A. Fumihito et al., ONE SUBSPECIES OF THE RED JUNGLEFOWL (GALLUS-GALLUS GALLUS) SUFFICES AS THE MATRIARCHIC ANCESTOR OF ALL DOMESTIC BREEDS, Proceedings of the National Academy of Sciences of the United Statesof America, 91(26), 1994, pp. 12505-12509
The noncoding control region of the mitochondrial DNA of various galli
naceous birds was studied with regard to its restriction fragment leng
th polymorphism (RFLP) and sequences of the first 400 bases. Tandem du
plication of the 60-base unit was established as a trait unique to the
genus Gallus, which is shared neither by pheasants nor by quails. Unl
ike its close ally Gallus varius (green junglefowl), the red junglefow
l Gallus gallus is a genetically very diverse species; the 7.0% sequen
ce divergence was seen between those from Thailand (G. g. gallus and G
. g. spadiceus) and the other from the Indonesian island of Java (G. g
. Bankiva). Furthermore, the divergence increased to 27.83% if each tr
ansversion is regarded as an equivalent of 10 transitions. On the othe
r hand, a mere 0.5-3.0% difference (all transitions) separated various
domestic breeds of the chicken from two G. g. gallus of Thailand, thu
s indicating a single domestication event in the area inhabited by thi
s subspecies of the red junglefowl as the origin of all domestic breed
s. Only transitions separated six diverse domesticated breeds. Neverth
eless, a 2.75% difference was seen between RFLP type I breeds (White L
eghorn and Nagoya) and a RFLP type VIII breed (Ayam Pelung). The above
data suggested that although the mitochondrion of RFLP type V was the
main contributor to domestication, hens of other RFLP types also cont
ributed to this event.