Molecular cloning of an elongation factor 1alpha and its mRNA localization in testis of the Nile tilapia Oreochromis niloticus

Abstract

During spermatogenesis, many proteins are synthesized in the testis prior to the completion of sperm maturation. Many components are involved in the testicular protein synthesis and one of the components that is implicated in the polypeptide chain elongation is elongation factor 1α. In the present study, the molecular cloning of elongation factor 1α (EF‐1α) was conducted from a testis cDNA library of the Nile tilapia. The cDNA for tilapia EF‐1α (tEF‐1α) contains a complete open reading frame encoding 462 amino acids. The predicted amino acid sequence of EF‐1α shows an approximate 90% similarity to those identified in other teleost fish, such as medaka, sea bream and zebrafish. Northern blotting revealed that the gene is expressed in all of the examined tissues and in ovulated eggs. The results of in situ hybridization indicate that the gene is expressed specifically in Leydig cells in testis, suggesting the involvement of EF‐1α as an actin‐binding protein in the cluster formation of Leydig cells. In the ovary, the gene is expressed in the perinucleolus stage of oocytes, suggesting that EF‐1α is also implicated in oocyte growth.

Heterozygous mutation of eEF1A1b resulted in spermatogenesis arrest and infertility in male tilapia, Oreochromis niloticus

“…Fruit flies ( Drosophila melanogaster ) have two eEF1A genes, one of which is expressed only in certain life history stages 3 4 . In teleosts, only one eEF1A gene has been reported in zebrafish ( Danio rerio ), sea bream ( Sparus aurata ), Nile tilapia ( Oreochromis niloticus ) and medaka ( Oryzias latipes ) 5 6 7 8 . Recently, five eEF1A genes, referred to as eEF1A1-4 and 42Sp50 , have been isolated and their relative expressions are different in ten tissues in flatfish ( Solea senegalensis ) 9 .…”

Effects of seawater and freshwater challenges on the Gh/Igf system in the saline-tolerant blackchin tilapia (Sarotherodon melanotheron)

“…ZF gene and protein nomenclature rules were followed ( 31 ). TaqMan real-time PCR assays were created ( Table 1 ) based on mRNA sequences of tilapia species, i.e., Sarotherodon melanotheron prl ( 32 ), Oreochromis mossambicus igf1 ( 33 ), igf2 ( 34 ), and RNA ribosomal 18s ( rna18s) ( 35 ), and Oreochromis niloticus gh ( 36 ), ghr1 ( 37 ), tnfa ( 38 ), actin beta (actb) ( 39 ), and eukaryotic translation elongation factor 1a (eef1a) ( 40 ), as previously described ( 26 , 28 , 41 – 43 ). Taqman probes were dually labelled at the 5’ end with the fluorescent reporter dye FAM and at the 3’ end with the quencher TAMRA.…”

Molecular characterization and expression analysis of five different elongation factor 1 alpha genes in the flatfish Senegalese sole (Solea senegalensis Kaup): Differential gene expression and thyroid hormones dependence during metamorphosis

“…Whereas eEF1A1 is expressed in all tissues, eEF1A2 is only present in brain, heart, and skeletal muscle, which are tissues composed of cells locked in a state of nonproliferation [ 40 , 45 , 49 , 50 ]. In teleosts, only one actively transcribed eEF1A gene has been reported in Danio rerio [ 51 ], Sparus aurata [ 52 ], Oreochromis niloticus [ 53 ], and Oryzias latipes [ 54 ]. In flatfish, partial sequences of one expressed eEF1A gene have been described in Scophthalmus maximus [ 55 ], Paralichthys olivaceus [ 56 ], and Paralichthys lethostigma [ 57 ].…”