Molecular phylogeny of one extinct and two critically endangered Central Asian sturgeon species (genus Pseudoscaphirhynchus) based on their mitochondrial genomes.

The enigmatic and poorly studied sturgeon genus Pseudoscaphirhynchus (Scaphirhynchinae: Acipenseridae) comprises three species: the Amu Darya shovelnose sturgeon (Pseudoscaphirhynchus kaufmanni (Bogdanow)), dwarf Amu Darya shovelnose sturgeon P. hermanni (Kessler), and Syr Darya shovelnose sturgeon (P. fedtschenkoi (Bogdanow). Two species - P. hermanni and P. kaufmanni - are critically endangered due to the Aral Sea area ecological disaster, caused by massive water use for irrigation to support cotton agriculture, subsequent pesticide pollution and habitat degradation. For another species - P. fedtschenkoi - no sightings have been reported since 1960-s and it is believed to be extinct, both in nature and in captivity. In this study, complete mitochondrial (mt) genomes of these three species of Pseudoscaphirhynchus were characterized using Illumina and Sanger sequencing platforms. Phylogenetic analyses showed the significant divergence between Amu Darya and Syr Darya freshwater sturgeons and supported the monophyletic origin of the Pseudoscaphirhynchus species. We confirmed that two sympatric Amu Darya species P. kaufmanni and P. hermanni form a single genetic cluster, which may require further morphological and genetic study to assess possible hybridization, intraspecific variation and taxonomic status and to develop conservation measures to protect these unique fishes.

The complete mitochondrial genome of the extinct Pleistocene horse (Equus cf. lenensis) from Kotelny Island (New Siberian Islands, Russia) and its phylogenetic assessment.

The complete mitochondrial genome from the Pleistocene stallion horse (Equus cf. lenensis) which complete skull was found in 1901 on Kotelny Island (New Siberian Archipelago, Sakha Republic, Russia) is published in this paper. The mitochondrial DNA (mtDNA) is 16,584 base pairs (bp) in length and contained 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes. The overall base composition of the genome in descending order was 32.3% - A, 28.5% - C, 13.4% - G, 25.8% - T without a significant AT bias of 58.2%.

Study of Alzheimer family case reveals hemochromotosis-associated HFE mutation.

We report a family case of type II early-onset Alzheimer's disease (AD) inherited over three generations. None of the patients in the family had mutations in the genes believed to be the major risk factors for AD, such as APP, presenilin 1 or 2. Targeted exome sequencing of 249 genes that were previously reported to be associated with AD revealed a rare mutation in hemochromatosis (HFE) gene known to be associated with hemochromotosis. Compared to previous studies, we show that HFE mutation can possess the risk of AD in transferrin-, APOE- and APP-normal patients.

High-throughput SNP-genotyping analysis of the relationships among Ponto-Caspian sturgeon species.

Legally certified sturgeon fisheries require population protection and conservation methods, including DNA tests to identify the source of valuable sturgeon roe. However, the available genetic data are insufficient to distinguish between different sturgeon populations, and are even unable to distinguish between some species. We performed high-throughput single-nucleotide polymorphism (SNP)-genotyping analysis on different populations of Russian (Acipenser gueldenstaedtii), Persian (A. persicus), and Siberian (A. baerii) sturgeon species from the Caspian Sea region (Volga and Ural Rivers), the Azov Sea, and two Siberian rivers. We found that Russian sturgeons from the Volga and Ural Rivers were essentially indistinguishable, but they differed from Russian sturgeons in the Azov Sea, and from Persian and Siberian sturgeons. We identified eight SNPs that were sufficient to distinguish these sturgeon populations with 80% confidence, and allowed the development of markers to distinguish sturgeon species. Finally, on the basis of our SNP data, we propose that the A. baerii-like mitochondrial DNA found in some Russian sturgeons from the Caspian Sea arose via an introgression event during the Pleistocene glaciation. In the present study, the high-throughput genotyping analysis of several sturgeon populations was performed. SNP markers for species identification were defined. The possible explanation of the baerii-like mitotype presence in some Russian sturgeons in the Caspian Sea was suggested.