Variability of myostatin genes in rainbow trout (Oncorhynchus mykiss) strains exhibiting distinct hyperplastic growth: preliminary results (original) (raw)
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Genetic variation at the myostatin locus
… improvement: making it …, 2007
MSTN is a potent negative regulator of skeletal muscle development, and specific nucleotide variants within the coding regions of MSTN are responsible for extreme muscular hypertrophy in cattle. However, these mutations do not account for all heavily muscled phenotypes, and this paper describes additional polymorphic sites within the gene and their heritable combinations. Eighteen polymorphisms were identified in the critical regulatory regions of MSTN, including the loss-offunction mutation nt821del11. Forty-six cattle of Angus origin were genotyped at each of the polymorphic sites. Haplotypes were inferred and the variants were found to segregate in 9 haplotypes. This analysis provides a comprehensive investigation of genetic variation and haplotype diversity at the MSTN locus.
Endocrinology, 2007
Myostatin is an extremely potent negative regulator of vertebrate skeletal muscle development. A phylogenetic analysis suggests that salmonids should possess four distinct genes, although only MSTN-1 orthologs have been characterized. Described herein are the rainbow trout (rt) MSTN-2a and -2b genes and subsequence analysis of their promoters and their quantitative expression profiles. Both genes are similarly organized, contain several putative myogenic response elements, and are legitimate MSTN-2 orthologs based on Bayesian analyses. However, rtMSTN-2b contains two in-frame stop codons within the first exon and unspliced variants of both transcripts were expressed in a tissue-specific manner. Complete splicing of rtMSTN-2a oc-curred only in brain, where expression is highest, whereas rtMSTN-2b transcripts were mostly present in unspliced forms. The presence of stop codons in the rtMSTN-2b open reading frame and the expression of mostly unspliced transcripts indicate that this particular homolog is a pseudogene. These results confirm our previous phylogenetic analysis and suggest that all salmonids likely possess four distinct myostatin genes. The tissue-specific expression and differential processing of both rtMSTN-2 transcripts as well the pseudogenization of rtMSTN-2b may reflect compensatory and adaptive responses to tetraploidization and may help limit rtMSTN-2a's influences primarily to neural tissue. (Endocrinology 148: 2106 -2115, 2007) First
A proposed nomenclature consensus for the myostatin gene family
2007
EVER SINCE ITS DISCOVERY in 1997 (11), myostatin and its negative effects on skeletal muscle mass have understand- ably captivated many biomedical, agricultural, and compar- ative biologists, since the gains in muscle mass associated with the myostatin null phenotype have never been repro- duced by the administration of growth promoters regardless of species or mode of administration (9). The potential
Egyptian Journal of Genetics and Cytology, 2018
Myostatin (MSTN) gene expressed mainly in muscles of animals and human. It acts as a negative regulator of skeletal muscle development that limits skeletal muscle mass. Several mutations have been identified in the MSTN gene which natu-rally occurred in this gene leading to in-crease in skeletal muscle mass conse-quently better growth performance for animal. It has been considered as a candi-date gene for meat selection programs in domestic animals. Therefore, this study aimed to use Polymerase Chain Reaction Single-Strand Conformation Polymor-phism (PCR-SSCP) method to explore genetic polymorphisms of the part of in-tron 2, the coding sequence of exon 3 and a part of the 3’ untranslated region of MSTN gene in rabbits. Also the study evaluated genetic polymorphism of the MSTN gene on slaughter traits and some blood constituents as plasma total protein, Albumin, Globulin, serum Ca and IP in addition to the effect of line and sex on the above traits was also studied in the present inv...
BMC Evolutionary Biology, 2012
Background: Most fishes possess two paralogs for myostatin, a muscle growth inhibitor, while salmonids are presumed to have four: mstn1a, mstn1b, mstn2a and mstn2b, a pseudogene. The mechanisms responsible for preserving these duplicates as well as the depth of mstn2b nonfunctionalization within the family remain unknown. We therefore characterized several genomic clones in order to better define species and gene phylogenies. Results: Gene organization and sequence conservation was particularly evident among paralog groupings and within salmonid subfamilies. All mstn2b sequences included in-frame stop codons, confirming its nonfunctionalization across taxa, although the indels and polymorphisms responsible often differed. For example, the specific indels within the Onchorhynchus tshawytscha and O. nerka genes were remarkably similar and differed equally from other mstn2b orthologs. A phylogenetic analysis weakly established a mstn2b clade including only these species, which coupled with a shared 51 base pair deletion might suggest a history involving hybridization or a shared phylogenetic history. Furthermore, mstn2 introns all lacked conserved splice site motifs, suggesting that the tissue-specific processing of mstn2a transcripts, but not those of mstn2b, is due to alternative cis regulation and is likely a common feature in salmonids. It also suggests that limited transcript processing may have contributed to mstn2b nonfunctionalization. Conclusions: Previous studies revealed divergence within gene promoters while the current studies provide evidence for relaxed or positive selection in some coding sequence lineages. These results together suggest that the salmonid myostatin gene family is a novel resource for investigating mechanisms that regulate duplicate gene fate as paralog specific differences in gene expression, transcript processing and protein structure are all suggestive of active divergence.
