43 research outputs found
T-Cell Receptor Repertoire Sequencing and Its Applications: Focus on Infectious Diseases and Cancer
The immune system is a dynamic feature of each individual and a footprint of our unique internal and external exposures. Indeed, the type and level of exposure to physical and biological agents shape the development and behavior of this complex and diffuse system. Many pathological conditions depend on how our immune system responds or does not respond to a pathogen or a disease or on how the regulation of immunity is altered by the disease itself. T-cells are important players in adaptive immunity and, together with B-cells, define specificity and monitor the internal and external signals that our organism perceives through its specific receptors, TCRs and BCRs, respectively. Today, high-throughput sequencing (HTS) applied to the TCR repertoire has opened a window of opportunity to disclose T-cell repertoire development and behavior down to the clonal level. Although TCR repertoire sequencing is easily accessible today, it is important to deeply understand the available technologies for choosing the best fit for the specific experimental needs and questions. Here, we provide an updated overview of TCR repertoire sequencing strategies, providers and applications to infectious diseases and cancer to guide researchers' choice through the multitude of available options. The possibility of extending the TCR repertoire to HLA characterization will be of pivotal importance in the near future to understand how specific HLA genes shape T-cell responses in different pathological contexts and will add a level of comprehension that was unthinkable just a few years ago
Sex-biased parental care and sexual size dimorphism in a provisioning arthropod
The diverse selection pressures driving the evolution of sexual size dimorphism (SSD) have long been debated. While the balance between fecundity selection and sexual selection has received much attention, explanations based on sex-specific ecology have proven harder to test. In ectotherms, females are typically larger than males, and this is frequently thought to be because size constrains female fecundity more than it constrains male mating success. However, SSD could additionally reflect maternal care strategies. Under this hypothesis, females are relatively larger where reproduction requires greater maximum maternal effort – for example where mothers transport heavy provisions to nests.
To test this hypothesis we focussed on digger wasps (Hymenoptera: Ammophilini), a relatively homogeneous group in which only females provision offspring. In some species, a single large prey item, up to 10 times the mother’s weight, must be carried to each burrow on foot; other species provide many small prey, each flown individually to the nest.
We found more pronounced female-biased SSD in species where females carry single, heavy prey. More generally, SSD was negatively correlated with numbers of prey provided per offspring. Females provisioning multiple small items had longer wings and thoraxes, probably because smaller prey are carried in flight.
Despite much theorising, few empirical studies have tested how sex-biased parental care can affect SSD. Our study reveals that such costs can be associated with the evolution of dimorphism, and this should be investigated in other clades where parental care costs differ between sexes and species
The Fruit Flies (Diptera, Tephritidae) in Bhutan: New Faunistic Records and Compendium of Fauna
Based on a field survey from 2017, twenty-three species are reported from Bhutan for the first time: Acroceratitis ceratitina, A. hardyi, Anomoia approximata, Bactrocera connecta, B. latifrons, B. nigrifacia, B. syzygii, Campiglossa sororcula, Cecidochares connexa, Dacus jacobi, Gastrozona fasciventris, Hoplandromyia antelopa, Lenitovena ultima, Ptilona confinis, Rioxoptilona dunlopi, R. formosana, R. vaga, Spathulina acroleuca, Themara yunnana, Trypeta indica, Zeugodacus apiciflavus, Z. diversus, and Z. fereuncinatus. Four species of the genera Cornutrypeta, Hemilea, Morinowotome, and Vidalia are also recorded for the first time, but the precise determination to species needs additional study and material. As the result, 71 species is listed from Bhutan by far. Their taxonomic position and key characters are discussed. Illustrations for most of the newly recorded species are given
Comprehensive inventory of true flies (Diptera) at a tropical site
Estimations of tropical insect diversity generally suffer from lack of known groups or faunas against which extrapolations can be made, and have seriously underestimated the diversity of some taxa. Here we report the intensive inventory of a four-hectare tropical cloud forest in Costa Rica for one year, which yielded 4332 species of Diptera, providing the first verifiable basis for diversity of a major group of insects at a single site in the tropics. In total 73 families were present, all of which were studied to the species level, providing potentially complete coverage of all families of the order likely to be present at the site. Even so, extrapolations based on our data indicate that with further sampling, the actual total for the site could be closer to 8000 species. Efforts to completely sample a site, although resource-intensive and time-consuming, are needed to better ground estimations of world biodiversity based on limited sampling
Changes to the Fossil Record of Insects through Fifteen Years of Discovery
The first and last occurrences of hexapod families in the fossil record are compiled from publications up to end-2009. The major features of these data are compared with those of previous datasets (1993 and 1994). About a third of families (>400) are new to the fossil record since 1994, over half of the earlier, existing families have experienced changes in their known stratigraphic range and only about ten percent have unchanged ranges. Despite these significant additions to knowledge, the broad pattern of described richness through time remains similar, with described richness increasing steadily through geological history and a shift in dominant taxa, from Palaeoptera and Polyneoptera to Paraneoptera and Holometabola, after the Palaeozoic. However, after detrending, described richness is not well correlated with the earlier datasets, indicating significant changes in shorter-term patterns. There is reduced Palaeozoic richness, peaking at a different time, and a less pronounced Permian decline. A pronounced Triassic peak and decline is shown, and the plateau from the mid Early Cretaceous to the end of the period remains, albeit at substantially higher richness compared to earlier datasets. Origination and extinction rates are broadly similar to before, with a broad decline in both through time but episodic peaks, including end-Permian turnover. Origination more consistently exceeds extinction compared to previous datasets and exceptions are mainly in the Palaeozoic. These changes suggest that some inferences about causal mechanisms in insect macroevolution are likely to differ as well
Nesting behavior and nest distributions of Ammophila gracilis Lepeletier (Hymenoptera: Sphecidae) in Brazil
Volume: 5Start Page: 240End Page: 24
Revision of the mexicana-group of the cycloteline genus Ozodiceromyia Bigot (Diptera: Therevidae)
Volume: 102Start Page: 561End Page: 60
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Novel biology for tephrochlamys rufiventris (Meigen, 1830) (Diptera: Heleomyzidae)
A heleomyzid fly Tephrochlamys rufiventris (Meigen, 1830), was reared from a form of blue cheese aging in a refrigerated, dark, aging room of a small northern California creamery. The third-instar larva is redescribed and the puparium is described for the first time