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Belugas, Delphinapterus leucas, are one of only three whale species endemic to Arctic and sub-Arctic seas. They are found in both the Atlantic and Pacific Arctic and sub-Arctic, and are managed at a regional or national level within each of the five Arctic-range countries, along with international fora used to share information and management strategies. Genetic data--primarily mtDNA control region sequences and microsatellites--have played an important role in defining appropriate management units. Here, we review the genetic studies published to date and, for the first time, present a range-wide, circumpolar analysis of levels of mtDNA diversity and differentiation in beluga stocks. Our meta analysis is based on 302 bp of overlapping mtDNA control region sequence and includes 2,933 individuals spanning all 21 recognized beluga stocks. We find that all stocks are significantly differentiated from each other, except in five cases. Belugas in the St. Lawrence Estuary are the most distinct--the stock has the lowest range-wide level of genetic diversity and, with only two haplotypes present not found elsewhere, it is also the most well differentiated. Belugas in the Barents, Kara, and Laptev Seas stock have the highest level of diversity, supporting that this geographically far-ranging stock may harbor several distinct sub-units. Our study showcases insights gained from studying species at a range-wide level, while highlighting the challenges associated with compiling and comparing data from various publications with different study designs., Introduction Belugas (also known as white whales, Delphinapterus leucas) have a discontinuous circumpolar distribution and are one of only two toothed whale species found in the Arctic year round (O'Corry-Crowe, [...]

Author(s): Oscar Puebla [sup.1] Author Affiliations: (Aff1) 0000 0000 9056 9663, grid.15649.3f, GEOMAR Helmholtz Centre for Ocean Research Kiel, Evolutionary Ecology of Marine Fishes, , Düsternbrooker Weg 20, 24105, Kiel, [...]

We describe an automated system for high-resolution profiling of human mitochondrial DNA (mtDNA) based upon multiplexed polymerase chain reaction (PCR) followed by desolvation and direct analysis using electrospray ionization mass spectrometry (PCR/ESI-MS). The assay utilizes 24 primer pairs that amplify targets in the mtDNA control region, including the hypervarlable regions typically sequenced in a forensic analysis. Profiles consisting of product base compositions can be stored in a database, compared to each other, and compared to sequencing results. Approximately 94% of discriminating information obtained by sequencing is retained with this technique. The assay is more discriminating than sequencing minimum HV1 and HV2 regions because it interrogates more of the mitochondrial genome. A profile compared to a population database can be subjected to the same statistics used for assessing the significance of concordant mtDNA sequences. The assay is not hindered by length heteroplasmy, can directly analyze template mixtures, and has a sensitivity of 99% of trials producing a full profile with automated analysis. The technique has direct application to analysis of forensic biological evidence.

Abstract: In a previous phylogeographic study of the rodent Calomys musculinus, 24 haplotypes of the mitochondrial DNA D-loop region were detected using the restriction fragment length polymorphism technique (PCR-RFLP). Seven [...]

Limitations of using mitochondrial DNA barcodes include the possibility that they may provide potentially inadequate data for characterizing species.

Toxicity identification research is conducted in cooked fish liver. Assaying is done to identify food poisoning elements and mitochondrial Deoxyribonucleic Acid.

ABSTRACT Sequencing analysis was used to characterize a mtDNA D-loop amplicon of 838 bp. Four pallid sturgeons, Scaphirhynchusalbus, and four shovelnose sturgeons, S. platorynchus, from four states (Illinois, Louisiana, Montana, [...]

Allen L. Szalanski [1,3] Kevin E. Church [2] David W. Oates [2] Richard Bischof [2] Thomas O. Powers [1] ABSTRACT Genetic variation within and among wild Turkey, Meleagris gallopavo, subspecies [...]

Five genetically distinct lion populations roam in Africa and Asia--a finding that hints at greater diversity in these animals than previously thought. A team led by Ross Barnett, now at [...]

Although stem cells were initially thought to be the magic bullet for numerous diseases, translation of a stem cell-based cure into the clinic is still a work in progress. Basic [...]

Ancient DNA (aDNA) extracted from prehistoric biological material has proved to be a valuable tool for testing a number of hypotheses concerning phylogenetic relationships, migrations, and prehistoric population histories. However, as aDNA is exists in low copy number and is highly degraded, contamination and authentification of the results remain significant problems. Additionally, PCR-mediated base-misincorporations due to postmortem modifications in the DNA may also significantly influence the results from ancient sequence data. The presence of even a small number of misidentified polymorphisms can dramatically affect diversity measures drawn from these sequences as well as the perceived phylogenetic relationships between different DNAs. We compare polymorphic positions in modern and ancient mtDNA to see if mutations reported in aDNA studies are likely to contain errors. Additionally, we examine effects errors may have on diversity estimates drawn from aDNA.

In a recent high-resolution study of Y-chromosome variation it has been observed that the haplotype 117 (belonging to the haplogroup IX) occurs at a frequency ranging from 0% to 95% in northern Cameroon. This finding is of particular interest since the 117 haplotype seems to have been involved in a back migration from Asia to Africa. As a logical development of this study, we have analyzed mitochondrial variation in the same populations analyzed for Y chromosomes (Bakaka, Bamileke, Daba, Ewondo, Fali, Fulbe, Ouldeme and Tali) and in four additional populations (Bassa, Mandara, Tupuri and Podokwo). We analyzed the hypervariable region-1 by a standard sequencing method and 4 nucleotide positions of the mtDNA coding region (10400, 12308 and 12705, 10873) using the Snapshot method in a total of 439 individuals. We observed five different haplogroups, three of which ate sub-Saharan (L1, L2, L3), one northern African (U6) and one European (U5). The presence of the northern African haplogroup (among Podokwo and Uldeme) could be due to recent gene flow from north-eastern Africa. The U5 haplogroup was found only in one Fulbe individual. The lack of Asian haplogroups in Cameroon suggests that the migratory flow which spread the 117 haplotype was conducted predominantly by males and that the female contribution, ir present, was not as large to escape extinction by genetic drift.