A single nucleotide polymorphism possibly associated with fat deposition is methylated in the bovine TFAM promoter

Abstract

A single nucleotide polymorphism possibly associated with fat deposition is methylated in the bovine TFAM promoterMitochondrial transcription factor A (TFAM) is a nuclear-encoded mitochondrial protein that plays an important role in energy metabolism and is a candidate gene for fat deposition in cattle and human. In the present study, we characterized the methylation status of bovine TFAM promoter flanking the single nucleotide polymorphism (SNP) rs42159487C>T, previously reported to affect fat deposition. Our results showed that the cytosine at this SNP position is methylated and therefore results in gain/loss of the functional CpG locus (5 m C>T). Promoter constructs developed based on three TFAM SNPs showed that the C/C/C haplotype associated with fat deposition in beef cattle had lower promoter function/activity than A/T/T haplotype. Our results imply that genetic variability underlying gain/loss of the CpG sites in the nuclear-encoded mitochondrial proteins might be good candidate loci for fat deposition phenotypes.Key words: cattle; genetics; genetic polymorphism; candidate genes; gene promoters; TFAM; DNA methylation; CpG island; fat deposition Polimorfno kandidatno mesto, povezano z nalaganjem maščo-be, je metilirano v promotorju gena TFAM pri goveduMitohondrijski transkripcijski faktor A (TFAM) je v jedru kodiran mitohondrijski protein, ki igra pomembno vlogo pri energetskem metabolizmu in je kandidatni gen za nalaganje maščobe pri govedu in človeku. V raziskavi smo opredelili metilacijski status promotorja gena TFAM pri govedu na polimorfnem mestu rs42159487C>T, ki je bil v predhodnih objavah povezan z nalaganjem maščobe. Rezultati so pokazali, da je citozin na mestu tega polimorfizma metiliran in zato povzroča pridobitev/izgubo funkcionalnega CpG lokusa (5mC>T). S promotorskim konstruktom, razvitim na osnovi treh polimorfizmov gena TFAM, smo dokazali, da je haplotip C/C/C, povezan z višjo vsebnostjo maščobe, imel nižjo promotorsko aktivnost v primerjavi s haplotipom A/T/T. Rezultati nakazujejo, da predstavlja genetska variabilnost, povezana s pridobitvijo/ izgubo CpG mest v jedru kodiranih mitohondrijskih proteinov, dobre kandidatne lokuse za študij genetskega ozadja nalaganja maščobe.