Seminar "PRE-NEURONAL SEROTONIN: A NEW OLD FUNCTION OF ANCIENT MOLECULE" by Dr. Evgeny Ivashkin

Ecology and Evolution Unit (Mikheyev Unit) would like to invite you to a seminar by Dr. Evgeny Ivahskin from Institute of Developmental Biology RAS.

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Date:   April 4th, Wednesday, 2018

Time:   1:30 pm – 2pm

Venue: Meeting Room C209, Level C, Centre Building

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Speaker: Dr. Evgeny Ivashkin

Title: PRE-NEURONAL SEROTONIN: a new old function of ancient molecule

Affiliation: Institute of Developmental Biology RAS, Moscow, Russia

Abstract:

Serotonin and dopamine are widely known as neurotransmitters and humoral regulators of different processes in developing embryo and adult body. At the same time, it’s much less known that these substances seem to appear as a signaling molecule at the very early steps of evolution hundreds of millions of years prior to first neurons evolved. Serotonin occurs in prokaryotes, plants, protists and expressed in any of the multicellular animals ever studied. Our data suggests importance of serotonin in the regulation of locomotion and feeding of the most ancient and enigmatic animal - placozoan Trichoplax adhaerens which is lack of nervous system and neurons at all. On the other hand, in higher animals including human monoamines are expressed in the embryos on all stages including male and female gametes, zygote and very early stages of development. However, the role of monoamines in early pre-neuronal development is merely understood.

It is worth mentioning that early developmental stages are especially crucial and are the key for implementation of parental effects. Many embryonic features that will influence the resulting fitness, behavioral modality and future reproductive success of the progeny are initiated during early development. External environmental factors significantly influence organisms at non-genetic level and, in this way, impact the progeny. A number of important characteristics vary under the influence of parental effects and include the dynamics of development and growth, body size, metabolic levels as well as behavioral plasticity. The progenies may retain the non-genetic memory up to three generations after parents were exposed to abnormal temperature, nutrition level, dietary composition, hypoxia, photoperiod, social environment or activity of predators. Generally, non-genetic transfer of information to the progeny is widely spread in nature and varies in terms of molecular mechanisms.

Using freshwater gastropods as a model recently we have discovered an entirely new phenomenon – direct transmission of signal about the physiological condition of the mother’s body to a progeny through the local serotonergic system in the female’s reproductive organs. Such a transmission occurs by means of serotonin content in zygote and early embryo. The entire system includes serotonin receptors, enzymes of serotonin metabolism and transport. Moreover, it recruits the process of monoaminylation (transglutaminase-mediated covalent binding of serotonin to glutamines residues in proteins). We continued our study in this field and our recent research performed on the early embryos of sea urchins and zebrafish revealed some prospective targets for monoaminylation. We hypothesized that both discovered molecular mechanism and principle itself are conservative and vastly distributed in the animals’ phyla. In particular, in sea urchins we have described competitive monoaminylation of proteins in blastomeres with serotonin and dopamine as a direct determinant of primary cilia length at blastula stage. In zebrafish we found that serotonin content in the blastomeres of an early embryo can retain in differentiating cells and directly affect further neural development. Our most recent data suggests that modulation of serotonin level in the pre-implantation embryos of mouse affects behavioral patterns in the age of at least up to 3 months. And thus, our concept may be applicable for human.