Exploring meiotic recombination and its potential benefits in South African beef cattle : a review

Abstract

Meiotic recombination is a key evolutionary process that generates novel allele combinations during prophase I of meiosis, promoting genetic diversity and enabling the selection of desirable traits in livestock breeding. Although its molecular mechanisms are well-characterised in model organisms such as humans and mice, studies in African indigenous cattle, particularly South African breeds, remain scarce. Key regulators of recombination, including PRDM9, SPO11, and DMC1, play essential roles in crossover formation and genome stability, with mutations in these genes often linked to fertility defects. Despite the Bonsmara and Nguni breeds’ exceptional adaptability to arid and resource-limited environments, little is known about how recombination contributes to their unique genetic architecture and adaptive traits. This review synthesises the current knowledge on the molecular basis of meiotic recombination, with a focus on prophase I events and associated structural proteins and enzymes. It also highlights the utility of genome-wide tools, particularly high-density single nucleotide polymorphism (SNP) markers for recombination mapping. By focusing on the underexplored recombination landscape in South African beef cattle, this review identifies key knowledge gaps. It outlines how recombination studies can inform breeding strategies aimed at enhancing genetic improvement, conservation, and the long-term sustainability of local beef production systems.

SIMPLE SUMMARY By generating novel allele combinations during prophase I of meiosis, meiotic recombination is a fundamental evolutionary mechanism that enhances genetic diversity and supports the selection of desirable traits in livestock breeding. This process is crucial for improving the genetic potential of livestock through selective breeding. While recombination has been studied in commercial cattle breeds from Europe and North America, it remains unexplored and not understood in South African beef cattle, especially the Bonsmara and Nguni breeds. These indigenous breeds are highly valued for their adaptability to harsh, resource-limited environments, yet the genetic mechanisms underlying their resilience and productivity are not well characterised. This review explores how genome-wide technologies, especially those using high-density single nucleotide polymorphism (SNP) markers, can be used to map recombination patterns and identify genes involved in key traits. Applying these tools to South African cattle could enhance breeding strategies by improving the accuracy of selecting animals with a superior genetic merit. Understanding recombination in these breeds will also support their conservation and sustainable use. Ultimately, this knowledge has significant implications for advancing food security, promoting rural development, and ensuring the long-term adaptability of South African beef cattle under climate change.