This Article Full Text Full Text (PDF) All Versions of this Article: 135/5/657    most recent REP-07-0577v1 Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Basu, B. Articles by Panicker, M. M Search for Related Content PubMed PubMed Citation Articles by Basu, B. Articles by Panicker, M. M

Serotonin in pre-implantation mouse embryos is localized to the mitochondria and can modulate mitochondrial potential

¹ National Centre for Biological Sciences, Tata Institute of Fundamental Research, UAS-GKVK Campus, Bellary Road, Bangalore 560065, India² Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005, India³ Institute of Bioinformatics, International Tech Park Ltd, 560066 Bangalore, India⁴ Department of Biological Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005, India

Correspondence should be addressed to B Basu; Email: basudha{at}ncbs.res.in; M M Panicker; Email: panic{at}ncbs.res.in

Serotonin is reported to be present in early embryos of many species and plays an important role in early patterning. Since it is a fluorophore, it can be directly visualized using fluorescence microscopy. Here, we use three-photon microscopy to image serotonin in live pre-implantation mouse embryos. We find that it is present as puncta averaging 1.3 square microns and in concentrations as high as 442 mM. The observed serotonin puncta were found to co-localize with mitochondria. Live embryos pre-incubated with serotonin showed a higher mitochondrial potential, indicating that it can modulate mitochondrial potential. Pre-implantation mouse embryos were also examined at various developmental stages for the presence of transcripts of the peripheral and neuronal forms of tryptophan hydroxylase (Tph1 and Tph2 respectively) and the classical serotonin transporter (Slc6a4). Transcripts of Tph2 were seen in oocytes and in two-cell stages, whereas transcripts of Tph1 were not detected at any stage. Transcripts of the transporter, Slc6a4, were present in all pre-implantation stages investigated. These results suggest that serotonin in embryos can arise from a combination of synthesis and uptake from the surrounding milieu.