scholarly journals Environmental and Genetic Effects on the Asymmetry Phenotype: Diazinon Resistance in the Australian Sheep Blowfly, Lucilia cuprina

Genetics ◽  
1996 ◽  
Vol 144 (1) ◽  
pp. 229-239
Author(s):  
Kris Freebairn ◽  
Janet L Yen ◽  
John A McKenzie
Keyword(s):  
Larval Density ◽  
Relative Fitness ◽  
Standard Laboratory ◽  
Rearing Conditions ◽  
Different Temperatures ◽  
Population Cage ◽  
Australian Sheep ◽  
The Asymmetry ◽  
Developmental Conditions ◽  
Concentration Asymmetry

Abstract The asymmetry phenotype of diazinon-resistant flies lacking a fitness/asymmetry Modfier (+/+; R/−) was dominant and independent of developmental temperature, larval density and diazinon concentration. Asymmetry score, pooled over three bristle characters, was ~50% greater for these phenotypes than for those of modified genotypes (M/−; −/− ) and unmodified susceptibles (+ /+ ; S/S) reared under standard laboratory conditions. Modified and susceptible phenotypes showed increased asymmetry score for temperatures and larval densities above and below standard rearing conditions; a positive correlation was observed between diazinon concentration and asymmetry score. Single and multiple environmental stresses resulted in similar scores that approached, but never exceeded, those of unmodified resistant phenotypes. Irrespective of the developmental conditions anti-symmetry and fluctuating asymmetry were typically observed for each bristle character of unmodified resistant and the modified and susceptible phenotypes, respectively. Thus while similar asymmetry scores could arise from genetic or environmental effects, asymmetry pattern was genetically based. Population cage analyses at different temperatures and larval densities showed a negative association between mean asymmetry and relative fitness.

Study of the Hydration Process of Synthetic Preparation of Ettringite by Direct Addition of Aluminum Sulfate and Calcium Hydroxide

2018 ◽  
Vol 276 ◽  
pp. 60-65
Author(s):  
Marcela Fridrichová ◽  
Dominik Gazdič ◽  
Jana Mokrá ◽  
Karel Dvořák
Keyword(s):  
Calcium Hydroxide ◽  
Aluminum Sulfate ◽  
Xrd Analysis ◽  
Standard Laboratory ◽  
X Ray Diffraction ◽  
X Ray ◽  
Saturated Water ◽  
Direct Addition ◽  
Different Temperatures ◽  
The Stability

The stability of ettringite as high-watery mineral is highly dependent on the ambient temperature. Under standard laboratory conditions, onset of decomposition of this phase occurs at temperature of 80°C already and the theoretical temperature of the complete decomposition of ettringite is 180°C. Ettringite decomposition can occur at significantly different temperatures under humidity conditions other than the laboratory ones. Within the work verification of the possibility of synthetic preparation of ettringite by direct addition of aluminum sulfate, Al2(SO4)3·18H2O, and calcium hydroxide, Ca (OH)2, as an alternative method to the yeelimite hydration procedure was carried out. The stability of the resulting systems was examined in two different environments, namely in a laboratory environment and the environment of saturated water vapour. The phase composition of the samples was determined by X-ray diffraction (XRD) analysis, thermal analysis and scanning electron microscopy (SEM).

Predicting resistance and managing susceptibility to cyromazine in the Australian sheep blowfly Lucilia cuprina

1996 ◽  
Vol 36 (4) ◽  
pp. 413 ◽  
Author(s):  
YL Yen ◽  
P Batterham ◽  
B Gelder ◽  
JA McKenzie
Keyword(s):  
Single Gene ◽  
Limited Range ◽  
Resistance Mechanisms ◽  
Lucilia Cuprina ◽  
Relative Fitness ◽  
Laboratory Studies ◽  
Effective Strategies ◽  
Evolution Of Resistance ◽  
Australian Sheep ◽  
Line Analysis

Four cyromazine-resistant variants of Lucilia cuprina were selected after ethyl methanesulfonate mutagenesis and screening above the concentration of cyromazine lethal to susceptibles. Resistance is controlled by a single gene in each variant. Two resistance loci have been identified, one (Cyr 4) closely linked to the marker 'reduced eyes' on chromosome IV, the other (Cyr 5) closely linked to the 'stubby bristles' marker on chromosome V. Concentration-mortality line analysis shows resistance ratios are low (1.5-3x). One variant [Cyr 4(2)] is viable as a homozygote, the others are lethal [Cyr 4(1)] or, at best subvital [Cyr 5(1) and Cyr 5(2)]. Competition experiments between resistant heterozygotes and susceptibles show that resistance to cyromazine is selected for over a limited range of concentrations. The capacity of laboratory studies to predict likely resistance mechanisms before they evolve in the field is discussed. The use of genetic, toxicological and relative fitness data arising from these studies to devise the most effective strategies of insecticide usage while minimising the evolution of resistance is emphasised.

scholarly journals Incubation Temperature Affects Duckling Body Size and Food Consumption Despite No Effect on Associated Feeding Behaviors

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
S F Hope ◽  
R A Kennamer ◽  
A T Grimaudo ◽  
J J Hallagan ◽  
W A Hopkins
Keyword(s):  
Food Consumption ◽  
Incubation Temperature ◽  
Phenotypic Differences ◽  
Structural Size ◽  
Avian Incubation ◽  
Different Temperatures ◽  
Lower Temperature ◽  
Incubation Temperatures ◽  
Developmental Conditions ◽  
And Behavior

