Biology subjects

Rodina, M.

Publications and source records attributed to Rodina, M..

3 recordsLinked to original sources

bioRxiv2025

Mitochondria as Indispensable Yet Replaceable Components of Germ Plasm: Insights into Primordial Germ Cell Specification in Non-Teleost Sturgeons

While it is widely recognized that mitochondria are components of germ plasm, their specific role in the formation and specification of primordial germ cells (PGCs) remains poorly understood. Furthermore, it has not been established whether mitochondria in germ plasm possess unique characteristics essential for their function. In this study, we demonstrate that mitochondria are indispensable for PGCs development in non-teleost fishes and that their role is not dependent on their origin from germ plasm. Using sturgeon embryos, we showed that UV radiation applied to the vegetal pole effectively eliminates germ plasm, including mitochondria, and prevents PGCs formation. Remarkably, we restored germ plasm function and PGCs development by injecting mitochondria derived from donor eggs, even when these mitochondria were not originally part of the germ plasm. Transplanted mitochondria were successfully identified in larval PGCs using a fluorescent PKH26 tracer, and in interspecies transplantation experiments, their presence was confirmed using species-specific mtDNA and mtRNA primers in larvae and individual PGCs. Our findings reveal that mitochondria are critical but not germ plasm-specific determinants of PGCs formation. This study provides novel insights into the developmental pathways of germ cells and establishes a previously unrecognized flexibility in mitochondrial functionality within the germline. These findings also offer a potential method for conserving matrilineal genetics in critically endangered species like sturgeons, while simultaneously opening new avenues for studying germlines with high interspecies mitochondrial heteroplasmy and contributing to broader evolutionary and conservation biology.

developmental biology↗

bioRxiv2024

Fertilization by short-term stored sperm alters DNA methylation patterns in common carp (Cyprinus carpio) embryos at single-base resolution

Short-term storage of sperm in vitro is widely used for artificial fertilization in aquaculture. It has been shown that short-term storage affects sperm motility characteristics, resulting in diminished fertility. However, the detrimental effects of short-term sperm storage on embryos development have remained largely unexplored in single-base methylome resolution. The main aim of the present study was to investigate DNA methylation in the offspring of common carp (Cyprinus carpio) derived from short-term stored sperm. Sperm were stored in artificial seminal plasma on ice (0-2{degrees}C) for 0, 3 and 6 days in vitro, fertilization was performed using oocytes from a single female, and embryos were collected at the mid-blastula stage. Sperm and embryo DNA was extracted, analysed by liquid chromatography with tandem mass spectrometry (LC-MS/MS) and whole genome bisulfite sequencing (WGBS). DNA methylation was then assessed. Sperm storage showed negative effects on motility, viability and DNA integrity, but had no effect on global DNA methylation of spermatozoa and resulting embryos. Results from the WGBS showed that methylation of 3313 genes was affected in the embryos fertilized with the 6-day-stored sperm, and the differentially methylated regions (DMRs) identified were mainly involved in cell adhesion, calcium, mitogen-activated protein kinase and adrenergic signalling, melanogenesis, metabolism and RNA transport. Such results suggest that prolongation of storage time may have certain impacts on embryonic development. These initial results provide valuable information for future consideration of the DNA methylome in embryos generated from short-term stored sperm, which is widely used for genetic management of broodstock in aquaculture.

molecular biology↗

bioRxiv2021

Does the rainbow trout ovarian fluid guide the spermatozoon on its way to the egg?

Fertilization of freshwater fish occurs in an environment that may negatively affect the gametes; therefore, the specific mechanisms triggering the encounters of gametes would be highly expedient. The egg and ovarian fluid (OF) are likely the primary sources of these triggers in fish that we confirmed here for rainbow trout Oncorhynchus mykiss. The ovarian fluid significantly affected the spermatozoa performance: it supported high velocity for a more extended period and changed the motility pattern from tumbling in water to straightforward moving in the ovarian fluid. Rainbow trout OF induced a trapping chemotaxis-like effect on activated male gametes, and this effect depended on the properties of the activating media. The interaction of the spermatozoa with the attracting agents was accompanied by their "turn-and-run" behavior involving asymmetric flagellar beating and Ca2+ concentration bursts in the bent flagella segment, characteristic of the chemotactic response. Collectively, the ovarian fluid creates the optimal environment for rainbow trout spermatozoa performance, being an effective promoter of fertilization. The individual peculiarities of the egg (ovarian fluid) - sperm interaction in rainbow trout reflect the specific features of the spawning process in this species.

ecology↗