Search results for "Leptin"
showing 10 items of 249 documents
Repeated exposure of fluazinam fungicides affects gene expression profiles yet carries no costs on a nontarget pest
2021
Fungicides are used to control pathogenic fungi of crop species, but they have also been shown to alter behavioral, life history and fitness related traits of non-target insects. Here, we tested the fungicide effects on feeding behavior, survival and physiology of the non-target pest insect, the Colorado potato beetle (Leptinotarsa decemlineata). Feeding behavior was studied by a choice test of adult beetles, which were allowed to choose between a control and a fungicide (fluazinam) treated potato leaf. Larval survival was recorded after 24-hour and 72-hour exposure to control and fungicide-treated leaves with two different concentrations. The adults did not show fungicide avoidance behavio…
Juveniilihormonin vaikutus munantuotantoon ja seksuaaliseen antagonismiin koloradonkuoriaisilla
2012
Hormonitoiminta on yksi eliöiden säätelyjärjestelmistä. Hyönteisillä keskeisessä osassa hormonisäätelyä ovat juveniilihormonit (JH). Niiden määrä yksilöiden elimistössä säätelee monia asioita yksilöiden kehityksestä lisääntymistoimintoihin. Juuri tehokas lisääntyminen onkin eliöiden tärkeimpiä tehtäviä. Hormonitoiminta pitää yllä evoluution myötä eri lajeille ja lajiryhmille kehittyneitä erilaisia lisääntymisstrategioita: jotkin lisääntyvät harvakseltaan mutta huolehtivat poikasistaan, toiset tuottavat paljon jälkeläisiä, jotka ne jättävät selviämään yksin. Sukupuolten välillä on kuitenkin eroja optimaalisessa lisääntymisstrategiassa. Naaraat joutuvat kuluttamaan jälkeläisten tuottamiseen k…
Data from: Stress for invasion success? Temperature stress of preceding generations modifies the response to insecticide stress in an invasive pest i…
2012
Adaptation to stressful environments is one important factor influencing species invasion success. Tolerance to one stress may be complicated by exposure to other stressors experienced by the preceding generations. We studied whether parental temperature stress affects tolerance to insecticide in the invasive Colorado potato beetle Leptinotarsa decemlineata. Field-collected pyrethroid-resistant beetles were reared under either stressful (17°C) or favourable (23°C) insecticide-free environments for three generations. Then, larvae were exposed to pyrethroid insecticides in common garden conditions (23°C). Beetles were in general tolerant to stress. The parental temperature stress alone affect…
Ecological and genetic factors contributing to invasion success : the northern spread of the Colorado potato beetle (Leptinotarsa decemlineata)
2008
Sanna Boman tutki väitöskirjassaan koloradonkuoriaisen potentiaalia levitä Suomeen. Hän selvitti kuoriaisten mahdollisuuksia selviytyä alhaisissa lämpötiloissa ja kykyä sopeutua Suomen viileään ilmastoon.Boman havaitsi, että koloradonkuoriaisella on potentiaalia levitä Suomeen pysyvästi, sillä geneettiset tekijät ja Suomen kesälämpötilat eivät rajoita koloradonkuoriaisen selviytymistä pohjoisessa.Koloradonkuoriaisilla on geneettistä vaihtelua elinkiertopiirteissä, kuten kehitysajassa ja koossa, minkä avulla kuoriaiset voivat sopeutua entistä paremmin uusiin olosuhteisiin, esimerkiksi alhaiseen lämpötilaan. Koloradonkuoriaiset pystyvät kehittymään ja selviytymään Suomen normaaleissa kesäolos…
Immune-inflammatory and metabolic effects of high dose furosemide plus hypertonic saline solution (HSS) treatment in cirrhotic subjects with refracto…
2016
Introduction Patients with chronic liver diseases are usually thin as a result of hypermetabolism and malnutrition expressed by reduced levels of leptin and impairment of other adyponectins such as visfatin. Aims We evaluated the metabolic and inflammatory effects of intravenous high-dose furosemide plus hypertonic saline solutions (HSS) compared with repeated paracentesis and a standard oral diuretic schedule, in patients with cirrhosis and refractory ascites. Methods 59 consecutive cirrhotic patients with refractory ascites unresponsive to outpatient treatment. Enrolled subjects were randomized to treatment with intravenous infusion of furosemide (125-250mg⁄bid) plus small volumes of HSS …
