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MfA
01-10-2016, 05:05 PM
Licia Colli, Hovirag Lancioni et al. Whole mitochondrial genomes unveil the impact of domestication on goat matrilineal variability
(http://bmcgenomics.biomedcentral.com/articles/10.1186/s12864-015-2342-2)

Abstract

Background
The current extensive use of the domestic goat (Capra hircus) is the result of its medium size and high adaptability as multiple breeds. The extent to which its genetic variability was influenced by early domestication practices is largely unknown. A common standard by which to analyze maternally-inherited variability of livestock species is through complete sequencing of the entire mitogenome (mitochondrial DNA, mtDNA).

Results
We present the first extensive survey of goat mitogenomic variability based on 84 complete sequences selected from an initial collection of 758 samples that represent 60 different breeds of C. hircus, as well as its wild sister species, bezoar (Capra aegagrus) from Iran. Our phylogenetic analyses dated the most recent common ancestor of C. hircus to ~460,000 years (ka) ago and identified five distinctive domestic haplogroups (A, B1, C1a, D1 and G). More than 90 % of goats examined were in haplogroup A. These domestic lineages are predominantly nested within C. aegagrus branches, diverged concomitantly at the interface between the Epipaleolithic and early Neolithic periods, and underwent a dramatic expansion starting from ~12–10 ka ago.

Conclusions
Domestic goat mitogenomes descended from a small number of founding haplotypes that underwent domestication after surviving the last glacial maximum in the Near Eastern refuges. All modern haplotypes A probably descended from a single (or at most a few closely related) female C. aegagrus. Zooarchaelogical data indicate that domestication first occurred in Southeastern Anatolia. Goats accompanying the first Neolithic migration waves into the Mediterranean were already characterized by two ancestral A and C variants. The ancient separation of the C branch (~130 ka ago) suggests a genetically distinct population that could have been involved in a second event of domestication. The novel diagnostic mutational motifs defined here, which distinguish wild and domestic haplogroups, could be used to understand phylogenetic relationships among modern breeds and ancient remains and to evaluate whether selection differentially affected mitochondrial genome variants during the development of economically important breeds.

lgmayka
01-10-2016, 08:49 PM
I feel obliged to say it again: Attempts to reconstruct the history of animal domestication require analysis of Y chromosomes, not just mitochondrial DNA. The existence of multiple mtDNA haplogroups does not imply a "second event of domestication." The same patrilineage could have impregnated both.

Isidro
01-10-2016, 09:45 PM
Although I agree in principle that reconstructing the history of animal domestication analysis of Y chromosomes is important is not a requirement as a first domestication, since it would be assumed the original or first domestication occurred with the male of the species cancelling the possibility of a feral insemination event.


I feel obliged to say it again: Attempts to reconstruct the history of animal domestication require analysis of Y chromosomes, not just mitochondrial DNA. The existence of multiple mtDNA haplogroups does not imply a "second event of domestication." The same patrilineage could have impregnated both.

lgmayka
01-10-2016, 10:24 PM
Although I agree in principle that reconstructing the history of animal domestication analysis of Y chromosomes is important is not a requirement as a first domestication, since it would be assumed the original or first domestication occurred with the male of the species cancelling the possibility of a feral insemination event.
After that first male is domesticated (possibly because he happened to have a useful mutation making that easier), the only way to continue the domestication is to lead him to inseminate at least one, and probably multiple, females--who could be of many different mtDNA haplogroups. In anthropological terms, this would all be one "domestication event."

Isidro
01-11-2016, 12:57 AM
So the female could not have been inseminated unless the male was domesticated?...that was my point, the female could be domesticated without the necessity of a male domestication.Like I stated in my prior post, I think the Y lines are important to follow but many y lines can and probably have died along the way in any case.


After that first male is domesticated (possibly because he happened to have a useful mutation making that easier), the only way to continue the domestication is to lead him to inseminate at least one, and probably multiple, females--who could be of many different mtDNA haplogroups. In anthropological terms, this would all be one "domestication event."