The aim of the study was to investigate the restriction fragment length polymorphism (RFLP) of the exon 1–3 fragments from the myostatin gene in two tilapia species, Oreochromis aureus and Oreochromis niloticus. Tissue samples were collected from a total of 50 fish, and the total genomic DNA was extracted and used for PCR amplification. Particular regions of exon 1–3 from the myostatin gene (390, 435 and 342 bp, respectively) were amplified with specific primers for each exon region by using PCR. The PCR-amplified products of each exon region were digested with appropriate restriction endonuclease enzymes and analysed using agarose gel electrophoresis.
Gene, 2007
Whereas the negative muscle regulator myostatin (MSTN) in mammals is almost exclusively expressed in the muscle by a single encoding gene, teleost fish possess at least two MSTN genes which are differentially expressed in both muscular and non-muscular tissues. Duplicated MSTN-1 genes have previously been identified in the tetraploid salmonid genome. From Atlantic salmon we succeeded in isolating the paralogous genes of MSTN-2, which shared about 70% identity with MSTN-1a and -1b. The salmon MSTN-2a cDNA encoded a predicted protein of 363 residues and included the conserved C-terminal bioactive domain. MSTN-2a seemed to be primarily expressed in the brain, and a functional role of teleost MSTN-2 in the neurogenesis similar to the inhibitory action of the closely related GDF-11 in the mammalian brain was proposed. In contrast, a frame-shift mutation in exon 1 of salmon MSTN-2b would lead to the synthesis of a putatively non-functional truncated protein. The absence of processed MSTN-2b mRNA in the examined tissues indicated that this gene has become a non-functional pseudogene. The differential, but partially overlapping, expression patterns of salmon MSTN-2a, -1a and -1b in muscular and non-muscular tissues are probably due to the different arrangement of the potential cis-acting regulatory elements identified in their putative promoter regions. Single and paired E-boxes in the MSTN-1b promoter were shown to bind both homo-and hetero-dimers of the myogenic regulatory factor MyoD and E47 in vitro of importance for initiating the myogenic program. Analyses of nucleotide substitution patterns indicated that the teleost MSTNs essentially have evolved under purifying selection, but a subset of amino acid sites under positive selective pressure were identified within the MSTN1 branch. The results may reflect the evolutionary forces related to adoption of the different functional roles proposed for the teleost MSTN isoforms. The phylogenetic analysis of multiple vertebrate MSTNs suggested at least two separate gene duplication events in the fish lineage. Linkage analysis of polymorphic microsatellites within intron 2 of salmon MSTN-1a and -1b mapped the two genes to different linkage groups in agreement with the tetraploid origin of the duplicated salmonid MSTN-1 and MSTN-2 genes.
BMC Genetics, 2013
Background: Myostatin (MSTN) belongs to the transforming growth factor-β superfamily and is a potent negative regulator of skeletal muscle development and growth in mammals. Most teleost fish possess two MSTN paralogues. However, as a consequence of a recent whole genome-duplication event, salmonids have four: MSTN-1 (−1a and -1b) and MSTN-2 (−2a and -2b). Evidence suggests that teleost MSTN plays a role in the regulation of muscle growth. In the current study, the MSTN-1b gene was re-sequenced and screened for SNP markers in a commercial population of Atlantic salmon. After genotyping 4,800 progeny for the discovered SNPs, we investigated their association with eight harvest traits -four body-weight traits, two ratios of weight traits, flesh colour and fat percentage -using a mixed model association analysis. Results: Three novel SNPs were discovered in the MSTN-1b gene of Atlantic salmon. One of the SNPs, located within the 5′ flanking region (g.1086C > T), had a significant association with harvest traits (p < 0.05), specifically for: Harvest Weight (kg), Gutted Weight (kg), Deheaded Weight (kg) and Fillet Weight (kg). The haplotype-based association analysis was consistent with this result because the two haplotypes that showed a significant association with body-weight traits, hap4 and hap5 (p < 0.05 and p < 0.01, respectively), differ by a single substitution at the g.1086C > T locus. The alleles at g.1086C > T act in an additive manner and explain a small percentage of the genetic variation of these phenotypes. Conclusions: The association analysis revealed that g.1086C > T had a significant association with all body-weight traits under study. Although the SNP explains a small percentage of the variance, our results indicate that a variation in the 5′ flanking region of the myostatin gene is associated with the genetic regulation of growth in Atlantic salmon.