Search results for "SCA"

How many scales on the wings? A case study based on Colias crocea (Geoffroy, 1785) (Hexapoda: Lepidoptera, Pieridae)

2019

Abstract The covering by scales of the wings of Lepidoptera contributes to multiple functions that are critical for their survival and reproduction. In order to gain a better understanding about their distribution, we have exhaustively studied 4 specimens of Colias crocea (Geoffroy, 1785). We have quantified the sources of variability affecting scale density. The results indicate that the scale covering of butterfly wings may be remarkably heterogeneous, and that the importance of the sources of variability differs between forewings and hindwings. Thus, in forewing the greatest variability occurs between sectors, while in the hindwings it occurs between sides, with a higher density of scale…

Postmating–prezygotic isolation between two allopatric populations of Drosophila montana: fertilisation success differs under sperm competition

2016

This study was funded by the Academy of Finland (grant 250999 to O. A.-H.). Postmating but prezygotic (PMPZ) interactions are increasingly recognized as a potentially important early-stage barrier in the evolution of reproductive isolation. A recent study described a potential example between populations of the same species: single matings between Drosophila montana populations resulted in differential fertilisation success because of the inability of sperm from one population (Vancouver) to penetrate the eggs of the other population (Colorado). As the natural mating system of D. montana is polyandrous (females remate rapidly), we set up double matings of all possible crosses between the sa…

Evolutionary history and species delimitations:a case study of the hazel dormouse, Muscardinus avellanarius

2017

Robust identification of species and significant evolutionary units (ESUs) is essential to implement appropriate conservation strategies for endangered species. However, definitions of species or ESUs are numerous and sometimes controversial, which might lead to biased conclusions, with serious consequences for the management of endangered species. The hazel dormouse, an arboreal rodent of conservation concern throughout Europe is an ideal model species to investigate the relevance of species identification for conservation purposes. This species is a member of the Gliridae family, which is protected in Europe and seriously threatened in the northern part of its range. We assessed the exten…

Enemy recognition is linked to soldier size in a polymorphic stingless bee

2017

Many ant and termite colonies are defended by soldiers with powerful mandibles or chemical weaponry. Recently, it was reported that several stingless bee species also have soldiers for colony defence. These soldiers are larger than foragers, but otherwise lack obvious morphological adaptations for defence. Thus, how these soldiers improve colony fitness is not well understood. Robbing is common in stingless bees and we hypothesized that increased body size improves the ability to recognize intruders based on chemosensory cues. We studied the Neotropical species Tetragonisca angustula and found that large soldiers were better than small soldiers at recognizing potential intruders. Larger so…

Opinions 97, 98 and 99

2020

The International Committee on Systematics of Prokaryotes has formally endorsed the conclusions of the Judicial Commission on three pending Requests for an Opinion, thereby allowing the corresponding Opinions to be issued. According to Opinion 97, the request for the conservation of the name Streptomyces scabies is denied, allowing the continued use of the correction Streptomyces scabiei . Opinions 98 and 99 conclude that in the absence of associated authentic type material, the names Bacillus aeolius and Pectinatus portalensis , respectively, are not validly published.

Gastrointestinal parasites of two populations of Arctic foxes (Vulpes lagopus) from north-east Greenland

2017

Parasitological examination of 275 faecal samples from Arctic foxes (Vulpes lagopus) collected at Zackenberg Valley and Karupelv Valley in north-east Greenland from 2006 to 2008 was conducted using sieving and microscopy. Overall, 125 (45.5%) samples contained parasite eggs of Taenia crassiceps, Taenia serialis, Toxascaris leonina, Eucoleus boehmi, Physalopteridae and Ancylostomatidae, and Strongyloides-like larvae. As long-term ecological studies are conducted at both sampling locations, the present findings constitute a baseline data set for further parasitological monitoring.

Boosting Biomass Quantity and Quality by Improved Mixotrophic Culture of the Diatom Phaeodactylum tricornutum

2021

Diatoms are photoautotrophic unicellular algae and are among the most abundant, adaptable, and diverse marine phytoplankton. They are extremely interesting not only for their ecological role but also as potential feedstocks for sustainable biofuels and high-value commodities such as omega fatty acids, because of their capacity to accumulate lipids. However, the cultivation of microalgae on an industrial scale requires higher cell densities and lipid accumulation than those found in nature to make the process economically viable. One of the known ways to induce lipid accumulation in Phaeodactylum tricornutum is nitrogen deprivation, which comes at the expense of growth inhibition and lower c…

Clone-Dependent Expression of Esca Disease Revealed by Leaf Metabolite Analysis

2019

International audience; Grapevine trutk diseases, especially Esca, are of major concern since they gradually alter vineyards worldwide and cause heavy economic losses. The expression of Esca disease symptoms depends on several factors, including the grapevine cultivar. In this context, a possible clone-dependent expression of the Esca disease was studied. Two clones of 'Chardonnay' grown in the same plot were compared according to their developmental and physiological traits, metabolome, and foliar symptom expression. Analysis of their leaf metabolome highlighted differences related to symptom expression. Interestingly, the content of a few specific metabolites exhibited opposite variations…

Seasonal genetic variation associated with population dynamics of a poecilogonous polychaete worm

2017

Poecilogonous species show variation in developmental mode, with larvae that differ both morphologically and ecologically. The spionid polychaete Pygospio elegans shows variation in developmental mode not only between populations, but also seasonally within populations. We investigated the consequences of this developmental polymorphism on the spatial and seasonal genetic structure of P. elegans at four sites in the Danish Isefjord‐Roskilde‐Fjord estuary at six time points, from March 2014 until February 2015. We found genetic differentiation between our sampling sites as well as seasonal differentiation at two of the sites. The seasonal genetic shift correlated with the appearance of new s…

2016

Most large mammals have constantly been exposed to anthropogenic influence over decades or even centuries. Because of their long generation times and lack of sampling material, inferences of past population genetic dynamics, including anthropogenic impacts, have only relied on the analysis of the structure of extant populations. Here, we investigate for the first time the change in the genetic constitution of a natural red deer population over two centuries, using up to 200-year-old antlers (30 generations) stored in trophy collections. To the best of our knowledge, this is the oldest DNA source ever used for microsatellite population genetic analyses. We demonstrate that government policy …