MtDNA control region
Encyclopedia
The mtDNA control region is an area of the mitochondrial genome which is non-coding DNA. It is the most polymorphic
region of the human mtDNA genome, with polymorphism concentrated in hypervariable regions. The average nucleotide diversity
in these regions is 1.7%. Despite this variability, an RNA
transcript from this region has a conserved secondary structure
(pictured) which has been found to be under selective pressure.
The mtDNA control region contains the origin of replication
of one strand, and the origin of transcription
for both strands. There is also an open reading frame
thought to code for 7s ribosomal RNA
in humans but not in mice or cows, where it has been deleted.
are sometimes used synonymously in the literature; specifically the control region includes the D-loop along with adjacent transcription promoter regions. For this reason, the control region is also known by the acronym DLP, standing for D-Loop and associated Promoters.
have been linked with endurance
capacity in human subjects. A 2002 study sequenced
the control region of 55 subjects and compared their haplotype with the increase in VO2 max
after an eight-week training program
. They found that different haplotypes were significantly
linked with the subjects endurance. It was speculated that this was because the control region affects replication and transcription in the mitochondria.
Polymorphism (biology)
Polymorphism in biology occurs when two or more clearly different phenotypes exist in the same population of a species — in other words, the occurrence of more than one form or morph...
region of the human mtDNA genome, with polymorphism concentrated in hypervariable regions. The average nucleotide diversity
Nucleotide diversity
Nucleotide diversity is a concept in molecular genetics which is used to measure the degree of polymorphism within a population.One commonly used measure of nucleotide diversity was first introduced by Nei and Li in 1979...
in these regions is 1.7%. Despite this variability, an RNA
RNA
Ribonucleic acid , or RNA, is one of the three major macromolecules that are essential for all known forms of life....
transcript from this region has a conserved secondary structure
Secondary structure
In biochemistry and structural biology, secondary structure is the general three-dimensional form of local segments of biopolymers such as proteins and nucleic acids...
(pictured) which has been found to be under selective pressure.
The mtDNA control region contains the origin of replication
Origin of replication
The origin of replication is a particular sequence in a genome at which replication is initiated. This can either be DNA replication in living organisms such as prokaryotes and eukaryotes, or RNA replication in RNA viruses, such as double-stranded RNA viruses...
of one strand, and the origin of transcription
Transcription (genetics)
Transcription is the process of creating a complementary RNA copy of a sequence of DNA. Both RNA and DNA are nucleic acids, which use base pairs of nucleotides as a complementary language that can be converted back and forth from DNA to RNA by the action of the correct enzymes...
for both strands. There is also an open reading frame
Open reading frame
In molecular genetics, an open reading frame is a DNA sequence that does not contain a stop codon in a given reading frame.Normally, inserts which interrupt the reading frame of a subsequent region after the start codon cause frameshift mutation of the sequence and dislocate the sequences for stop...
thought to code for 7s ribosomal RNA
Ribosomal RNA
Ribosomal ribonucleic acid is the RNA component of the ribosome, the enzyme that is the site of protein synthesis in all living cells. Ribosomal RNA provides a mechanism for decoding mRNA into amino acids and interacts with tRNAs during translation by providing peptidyl transferase activity...
in humans but not in mice or cows, where it has been deleted.
Distinction from D-loop
The control region and mtDNA D-loopD-loop
In molecular biology, a displacement loop or D-loop is a DNA structure where the two strands of a double-stranded DNA molecule are separated for a stretch and held apart by a third strand of DNA. The third strand has a base sequence which is complementary to one of the main strands and pairs with...
are sometimes used synonymously in the literature; specifically the control region includes the D-loop along with adjacent transcription promoter regions. For this reason, the control region is also known by the acronym DLP, standing for D-Loop and associated Promoters.
Endurance study
mtDNA control region haplotypesHaplotype
A haplotype in genetics is a combination of alleles at adjacent locations on the chromosome that are transmitted together...
have been linked with endurance
Endurance
Endurance is the ability for a human or animal to exert itself and remain active for a long period of time, as well as its ability to resist, withstand, recover from, and have immunity to trauma, wounds, or fatigue. In humans, it is usually used in aerobic or anaerobic exercise...
capacity in human subjects. A 2002 study sequenced
Genetic sequencing
Genetic Sequencing may refer to:* DNA sequencing* Full genome sequencing...
the control region of 55 subjects and compared their haplotype with the increase in VO2 max
VO2 max
VO2 max is the maximum capacity of an individual's body to transport and use oxygen during incremental exercise, which reflects the physical fitness of the individual...
after an eight-week training program
Endurance training
Endurance training is the deliberate act of exercising to increase stamina and endurance. Exercises for endurance tends to be aerobic in nature versus anaerobic movements. Aerobic exercise develops slow twitch muscles...
. They found that different haplotypes were significantly
Statistical significance
In statistics, a result is called statistically significant if it is unlikely to have occurred by chance. The phrase test of significance was coined by Ronald Fisher....
linked with the subjects endurance. It was speculated that this was because the control region affects replication and transcription in the mitochondria.