Evolution of parthenogenetic reproduction in Caucasian rock lizards: A review.

Despite numerous works devoted to hybrid origin of parthenogenesis in reptiles, the causes of hybridization between different species, resulting in the origin of parthenogenetic forms, remain uncertain. Recent studies demonstrate that sexual species considered parental to parthenogenetic rock lizards ( spp.) avoid interspecific mating in the secondary overlap areas.

Cytogenetic Analysis of the Bimodal Karyotype of the Common European Adder, (Viperidae).

is the species with the largest range of snakes on Earth and one of the largest among reptiles in general. It is also the only snake species found in the Arctic Circle. is the most involved species of the genus in the process of interspecific hybridization in nature.

XX/XY sex chromosomes in a blind lizard (Dibamidae): Towards understanding the evolution of sex determination in squamates.

The reconstruction of the evolutionary history of sex determination in squamate reptiles (lizards and snakes) is complicated by missing data in many lineages, erroneous reports, and often questionable inferences on state homology. Therefore, despite the large effort, the reconstruction of the ancestral sex determination in squamate reptiles is still controversial. With the hope to shed light on this problem, we aspired to identify the sex chromosome gene content in Dibamus deharvengi, the representative of the family Dibamidae, the putative sister clade to all other squamates.

DNA Environment of Centromeres and Non-Homologous Chromosomes Interactions in Mouse.

Although the pericentromeric regions of chromosomes that are enriched in tandemly repeated satellite DNA represent a significant part of eukaryotic genomes, they remain understudied, which is mainly due to interdisciplinary knowledge gaps. Recent studies suggest their important role in genome regulation, karyotype stability, and evolution. Thus, the idea of satellite DNA as a junk part of the genome has been refuted.

Meiotic synapsis of homeologous chromosomes and mismatch repair protein detection in the parthenogenetic rock lizard Darevskia unisexualis.

Parthenogenetic species of Caucasian rock lizards of the genus Darevksia are important evidence for reticulate evolution and speciation by hybridization in vertebrates. Female-only lineages formed through interspecific hybridization have been discovered in many groups. Nevertheless, critical mechanisms of oogenesis and specifics of meiosis that provide long-term stability of parthenogenetic species are still unknown.

In vitro derived female hPGCLCs are unable to complete meiosis in embryoid bodies.

The fundamental question about the functionality of in vitro derived human primordial germ cell-like cells remains unanswered, despite ongoing research in this area. Attempts have been made to imitate the differentiation of human primordial germ cells (hPGCs) and meiocytes in vitro from human pluripotent stem cells (hPSCs). A defined system for developing human haploid cells in vitro is the challenge that scientists face to advance the knowledge of human germ cell development.

Evolution of the parthenogenetic rock lizard hybrid karyotype: Robertsonian translocation between two maternal chromosomes in Darevskia rostombekowi.

Darevskia rostombekowi, the most outstanding of the seven known parthenogenetic species in the genus Darevskia, is the result of an ancestral cross between two bisexual species Darevskia raddei and Darevskia portschinskii. The chromosomal set of this species includes a unique submetacentric autosomal chromosome; the origin of this chromosome was unresolved as only acrocentric chromosomes are described in the karyotypes of Darevskia genus normally. Here, we applied a suite of molecular cytogenetic techniques, including the mapping of telomeric (TTAGGG) n repeats using fluorescence in situ hybridization (FISH), comparative genomic hybridization (CGH), and whole-chromosome painting (WCP) in both D.

Cytogenetic mechanisms of unisexuality in rock lizards.

Darevskia rock lizards is a unique complex taxa, including more than thirty species, seven of which are parthenogenetic. In mixed populations of Darevskia lizards, tri- and tetraploid forms can be found. The most important issues in the theory of reticulate evolution of Darevskia lizards are the origin of parthenogenetic species and their taxonomic position.

Extraordinary centromeres: differences in the meiotic chromosomes of two rock lizards species and .

According to the synthesis of 30 years of multidisciplinary studies, parthenogenetic species of rock lizards of genus were formed as a result of different combination patterns of interspecific hybridization of the four bisexual parental species: , , , and . In particular, and are considered as the parental species for the parthenogenetic species . Here for the first time, we present the result of comparative immunocytochemical study of primary spermatocyte nuclei spreads from the leptotene to diplotene stages of meiotic prophase I in two species: and .

Reorganization of the Y Chromosomes Enhances Divergence in Israeli Mole Rats (Spalacidae, Rodentia): Comparative Analysis of Meiotic and Mitotic Chromosomes.

The Y chromosome in mammals is variable, even in closely related species. Middle East blind mole rats demonstrate autosomal variability, which probably leads to speciation. Here, we compare the mitotic and meiotic chromosomes of mole rats.