Search results for "Polymorphism"
showing 8 items of 1968 documents
Weak warning signals can persist in the absence of gene flow
2019
Aposematic organisms couple conspicuous warning signals with a secondary defense to deter predators from attacking. Novel signals of aposematic prey are expected to be selected against due to positive frequency-dependent selection. How, then, can novel phenotypes persist after they arise, and why do so many aposematic species exhibit intrapopulation signal variability? Using a polytypic poison frog (Dendrobates tinctorius), we explored the forces of selection on variable aposematic signals using 2 phenotypically distinct (white, yellow) populations. Contrary to expectations, local phenotype was not always better protected compared to novel phenotypes in either population; in the white popul…
Defense against predators incurs high reproductive costs for the aposematic moth Arctia plantaginis
2020
Abstract To understand how variation in warning displays evolves and is maintained, we need to understand not only how perceivers of these traits select color and toxicity but also the sources of the genetic and phenotypic variation exposed to selection by them. We studied these aspects in the wood tiger moth Arctia plantaginis, which has two locally co-occurring male color morphs in Europe: yellow and white. When threatened, both morphs produce defensive secretions from their abdomen and from thoracic glands. Abdominal fluid has shown to be more important against invertebrate predators than avian predators, and the defensive secretion of the yellow morph is more effective against ants. Her…
Evolution of signal diversity: predator-prey interactions and the maintenance of warning colour polymorphism in the wood tiger moth Arctia plantaginis
2017
Aposematic organisms avoid predation by advertising defences with warning signals. The theory of aposematism predicts warning signal uniformity, yet variation in warning coloration is widespread. The chemically defended wood tiger moth Arctia plantaginis shows both geographic variation and local polymorphism in warning coloration. In this thesis, I studied whether predation by local avian predators is driving the evolution of wood tiger moth warning colours. The close relatives of the wood tiger moth designated here to genus Arctia do not show similar colour polymorphism. The wood tiger moth is thus apparently under evolutionary radiation and provides a natural laboratory for observing curr…
Diversity in warning coloration: selective paradox or the norm?
2019
Aposematic theory has historically predicted that predators should select for warning signals to converge on a single form, as a result of frequency-dependent learning. However, widespread variation in warning signals is observed across closely related species, populations and, most problematically for evolutionary biologists, among individuals in the same population. Recent research has yielded an increased awareness of this diversity, challenging the paradigm of signal monomorphy in aposematic animals. Here we provide a comprehensive synthesis of these disparate lines of investigation, identifying within them three broad classes of explanation for variation in aposematic warning signals: …
The complete mitochondrial genome of the wood tiger moth (Arctia plantaginis) and phylogenetic analyses within Arctiinae
2021
We report the assembly and annotation of the complete mitochondrial genome of the warningly-coloured wood tiger moth (Arctia plantaginis) and investigate its phylogenetic position within Arctiinae. The A.plantaginis mitogenome is 15,479 bp long with 13 protein-coding genes, 22 transfer RNAs, 2 ribosomal RNA genes, and an A + T-rich region (D-loop). The phylogenetic analyses based on 13 protein-coding genes showed A.plantaginis clustering within a clade of species with white wings and yellow or red bodies. This result can be useful in understanding the evolution of coloration in Arctiid moths. Peer reviewed
Incidence and dynamics of active cytomegalovirus infection in allogeneic stem cell transplant patients according to single nucleotide polymorphisms i…
2014
Single nucleotide polymorphisms (SNPs) in genes involved in the activation or regulation of innate and adaptive immune responses may modulate the susceptibility to and the natural history of certain chronic viral infections. The current study aimed to investigate whether donor and recipient SNPs in the chemokine receptor 5 (rs1800023), monocyte chemoattractant protein 1 (rs13900), interleukin-10 (rs1878672), and Toll-like receptor 9 (rs352140) genes would exert any influence on the rate of incidence and features of CMV DNAemia in the allogeneic stem cell transplantation setting. This was a retrospective observational multicenter study. The cohort consisted of 102 non-consecutive allogeneic …
A single tube PCR assay for detecting viruses and their recombinants that cause tomato yellow leaf curl disease in Mediterranean basin
2007
Tomato yellow leaf curl disease (TYLCD) is well known in Mediterranean countries, where it has been causing severe losses in tomato crops for decades. Until recently, two viruses (with several isolates) in the genus Begomovirus, family Geminiviridae, have been associated with the epidemics: Tomato yellow leaf curl virus (TYLCV) and Tomato yellow leaf curl Sardinia virus (TYLCSV). However, recombinants between these, such as Tomato yellow leaf curl Malaga virus (TYLCMalV), are spreading, and new methods for detecting all viruses present in the region are needed. By considering all DNA sequences available of viruses causing TYLCD in the Mediterranean basin, a PCR/RFLP protocol was developed t…
Genetic variability at αs2-casein gene in Girgentana dairy goat breed
2014
Casein genes are highly polymorphic and the high degree of variability has qualitative and quantitative effects on milk composition thereby affecting chemical, physical and technological properties of goat milk. The aim of this work was to evaluate the genetic polymorphisms of the αs2-casein (CSN1S2) gene in the endangered Girgentana dairy goat breed in order to assess the genotypes distribution, as it is known genotype influences technological and nutritional milk properties. The study was performed on 207 sample of Girgentana goat breed, analysed with different PCR protocols. The most frequent alleles was A (0.722), followed by F (0.225), C (0.051) and E (0.002) while B, D and 0 alleles w…