Theory of J1c's advantage over J1b and J1d


Posts: 47
Joined: Wed Mar 14, 2012 6:57 pm

MtDNA:
J1c3i
PostPosted: Wed Apr 25, 2012 3:19 pm
At 23andme, Ann Turner indicated there was a batch of new articles posted at The Journal of Genetic Genealogy. One of which, is a June 2011 "On the Structure and Age of Haplogroup JT ˗ A Phylogenetic Tour" by
J. J. (Jim) Logan:
http://www.jogg.info/72/files/Logan.pdf

One passage that intrigued me was:

"Thirdly, within Haplogroup J1 the size of clade J1c is three times as large as J1b and J1d combined. The obvious question is why was J1c so advantaged. This graphic was also drawn to bring out the star-like characteristic of this clade. A likely interpretation of this is that there has been very rapid growth in this population and that there has not been enough time for the drift to result in fixation to fewer well defined clades. Perhaps the J1c clade was at the very front of the "wave of advance" associated with advancement of farming from the Near East into Europe (Slatkin and Hudson, 1991; Rogers and Harpending, 1992; Excoffier and Ray, 2008)."

Could the rapid growth of J1c in Europe be related to the mutation that affects coupling efficiency such that there is a trade-off between highly efficient ATP production and increased heat release in colder temperatures? In the 2009 study, "Mitochondrial DNA Haplogroups influence AIDS Progression" the J1 association signal for accelerated AIDS progression is driven largely by the J1c-14798* haplotype and specific mutations are listed as possibly playing a role:
3010 G>A
13708G>A
14798T>C
A12308G
A1811G

The study found that "uncoupled haplogroups with lower ATP and ROS production (U5 and J) are associated with accelerated disease, whereas more tightly coupled groups (H3 and H4, H5, and H6) are associated with protection, suggesting mitochondrial functional variation plays a role in AIDS progression" resulting in: exacerbat(ing) the energetic effects of the mtDNA depletion [19], disruption of oxidative phosphorylation, antioxidant enzyme deficiency [21], apoptosis [12, 13, 15], and increased oxidative damage observed during AIDS progression." This achilles heel, if you will, of J1c- it's uncoupled nature, is also an adaptive trait for heat release in colder climates.
Mitochondrial DNA Haplogroups influence AIDS Progression
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2699618/

So, what other possible explanations are there for J1c's "advantage" over J1b and J1d? Does anyone know the prevalence of the different subclades in the world?
mtDNA: J1c3i
Husband/son: B1778 R-L226 Frawley from Rathkeale, Limerick, Ireland
Grandpa: 259187 R-L21 DF13+ Griffith from Cardigan, Wales
M102536
23andme V3 upgrade, I'm on openSNP

Return to Haplogroup J (mtDNA)

Who is online

Users browsing this forum: No registered users and 1 guest