Mitochondria are the powerhouses of the cell and are involved in processes like cell signalling, differentiation, death, and growth regulation. Mitochondrial DNA is usually inherited maternally through the egg. Exceptions in the universal genetic code in mitochondria provide evidence of their ancient evolutionary origin. Studying the control region of mitochondrial DNA through PCR amplification and statistical analysis can help determine the genetic relationships between organisms like determining Hawaiian green sea turtles are genetically isolated from other Pacific populations.

1. Mitochondria
Using an ancient genome to derive the
evolutionary relatedness among species.

2. What are they?
The powerhouses of the cell
Also involved in intracellular signalling, cell differentiation, cell
death, as well as the control of the cell cycle and cell growth

3. Inheritance of Mitochondria
In most multicellular organisms, mtDNA is inherited from the
mother (maternally inherited).
Mechanisms for this include:
simple dilution (an egg contains 100,000 to 1,000,000 mtDNA
molecules, whereas a sperm contains only 100 to 1000);
degradation of sperm mtDNA in the fertilized egg; and
failure of sperm mtDNA to enter the egg.

5. Evidence of an ancient origin?
Exceptions to the universal genetic code (UGC) in mitochondria
Organism Codon Standard Mitochondria
Mammals AGA, AGG Arginine Stop codon
Invertebrates AGA, AGG Arginine Serine
Fungi CUA Leucine Threonine
All of the AUA Isoleucine Methionine
above UGA Stop codon Tryptophan

7. REs are sequence-specific nucleases

11. Methods Overview
• Collect samples
• Isolate mtDNA
• PCR amplify control region
• Statistical analyses

12. Sample Collection

15. mtDNA Control Region
1. Largest non-coding region of
the mt-genome
2. Concentrated area of
polymorphism
3. Contains Origin of Replication
and Origin of Transcription

19. Conclusion
Hawaiian green turtles are genetically isolated
from the rest of the Pacific; e.g. they are one
discrete genetic stock