Putative role of Brugada syndrome genes in familial atrial fibrillation.

OBJECTIVE: Familial atrial fibrillation (FAF), a not uncommon arrhythmia of the atrium, is characterized by heritability, early onset and absence of other heart defects. The molecular and genetic basis is still not completely clear and genetic diagnosis cannot be achieved in about 90% of patients. In this study, we present the results of genetic screening by next generation sequencing in affected Russian families. PATIENTS AND METHODS: Sixty subjects (18 probands and 42 relatives) with a clinical diagnosis of FAF were enrolled in the study. Since AF frequently associates with other cardiomyopathies, we included all genes that were known to be associated with these disorders at the time of our study. All probands were therefore systematically screened for 47 genes selected from the literature. RESULTS: Our study revealed that seven variants co-segregated with the clinical phenotype in seven families. Interestingly, four out of six genes and three out of seven variants have already been associated with Brugada syndrome in the literature. CONCLUSIONS: To our knowledge, this is the first report of association of the CACNA1C, CTNNA3, PKP2, ANK2 and SCN10A genes with FAF; it is also the first study in Russian families.

New Data on Dinosaurs of the Crimean Peninsula.

Reexamination of the holotype of Riabininohadros weberae from the Upper Cretaceous (upper Maastrichtian) of the Crimean Peninsula (Besh-Kosh) allowed determination of previously unknown elements of the femur, astragalus, and calcaneus. This taxon shows a set of primitive characters observed in iguanodontids and basal ornithischians and is referred to as Styracosterna indet. The second dinosaur specimen from Crimea (Aleshino) is a fragmentary skeleton, including cervical and dorsal vertebrae. It possibly belongs to advanced iguanodontids or primitive hadrosauroids. Thus, in the Maastrichtian of the Crimean Peninsula, at least two dinosaur species coexisted.

A New Stem Placental Mammal from the Early Cretaceous of Mongolia.

A new taxon of stem placentals, Hovurlestes noyon gen. et sp. nov. from the Early Cretaceous of Mongolia (Höovör locality) is described. The new taxon differs from members of the genus Prokennalestes from Höovör in the single-rooted canine and the presence of cusp e, which is an enhancing interlocking between anterior molars (m1 and m2). Hovurlestes noyon gen. et sp. nov. is one of the rarest mammal taxa from Höovör, which expands morphological diversity of the earliest Eutheria.

Late Cretaceous relatives of rabbits, rodents, and other extant eutherian mammals.

Extant eutherian mammals and their most recent common ancestor constitute the crown group Placentalia. This taxon, plus all extinct taxa that share a more recent common ancestor with placentals than they do with Metatheria (including marsupials), constitute Eutheria. The oldest well documented eutherian-dominated fauna in the world is Dzharakuduk, Uzbekistan. Among eutherians that it yields is Kulbeckia, an 85-90-Myr-old member of Zalambdalestidae (a family of Late Cretaceous Asian eutherians). This extends Zalambdalestidae back by some 10 million years from sites in the Gobi Desert, Mongolia. A phylogenetic analysis of well described Late Cretaceous eutherians strongly supports Zalambdalestidae, less strongly supports 'Zhelestidae' (a Late Cretaceous clade related to Tertiary ungulates), but does not support Asioryctitheria (a group of Late Cretaceous Asian eutherians). A second analysis incorporating placentals from clades that include rodents (Tribosphenomys), lagomorphs (Mimotona) and archaic ungulates (Protungulatum and Oxyprimus) strongly supports Zalambdalestidae in a clade with Glires (rabbits, rodents and extinct relatives) and less strongly 'Zhelestidae' within a clade that includes archaic ungulates ('condylarths'). This argues that some Late Cretaceous eutherians belong within the crown group Placentalia. The ages of these taxa are in line with molecularly based estimates of 64-104 Myr ago (median 84 Myr ago) for the superordinal diversification of some placentals, but provide no support for a Late Cretaceous diversification of extant placental orders.