Uncovering How Ethiopian Local Chickens Adapt Naturally

Jim Crocker
21st March, 2024

Uncovering How Ethiopian Local Chickens Adapt Naturally

Image Source: Ernesto Alejandro Pérez (photographer)

Key Findings

  • Study in Ethiopia finds local chickens adapt genetically to their diverse environments
  • Chickens at high altitudes show genetic traits for coping with low oxygen levels
  • Findings aid breeding programs to improve chicken resilience to climate change
In the tropical regions, climate change poses a significant challenge to livestock production, impacting the availability of resources like feed and water, the prevalence of diseases, and the overall biodiversity. Understanding how local livestock adapts to their environments is crucial, especially for designing breeding programs that aim to bolster both productivity and resilience in the face of these changes. Wageningen University & Research has embarked on a study[1] to shed light on this issue, focusing on Ethiopian indigenous chickens, which are integral to the livelihoods of many rural households in Ethiopia[2]. Ethiopian indigenous chickens are a prime example of livestock that has been shaped by their environment due to the country's diverse agroecologies and long history of domestication[2]. This study leverages a wealth of environmental, genomic, and phenotypic data to explore the adaptability of these chickens to various environmental conditions. By adopting a hybrid sampling strategy, researchers were able to encompass a broad spectrum of biological and ecological variability across Ethiopia. The environmental data consisted of average values of 34 variables related to climate, vegetation, and soil, collected over three decades at 260 locations. The biological dataset was equally comprehensive, featuring whole genome sequences and measurements of eight different traits from 513 chickens across 26 populations distributed along four elevation gradients. To identify the genetic markers of adaptation, the study employed signatures of selection analyses, specifically [Formula: see text] and XP-EHH, which are methods used to detect regions of the genome that have been shaped by natural selection. Redundancy analyses (RDA) were also used to pinpoint associations between genotypes and environmental factors, as well as between genotypes and phenotypic traits. The RDA revealed 1909 outlier single nucleotide polymorphisms (SNPs), which are variations in the DNA sequence, linked with six environmental factors that drive adaptive phenotypic variation. Additionally, 2430 outlier SNPs were associated with five different traits. Interestingly, there was a significant overlap between the regions identified by both [Formula: see text] and XP-EHH, indicating that these methods are homing in on similar areas of the genome affected by selection. The study found that while genetic differences between elevation gradients were generally low, the XP-EHH signals were strongest between different agroecologies, suggesting that altitude plays a significant role in shaping the genetic landscape of these populations. This finding is in line with other research that has identified physiological and morphological adaptations in high-altitude ruminants[3], underscoring the importance of altitude as an environmental selective pressure. Genes involved in the calcium signaling pathway and those related to hypoxia-inducible factor (HIF) transcription factors were found to be under selection in high-altitude chicken populations. These genes are crucial for physiological responses to low oxygen levels, a condition prevalent in high-altitude environments. The study also found selection signals in genes related to sports performance (GALNTL6), which may indicate adaptations to the physical demands of living at high altitudes. The significance of this study lies in its interdisciplinary approach, combining landscape genomics with environmental and phenotypic analyses, to unravel the complex relationship between genetics, environment, and traits. It builds upon previous work[2][4][5] by providing a more nuanced understanding of how indigenous livestock populations adapt to their environments. For instance, earlier studies have used similar methodologies to investigate the genetic basis of adaptation to environmental stressors in African chickens[5], and the importance of sampling strategies in landscape genomics[4]. This research not only contributes to our understanding of the genetic basis of adaptation but also has practical implications for breeding programs. By identifying the genetic markers associated with desirable traits and environmental resilience, breeders can make more informed decisions to enhance the productivity and sustainability of indigenous livestock populations in the face of climate change. The findings from Wageningen University & Research highlight the intricate dance between genetics and environment and pave the way for future efforts to safeguard the livelihoods of those who depend on these vital animal populations.

GeneticsEcologyAnimal Science

References

Main Study

1) Landscape genomics reveals regions associated with adaptive phenotypic and genetic variation in Ethiopian indigenous chickens.

Published 18th March, 2024

https://doi.org/10.1186/s12864-024-10193-6

Related Studies

2) Species and Phenotypic Distribution Models Reveal Population Differentiation in Ethiopian Indigenous Chickens.

https://doi.org/10.3389/fgene.2021.723360

3) Selection signatures for high-altitude adaptation in ruminants.

https://doi.org/10.1111/age.12900

4) Sampling strategy optimization to increase statistical power in landscape genomics: A simulation-based approach.

https://doi.org/10.1111/1755-0998.13095

5) Natural Selection Footprints Among African Chicken Breeds and Village Ecotypes.

https://doi.org/10.3389/fgene.2019.00376


Related Articles

An unhandled error has occurred. Reload 🗙