Dmitry Dedukh

• PhD
• PhD at St Petersburg University

Reproduction without males is common among various animal taxa, however, it is rarely encountered in vertebrates. The discovery of obligate parthenogenesis, which does not require the participation of males for reproduction, by Ilya Sergeevich Darevsky, has contributed significantly to the development of evolutionary biology. In the middle of the l...

Among vertebrates, obligate parthenogenesis occurs exclusively in squamate reptiles. Premeiotic endoreplication in a small subset of developing oocytes has been documented as the mechanism of production of unreduced eggs in minutely explored obligate parthenogenetic lineages, namely in teiids and geckos. The situation in the lacertid genus Darevski...

The transition from sexual reproduction to asexuality is often triggered by hybridization. The gametogenesis of many hybrid asexuals involves premeiotic genome endoreplication leading to bypass hybrid sterility and forming clonal gametes. However, it is still not clear when endoreplication occurs, how many gonial cells it affects and whether its ra...

We review knowledge about the roles of sex chromosomes in vertebrate hybridization and speciation, exploring a gradient of divergences with increasing reproductive isolation (speciation continuum). Under early divergence, well-differentiated sex chromosomes in meiotic hybrids may cause Haldane-effects and introgress less easily than autosomes. Undi...

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

Interspecific hybridization is a powerful evolutionary force. However, the investigation of hybrids requires the application of methodologies that provide efficient and indubitable identification of both parental subgenomes in hybrid individuals. Repetitive DNA, and especially the satellite DNA sequences (satDNA), can rapidly diverge even between c...

In most organisms, cells typically maintain genome integrity, as radical genome reorganization leads to dramatic consequences. However, certain organisms, ranging from unicellular ciliates to vertebrates, are able to selectively eliminate specific parts of their genome during certain stages of development. Moreover, partial or complete elimination...

Many closely related species are capable of mating to produce hybrid offspring, which are usually sterile. Nevertheless, altering the gametogenesis of hybrid offspring can rescue hybrids from sterility by enabling asexual reproduction. Hybridogenesis is one of the most complicated asexual reproductive modes, and it includes drastic genome reorganiz...

Formation of species generally occurs in a continuum from potentially intermixing populations to independent entities isolated from other species by pre- and postzygotic barriers. Especially the establishment of hybrid sterility (HS) is a hallmark of speciation, which usually emerges at different rates between hybrid sexes. However, although HS is...

DNA elimination is a radical form of gene silencing and occurs both in somatic and germ cells. The programmed DNA elimination occurs during gametogenesis in interspecies hybrids that reproduce by hybridogenesis (stick insects, fishes, and amphibians) and concerns removal of whole genomes of one of the parental species and production of clonal gamet...

Background Interspecies animal hybrids can employ clonal or hemiclonal reproduction modes where one or all parental genomes are transmitted to the progeny without recombination. Nevertheless, some interspecies hybrids retain strong connection with the parental species needed for successful reproduction. Appearance of polyploid hybrid animals may pl...

Amphibian and bird karyotypes typically have a complex organization, which makes them difficult for standard cytogenetic analysis. That is, amphibian chromosomes are generally large, enriched with repetitive elements, and characterized by the absence of informative banding patterns. The majority of avian karyotypes comprise a small number of relati...

The European water frog (Pelophylax esculentus) complex represents a unique and adequate model system for the study of interspecific hybridization and the mechanisms enabling interspecific hybrids to overcome the reproductive barriers. The difficulties in the study of individuals from the P. esculentus complex are associated with high polymorphism...

Incompatibilities between parental genomes decrease viability of interspecific hybrids; however , deviations from canonical gametogenesis such as genome endoreplication and elimination can rescue hybrid organisms. To evaluate frequency and regularity of genome elimination and endoreplication during gametogenesis in hybrid animals with different plo...

Background Hybridogenesis (hemiclonal inheritance) is a kind of clonal reproduction in which hybrids between parental species are reproduced by crossing with one of the parental species. European water frogs (Pelophylax esculentus complex) represent an appropriate model for studying interspecies hybridization, processes of hemiclonal inheritance an...

Hybridogenesis represents one of known clonal ways by which interspecies hybrids can be reproduced. During hybridogenesis, gametogenesis proceeds with deviations, when one of the parental genomes can be eliminated while the other one can be endoreduplicated. Among natural interspecies hybrids, Pelophylax esculentus as a hybrid between P. ridibundus...

The records of bisexual all-triploid populations of B. baturae in the southern Pamir (Tajikistan) and B. zamdaensis in the Spiti River valley (India) are described. Genome size, karyotypes, 16S rRNA sequences and allozyme variation are studied. Taxonomic status, genetic reproductive pattern and distribution of the toads are discussed.