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1.
BMC Res Notes ; 11(1): 243, 2018 Apr 13.
Article de Anglais | MEDLINE | ID: mdl-29653594

RÉSUMÉ

OBJECTIVE: In the Bronze Age Hallstatt metropolis ('Salzkammergut' region, Upper Austria), salt richness enabled the preservation of pork meat to sustain people's livelihood suggesting an organized meat production industry on a yearly basis of hundreds of pigs. To pattern the geographic and temporal framework of the early management of pig populations in the surrounding areas of Hallstatt, we want to gain insights into the phylogeographic network based on DNA sequence variation among modern pigs, wild boars and prehistoric (likely) domestic pigs. RESULTS: In this pilot study, we successfully adapted ancient DNA extraction and sequencing approaches for the analysis of mitochondrial DNA sequence variation in ten prehistoric porcine teeth specimens. Minimum-spanning network analyses revealed unique mitochondrial control region DNA haplotypes ranging within the variation of modern domestic pig and wild boar lineages and even shared haplotypes between prehistoric and modern domestic pigs and wild boars were observed.


Sujet(s)
ADN ancien/analyse , ADN mitochondrial/analyse , Analyse de séquence d'ADN/méthodes , Chlorure de sodium , Sus scrofa/génétique , Animaux , Autriche , Mine , Projets pilotes
2.
Sci Rep ; 7(1): 5948, 2017 07 20.
Article de Anglais | MEDLINE | ID: mdl-28729611

RÉSUMÉ

Tripneustes is one of the most abundant and ecologically significant tropical echinoids. Highly valued for its gonads, wild populations of Tripneustes are commercially exploited and cultivated stocks are a prime target for the fisheries and aquaculture industry. Here we examine Tripneustes from the Kermadec Islands, a remote chain of volcanic islands in the southwest Pacific Ocean that mark the boundary of the genus' range, by combining morphological and genetic analyses, using two mitochondrial (COI and the Control Region), and one nuclear (bindin) marker. We show that Kermadec Tripneustes is a new species of Tripneustes. We provide a full description of this species and present an updated phylogeny of the genus. This new species, Tripneustes kermadecensis n. sp., is characterized by having ambulacral primary tubercles occurring on every fourth plate ambitally, flattened test with large peristome, one to two occluded plates for every four ambulacral plates, and complete primary series of interambulacral tubercles from peristome to apex. It appears to have split early from the main Tripneustes stock, predating even the split of the Atlantic Tripneustes lineage. Its distinction from the common T. gratilla and potential vulnerability as an isolated endemic species calls for special attention in terms of conservation.


Sujet(s)
Spéciation génétique , Iles , Echinoidea/génétique , Climat tropical , Animaux , Séquence nucléotidique , Complexe IV de la chaîne respiratoire/génétique , Haplotypes/génétique , Océan Pacifique , Phylogenèse , Echinoidea/anatomie et histologie , Spécificité d'espèce
3.
BMC Evol Biol ; 17(1): 138, 2017 Jun 13.
Article de Anglais | MEDLINE | ID: mdl-28610555

RÉSUMÉ

BACKGROUND: Cylindrus obtusus is one of the most prominent endemic snail species of the Eastern Alps. It is restricted to alpine meadows and calcareous rocky habitats above 1500 m. Peculiar intraspecific differences have been observed in its genital tract in the eastern populations the two mucus glands associated with the love dart sac are highly variable, while almost no variation was observed in the western populations. This raises the question whether the mode and success of reproduction of the respective populations are different. To find out whether these anatomical differences reflect genetic differentiation, which might be an indication for distinct glacial refugia, we investigated a 650 bp fragment of the mitochondrial cytochrome oxidase subunit 1 gene (COI) (280 individuals) and 9 microsatellite loci from samples (487 individuals from 29 populations) covering the whole distribution range of the species. RESULTS: The COI sequences show a geographic differentiation between eastern, central and western populations. The westernmost localities, which were covered under ice sheets during glacial periods, are characterized by extreme low variability. Overall genetic distances among all individuals are small (max. 1.7% p-distance). The microsatellite analysis reveals a high differentiation between populations, implying restriction of gene flow. The highest genetic variability was found in the central populations. Remarkably, nearly all individuals from the eastern populations, which are more variable in their genital morphology, are homozygous in all microsatellite loci, although different alleles were found within populations. CONCLUSIONS: The most peculiar outcome of the study is the strong evidence for selfing in C. obtusus as indicated by the microsatellite data in the easternmost populations. This finding is supported by the deformation of the mucus glands in the same populations. Since mucus glands play an important role in sexual reproduction, it seems plausible that in selfing organisms these structures are reduced. The phylogeographic structure revealed by COI sequences implies that the species has survived the ice ages within the Calcareous Alps. The small genetic distances among all individuals (max. 1.7%) suggest that C. obtusus has experienced severe bottlenecks in the past.


Sujet(s)
Variation génétique , Escargots/génétique , Animaux , Évolution biologique , ADN mitochondrial/génétique , Écosystème , Complexe IV de la chaîne respiratoire/génétique , Europe , Flux des gènes , Couche de glace , Phylogenèse , Phylogéographie , Analyse de séquence d'ADN , Escargots/physiologie
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