1,720,962 research outputs found
Microsatellite markers for population genetic studies of the giant red shrimp Aristaeomorpha foliacea (Crustacea Decapoda)
No full textMicrosatellite markers have been isolated and characterized from the giant red shrimp Aristaeomorpha foliacea in order to investigate on the presence of distinct stocks in the Western Mediterranean Sea. Polymorphism of the newly obtained loci was assessed in a restricted sample of 30 specimens, nine loci provided markers with polymorphism (range 2–19 alleles per locus). Six loci, the most polymorphic and easiest to amplify and to score, were tested in a larger sample of 6 populations from the Western Mediterranean Sea. Microsatellite data revealed a substantial genetic homogeneity and no signs of recent bottlenecks, suggesting the existence of a high gene flow that connects all population
Population genetics of the red and blue shrimp Aristeus antennatus in the Western Mediterranean Sea
No full textPOPULATION GENETICS OF THE RED AND BLUE SHRIMP ARISTEUS ANTENNATUS IN THE WESTERN MEDITERRANEAN SEA
No full textTo investigate on the presence of distinct stocks in the Western Mediterranean Sea, genetic
variation at 8 microsatellite loci was analyzed for eleven samples of the blue and red shrimp Aristeus
antennatus (Crustacea, Decapoda) from the Western Mediterranean basin. High level of gene flow and no
evidence of genetic partitioning were discovered. No significant genetic variation was found even when
populations from exploited versus deep-water unexploited grounds were compared. All the results are
consistent with the biology of the species, in particular the extensive pelagic larval stage and adult
migration that allow high dispersal and connectivity, at least at the spatial scale investigated in this study
First isolation and characterization of genomic-SSRs markers for the giant red shrimp Aristaeomorpha foliacea (Risso, 1827)
No full textFourteen microsatellite markers were isolated from the giant red shrimp Aristaeomorpha foliacea (Risso, 1827) using the FIASCO protocol (fast isolation by AFLP of sequences containing repeats). Polymorphism was assessed in 30 individuals from two localities of the western Mediterranean basin (N = 20 from Sardinia and N = 10 from Sicily); nine loci showed polymorphism with 2 to 19 alleles per locus (average: 8.9). Polymorphic information content ranged from 0.36 to 0.91, and the observed and expected heterozygosities ranged from 0.50 to 0.97 and from 0.47 to 0.93, respectively. Two loci showed significant deviation from Hardy-Weinberg equilibrium, and evidence of linkage disequilibrium was found for only one locus pair. These loci are the first to be characterized in A. foliacea and could be effective tools for the investigation of genetic diversity, population structure, and demographic connectivity, useful information for the management of this important commercial resourc
Isolation and characterization of 14 polymorphic microsatellite markers for the blue and red shrimp, Aristeus antennatus (Crustacea, Decapoda)
No full textEighteen microsatellite loci were isolated and characterized from the blue and red shrimp, Aristeus antennatus Risso 1816, a commercially exploited marine crustacean widely distributed throughout the Mediterranean Sea and in the eastern Atlantic. Polymorphism was assessed in a population (n = 20) from the southwestern Sardinian seas; 14 loci resulted polymorphic and showed from three to 13 alleles. The observed heterozygosity ranged from 0.2 to 0.85. These microsatellites will be potentially useful for the study of A. antennatus population genetic structure
An unusual finding of Sepietta oweniana (Cephalopoda: Sepiolidae) egg clutch
Full text linkAn unusual finding of Sepietta oweniana egg clutch at 544 m depth is described within an updating study of the reproductive aspects of the species in Sardinian waters. Egg species identity was determined by genetic analysis and morphological and biometrical data of the eggs, embryos and one newly hatched specimen are reported and discussed. Illustrations of the eggs, spermatophores and spermatangia by photographic material are also included. Data on bathymetric distribution and sexual maturity are reported and compared with data already available for the species in other geographical areas of distributio
Spatio-Temporal genetic analysis of bluefin tuna, Thunnus thynnus L., caught by the Sardinian traps
No full textFurther insights on the genetic structure and connectivity in Octopus vulgaris (Mollusca, Cephalopoda) inferred by mitochondrial COI sequences
No full textThe genetic variability of the COI gene was studied in the common octopus, Octopus vulgaris Cuvier, 1797. A total of 222
individuals from 7 sampling sites were analysed with the aim of elucidating patterns of genetic variation along the coasts of
Sardinia (Western Mediterranean). A total of 17 different haplotypes were identified with four principal haplotypes recorded in all
locations. The pairwise Fst and AMOVA revealed a high gene flow and the lack of significant genetic differentiation among
populations. All COI sequences were compared with those available in GenBank for the species; the results obtained show a high
sequence divergence among O. vulgaris from different geographic locations and emphasize the need for more detailed
phylogeographic and/or taxonomic studies to exclude the presence of cryptic specie
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
- …
