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Biography

A Solovyeva got her MSc degree in Biology from Saint Petersburg State University in the year 2013. Currently, she is pursuing her PhD from Institute of Cytology RAS. She has published 3 papers in reputed journals. She is interested in Molecular and Cell Biology, Histology, Invertebrate Zoology, Developmental Genomics and Evolution.

Abstract

Transposable elements (TEs) are widely spread in all phylogenetic groups and comprise a significant part of eukaryotic genomes. A marine trematode – Himasthla elongata possesses an alternation of sex and parthenogenetic stages. It was believed that trematode parthenitae constitutes a clonal population. But their larvae have different infectivity rates. Thereby, the polymorphism could be expected and it increases the chance for successful host invasion. We found that the S-SAP (Sequence-Specific Amplification Polymorphism) method revealed clonal variability in the H. elongata larvae genomes. The aim was to determine the main components of the variable bands and which could be the source of clonal diversity. Cloning of several bands from S-SAP patterns and their sequence analysis allowed finding the presence of CR1-like and RTEX-like non-LTR (Long Terminal Repeat) TE fragments in the conservative regions in electrophoresis pattern and non-LTR and LTR-like fragments in variable zones. Some sequences are found in transcriptome and seem to belong to active TE copies. The fragment 7.5 cloned from variable bands doesn’t have any ORFs. Dot hybridization revealed that 7.5 prevail in high and medium molecular length bands of S-SAP patterns and it is also present transcriptome. According to PCR analysis, 7.5 seems to be a part of CR1-like elements, but it forms clusters near pericentromeric and subtelomeric zones at chromosomes i.e. near satellite DNA regions. Thus, we suppose that mobile genetic elements play a key role in trematode clonal polymorphisms occurrence.