Fecundity
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Methyl benzimidazole carbamate fungicides, including benomyl, are widely used in agriculture, and to eliminate entomopathogenic infections. We treated queens of Myrmica rubra (Hymenoptera:Formicidae) infected or not by Rickia wasmannii (Laboulbeniales:Laboulbeniaceae) with benomyl, 1mg/ml p.o. for six weeks. Benomyl did not treat the infection, and the treatment alone caused strong decrease in the fecundity of control healthy queens from 18.0±8.4 to 3.7±5.2eggs per healthy queen. This is the first evidence on severe adverse effects of methyl benzimidazole carbamate fungicide on the fecundity of insects, which might be responsible for altered species composition of ant assemblages in the cultural landscape.
- MeSH
- benomyl toxicita MeSH
- fertilita účinky léků MeSH
- Formicidae účinky léků parazitologie MeSH
- průmyslové fungicidy toxicita MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Structural body size and adult feeding conditions seem to be important determinants of fitness in income breeding species. However, little is known about the relative importance of structural body size and nutritional state on fecundity and winter survival in carabids. In this study, two separate experiments were performed. The effects of the structural body size of females (expressed as the length of the elytra and the width of the pronotum) and the effect of starvation on the fecundity of the ground beetle Anchomenus dorsalis (Pontoppidan, 1763) were investigated in the "fecundity experiment." The influence of structural body size, feeding conditions (full, partial, or no feeding) before the winter, and behavior during the winter (burrowing into the substrate) on winter survival in A. dorsalis females were studied in the "overwintering experiment." Egg production was positively influenced by both the structural body size of females and adult feeding. The effect of structural body size on the number of eggs laid outweighed the effect of feeding. However, the total fecundity (the number of eggs laid plus the number of mature eggs in ovaries) were more strongly affected by feeding in comparison to the structural body size of females. Interestingly, there was no significant effect of structural body size, feeding before winter, or behavior during winter on the survival of A. dorsalis females during the winter. However, our overwintering results could be affected by extreme weather conditions throughout experimental season and by the experimental design, which is discussed in detail.
- MeSH
- brouci fyziologie MeSH
- chování zvířat MeSH
- fertilita fyziologie MeSH
- fyziologie výživy zvířat * MeSH
- kladení vajíček MeSH
- ovum MeSH
- roční období MeSH
- velikost těla * MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Lepeophtheirus simplex Ho, Gómez et Fajer-Avila, 2001 is a parasite of Sphoeroides annulatus (Jenyns), an economically important fish species, with potential for aquaculture, in northwestern Mexico. The goal of this study was to describe the developmental stages under experimental conditions and seasonal fecundity of this parasite on wild fish. There are two naupliar, one copepodid, two chalimus and two pre-adult stages preceding the adult of L. simplex. The results support previous findings, which point out that the life cycle of the caligid copepods includes only six post-naupliar stages. The generation time from egg extrusion to adult for L. simplex was approximately 10 days at 22 °C. The body length of the ovigerous females ranged between 2.2 and 4.1 mm, and its fecundity between 12 and 36 eggs per string. Fecundity was negatively correlated with the egg size and positively correlated with the egg string length. Our data did not reveal significant differences in fecundity among sampling months, but ovigerous females were significantly larger in March (when water temperature was 22 °C) than in June and July (when water temperature was 30 °C). To some extent, our fecundity results contrast with those found in species of sea lice from higher latitudes. Undoubtedly, biological information on different species of sea lice from different environmental conditions will enhance our understanding of their infection strategies and will be valuable, given the increasing interest in marine fish farming in Mexico.
- MeSH
- Copepoda * anatomie a histologie růst a vývoj MeSH
- fertilita MeSH
- ovum cytologie MeSH
- pohlavní dimorfismus MeSH
- stadia vývoje MeSH
- statistika jako téma MeSH
- teplota MeSH
- Tetraodontiformes * parazitologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Mexiko MeSH
Infectious diseases are known to regulate population dynamics, an observation that underlies the use of pathogens as control agents of unwanted populations. Sterilizing rather than lethal pathogens are often suggested so as to avoid unnecessary suffering of the infected hosts. Until recently, models used to assess plausibility of pathogens as potential pest control agents have not included a possibility that reduced fecundity of the infected individuals may save their energy expenditure on reproduction and thus increase their longevity relative to the susceptible ones. Here, we develop a model of host-pathogen interaction that builds on this idea. We analyze the model for a variety of infection transmission functions, revealing that the indirect effect of sterilizing pathogens on mortality of the infected hosts, mediated by a fecundity-longevity trade-off, may cause hosts at endemic equilibria to attain densities higher than when there is no effect of pathogens on host mortality. On the other hand, an opposite outcome occurs when the fecundity-longevity trade-off is concave or when the degree of fecundity reduction by the pathogen is high enough. This points to a possibility that using sterilizing pathogens as agents of pest control may actually be less effective than previously thought, the more so since we also suggest that if sexual selection acts on the host species then the presence of sterilizing pathogens may even enhance host densities above the levels achieved without infection.
