Search results for "GENETICS"
showing 10 items of 12494 documents
Contrasting biogeographical patterns in Margarella (Gastropoda: Calliostomatidae: Margarellinae) across the Antarctic Polar Front
2021
International audience; Members of the trochoidean genus Margarella (Calliostomatidae) are broadly distributed across Antarctic and sub-Antarctic ecosystems. Here we used novel mitochondrial and nuclear gene sequences to clarify species boundaries and phylogenetic relationships among seven nominal species distributed on either side of the Antarctic Polar Front (APF). Molecular reconstructions and species-delimitation analyses recognized only four species: M. antarctica (the Antarctic Peninsula), M. achilles (endemic to South Georgia), M. steineni (South Georgia and Crozet Island) and the morphologically variable M. violacea (=M. expansa, M. porcellana and M. pruinosa), with populations in s…
Variable crab camouflage patterns defeat search image formation.
2021
Understanding what maintains the broad spectrum of variation in animal phenotypes and how this influences survival is a key question in biology. Frequency dependent selection – where predators temporarily focus on one morph at the expense of others by forming a “search image” – can help explain this phenomenon. However, past work has never tested real prey colour patterns, and rarely considered the role of different types of camouflage. Using a novel citizen science computer experiment that presented crab “prey” to humans against natural backgrounds in specific sequences, we were able to test a range of key hypotheses concerning the interactions between predator learning, camouflage and mor…
Adaptation to environmental stress at different timescales
2020
Environments are changing rapidly, and to cope with these changes, organisms have to adapt. Adaptation can take many shapes and occur at different speeds, depending on the type of response, the trait, the population, and the environmental conditions. The biodiversity crisis that we are currently facing illustrates that numerous species and populations are not capable of adapting with sufficient speed to ongoing environmental changes. Here, we discuss current knowledge on the ability of animals and plants to adapt to environmental stress on different timescales, mainly focusing on thermal stress and ectotherms. We discuss within-generation responses that can be fast and induced within minute…
UV-screening and springtime recovery of photosynthetic capacity in leaves of Vaccinium vitis-idaea above and below the snow pack
2019
International audience; Evergreen plants in boreal biomes undergo seasonal hardening and dehardening adjusting their photosynthetic capacity and photoprotection; acclimating to seasonal changes in temperature and irradiance. Leaf epidermal ultraviolet (UV)-screening by flavonols responds to solar radiation, perceived in part through increased ultraviolet-B (UV-B) radiation, and is a candidate trait to provide cross-photoprotection. At Hyytiälä Forestry Station, central Finland, we examined whether the accumulation of flavonols was higher in leaves of Vaccinium vitis-idaea L. growing above the snowpack compared with those below the snowpack. We found that leaves exposed to colder temperature…
Re-examining the rare and the lost : a review of fossil Tortricidae (Lepidoptera)
2018
We re-evaluate eleven fossils that have previously been assigned to the family Tortricidae, describe one additional fossil, and assess whether observable morphological features warrant confident assignment of these specimens to this family. We provide an overview of the age and origin of the fossils and comment on their contribution towards understanding the phylogeny of the Lepidoptera. Our results show that only one specimen, Antiquatortia histuroides Brown & Baixeras gen. and sp. nov., shows a character considered synapomorphic for the family. Six other fossils ( Electresia zalesskii Kusnezov, 1941; Tortricidrosis inclusa Skalski, 1973; Tortricites skalskii Kozlov, 1988; Tortricibaltia d…
Alu insertion polymorphisms in the African Sahel and the origin of Fulani pastoralists.
2017
The origin of Western African pastoralism, represented today by the Fulani nomads, has been a highly debated issue for the past decades, and has not yet been conclusively resolved.This study focused on Alu polymorphisms in sedentary and nomadic populations across the African Sahel to investigate patterns of diversity that can complement the existing results and contribute to resolving issues concerning the origin of West African pastoralism.A new dataset of 21 Alu biallelic markers covering a substantial part of the African Sahel has been analysed jointly with several published North African populations.Interestingly, with regard to Alu variation, the relationship of Fulani pastoralists to …
Formally described species woefully underrepresent phylogenetic diversity in the common lichen photobiont genus Trebouxia (Trebouxiophyceae, Chloroph…
2020
Lichens provide valuable systems for studying symbiotic interactions. In lichens, these interactions are frequently described in terms of availability, selectivity and specificity of the mycobionts and photobionts towards one another. The lichen-forming, green algal genus Trebouxia Puymaly is among the most widespread photobiont, associating with a broad range of lichen-forming fungi. To date, 29 species have been described, but studies consistently indicate that the vast majority of species-level lineages still lack formal description, and new, previously unrecognized lineages are frequently reported. To reappraise the diversity and the evolutionary relationships of species-level lineages …
Survey of five major grapevine viruses infecting Blatina and Žilavka cultivars in Bosnia and Herzegovina
2021
The sanitary status of grapevines has not yet been considered sufficiently in vineyards throughout Bosnia and Herzegovina (BiH). An extensive survey of five major grapevine viruses in the country was carried out in 2019. A total of 630 samples from the two dominant autochthonous cultivars, named Žilavka and Blatina, were tested by DAS-ELISA for the presence of grapevine leafroll-associated viruses (GLRaV-1 and 3), grapevine fleck virus (GFkV), grapevine fanleaf virus (GFLV) and Arabis mosaic virus (ArMV). Eighty-eight % of the samples were positive for at least one virus, and all five viruses were detected, thought with different incidence, i.e. GLRaV-3 (84%), GFLV (43%), GLRaV-1 (14%), GFk…
Begomoviruses Infecting Tomato Crops in Panama
2015
The key regions in Panama involved in open field- and greenhouse-grown commercial tomato production, including the Chiriquí, Veraguas, Herrera, Los Santos, Coclé and Panama Oeste provinces, were surveyed for the incidence and distribution of begomoviruses in the growing seasons of 2011 and 2012. The surveys took place in 14 of the 51 districts of the above-mentioned provinces and comprised all relevant tomato production areas of the provinces. A total of 28 tomato plots were surveyed. The exact location of each plot was geo-referenced using a hand-held Global Positioning System unit. In total, 319 individual tomato plants (181 in 2011 and 138 in 2012) were sampled. Plants displayed diverse …
Impact of Rearing Conditions on the Ambrosia Beetle’s Microbiome
2018
Ambrosia beetles, along with termites and leafcutter ants, are the only fungus-farming lineages within the tree of life. Bacteria harbored by ambrosia beetles may play an essential role in the nutritional symbiotic interactions with their associated fungi