Banca de DEFESA: LUIS ANTONIO CASTILLO CEVALLOS

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : LUIS ANTONIO CASTILLO CEVALLOS
DATE: 26/08/2024
TIME: 09:00
LOCAL: remoto
TITLE:

GENETIC DIVERSITY AND POPULATION STRUCTURE OF LOCALLY ADAPTED SOUTH AMERICAN AND EUROPEAN GOATS

KEY WORDS:

 Genetic variability, native goats, landscape genetics, quantitative synthesis, bibliometrics

PAGES: 147
BIG AREA: Ciências Agrárias
AREA: Zootecnia
SUBÁREA: Genética e Melhoramento dos Animais Domésticos
SUMMARY:

Locally adapted goats are vital for the economy and culture, and they also represent an important reservoir of genetic diversity. However, they face significant threats such as replacement by specialized breeds and the impacts of climate change. Understanding the genetic diversity and structure of these populations is crucial for implementing effective conservation and sustainable management strategies. In this context, our goal was to investigate genetic diversity patterns, population structure, and genetic relationships within and between locally adapted goat populations in South America and Europe, using an integrated approach that includes landscape genetics and metaanalysis of primary study results. Additionally, we conducted a bibliometric analysis to map trends and patterns in research on molecular genetic variation in goats, covering three studies. In the first study, we explored the influence of geography on the genetic diversity and structure of locally adapted goat breeds in Brazil, Spain, and Ecuador. Genotypic information from 15 populations (561 goats) obtained from a panel of 23 microsatellite markers was used, including six local Brazilian breeds, three Spanish breeds, one Ecuadorian breed, one population with no defined racial standard and four exotic breeds, together with their respective geospatial information. The analyses revealed significant levels of genetic diversity in local breeds, with Spanish breeds (Ho = 0.629 and He = 0.685) and the Ecuadorian breed (Ho = 0.628 and He = 0.704) showing greater diversity compared to Brazilian breeds (Ho = 0.583 and He = 0.628). Brazilian breeds Moxotó and Serrana Azul exhibited the lowest genetic diversity. Significant correlations between geographical and genetic distances indicated that geographic isolation is a crucial factor in genetic differentiation among breeds (R² = 0.59; P = 0.000000), and identified genetic barriers restricting gene flow between some populations, creating a geographic pattern of genetic variation and differentiation. In the second study, a meta-analysis compared genetic diversity between native South American and European goat populations. Articles exploring the genetic diversity of these populations using microsatellite markers and SNPs were analyzed. Results showed lower genetic diversity in South American breeds, with negative effect sizes (Hedges’ g) significantly different from zero for mean number of alleles (MNA = -0.22), observed heterozygosity (Ho = -2.08), and expected heterozygosity (He = -0.59). These findings suggest an asymmetric reduction in genetic diversity in South American populations, influenced by different genetic and demographic mechanisms underlying the establishment of goat populations in the two regions. In the third study, a bibliometric analysis was conducted to understand the dynamics and trends in research on genetic diversity in goats, covering the period from 1999 to 2023. Using data from the Web of Science database, the analysis revealed a linear growth in academic output, with an annual growth rate of 8.86%, surpassing many other fields of knowledge. Molecular technologies have evolved significantly, transitioning from microsatellites to SNPs and the emergence of advanced methodologies such as WGS and GBS. The analysis highlighted 1586 researchers, with Verma NK, Aggarwal RAK, and Dixit SP from NBAGR in India, and Martinez AM and Delgado JV from the University of Córdoba in Spain, as the most prolific. International collaboration, particularly in Europe and Asia, was crucial for the field's advancement, with 59% of European countries and 47% of Asian countries involved in research. Europe and Asia are leading in growth, with annual growth rates of 15% or more in 25% and 22% of their countries, respectively. In contrast, Africa, the Americas, and Oceania face challenges limiting their expansion. Approximately 29.7% of articles were published in high-impact journals (≥ 3), and 45.2% in open-access journals, with an average impact factor of 2.5, promoting the dissemination of scientific knowledge. Together, the three chapters of this thesis provide a comprehensive understanding of genetic diversity, population structure, and research trends in locally adapted goats, offering essential information for developing effective conservation and sustainable management strategies to preserve the rich genetic diversity of goat populations in the face of current threats. 

COMMITTEE MEMBERS:
Presidente - LAURA LEANDRO DA ROCHA
Externo à Instituição - ADERBAL CAVALCANTE NETO
Externo à Instituição - EDGAR LENIN AGUIRRE - UNL
Externo à Instituição - HENRIQUE SILVA SÉRVIO
Externo à Instituição - RICCARDO BOZZI - UDS di Pavia