Relationships between Hha1 Calpastatin Gene Polymorphism, Growth Performance, and Meat Characteristics of Awassi Sheep.

Khaleel I Jawasreh,Ahmad H Al-Amareen,Pauline Y Aad

doi:10.3390/ani9090667

Abstract

Simple SummaryThe Awassi sheep is a very important breed, and using molecular selection to enhance meat production is important. Following genotyping of Awassi sheep housed at two different research stations in Jordan, three genotypes were identified for the calpastatin Hha1 gene. Following a fattening trial, the polymorphic calpastatin gene affected final (marketing) body weight and longissimus muscle width. Hha1 restriction sites found in Calpastatin gene can be used for molecular marker-assisted selection in Awassi for meat purposes.Advances in molecular genetics have allowed the identification of genes that can enhance livestock production. The aim of this study was to investigate possible relationships between the calpastatin (CAST) Hha1 gene polymorphisms and growth performance, carcass characteristics, and meat quality in Awassi sheep. A total of 87 blood samples were collected from two-week-old Awassi ram lambs. The amplification of the CAST Hha1 gene yielded a fragment of 622 bp. Three CAST genotypes were found in Awassi sheep: MM for two fragments (385 bp and 281 bp), MN for three fragments (622 bp, 385 bp, and 281 bp), and NN for only one fragment (622 bp). The M and N allele frequencies of the CAST Hha1 genotypes were 0.765 and 0.235, respectively, while the genotypic frequencies of MM, MN, and NN were 0.586, 0.356, and 0.057, respectively. Based on CAST Hha1 gene polymorphisms, three groups of lambs (MM: n = 8; MN: n = 6; and NN: n = 3 genotypes) were subjected to a fattening period of 70 days to investigate growth performance and meat characteristics. Only the final body weight and longissimus muscle width were significantly different between the three genotypes, while no significant differences were detected in any other carcass characteristics and meat quality parameters. In this study, new variants were observed in CAST using the Hha1 restriction site, potentially assisting in Awassi sheep breeding and selection programs to improve final body weight and longissimus muscle width.

Highlights

Awassi sheep is a multi-purpose, fat-tailed sheep breed [1], predominantly found in Jordan and the Middle East [1]
New variants were observed in CAST using the Hha1 restriction site, potentially assisting in Awassi sheep breeding and selection programs to improve final body weight and longissimus muscle width
New variants were observed in CAST using the Hha1 restriction site, with the NN genotype of the calpstatin gene presenting a low frequency in the Awassi flock; this accounts for the low number of samples analyzed, a major limit of this research

Summary

Introduction

Awassi sheep is a multi-purpose, fat-tailed sheep breed [1], predominantly found in Jordan and the Middle East [1] This breed is well-adapted to harsh environmental conditions [2], and is used for both meat and milk production [1]. In recent years, substantial advances have been made through the application of molecular genetics in the identification of different chromosomal regions and loci that affect traits of interest in livestock production [3]. This has provided opportunities to launch genetic. CAST works by inhibiting protease enzymes that degrade muscle protein, and influences meat production, tenderness, and quality [6]

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