HVR 2 help

[Artemis]

Hi,

First off I belong to Haplogroup I. I got my HVR2 results back not to long ago and noticed from searching all HVR2 results posted that only three other people besides myself have 202G in their sequence, can anyone tell me how rare this is and if it means anything as far as ancestry.

[vraatyah]

Hi,

First off I belong to Haplogroup I

list the whole set of your mutations, please. Both HVS1 and HVS2.

[Artemis]

Hvr1: 16129a,16172c,16223t,16311c,16391a,16519c

Hvr2: 73g,199c,202g,203a,204c,250c,263g,315.1c,455.1t,57 3.1c,573.2c

[vraatyah]

Hvr1: 16129a,16172c,16223t,16311c,16391a,16519c

Hvr2: 73g,199c,202g,203a,204c,250c,263g,315.1c,455.1t,57 3.1c,573.2c

Artemis,

I haven't ever seen 202G in haplogroup I background, at least in the published literature, while it is firmly present in B4b1 sequences which share the transition at 199 with I. The fact is that a bunch of haplogroup-defining mutations around 200th site results in some kind of instability in this region, i.e. a rise of further mutations. As you know, 203 (with several coding region mutations) defines I1a haplogroup; 455.1T is a further branching point within it. If you've already found sequences that share there mutations with your type, those matches are likely to be closer related to you than any other I1a. As to the possible region of origin, it seems to be too wide. I have about 70 I-203 sequences in my database, the major "contributors" are Iceland, Portugal, Finland and, to a lesser extent, Eastern Europe, particularly Hungarian Gypsy. Among the published complete sequences, your closest match is this one from Portugal:

EF177414, Pereira et al. 2006

73-199-203-204-250-263-309.1C-315.1C-455.1T-
574C-750-1438-1719-2706-3107d-3447-3990-4529T-
4769-5460-6734-7028-8251-8616T-8860-9947-10034-
10238-10398-10454-10915-11719-12501-12705-13780-
14766-15043-15326-15924-
16129-16172-16223-16311-16391-16519

I think, if your matches with 202 (those you found at the mitosearch) are all from the same location, it would be a good guess. In phylogeny, if a marker is not considered "weighty" for some reasons, but it is shared by some (related) taxa from the same geographical area, it would be an extra argument to claim the common origin of the species sharing this marker. That's about your 202G.

Valery

[Artemis]

Thank You for the information. The other people with 202G are not all from Hap I, the one that is claims the farthest maternal ancestor is from the British Isles and the other from Hap B farthest ancestor is from Japan, but of course this does not take into account that their could have been marriages between people from other areas of the world that would contribute to the sequence.

[vraatyah]

The other people with 202G are not all from Hap I

only the matches of hg I make sense, with identical (or very close) HVS1. They should also have either 203 or 455.1T in HVS2.

this does not take into account that their could have been marriages between people from other areas of the world that would contribute to the sequence.

Artemis, I don't understand the latter phrase. mtDNA is an isolated DNA molecule inherited without any kind of recombination. One and only one lineage (your mother, her mother etc) may "contribute" to your sequence.

[Artemis]

I do not know much about mitacondrial DNA, so any information is valuble. If I share a specific sequence, or part of a sequence with another person does that mean that some where in the past my mother's ancestors shared a common ancestor with that person's maternal great ancestors even though I do not share the exact complete sequence?

[vraatyah]

I do not know much about mitacondrial DNA, so any information is valuble. If I share a specific sequence, or part of a sequence with another person does that mean that some where in the past my mother's ancestors shared a common ancestor with that person's maternal great ancestors even though I do not share the exact complete sequence?

Exactly. Basically, any correct phylogeny should be based on the full sequences only. The mitochondrial phylogeny is already constructed on the base of such complete sequences. If we know where a particular incomplete sequence could be placed in the phylogenetic tree (i.e. its haplogroup, by comparing it with all known complete sequences) we also know which sequences are closely related to this one - they are exactly those in the same haplogroup.