Andrey V Bayramov

The origin of paired appendages became one of the most important adaptations of vertebrates, allowing them to lead active lifestyles and explore a wide range of ecological niches. The basic form of paired appendages in evolution is the fins of fishes. The problem of paired appendages has attracted the attention of researchers for more than 150 year...

Lamprey homologues of the classic embryonic inducer Noggin are similar in expression pattern and functional properties to Noggin homologues of jawed vertebrates. All noggin genes of vertebrates apparently originated from a single ancestral gene as a result of genome duplications. nogginA, nogginB and nogginC of lampreys, like noggin1 and noggin2 of...

Secreted proteins of the Noggin family serve as pivotal regulators of early development and cell diferentiation in all multicellular animals, including vertebrates. Noggin1 was identifed frst among all Noggins. Moreover, it was described as the frst known embryonic inducer specifcally secreted by the Spemann organizer and capable of inducing a seco...

Foxg1 is a key regulator of the early development of the vertebrate forebrain and sensory organs. In this study, we describe for the first time three foxg1 paralogues in lamprey, representative of one of two basally diverged lineages of vertebrates—the agnathans. We also first describe three foxg1 genes in sterlet—representative of one of the evolu...

The secreted protein Noggin1 was the first discovered natural embryonic inducer produced by cells of the Spemann organizer. Thereafter, it was shown that vertebrates have a whole family of Noggin genes with different expression patterns and functional properties. For example, Noggin1 and Noggin2 inhibit the activity of BMP, Nodal/Activin and Wnt-be...

Studies of the temporal and spatial features of expression of regulatory genes in modern representatives of phylogenetically important evolutionarily ancient groups of vertebrates can be very informative for identifying the molecular mechanisms underlying the emergence of new structures and morphological features in ancestral vertebrates. One of th...

The emergence of paired appendages is one of the most important adaptations of vertebrates; it provided the opportunity to lead an active lifestyle and develop a wide range of ecological niches. Fish fins are a basic form of paired appendages in evolution. The problem of the emergence of paired appendages has attracted the attention of researchers...

Secreted proteins of the Noggin family serve as pivotal regulators of early development and cell differentiation in all multicellular animals, including vertebrates. Noggin1 was identified first among all Noggins. Moreover, it was described as the first known embryonic inducer specifically secreted by the Spemann organizer and capable of inducing a...

The basic knowledge about the development and formation of the body plan of vertebrates (Verte-brata) was obtained while working with traditional and generally accepted model objects, such as the embryos of mice (Muridae), chickens (Gallus), bony fish (Teleostei), clawed frogs (Xenopus). At the same time, for understanding the evolutionary history...

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

One of the most important evolutionary innovations of vertebrates is a complexly structured telencephalon, which provides higher forms of nervous activity in animals and humans. This work is devoted to the study of the appearance of the telencephalon in the early stages of vertebrate evolution. At the same time, there is reason to believe that lamp...

The Agr family genes, Ag1, Agr2, and Agr3, encode for the thioredoxin domain containing secreted proteins and are specific only for vertebrates. These proteins are attracting increasing attention due to their involvement in many physiological and pathological processes, including exocrine secretion, cancer, regeneration of the body appendages, and...

Agnathans, the most ancient of the extant vertebrates, evoke steadily increasing interest as the object of research on the basic processes of vertebrate ontogeny. Lampreys have been more accessible to researchers than myxines (hagfish), representatives of the other class of jawless vertebrates, for more than 100 years. Studies on the functional and...

As a result of the analysis of the promoter region of the Xanf1 gene encoding the transcriptional regulator of the early development of the forebrain in the clawed frog, we found several promoter elements responsible for the expression of this gene and its localization in the anterior head region of the neural plate at the early neurula stage. A se...

The presence of a complex structured brain, the anterior department of which (telencephalon) has no analogues in other groups of animals, is a significant peculiarity of vertebrates (including the human). Previously, a vertebrate-specific monogenic class of homeobox genes Anf, which plays a key role in the development of telencephalon, was discover...

Interactions of the secreted protein XAgr2 of the Agr (anterior gradient proteins) family with six submembrane proteins, Tfp1–6, from the family of three-finger proteins Ly6 were studied in Xenopus laevis embryos. Earlier, other authors have shown that the newt homologue of XAgr2 is able to bind the Prod1 three-finger protein, which participates in...