- MeSH
- dlouhověkost * MeSH
- energetický metabolismus * MeSH
- fertilita * MeSH
- interakce hostitele a patogenu * MeSH
- kontrola škůdců MeSH
- populační dynamika MeSH
- sterilizace MeSH
- teoretické modely * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
BACKGROUND AND AIMS: Schistosoma mansoni infection is one of the worldwide leading causes of liver fibrosis and portal hypertension. The objective of this study was to evaluate whether polyhydroxylated bile acids (BAs), known to protect mice from the development of acquired cholestatic liver injury, counteract S. mansoni-induced inflammation and fibrosis. METHODS: Adult FVB/N wild type (WT) and Abcb11/Bsep-/- mice were infected with either 25 or 50 S. mansoni cercariae. Eight weeks post infection, effects on liver histology, serum biochemistry, gene expression profile of proinflammatory cytokines and fibrotic markers, hepatic hydroxyproline content and FACS analysis were performed. RESULTS: Bsep-/- mice infected with S. mansoni showed significantly less hepatic inflammation and tendentially less fibrosis compared to infected WT mice. Despite elevated alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase levels in infected Bsep-/- mice, inflammatory cells such as M2 macrophages and Mac-2/galectin-3+ cells were reduced in these animals. Accordingly, mRNA-expression levels of anti-inflammatory cytokines (IL-4 and IL-13) were increased in Bsep-/- mice upon infection. Furthermore, infected Bsep-/- mice exhibited decreased hepatic egg load and parasite fecundity, consequently affecting the worm reproduction rate. This outcome could arise from elevated serum BA levels and lower blood pH in Bsep-/- mice. CONCLUSIONS: The loss of Bsep and the resulting changes in bile acid composition and blood pH are associated with the reduction of parasite fecundity, thus attenuating the development of S. mansoni-induced hepatic inflammation and fibrosis.
- MeSH
- cytokiny metabolismus MeSH
- fertilita MeSH
- jaterní cirhóza prevence a kontrola etiologie MeSH
- játra patologie MeSH
- myši MeSH
- paraziti * MeSH
- Schistosoma mansoni MeSH
- schistosomiasis mansoni * komplikace MeSH
- zánět patologie MeSH
- žlučové kyseliny a soli metabolismus MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
How symbioses between bacteria and aquatic animals influence food webs in freshwater ecosystems is a fundamental question in ecology. We investigated symbiosis between a crustacean zooplankton Daphnia magna and its dominant bacterial symbiont Limnohabitans, an abundant and globally distributed freshwater Betaproteobacteria. Aposymbiotic juvenile Daphnia were prepared and exposed to any of four Limnohabitans sp. - Limnohabitans strains DM1, 2KL-3, 2KL-7 and Limnohabitans planktonicus strain II-D5, all previously found in D. magna digestive tract or culture. Re-infected Daphnia were cultured until they produced the first clutch of juveniles. Limnohabitans strain DM1 and L. planktonicus strain II-D5 successfully re-infected Daphnia through single exposure at the first instar juvenile stage. In contrast to aposymbiotic Daphnia that produced non-viable juveniles, re-infected Daphnia produced viable juveniles and increased fecundity to levels of that of symbiotic Daphnia. Re-infected Daphnia did not increase their number of eggs nor growth rates. Limnohabitans strains 2KL-7 and 2KL-3 could not recover fecundity even in multiple exposures during culture. This study shows the functional evidence demonstrating that a single bacterium Limnohabitans regulates fecundity of the consumer Daphnia through symbiosis. Our results indicated that symbiotic relationship between major bacterioplankton and zooplankton is important for maintaining the population of zooplankton in freshwater ecosystems.
