Search results for " Variation"
showing 10 items of 1712 documents
Sequential variation in genomic RNA patterns of human rotaviruses isolated from infantile gastroenteritis
1986
The incidence and RNA electrophoretypes of rotaviral isolates obtained from infants and young children with acute gastroenteritis were studied from October, 1985 through April, 1986. Analysis of the viral RNA was carried out by Polyacrylamide gel electrophoresis followed by silver staining. Fourteen electrophoretypes were identified. A single dominant electrophoretype was found during the first months of the rotavirus seasonal outbreak. In contrast, a large variety of RNA patterns were observed during the latter portion of the study period. Subgrouping of rotavirus isolates by a double-sandwich enzyme-linked immunosorbent assay using monoclonal-detecting antibodies showed that all strains b…
Allozyme electrophoresis: its application to rotifers
1998
Allozyme electrophoresis is a well established technique for revealing genetic variation that has given useful results in a wide range of organisms. However, in rotifers it has been applied scarcely and only in a few species. In this paper the methods of acetate allozyme electrophoresis are introduced, including laboratory setup, equipment and staining recipes that have been successfully applied to brachionid rotifers. In addition, the literature published on allozyme electrophoresis in rotifers is reviewed and the main results and future prospects of the technique are discussed. We conclude that, despite the onset of DNA techniques, allozyme electrophoresis is promising and can yield impor…
C8 Reference Typing Report and Nomenclature Recommendation
1990
Using two different typing techniques (i.e. polyacrylamide gel isoelectric focusing (PAGIF) with Western blot and SDS-polyacrylamide gel electrophoresis of precipitated C8 under nonreducing conditions with Western blot), the following observations were made during the reference typing for C81 (C8A). The Japanese variant A1J is probably identical with A1Cauc, whereas B1J is definitely different from B1Cauc and could therefore provisionally be named HB3'. Variant 'A2' from Japan is focused in an intermediate position, but different from M1 and could be named 'M2'. Both variants possess normal A subunits. B2 from Japan is clearly different from B1Cauc and should retain its designation. In PAGI…
Absence of spatial genetic structure in common dentex (Dentex dentex Linnaeus, 1758) in the Mediterranean Sea as evidenced by nuclear and mitochondri…
2018
International audience; The common dentex, Dentex dentex, is a fish species which inhabits marine environments in the Mediterranean and Northeast Atlantic regions. This is an important species from an ecological, economic and conservation perspective, however critical information on its population genetic structure is lacking. Most samples were obtained from the Mediterranean Sea (17 sites) with an emphasis around Corsica (5 sites), plus one Atlantic Ocean site. This provided an opportunity to examine genetic structuring at local and broader scales to provide science based data for the management of fishing stocks in the region. Two mitochondrial regions were examined (D-loop and COI) along…
Ancient DNA reveals prehistoric gene-flow from Siberia in the complex human population history of North East Europe.
2013
North East Europe harbors a high diversity of cultures and languages, suggesting a complex genetic history. Archaeological, anthropological, and genetic research has revealed a series of influences from Western and Eastern Eurasia in the past. While genetic data from modern-day populations is commonly used to make inferences about their origins and past migrations, ancient DNA provides a powerful test of such hypotheses by giving a snapshot of the past genetic diversity. In order to better understand the dynamics that have shaped the gene pool of North East Europeans, we generated and analyzed 34 mitochondrial genotypes from the skeletal remains of three archaeological sites in northwest Ru…
Is the population genetic structure of complex life cycle parasites determined by the geographic range of the most motile host?
2010
Due to their particular way of life, dispersal of parasites is often mediated by their host's biology. Dispersal distance is relevant for parasites because high degree of dispersal leads to high gene flow, which counters the rate of parasite local adaptation in the host populations. Parasites with complex life cycles need to exploit sequentially more than one host species to complete their life cycle. Most trematode parasites have such complex life cycles involving invertebrate and vertebrate hosts. The spatial scales of invertebrate and vertebrate host populations are often different, which may decrease the probability that the parasite cycles locally in the intermediate host population. W…
Climate change and genetic structure of leading edge and rear end populations in a northwards shifting marine fish species, the corkwing wrasse (Symp…
2013
Published version of an article in the journal:PLoS ONE. Also available from the Public Library of Science: http://dx.doi.org/10.1371/journal.pone.0067492 Open Access One mechanism by which marine organisms may respond to climate shifts is range shifts. The corkwing wrasse (Symphodus melops) is a temperate fish species, inhabiting the coasts of Europe, that show strong indications of current as well as historical (ice-age) range shifts towards the north. Nine neutral microsatellite DNA markers were screened to study genetic signatures and spatial population structure over the entire geographic and thermal gradient of the species from Portugal to Norway. A major genetic break (FST = 0.159 a…
Ancestry and demography and descendants of Iron Age nomads of the Eurasian Steppe
2017
During the 1st millennium before the Common Era (BCE), nomadic tribes associated with the Iron Age Scythian culture spread over the Eurasian Steppe, covering a territory of more than 3,500 km in breadth. To understand the demographic processes behind the spread of the Scythian culture, we analysed genomic data from eight individuals and a mitochondrial dataset of 96 individuals originating in eastern and western parts of the Eurasian Steppe. Genomic inference reveals that Scythians in the east and the west of the steppe zone can best be described as a mixture of Yamnaya-related ancestry and an East Asian component. Demographic modelling suggests independent origins for eastern and western g…
Low levels of relatedness on black grouse leks despite male philopatry
2008
In lekking species, males cluster on specific areas for display (the leks) and females generally prefer to copulate with males on large aggregations. The maintenance of leks in which only a few males reproduce might be explained if subordinate males gain indirect fitness benefits. By joining a lek on which relatives are displaying, subordinates might attract more females to the lek thereby increasing the mating opportunities of their kin. In black grouse, a genetic structure among leks has previously been found suggesting that relatives could display together. Using 11 microsatellite loci, we extended this result by testing for the presence of kin structures in nine black grouse leks (101 m…
Hybridization between mouse lemurs in an ecological transition zone in southern Madagascar
2009
Hybrid zones in ecotones can be useful model systems for the study of evolutionary processes that shape the distribution and discreteness of species. Such studies could be important for an improved understanding of the complex biogeography of Madagascar, which is renowned for its outstanding degree of small-scale endemism. Certain forest remnants in central Madagascar indicate that transitional corridors across the island could have connected microendemics in different forest types in the past. Evolutionary processes in such corridors are difficult to study because most of these corridors have disappeared due to deforestation in central Madagascar. We studied a hybrid zone in one of the few…