Landscape genomics and selection signatures of local adaptation of Eritrean indigenous cattle along environmental gradients

作者：Goitom S, Gicheha MG, Njonge FK, Kiplangat N · 发表于：Tropical animal health and production · 年份：2021 · DOI：10.1007/s11250-021-02837-6

Most parts of Eritrea are classified as arid and semi-arid land (ASALs) which are characterised by dryness, high ambient temperatures and low precipitation. The country has three different environmental landscapes: highland, Western lowland and Eastern lowland agro-ecological zones (AEZs). The geophysical and biophysical characteristics of the AEZs vary. Indigenous cattle which are mainly kept in extensive production system have to cope with the adverse climatic conditions of these AEZs. They have to adapt to the harsh climate, poor feed quality and endemic diseases and parasites and reproduction challenges in the AEZs. The underlying genetic basis of the indigenous cattle adaption to the specific AEZs in Eritrea is limited. In this study, it is hypothesized that the indigenous cattle have evolved and developed unique adaptive characteristics because of being reared in specific ecological landscapes. This was tested using the landscape genomics and analysis of selection signatures to ascertain the genetic basis of their adaptability to the nutritional and environmental constraints that characterise the AEZ conditions. The study was carried out in three different environmental landscapes: highland, Eastern lowland and Western lowland AEZs. Blood samples were collected from a total of 188 indigenous cattle populations sampled from the three AEZs. DNA was extracted and genotyped using the genotype by sequencing (GBS) method. Analysis revealed the existence of medium to high gene...