in mammalian genome).
9. Transcription of mitochondrial genes is polycistronic, an mRNA formed with sequences coding for many proteins.
10. The mitochondrial mode of inheritance is maternal. Therefore mitochondrial associated diseases are inherited maternally.
1.Nuclear DNA is double stranded and linear.
2. Nuclear DNA or genome is enveloped by nuclear membrane.
3. Nuclear genome is made of 3.3 billion DNA base pairs.
4. Only two copies of nuclear genome per somatic cell.
5. Nuclear genome has 20,000-25,000 genes including mitochondrial genes.
6. Nuclear genes codes for all proteins required for its function.
7. Nuclear genome has introns or non-coding DNA and accounts for 93% of total DNA.
8. Nuclear genes show universal codon pattern.
Examples: In nucleus, AUG codes for methionine and UGA is a stop codon.
9. Transcription of nuclear genes is monocistronic, an mRNA with sequence coding for a single protein.
10. The nuclear genome is inherited equally from both parents.
See the Difference between mitochondrial DNA and chloroplast DNA