Characterization of the increase in mitochondrial respiratory activity during zebrafish embryogenesis.
Drawing from both existing literature and our own research findings, we hypothesized that mitochondrial translation is active in early embryogenesis and contributes to synthesis and assembly of new respiratory complexes, which in turn lead to the increase in the activity of mitochondrial respiratory chain complexes during embryogenesis. However, while our results indicate that mitochondrial ribosomes are capable of translation even during the early stages of embryogenesis, blue native polyacrylamide gel electrophoresis (BN-PAGE) showed revealed that all the respiratory chain complexes are present already in activated oocytes and their abundance remains steady during the early stages of embryogenesis.
In order to identify potential mechanism that might contribute to the increase in mitochondrial activity, we analyzed protein and phospho-protein composition of isolated mitochondria at different stages of embryogenesis. Based on our proteomics results we focused on two potential mechanisms that might contribute to the increase in mitochondrial activity. Firstly, we observed an upregulation of endoplasmic reticulum proteins and cytoplasmic ribosome subunits while the total levels of these proteins remained constant over time. Currently, we are exploring this lead further.
Secondly, we noted a downregulation of proteins associated with mitochondrial fission as development progressed. We are actively investigating whether changes in mitochondrial morphology contribute to the observed increase in mitochondrial activity during development.
