AUTOSOMAL-DNA-L ArchivesArchiver > AUTOSOMAL-DNA > 2014-04 > 1397627125
From: Jim Bartlett <>
Subject: Re: [AUTOSOMAL-DNA] Need Help on Triangulated Groups or Phasing andChromosome Mapping
Date: Wed, 16 Apr 2014 01:45:25 -0400
I actually see both.
On some TGs the shared segments stack up pretty nicely. This is an indication that our MCRA passed the same segment down to all of us; or that the segments we each got had crossover points at significant hot spots (which would be normal)
On some other TGs the segments seem to all be overlapping in different ways. But for what I see, there are finite end points on the TG because that's what I got. My Matches may have a larger segment, but we can only share the overlapping portion we both have. In some cases the shared segments seem to vary over the TG such that two such segments in one TG don't overlap each other. I keep looking for a break (crossover) point near the middle of such a TG, but invariably there is a triangulated segment that spans both of the segments that don't overlap.
In general I have different crossover points on the two chromosomes. Sometimes they line up - probably at hot spots. But other that hot spots, there is nothing that looks the same. It's pretty much random for me. My last count was a little over 400 separate segments over 45 chromosomes (for men).
Jim - Sent from my iPhone - FaceTime!
On Apr 16, 2014, at 12:21 AM, "Eric S Johnson" <> wrote:
>> You'll note that the TGs on one row do NOT overlap each
>> other, but usually WILL overlap the TGs on the other row (chromosome). The
>> joints or gaps between TGs are staggered on the two rows.
> Jim, it's my impression the endpoints of the discrete HIRs which create TGs on each of my two chromosomes seem to usually line up with each other. That is, I'll see a dozen matches on chromosome 4 from from 177 to 187 mbp, of which some are on one chromosome (all match each other in FI:A) and the rest are on the other chromosome (all match each other in FI:A). There's always fuzziness around the ends; and often, a meta-TG will be broken up into two or three (discrete) micro-TGs; but the breakpoints on the two chromosomes between the HIR forming the basis of the two TGs at that address seems pretty consistent.
> Is this not your experience?