Mitochondrial differentiation and oxidative phosphorylation system capacity in rat embryo during placentation period

Abstract

Mitochondrial biogenesis and function are essential for proper embryo development; however, these processes have not been further studied during the placentation period, when important oxidative metabolism activation is taking place. Thus, the aim of the present study was to investigate the oxidative phosphorylation system (OXPHOS) enzymatic activities as well as the expression of genes involved in the coordinated regulation of both mitochondrial and nuclear genomes (peroxisome proliferatoractivated receptor-g coactivator-1a, nuclear respiratory factors 1 and 2, mitochondrial single-strand DNA-binding protein, mitochondrial transcription factor A), and mitochondrial function (cytochrome c oxidase subunit IV, cytochrome c oxidase subunit I and b-ATP phosphohydrolase) in rat embryo throughout the placentation period (gestational days 11, 12 and 13). Our results reflect that embryo mitochondria were enhancing their OXPHOS potential capacities, pointing out that embryo mitochondria become more differentiated during the placentation period. Besides, the current findings show that the mRNAs of the nuclear genes involved in mitochondrial biogenesis were downregulated, whereas their protein content together with the mitochondrial DNA expression were upregulated throughout the period studied. These data indicate that the molecular regulation of the mitochondrial differentiation process during placentation involves a post-transcriptional activation of the nuclear-encoded genes that would lead to an increase in both the nuclear-and mitochondrial-encoded proteins responsible for the mitochondrial biogenic process. As a result, embryo mitochondria would reach a more differentiated stage with a more efficient oxidative metabolism that would facilitate the important embryo growth during the second half of the pregnancy. Reproduction (2007) 134 147-154

Mitochondria Lead the Way: Mitochondrial Dynamics and Function in Cellular Movements in Development and Disease

“…During human embryogenesis, with increasing cell numbers and cellular activity, mitochondria appear elongated (Sathananthan and Trounson, 2000) with elaborate cristae architecture (Stern et al, 1971;Sathananthan and Trounson, 2000). A rapid increase in mitochondrial biogenesis, mtDNA number, OXPHOS activity is also observed in the placentation stage in rat embryos (Alcolea et al, 2007a;Alcolea et al, 2007b).…”

Deregulation of oxidative phosphorylation pathways in embryos derived in vitro from prepubertal and pubertal heifers based on whole-transcriptome sequencing

“…The OXPHOS pathway is a significant source of ATP production in mitochondria and depends on five multisubunit respiratory chain protein complexes that are directly involved in oocyte maturation [ 34 ], fertilization [ 35 ] and preimplantation development of embryos [ 36 , 37 ]. In the current study, we found that the first and fifth complexes of the respiratory chain had the highest number of DEGs.…”

In Vivo and In Vitro Matured Oocytes From Mice of Advanced Reproductive Age Exhibit Alternative Splicing Processes for Mitochondrial Oxidative Phosphorylation

“…In addition, the OXPHOS is the pathway with the most interactions with other pathways, as visualized by a PPI network. The OXPHOS pathway is the major source of ATP production in mitochondria and involves five multi-subunit protein complexes that are associated with oocyte maturation (14), fertilization (58), and embryonic development (59). Furthermore, studies have shown that mitochondria are the major source of ROS and, with increasing age, the amount of ROS increases, thus causing cellular damage and a decline in oocyte quality (51).…”