Saturday, November 29, 2008

Zimbabwean village chickens originate from Southeast Asia and India

A new study shows that village chickens (Gallus gallus) in Zimbabwe originate from two maternal mtDNA lineages. One of these lineages is from Southeast Asia, while the other is from India. The research also identified a third lineage that did not appear in Zimbabwe or other African chickens and likely originates in South China.
These chickens could have been brought by sea trade and logically then they would be related to the chicken species in Madagascar.

Anim Genet. 2008 Dec;39(6):615-22.Click here to read

Mitochondrial DNA D-loop sequences suggest a Southeast Asian and Indian origin of Zimbabwean village chickens.

Institute of Farm Animal Genetics, Friedrich-Loeffler-Institut, Höltystrasse 10, 31535 Neustadt, Germany.

This study sought to assess mitochondrial DNA (mtDNA) diversity and phylogeographic structure of chickens from five agro-ecological zones of Zimbabwe. Furthermore, chickens from Zimbabwe were compared with populations from other geographical regions (Malawi, Sudan and Germany) and other management systems (broiler and layer purebred lines). Finally, haplotypes of these animals were aligned to chicken sequences, taken from GenBank, that reflected populations of presumed centres of domestication. A 455-bp fragment of the mtDNA D-loop region was sequenced in 283 chickens of 14 populations. Thirty-two variable sites that defined 34 haplotypes were observed. In Zimbabwean chickens, diversity within ecotypes accounted for 96.8% of the variation, indicating little differentiation between ecotypes. The 34 haplotypes clustered into three clades that corresponded to (i) Zimbabwean and Malawian chickens, (ii) broiler and layer purebred lines and Northwest European chickens, and (iii) a mixture of chickens from Zimbabwe, Sudan, Northwest Europe and the purebred lines. Diversity among clades explained more than 80% of the total variation. Results indicated the existence of two distinct maternal lineages evenly distributed among the five Zimbabwean chicken ecotypes. For one of these lineages, chickens from Zimbabwe and Malawi shared major haplotypes with chicken populations that have a Southeast Asian background. The second maternal lineage, probably from the Indian subcontinent, was common to the five Zimbabwean chicken ecotypes, Sudanese and Northwest European chickens as well as purebred broiler and layer chicken lines. A third maternal lineage excluded Zimbabwean and other African chickens and clustered with haplotypes presumably originating from South China.