The protein Noggin4 of the African clawed frog Xenopus laevis has been shown to act as a modulator of the “noncanonical” Wnt/PCP-signaling pathway that plays an important role in the regulation of cell motility. Induction of disturbances in the expression of Noggin4 led to the activation of Wnt/PCP-pathway and the related anomalies of early embryon...

Accumulated evidence indicates that the core genetic mechanisms regulating early patterning of the brain rudiment in vertebrates are very similar to those operating during development of the anterior region of invertebrate embryos. However, the mechanisms underlying the morphological differences between the elaborate vertebrate brain and its simple...

Noggin proteins are important regulators of the early development of the vertebrate neural system. Previously, it has been traditionally thought that vertebrates have only one noggin gene (Noggin1), whose main function is the inhibition of BMP signaling pathway during the formation of dorsoventral polarity in embryos. Then other proteins of this fa...

We demonstrated that the secreted protein Noggin4 from Xenopus laevis was capable of the in vitro binding to the secreted factor Wnt8, one of the ligands of the Wnt/betaCatenin signaling pathway. It was also shown that posttranslational modifications occurring during secretion of these proteins from the embryonic cells were necessary for their effe...

Noggin4 is a Noggin family secreted protein whose molecular and physiological functions remain unknown. In this study, we demonstrate that in contrast to other Noggins, Xenopus laevis Noggin4 cannot antagonise BMP signalling; instead, it specifically binds to Wnt8 and inhibits the Wnt/β -catenin pathway. Live imaging demonstrated that Noggin4 diffu...

Previously, we found that the Noggin family proteins could bind to activin, a member of the TGF-β superfamily, and repress the corresponding signaling cascade. In this work, we characterized a mutant of the Xenopus laevis Noggin2 protein bearing a W203R substitution. This point mutation was shown to enhance the affinity of Noggin to activin, while...

Earlier we have revealed the ability of Noggin family proteins to bind a member of the TUF-β superfamily, ActivinB, and to repress the Activin-dependent Smad2 signaling cascade. In the present work we have characterized a mutant of the Xenopus laevis Noggin2, bearing the substitution W203R. We have shown that this point mutation enhances the affini...

We describe here the expression pattern of Noggin4 during the early development of the chick embryo (Gallus gallus). The expression of this gene starts with the onset of gastrulation (stage HH4), in two bilateral bands along the primitive streak, with a local maximum around Hensen's node. By the end of gastrulation, Noggin4 transcripts are distribu...

Noggin (Noggin1) protein inhibits Smad1-dependent TGF-β (BMP) signaling cascades by extracellular binding of BMP proteins. Recently, we identified two previously unknown members of the Noggin family, Noggin2 and Noggin4 proteins. In this work, using luciferase reporter constructs, it was shown that Noggin2 is able to inhibit in addition to the BMP-...

The secreted protein Noggin1 is an embryonic inducer that can sequester TGFβ cytokines of the BMP family with extremely high affinity. Owing to this function, ectopic Noggin1 can induce formation of the headless secondary body axis in Xenopus embryos. Here, we show that Noggin1 and its homolog Noggin2 can also bind, albeit less effectively, to Acti...

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...

Noggin is a neural inducer secreted by cells of the Spemann organizer. A single noggin gene was identified until very recently in all tested vertebrates. The only exception was zebrafish, in which two close homologs of noggin, named noggin1 and noggin3, and one gene more diverged from them, noggin2, were cloned. Nevertheless, finding of three zebra...

Expression of the homeobox gene Xanf-1 starts within the presumptive forebrain primordium of the Xenopus embryo at the midgastrula stage and is inhibited by the late neurula. Such stage-specific inhibition is essential for the normal development as the experimental prolongation of the Xanf-1 expression elicits severe brain abnormalities. To identif...

During early development of the nervous system in vertebrates, expression of the homeobox gene Anf/Hesx1/Rpx is restricted to the anterior neural plate subdomain corresponding to the presumptive forebrain. This expression is essential for normal forebrain development and ectopic expression of Xenopus Anf, Xanf1 (also known as Xanf-1), results in se...