Abstract. As a nicotinamide adenine dinucleotide (NAD)-dependent histone deacetylase
and ADP ribosyl transferase, the silent information regulator 7 (Sirtuin 7,
SIRT7) plays a crucial role in regulating the differentiation of adipocytes
and myoblasts, lipid metabolism, glucose metabolism, and cellular growth in
mammals. It has been hypothesized that SIRT7 affects growth traits in animals;
therefore, in this study, the potential insertion/deletion (indel) of genetic variations within
the ovine SIRT7 gene and their correlation with sheep growth traits
were explored. A total of 709 individuals from five Chinese
and Mongolian sheep breeds were analyzed. Two novel indel loci of the sheep
SIRT7 gene were detected and were named 5′ promoter
region-insertion-7 bp (5′ promoter region-7 bp) and 3′
UTR-insertion-17 bp (3′ UTR-17 bp), respectively. In all of the sheep breeds,
frequencies of the 5′ promoter region-7 bp mutation were low, whereas
mutations of 3′ UTR-17 bp were high in Tong sheep and Lanzhou fat-tail
sheep (LFTS). Furthermore, both indel polymorphisms had significant
associations with different growth characteristics (P<0.05). Among
these associations, the 3′ UTR-17 bp was highly correlated with rump width
in small-tail Han sheep (STHS, rams; P<0.01), and
individuals with the ID genotype had better chest depth values than those
with the II genotype. In this paper, two novel indels within the sheep
SIRT7 gene were identified, and genetic diversity and its
effects on body size traits were explored. These findings will potentially provide
useful DNA markers for the improvement of economic traits in sheep genetic breeding.