- MeSH
- Betaproteobacteria genetika růst a vývoj izolace a purifikace fyziologie MeSH
- Daphnia mikrobiologie fyziologie MeSH
- ekosystém MeSH
- fertilita MeSH
- potravní řetězec MeSH
- sladká voda mikrobiologie MeSH
- symbióza * MeSH
- zooplankton mikrobiologie fyziologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Infection with Fascioloides magna (Digenea) causes serious damage to liver tissue in definitive hosts represented by ruminants, especially cervids. The distribution of F. magna includes the indigenous areas in North America, and the areas to which F. magna was introduced-Central Europe, Southeast Europe, and Italy. The North American intermediate host of F. magna, the freshwater snail Pseudosuccinea columella (Lymnaeidae), is an invasive species recorded in South America, the Caribbean, Africa, Australia, and west and Southeast Europe. In Europe, Galba truncatula is the snail serving for transmission, but P. columella has potential to become here a new intermediate host of F. magna. Little is known about interactions between F. magna and P. columella. In this study, the susceptibility of P. columella (Oregon, USA) to the infection by a single miracidium of the Czech strain of F. magna and the influence of F. magna on snail fecundity, shell height, and survival were evaluated. The data show that the Oregon strain of P. columella is a highly suitable host for the Czech strain of F. magna, with the infection rate of 74 %. In addition, a negative effect on survival rate of infected snails was recorded only in the late phase of infection. The infection was accompanied by a major reduction in egg mass production and by a decrease in the number of eggs per egg mass. The shell height of infected snails did not significantly differ from that in unexposed controls.
- MeSH
- druhová specificita MeSH
- Fasciola hepatica klasifikace genetika patogenita MeSH
- fasciolóza epidemiologie parazitologie veterinární MeSH
- fertilita MeSH
- hlemýždi parazitologie MeSH
- játra parazitologie patologie MeSH
- míra přežití MeSH
- molekulární typizace MeSH
- ovum parazitologie MeSH
- vysoká zvěř parazitologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Afrika epidemiologie MeSH
- Austrálie epidemiologie MeSH
- Evropa epidemiologie MeSH
- Jižní Amerika epidemiologie MeSH
- karibský region epidemiologie MeSH
- Severní Amerika epidemiologie MeSH
In order to develop an understanding of the role of adjuvants in a popular glyphosate-based herbicide - Roundup® Concentrate Plus (RCP), on non-target organisms, the effects of pure glyphosate [N-(phosphonomethyl)-glycine], RCP and a non-ionic surfactant - polyethoxylated tallowamine (POEA) were studied in the fruit fly Drosophila melanogaster. Acute exposure to sub-lethal concentrations of RCP (15 μg/mL) and POEA (45 μg/mL) reduced (p < 0.001) lifespan of female flies compared to untreated controls or glyphosate (100 μg/mL). Negative geotaxis responses in female flies were reduced (p < 0.05) following acute exposure to sub-lethal concentrations of RCP and POEA whereas glyphosate did not significantly affect this response compared to untreated flies. Acute exposure to sub-lethal concentrations of RCP and POEA elevated (p < 0.05) protein carbonyl levels while markedly (p < 0.01) inhibiting carbonyl reductase activity whereas glyphosate treatment did not significantly affect protein carbonyl levels or carbonyl reductase activity. Fecundity was reduced (p < 0.05) following exposure to sub-lethal concentrations of RCP and POEA whereas glyphosate did not affect fecundity. In vitro treatment of ovarian stem sheath (OSS) cells with sub-lethal concentrations of RCP and POEA revealed decreased cell viability and enhanced caspase activity indicative of pro-apoptotic processes after 48 h compared to untreated controls. Glyphosate however was non-toxic at the concentration used. The results suggest that RCP and the surfactant POEA are more toxic than pure glyphosate and inhibit fecundity in Drosophila by impairing cell viability through enhanced apoptosis.
- MeSH
- adjuvancia farmaceutická toxicita MeSH
- apoptóza účinky léků MeSH
- buněčné linie MeSH
- dlouhověkost účinky léků MeSH
- Drosophila melanogaster účinky léků fyziologie MeSH
- fertilita účinky léků MeSH
- glycin analogy a deriváty toxicita MeSH
- herbicidy toxicita MeSH
- polyethylenglykoly toxicita MeSH
- povrchově aktivní látky toxicita MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
