No abstract

Background: Mosquitoes, being a nuisance species, are considered as one of the most important species in public health control programs due to their role as a vector in mosquito-borne diseases observed in humans and animals. We evaluated the susceptibility status of Culex pipiens collected from northern Izmir, Turkey in 2011–16. Methods: Mosquito larvae, collected from three different locations in northern İzmir, were reared in the laboratory. Adult susceptibility bioassays were performed using the WHO insecticide-impregnated papers including deltamethrin 0.05%, permethrin 0.75%, α-cypermethrin 0.05% and cyfluthrin 0.15%. In addition, adult bioassays were performed after the pre-exposure to piperonyl butoxide (PBO) to determine the contribution of P450 detoxification enzymes to the phenotypic resistance. Results: In all of the three populations, high levels of resistance were observed (mortalities<63%) to all of the four pyrethroids. Different pyrethroids but with the same mode of action can exhibit significantly different phenotypic re­sistance in a single population. PBO bioassays also showed that P450 detoxification enzymes can have diverse effects on different pyrethroids. Conclusion: Using just one chemical in a class of insecticide can be misleading for resistance studies

The aim of this preliminary study was to establish a primary insect cell culture from total embryos and embryonic brain tissues of Periplaneta americana, collected from Izmir, Turkey. Cells were cultured at 29?C in Grace?s insect medium for one month. In the embryonic brain tissue culture, single cells and cell clumps containing spherical and ovoid as well as dividing cells were observed. Single bipolar neurons were detected after 4 days in culture. Network systems comprised of bipolar neurons were observed on the 5th day of incubation. In addition, presumably glia cells were observed in the embryonic brain culture. In the total embryo culture, the cell population exhibited variable morphologies, including spherical, spindle-like, polygonal and giant cells after nearly 20 days; the culture covered almost half of the Petri dish area within 30 days. This preliminary study associated with Periplaneta americana primary cell culture is the first of its kind in Turkey. These results should contribute to the development of new insect cell lines that are indigenous to Turkey.

Sialic acids mainly occur as components on cell surface glycoproteins and glycolipids. They play a major role in the chemical and biological diversity of glycoconjugates. Although sialic acids exhibit great structural variability in vertebrates, glycoconjugates with sialic acids have also been determined in small amounts in invertebrates. It has been suggested that sialic acids play important roles in the development and function of the nervous system. Despite Bombyx mori being a model organism for the investigation of many physiological processes, sialic acid changes in its nervous system have not been examined during development and aging. Therefore, in this study we aimed to determine sialic acid changes in the nervous system of Bombyx mori during development and aging processes. Liquid chromatography-mass spectrometry (LC-MS) and lectin immunohistochemistry were carried out in order to find variations among different developmental stages. Developmental stages were selected as 3 rd instar (the youngest) and 5 th larval instar (young), motionless prepupa (the oldest) and 13-day-old pupa (adult development). At all stages, only Neu5Ac was present, however, it dramatically decreased during the developmental and aging stages. On the other hand, an increase was observed in the amount of Neu5Ac during the pupal stage. In immunohistochemistry experiments with Maackia amurensis agglutinin (MAA) and Sambucus nigra agglutinin (SNA) lectins, the obtained staining was consistent with the obtainedLC-MS results. These findings indicate that sialic acids are abundant at the younger stages but that they decrease in the insect nervous system during development and aging, similarly as in mammals.

The fat body, which takes part in many metabolic functions throughout the life cycle of insects, originates from mesoderm cells during the development of embryo (Canavoso et al., 2001;Haunerland & Shirk, 1995). It is a loose or compact cell mass arranged in thin layers with one or two cell thicknesses (Oliveira & Cruz-Landim, 2003).