Map of human migration out of Africa, according to Mitochondrial DNA. The numbers represent thousands of years before present time. The blue line represents the area covered in ice or tundra during the last great ice age. The North Pole is at the center. Africa, harboring the start of the migration, is at the top left and South America is at the far right.
A person's maternal ancestry can be traced using his or her Mitochondrial DNA (mtDNA). The DNA in the human mitochondria is passed down by the mother unchanged. One exception, which was linked to infertility, has been shown. Additionally, some people cite paternal DNA transmission as invalidating mtDNA testing [2], but this is not considered problematic in scholarly population genetics studies or genetic genealogy.
What gets tested
mtDNA by current conventions is divided into three regions. They are the coding region and two Hyper Variable Regions HVR1 and HVR2). All test results are compared to the mtDNA of a European in Haplogroup H2a2. This sample is known as the Cambridge Reference Sequence (CRS). A list of single nucleotide polymorphisms (SNPs) is returned. Any "mutations" or "transitions" that are found are simply differences from the CRS.
The test results are compared to another person's results to determine the time frame in which the two people shared a most recent common ancestor (MRCA). The two most common mtDNA tests are a sequence of HVR1 and a sequence of both HVR1 and HVR2. Some people are now choosing to have a full sequence performed. This is still somewhat controversial as it may reveal medical information.
Understanding test results
The most basic of mtDNA tests will sequence Hyper Variable Region 1 (HVR1). HVR1 nucleotides are numbered 16001-16569. Some test reports might omit the 16 prefix from HVR1 results. ie 519C and not 16519C.] Haplogroup
Most results include a prediction of mtDNA Haplogroup.
A person's maternal ancestry can be traced using his or her Mitochondrial DNA (mtDNA). The DNA in the human mitochondria is passed down by the mother unchanged. One exception, which was linked to infertility, has been shown. Additionally, some people cite paternal DNA transmission as invalidating mtDNA testing [2], but this is not considered problematic in scholarly population genetics studies or genetic genealogy.
What gets tested
mtDNA by current conventions is divided into three regions. They are the coding region and two Hyper Variable Regions HVR1 and HVR2). All test results are compared to the mtDNA of a European in Haplogroup H2a2. This sample is known as the Cambridge Reference Sequence (CRS). A list of single nucleotide polymorphisms (SNPs) is returned. Any "mutations" or "transitions" that are found are simply differences from the CRS.
The test results are compared to another person's results to determine the time frame in which the two people shared a most recent common ancestor (MRCA). The two most common mtDNA tests are a sequence of HVR1 and a sequence of both HVR1 and HVR2. Some people are now choosing to have a full sequence performed. This is still somewhat controversial as it may reveal medical information.
Understanding test results
The most basic of mtDNA tests will sequence Hyper Variable Region 1 (HVR1). HVR1 nucleotides are numbered 16001-16569. Some test reports might omit the 16 prefix from HVR1 results. ie 519C and not 16519C.] Haplogroup
Most results include a prediction of mtDNA Haplogroup.
Human mitochondrial DNA (mtDNA) haplogroups
If you belong to a Haplogroup that is distantly related to the CRS, then the prediction may be sufficient. Some companies test for specific mutations in the coding region. For large Haplogroups, such as mtDNA Haplogroup H, an extended test is offered to assign a sub-clade.
If you belong to a Haplogroup that is distantly related to the CRS, then the prediction may be sufficient. Some companies test for specific mutations in the coding region. For large Haplogroups, such as mtDNA Haplogroup H, an extended test is offered to assign a sub-clade.
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