Терёшина Мария Борисовна

Кандидат биологических наук


Научный сотрудник (Лаборатория молекулярных основ эмбриогенеза)

Тел.: +7 (495) 336-86-11

Эл. почта: ma-treshka@yandex.ru

Избранные публикации

  1. Ivanova A.S., Shandarin I.N., Ermakova G.V., Minin A.A., Tereshina M.B., Zaraisky A.G. (2015). The secreted factor Ag1 missing in higher vertebrates regulates fins regeneration in Danio rerio. Sci Rep 5, 8123 [+]

    Agr family includes three groups of genes, Ag1, Agr2 and Agr3, which encode the thioredoxin domain-containing secreted proteins and have been shown recently to participate in regeneration of the amputated body appendages in amphibians. By contrast, higher vertebrates have only Agr2 and Agr3, but lack Ag1, and have low ability to regenerate the body appendages. Thus, one may hypothesize that loss of Ag1 in evolution could be an important event that led to a decline of the regenerative capacity in higher vertebrates. To test this, we have studied now the expression and role of Ag1 in the regeneration of fins of a representative of another large group of lower vertebrates, the fish Danio rerio. As a result, we have demonstrated that amputation of the Danio fins, like amputation of the body appendages in amphibians, elicits an increase of Ag1 expression in cells of the stump. Furthermore, down-regulation of DAg1 by injections of Vivo-morpholino antisense oligonucleotides resulted in a retardation of the fin regeneration. These data are in a good agreement with the assumption that the loss of Ag1 in higher vertebrates ancestors could lead to the reduction of the regenerative capacity in their modern descendants.

    ID:1248
  2. Tereshina M.B., Ermakova G.V., Ivanova A.S., Zaraisky A.G. (2014). Ras-dva1 small GTPase regulates telencephalon development in Xenopus laevis embryos by controlling Fgf8 and Agr signaling at the anterior border of the neural plate. Biol Open , [+]

    We previously found that the small GTPase Ras-dva1 is essential for the telencephalic development in Xenopus laevis because Ras-dva1 controls the Fgf8-mediated induction of FoxG1 expression, a key telencephalic regulator. In this report, we show, however, that Ras-dva1 and FoxG1 are expressed in different groups of cells; whereas Ras-dva1 is expressed in the outer layer of the anterior neural fold, FoxG1 and Fgf8 are activated in the inner layer from which the telencephalon is derived. We resolve this paradox by demonstrating that Ras-dva1 is involved in the transduction of Fgf8 signal received by cells in the outer layer, which in turn send a feedback signal that stimulates FoxG1 expression in the inner layer. We show that this feedback signal is transmitted by secreted Agr proteins, the expression of which is activated in the outer layer by mediation of Ras-dva1 and the homeodomain transcription factor Otx2. In turn, Agrs are essential for maintaining Fgf8 and FoxG1 expression in cells at the anterior neural plate border. Our finding reveals a novel feedback loop mechanism based on the exchange of Fgf8 and Agr signaling between neural and non-neural compartments at the anterior margin of the neural plate and demonstrates a key role of Ras-dva1 in this mechanism.

    ID:1007
  3. Tereshina M.B., Bayramov A.V., Zaraisky A.G. (2011). Expression patterns of genes encoding small GTPases Ras-dva-1 and Ras-dva-2 in the Xenopus laevis tadpoles. Gene Expr. Patterns 11 (1-2), 156–61 [+]

    Small GTPases of the recently discovered Ras-dva family are specific to the Vertebrate phylum. In Xenopus laevis, Ras-dva-1 is expressed during gastrulation and neurulation in the anterior ectoderm where it regulates the early development of the forebrain and cranial placodes (Tereshina et al., 2006). In the present work, we studied the expression of Ras-dva-1 at later developmental stages. As a result, the Ras-dva-1 expression was revealed in the eye retina, epiphysis (pineal gland), hypophysis (pituitary), branchial arches, pharynx, oesophagus, stomach and gall bladder of swimming tadpoles. Additionally, we investigated for the first time the expression pattern of Ras-dva-2. This gene encodes a protein belonging to a novel sub-group of Ras-dva GTPases that we identified by phylogenetic analysis within Ras-dva family. In contrast to Ras-dva-1, Ras-dva-2 is not expressed before the swimming tadpole stage. At the swimming tadpole stage, however, Ras-dva-2 transcripts can be detected in the eye retina and brain. Later in development, the expression of Ras-dva-2 can also be revealed in the mesonephros and stomach.

    ID:549
  4. Tereshina M.B., Zaraisky A.G., Novoselov V.V. (2006). Ras-dva, a member of novel family of small GTPases, is required for the anterior ectoderm patterning in the Xenopus laevis embryo. Development 133 (3), 485–94 [+]

    Ras-like small GTPases are involved in the regulation of many processes essential for the specification of the vertebrate body plan. Recently, we identified the gene of novel small GTPase Ras-dva, which is specifically expressed at the anterior margin of the neural plate of the Xenopus laevis embryo. Now, we demonstrate that Ras-dva and its homologs in other species constitute a novel protein family, distinct from the previously known families of small GTPases. We show that the expression of Ras-dva begins during gastrulation throughout the anterior ectoderm and is activated by the homeodomain transcription factor Otx2; however, later on, Ras-dva expression is inhibited in the anterior neural plate by another homeodomain factor Xanf1. Downregulation of Ras-dva functioning by the dominant-negative mutant or by the antisense morpholino oligonucleotides results in severe malformations of the forebrain and derivatives of the cranial placodes. Importantly, although the observed abnormalities can be rescued by co-injection of the Ras-dva mRNA, they cannot be rescued by the mRNA of the closest Ras-dva homolog from another family of small GTPases, Ras. This fact indicates functional specificity of the Ras-dva signaling pathway. At the molecular level, downregulation of Ras-dva inhibits the expression of several regulators of the anterior neural plate and folds patterning, such as Otx2, BF-1 (also known as Foxg1), Xag2, Pax6, Slug and Sox9, and interferes with FGF8 signaling within the anterior ectoderm. By contrast, expression of the epidermal regulator BMP4 and its target genes, Vent1, Vent2b and Msx1, is upregulated. Together, the data obtained indicate that Ras-dva is an essential component of the signaling network that patterns the early anterior neural plate and the adjacent ectoderm in the Xenopus laevis embryos.

    ID:75