Biology subjects

Starunov, V. V.

Publications and source records attributed to Starunov, V. V..

3 recordsLinked to original sources

bioRxiv2023

Spontaneous Intersibling Polymorphism in the Development of Dopaminergic Neuroendocrine Cells in Sea Urchin Larvae: Impacts on the Expansion of Marine Benthic Species

Plasticity of the nervous system enables the formation of the most adaptive neural circuits and the corresponding behavior of animals. The mechanism by which plasticity arises during development and its involvement in animal adaptation is one of the astonishing questions. Sea urchin larvae are known for their evolutionary and ecological diversity as well as their developmental forms and behavioral patterns. This research addresses the intricate neuroendocrine adaptations that govern larval development of sea urchins, focusing on the coordination between dopaminergic (DA) and serotonergic (5-HT) neurons. The study reveals a heterochronic polymorphism in the appearance of post oral DA neurons and confirms the stable differentiation pattern of apical 5-HT neurons in the larvae of Mesocentrotus nudus and Paracentrotus lividus. We demonstrate that an increased number of DA cells and DA application correlate with downward swimming of the larvae. In contrast, 5-HT cells and serotonin application unsure larval upward swimming. As a result, the 5-HT/DA ratio underlay stage-dependent vertical distribution of the larvae within the water column. In larvae of the same age, the precise balance of 5-HT and DA cells underlie the basis for the different potentials of individuals for upward and downward swimming. This coordination in humoral regulation underlies shifts in larval behavior within a single generation. Based on our findings on DA-cells polymorphism, we have proposed a model illustrating how the balance between the serotonin and dopamine systems, shaped by heterochrony in DA cell appearance, impacts larval behavior, reduces competition between siblings and ensures optimal population expansion. The study explores the evolutionary and ecological implications of these neuroendocrine adaptations in marine species.

developmental biology↗

bioRxiv2019

Comparative genomic analysis of Cristatella mucedo provides insights into Bryozoan evolution and nervous system function

This manuscript has been withdrawn by the authors as it was submitted without the full consent of all the authors. Therefore, the authors do not wish this work to be cited as reference for the project. If you have any questions, please contact the corresponding author.

genomics↗

bioRxiv2019

Globins and hemogenic cells in the marine Annelid Platynereis dumerilii shed new light on blood evolution in Bilaterians

BackgroundHow vascular systems and their respiratory pigments evolved is still debated. While many animals present a vascular system, hemoglobin exists as a blood pigment only in a few groups (Vertebrates, Annelids, a few Arthropod and Mollusk species). Hemoglobins are formed of globin sub-units, belonging to multigene families, in various multimeric assemblages. It was so far unclear whether hemoglobin families from different Bilaterian groups had a common origin. ResultsTo unravel globin evolution in Bilaterians, we studied the marine Annelid Platynereis dumerilii, a species with a slow evolving genome. Platynereis exhibits a closed vascular system filled with extracellular hemoglobin. Platynereis genome and transcriptomes reveal a family of 19 globins, nine of which are predicted to be extracellular. Extracellular globins are produced by specialized cells lining the vessels of the segmental appendages of the worm, serving as gills, and thus likely participate in the assembly of the giant hexagonal bilayer hemoglobin of the worm. Extracellular globin mRNAs are absent in smaller juvenile, accumulate considerably in growing and more active worms and peak in swarming adults, as the need for O2 culminates. Next, we conducted a Metazoan-wide phylogenetic analysis of globins using data from complete genomes. We establish that five globin genes (stem globins) were present in the last common ancestor of Bilaterians. Based on these results, we propose a new nomenclature of globins, with five clades. All five ancestral stem-globin clades are retained in some Spiralians, while some clades disappeared early in Deuterostome and Ecdysozoan evolution. All known Bilaterian blood globin families are grouped in a single clade (clade I) together with intracellular globins of Bilaterians devoid of red blood. ConclusionsWe uncover a complex "pre-blood" evolution of globins, with an early gene radiation in ancestral Bilaterians. Circulating hemoglobins in various bilaterian groups evolved convergently, presumably in correlation with animal size and activity. However, all hemoglobins derive from a clade I globin, or cytoglobin, probably involved in intracellular O2 transit and regulation (clade I). The Annelid Platynereis is remarkable in having a large family of extracellular blood globins, while retaining all clades of ancestral Bilaterian globins.

evolutionary biology↗