The neural feedback loop between the brain and adipose tissues
2009
Communication également publiée dans le livre "Adipose tissue development: from animal models to clinical conditions" (ISBN 978-3-8055-9450-9) de C. Levy-Marchal et L. Pénicaud (eds); There are more and more data supporting the importance of nervous regulation of both white and brown adipose tissue mass. This short paper will review the different physiological parameters which are regulated such as metabolism (lipolysis and thermogeneis), secretory activity (leptin and other adipokines) but also to plasticity of adipose tissues (proliferation differentiation and apoptosis). The sensory innervation of white adipose issue and its putative role will be also described. Altogether these results …
Molecular Modelling on Leptin and the Ob Receptor as anti-obesity target
2012
Obesity is a chronic pathology with multi-factorial aetiology, characterized by extreme body weight due to storing of fat in the adipose tissue, caused by an increase of caloric income, decrease of energetic intake, or both. The body weight control is a mechanism finely regulated by several hormonal, metabolic, and nervous pathways. Recessive homozygous mutations in the ob/ob and db/db mouse strain cause extreme obesity. The products of the ob and db genes are leptin and its receptor, respectively (1,2). The leptin receptor is critical for energy homeostasis and regulation of food uptake. Leptin is a 16 kDa hormone that is mainly secreted by fat cells into the bloodstream. Under normal circ…
Effects of ajugarins and related neoclerodane diterpenoids on feeding behaviour of Leptinotarsa decemlineata and Spodoptera exigua larvae
2001
Three naturally occurring ajugarins and seven semisynthetic derivatives of them, possessing different functionalities in the decalin part, together with two natural furoneoclerodane diterpenes, have been assessed as feeding behavior modifying agents of larvae of the generalist Spodoptera exigua and a specialist like Leptinotarsa decemlineata. Ajugarin I and some of its derivatives exhibited a significant antifeedant activity against larvae of S. exigua in both choice and no-choice assays. Conversely, the furoneoclerodane diterpenes only presented antifeedant activity against larvae of L. decemlineata. These results indicate that the biological action of the tested substances is strongly mod…
A model species for agricultural pest genomics: the genome of the Colorado potato beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae)
2018
AbstractThe Colorado potato beetle is one of the most challenging agricultural pests to manage. It has shown a spectacular ability to adapt to a variety of solanaceaeous plants and variable climates during its global invasion, and, notably, to rapidly evolve insecticide resistance. To examine evidence of rapid evolutionary change, and to understand the genetic basis of herbivory and insecticide resistance, we tested for structural and functional genomic changes relative to other arthropod species using genome sequencing, transcriptomics, and community annotation. Two factors that might facilitate rapid evolutionary change include transposable elements, which comprise at least 17% of the gen…
Sublethal Pyrethroid Insecticide Exposure Carries Positive Fitness Effects Over Generations in a Pest Insect
2019
AbstractStress tolerance and adaptation to stress are known to facilitate species invasions. Many invasive species are also pests and insecticides are used to control them, which could shape their overall tolerance to stress. It is well-known that heavy insecticide usage leads to selection of resistant genotypes but less is known about potential effects of mild sublethal insecticide usage. We studied whether stressful, sublethal pyrethroid insecticide exposure has within-generational and/or maternal transgenerational effects on fitness-related traits in the Colorado potato beetle (Leptinotarsa decemlineata) and whether maternal insecticide exposure affects insecticide tolerance of offspring…