Endogenous Retroviral Insertions Indicate a Secondary Introduction of Domestic Sheep Lineages to the Caucasus and Central Asia between the Bronze and Iron Age.

Oskar Schroeder,Sabine Reinhold,Norbert Benecke,Kai Kaniuth,Zuogang Peng,Leonid Sverchkov,Andrey Belinskiy,Arne Ludwig,Kai Frölich

doi:10.3390/genes8060165

Abstract

Sheep were one of the first livestock species domesticated by humans. After initial domestication in the Middle East they were spread across Eurasia. The modern distribution of endogenous Jaagsiekte sheep retrovirus insertions in domestic sheep breeds suggests that over the course of millennia, successive introductions of improved lineages and selection for wool quality occurred in the Mediterranean region and most of Asia. Here we present a novel ancient DNA approach using data of endogenous retroviral insertions in Bronze and Iron Age domestic sheep from the Caucasus and Pamir mountain areas. Our findings support a secondary introduction of wool sheep from the Middle East between the Late Bronze Age and Iron Age into most areas of Eurasia.

Highlights

Domestic sheep remain the most important livestock in many regions of Asia to this day.First domesticated in the Fertile Crescent around 10,000 BP [1], they were subsequently spread over Eurasia
Our findings support a secondary introduction of wool sheep from the Middle East between the Late Bronze Age and Iron Age into most areas of Eurasia
Of special importance for the northeastern spread of domestic sheep, and goats and cattle are the Caucasus Mountains [2] and the foothills of the Hindukush and Pamir Mountains in eastern Central Asia [3]. These regions acted as pathways of introduction to northern Central Asia, which was otherwise blocked by inland seas and deserts

Summary

Introduction

Domestic sheep remain the most important livestock in many regions of Asia to this day.First domesticated in the Fertile Crescent around 10,000 BP [1], they were subsequently spread over Eurasia. Domestic sheep remain the most important livestock in many regions of Asia to this day. Of special importance for the northeastern spread of domestic sheep, and goats and cattle are the Caucasus Mountains [2] and the foothills of the Hindukush and Pamir Mountains in eastern Central Asia [3]. These regions acted as pathways of introduction to northern Central Asia, which was otherwise blocked by inland seas and deserts. The Caucasus region is one of the first areas into which domestic sheep were introduced from the Fertile Crescent. In the southern Caucasus, domestic sheep are attested around 8000 BP [4]

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Conclusion