In cockchafers of the genus Melolontha, there is a marked intraspecific polymorphism for morphological characters, making some specimens of one species resemble another. A cytogenetic and molecular (mitochondrial COI gene sequence) study of typical and atypical forms of M. melolontha and M. hippocastani, captured at the same period and area, was performed. Karyotypes and haplotypes clearly characterize each taxon, placing atypical specimens in one or the other species unambiguously. This formally discards the role of hybridization in phenotypic resemblance, as usually proposed. Karyotypes and haplotypes were compared to those of M. pectoralis and Phyllophaga pleei, a more distantly related Melolonthinae, and some Dynastinae species, to reconstruct their ancestral karyotype. The karyotype of M. melolontha is the most derivative and that of P. pleei the most conserved among the Melolonthinae studied, which fits with the phylogeny established by COI gene analysis. Both karyotypes and COI haplotypes demonstrate the proximity of M. pectoralis and M. melolontha. The karyotype of M. melolontha is polymorphic, without relationship with morphological variations. Finally, the existence of similar morphological variations in different Melolontha species and chromosomal polymorphism in M. melolontha is discussed in relation with a network (reticulated) mode of speciation.
European brown hare is a small game species spreading across Europe to Asia Minor, with important economic traits. Population genetics studies using mitochondrial DNA markers have revealed the existence of two major phylogeographic lineages, the European and the Anatolian. European lineage is further divided in the European type halpogroup and south-eastern European type halpogroup, while Anatolian consists only by the Anatolian/Middle Eastern type halpogroup. All three haplogroups show a discrete geographical distribution, with an overlapping zone forming in North-East Greece and Bulgaria, forming a contact zone. Despite the existence of a contact zone, European haplotype was never detected in Anatolia and vice versa, proposing the presence of genetic barriers responsible for this phenomenon. In this study, we analyzed the whole mitochondrial genomes of specimens originating from both lineages, aiming to detect the genetic and functional differentiation of the oxidative phosphorylation complexes that are encoded by mtDNA that could lead gradually to the reproductive isolation of the lineages.
The European brown hare (Lepus europaeus, Pallas 1778) is an important small game species in Europe. Due to its size and position in the food chain, as well as its life history, phenotypic variation and the relatively recent speciation events, brown hare plays an important role in the structure of various ecosystems and has emerged as an important species for population management and evolutionary studies. In order to identify informative SNPs for such studies, heart and liver tissues of three samples from the European lineage and a three-sample pool from the Anatolian lineage were subjected to RNA-Sequencing analysis. This effort resulted in 9496 well-assembled protein-coding sequences with close homology to human. After applying very stringent filtering criteria, 66185 polymorphic sites were identified in 7665 genes/cds and 2050 of those polymorphic sites are potentially capable of distinguishing the European from the Anatolian lineage. From these distinguishing mutations we focused on those in genes that are involved in cellular energy production, namely the glycolysis, Krebs cycle and the OXPHOS machinery. A selected set of SNPs was also validated by Sanger sequencing. By simulating the three European individuals as one pool, no substantial informative-SNP identification was lost, making it a cost-efficient approach. To our knowledge this is the first attempt to correlate the differentiation in both nuclear and mitochondrial genome between the two different lineages of L. europaeus with the observed spatial partitioning of the lineages of the species, proposing a possible mechanism that is maintaining the reproductive isolation of the lineages.
The objectives of this work were to study the prevalence and the patterns of antibiotic resistance of staphylococcal isolates from bulk-tank milk of goat herds across Greece, to assess possible associations of the presence of antibiotic resistance with the quality of milk in these herds and to evaluate herd-related factors potentially associated with the presence of antibiotic resistance among these staphylococcal isolates. A cross-sectional study was performed on 119 goat herds in Greece. Bulk-tank milk samples were collected for bacteriological examination; staphylococcal isolates were evaluated for resistance to 20 antibiotics. Oxacillin-resistant, resistant to at least one antibiotic, and multi-resistant staphylococcal isolates were recovered from 5.0%, 30.3%, and 16.0% of herds, respectively. Of 80 isolates, 7.5% were resistant to oxacillin, 50.0% were resistant to at least one antibiotic and 27.5% were multi-resistant. Resistance was seen more frequently among coagulase-negative staphylococci (59.3%) than among Staphylococcus aureus (23.8%). Resistance was more frequent against penicillin and ampicillin (41.3% of isolates) and fosfomycin (27.5%). No association was found with biofilm formation by staphylococci. For recovery of oxacillin-resistant isolates, the presence of working staff in the herds emerged as a significant factor; respective factors for the isolation of staphylococci resistant to at least one antibiotic were part-time farming and high (>10) number of systemic disinfections in the farm annually. The same three factors concurrently were also identified to be significant for the recovery of multi-resistant isolates.
We report the full polyprotein genomic sequence of a West Nile virus strain isolated from Eurasian magpies dying with neurologic signs in Greece. Our findings demonstrate the local genetic evolution of the West Nile virus strain responsible for a human disease outbreak in the country that began in 2010.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.