Mitochondrial transcription factor A (TFAM) is increased in rat embryo during placentation and associated with mitochondrial differentiation.
In the current study, the mitochondrial proliferationdifferentiation process was investigated in rat embryo during the placentation process, straight after organogenesis, when there is an important oxidative metabolism activation. For this purpose, on gestational days 11, 12 and 13 we studied the mitochondrial DNA (mtDNA) content and the relative gene expression of proteins involved in mtDNA replication (mitochondrial single strand DNA binding protein (mtSSB)), mtDNA transcription (mitochondrial transcription factor A (TFAM)), as well as in mitochondrial function (cytochrome c oxidase subunit I (COXI)). The results indicated that during placentation important changes in mitochondrial proliferation-differentiation process take place in rat embryo. There is a great decrease in cellular mtDNA content and a rise in the ratio between TFAM and mtDNA accompanied by an increase in COXI gene expression. Thus, we can conclude that on gestational day 13 mitochondrial differentiation predominates over mitochondrial proliferation in embryo cells. Besides, our work reveals that in a physiological condition such as embryonic development the TFAM levels change in order to regulate the transcriptional activity of mtDNA.
Grup de Metabolisme Energètic i Nutrició. Departament de Biologia Fonamental i Ciències de la Salut, Universitat de les Illes Balears, Palma de Mallorca, Spain.
Maria Pilar
MP
Alcolea
Bartomeu
B
Colom
Isabel
I
Lladó
Magdalena
M
Gianotti
Francisco J
FJ
García-Palmer
D000818:Animals; D001483:Base Sequence; D004272:DNA, Mitochondrial / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D003576:Electron Transport Complex IV / Q000235:genetics / Q000378:metabolism; D004622:Embryo, Mammalian / Q000378:metabolism; D005260:Female; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism; D010929:Placentation / Q000235:genetics / Q000502:physiology*; D011247:Pregnancy; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
D004272:DNA, Mitochondrial; D004268:DNA-Binding Proteins; D012333:RNA, Messenger; C489030:Tfam protein, rat; D014157:Transcription Factors; D003576:Electron Transport Complex IV