Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Titre : Genetic diversity and adaptation to environmental challenges of Ethiopian indigenous chicken

Auteur : Vallejo-Trujillo, A.R.

Université de soutenance : University of Nottingham

Grade : Doctor of Philosophy (PhD) 2021

Résumé partiel
Indigenous livestock species are characterized as being locally adapted, displaying low productivity but high levels of genetic diversity. They are usually resistant to diseases and suit smallholder farmers’ needs in harsh environments ; hence, they represent an important resource for achieving food security in developing countries. Understanding the genetic basis of their environmental adaptations has important implications for the design of breeding improvement programs. Likewise, it may guide conservation initiatives aiming to preserve their unique adaptive diversity. Both are equally important in the current climate change scenarios challenging agricultural production systems and threatening livestock diversity.

Under variable tropical ecologies and scavenging conditions, Ethiopian indigenous chickens exhibit unique adaptations to their environments. However, little is known about the genetic mechanisms of these environmental adaptations with, so far, no in-depth analysis of the agroclimatic adaptive stressors.

Here, an innovative approach - that integrates Ecological Niche Modelling (ENM) and genome analyses (signatures of positive selection and genomic-environmental association analyses) – is applied (i) to dissect Ethiopian chicken agro-ecologies leading to the identification of the key environmental stressors, (ii) to identify and to define Ethiopian chicken ecotypes, and (iii) to identify the genetic responses to key environmental stressors.

Mots clés  : Environmental adaptation, Ecotype, Ecological niche modelling, Ethiopian village chicken, Redundancy analysis, Selection signature analysis

Présentation