Phylogeography of asian sockeye salmon <i>Oncorhynchus nerka</i> from the data on variability of mitochondrial SNP loci: analysis of scenarios for post-glacial expansion of the species over Asian Pacific coast

Variability of three SNP loci allocated in the mitochondrial DNA ( One_CO1, One_Cytb_17, One_Cytb_26 ) is analyzed for sockeye salmon from its different habitats from Chukotka to Kuril Islands. Two basic haplotypes (GCC and GTT) are revealed in 20 samples of sockeye ( n = 33-100) from 15 lake-river systems. Their ratio is mostly equal, but GTT haplotype prevails in the populations from Kuril Islands (except Shumshu Island) and is absent in the sample from Commander Islands. This geographical pattern is presumably caused by historical-demographic events related to the species range formation in the middle-late Pleistocene: fragmentation of the areal and subsequent secondary contact between early diverged populations. Two scenarios are discussed, both with multiple expansions of the species to Asia during periods of oceanic transgression after Pleistocene glaciation. According to one of the scenarios, the GTT haplotype has more ancient origin somewhere on the mainland, whereas the GCC appeared much later in the central Kamchatka refugia. The second scenario presumes the origin of both haplotypes on Beringia Bridge where they diverged in the times of middle-Pleistocene (Wurm) glaciation

Intrapopulation differentiation of sockeye salmon <i>Oncorhynchus nerka</i> of the lake-river systems on eastern coast of Kamchatka

Intrapopulation differentiation of the two large population systems of sockeye salmon from the Kamchatka and Apuka Rivers in East Kamchatka is considered by analysis of 45 SNP loci. Four samples were analyzed: 2 from the lower Kamchatka River (20 specimens for early run and 100 specimens for late run), 1 from the basin of Lake Azabachye belonged to the same system ( n = 81), and 1 from the Apuka River (53 specimens for mass run). No genetic differences were found between the samples for early run and late run in the Kamchatka River, though the late run sockeye could be subdivided into two genetically and morphologically different groupings, probably spawning in different biotopes: the first represented by small, fast-growing and early maturing individuals and the second represented by bigger, late maturing ones. For the Apuka River, the hypothesis was corroborated on simultaneous run of two genetically and ecologically different groupings of sockeye salmon: they differed statistically by allele and genotype frequencies of SNP loci. The intrapopulation differentiation is comparable or even exceeds the interpopulation differences for sockeye salmon of neighbor populations, though it is unobvious for geographically remote populations. This differentiation is supposedly caused by differences of natural selection in some SNP loci for different habitats

Spatial and ecological structure of the sockeye salmon population Oncorhynchus nerka of Kuril Lake

This study examines the genetic structure of sockeye salmon populations in Kuril lake basin, focusing on the allelic frequencies of SNP loci that potentially carry an adaptive load. Our results reveal the division of sockeye salmon populations into three distinct groups: early river sockeye salmon and two groups of littoral sockeye salmon from the southern and northeastern shores of the lake. This division is supported by the genetic data, which shows that the populations are genetically distinct and have distinct allelic frequencies. Additionally, our analysis reveals that the neutral structure of the population is rather shallow, with only minor differences found between the two ecotypes of sockeye salmon - stream and littoral. These findings suggest that the genetic differences between the populations are primarily driven by adaptive processes, rather than neutral genetic drift

Trajectory of hiPSCs derived neural progenitor cells differentiation into dermal papilla-like cells and their characteristics

Abstract Dermal papilla cells (DPCs) play roles in key functions of the epidermis such as hair generation. The use of human induced pluripotent cells (hiPSCs) makes it possible to obtain DP-like cells and study the molecular mechanisms of DPC development during embryogenesis. In this work, we studied the phenotypic trajectory of hiPSCs during their differentiation into DP-like cells and evaluated the epithelial-mesenchymal interaction potential of the resulting cell line. Specifically, we differentiated hiPSCs into neural progenitor cells (NPCs) and subsequently into DP-like cells. Analysis of bulk RNA-seq data during this process enabled us to observe gene expression dynamics during five stages of dermal differentiation. Furthermore, functional assays (organoids in both collagen gels and hanging drop cultures and tubulogenesis assays) revealed that the dermal cell lines we generated could interact with epidermal cells

Self-Organization Provides Cell Fate Commitment in MSC Sheet Condensed Areas via ROCK-Dependent Mechanism

Multipotent mesenchymal stem/stromal cells (MSC) are one of the crucial regulators of regeneration and tissue repair and possess an intrinsic program from self-organization mediated by condensation, migration and self-patterning. The ability to self-organize has been successfully exploited in tissue engineering approaches using cell sheets (CS) and their modifications. In this study, we used CS as a model of human MSC spontaneous self-organization to demonstrate its structural, transcriptomic impact and multipotent stromal cell commitment. We used CS formation to visualize MSC self-organization and evaluated the role of the Rho-GTPase pathway in spontaneous condensation, resulting in a significant anisotropy of the cell density within the construct. Differentiation assays were carried out using conventional protocols, and microdissection and RNA-sequencing were applied to establish putative targets behind the observed phenomena. The differentiation of MSC to bone and cartilage, but not to adipocytes in CS, occurred more effectively than in the monolayer. RNA-sequencing indicated transcriptional shifts involving the activation of the Rho-GTPase pathway and repression of SREBP, which was concordant with the lack of adipogenesis in CS. Eventually, we used an inhibitory analysis to validate our findings and suggested a model where the self-organization of MSC defined their commitment and cell fate via ROCK1/2 and SREBP as major effectors under the putative switching control of AMP kinase

Long-Term Memory Formation in <i>Drosophila</i> Depends on the 3′UTR of CPEB Gene <i>orb2</i>

Activation of local translation in neurites in response to stimulation is an important step in the formation of long-term memory (LTM). CPEB proteins are a family of translation factors involved in LTM formation. The Drosophila CPEB protein Orb2 plays an important role in the development and function of the nervous system. Mutations of the coding region of the orb2 gene have previously been shown to impair LTM formation. We found that a deletion of the 3’UTR of the orb2 gene similarly results in loss of LTM in Drosophila. As a result of the deletion, the content of the Orb2 protein remained the same in the neuron soma, but significantly decreased in synapses. Using RNA immunoprecipitation followed by high-throughput sequencing, we detected more than 6000 potential Orb2 mRNA targets expressed in the Drosophila brain. Importantly, deletion of the 3′UTR of orb2 mRNA also affected the localization of the Csp, Pyd, and Eya proteins, which are encoded by putative mRNA targets of Orb2. Therefore, the 3′UTR of the orb2 mRNA is important for the proper localization of Orb2 and other proteins in synapses of neurons and the brain as a whole, providing a molecular basis for LTM formation

Proceedings Of The 23Rd Paediatric Rheumatology European Society Congress: Part Two

PubMe