Synopsis Developmental conditions can have consequences for offspring fitness. For example, small changes (<1°C) in average avian incubation temperature have large effects on important post-hatch offspring phenotypes, including growth rate, thermoregulation, and behavior. Furthermore, average incubation temperatures differ among eggs within the same nest, to the extent (i.e., >1°C) that differences in offspring phenotypes within broods should result. A potential consequence of within-nest incubation temperature variation is inequality in behaviors that could cause differences in resource acquisition within broods. To investigate this, we incubated wood duck (Aix sponsa) eggs at one of two ecologically-relevant incubation temperatures (35°C or 36°C), formed mixed-incubation temperature broods after ducklings hatched, and conducted trials to measure duckling behaviors associated with acquisition of heat (one trial) or food (three trials). Contrary to our predictions, we found no effect of incubation temperature on duckling behaviors (e.g., time spent occupying heat source, frequency of feeding bouts). However, we found evidence that ducklings incubated at the higher temperature consumed more food during the 1-h feeding trials, and grew faster in body mass and structural size (culmen and tarsus) throughout the study, than those incubated at the lower temperature. Apparent food consumption during the trials was positively related to culmen length, suggesting that differences in food consumption may be driven by structural size. This could result in positive feedback, which would amplify size differences between offspring incubated at different temperatures. Thus, our study identifies incubation temperature as a mechanism by which fitness-related phenotypic differences can be generated and even amplified within avian broods.

scholarly journals Social and physical environment independently affect oviposition decisions in Drosophila melanogaster

2021 ◽  
Author(s):  
Emily R. Churchill ◽  
Calvin Dytham ◽  
Jon R. Bridle ◽  
Michael D.F. Thom
Keyword(s):  
Drosophila Melanogaster ◽  
Spatial Distribution ◽  
Egg Production ◽  
Larval Density ◽  
Offspring Number ◽  
Resource Distributions ◽  
Distribution Of Resources ◽  
Social And Physical Environment ◽  
Developmental Conditions ◽  
Plastic Responses

AbstractIn response to environmental stimuli, including variation in the presence of conspecifics, animals show highly plastic responses in behavioural and physiological traits influencing reproduction. These responses have been extensively documented in males, but equivalent study of females is so far lacking. We expect females to be highly responsive to environmental variation, with significant impacts on fitness given females’ direct impact on offspring number, size, and developmental conditions. Using Drosophila melanogaster as a model, we manipulate (a) exposure to conspecific females, expected to influence their expectation of number of potential mates and larval density for their own offspring, and (b) test how prior consexual population density interacts with the spatial distribution of potential oviposition sites, with females expected to prefer clustered food resources that can support a larger number of eggs and larvae. After exposure to competition, females were slower to start copulating and reduced their copulation duration – the opposite effect to that observed in males previously exposed to rivals. There was a parallel and perhaps related effect on egg production, with females previously housed in groups laying fewer eggs than those that were housed in solitude. The spatial distribution of resources also influenced oviposition behaviour: females clearly preferred aggregated patches of substrate, being more likely to lay, and laying on more of the available patches, in the clustered environment. However, we found no significant interaction between prior housing conditions and resource patchiness, indicating that females did not perceive the value of different resource distributions differently when they were expecting either high or low levels of larval competition. While exposure to consexual competition influences copulatory behaviours, it is the distribution of oviposition resources that has a greater impact on oviposition decisions.

scholarly journals The Effects of Population Density on the Incidence of Developmental Deformities in Chemosensory Organs of Tobacco Hornworm Larvae (Lepidoptera: Sphingidae)

2020 ◽  
Vol 20 (4) ◽  
Author(s):  
Frank Hanson ◽  
Elizabeth Stanwyck ◽  
Alexander Bohorquez
Keyword(s):  
Life History ◽  
Population Density ◽  
Manduca Sexta ◽  
Life History Traits ◽  
Larval Density ◽  
Population Densities ◽  
Larval Population ◽  
Rate Of Development ◽  
Rearing Conditions ◽  
Chemosensory Organs

Abstract Cultures of Manduca sexta Johanssen in our laboratory were found to have larvae with missing or deformed mouthparts or antennae. Hypothesizing that these developmental deformities were caused by crowded rearing conditions, we reared larvae in four different population densities and recorded the incidence (% of larvae affected) and types of chemoreceptor deformities. Results showed that the incidence of these deformities was directly proportional to larval population density. Deformities of the maxilla and palp were the most frequent, followed by those of the antenna, epipharynx and maxillary styloconica. Life history traits of larval mass, food consumption, and rate of development were inversely related to larval density for both normal and deformed larvae. We discuss possible causes and mechanisms of these deformities and of changes to life history traits.

scholarly journals Multifarious selection through environmental change: acidity and predator-mediated adaptive divergence in the moor frog ( Rana arvalis )

2014 ◽  
Vol 281 (1780) ◽  
pp. 20133266 ◽  
Author(s):  
Andrés Egea-Serrano ◽  
Sandra Hangartner ◽  
Anssi Laurila ◽  
Katja Räsänen
Keyword(s):  
Environmental Change ◽  
Environmental Changes ◽  
Natural Populations ◽  
Relative Fitness ◽  
Adaptive Divergence ◽  
Rana Arvalis ◽  
Experimental Conditions ◽  
Larval Size ◽  
Rearing Conditions ◽  
Moor Frog

Environmental change can simultaneously cause abiotic stress and alter biological communities, yet adaptation of natural populations to co-changing environmental factors is poorly understood. We studied adaptation to acid and predator stress in six moor frog ( Rana arvalis ) populations along an acidification gradient, where abundance of invertebrate predators increases with increasing acidity of R. arvalis breeding ponds. First, we quantified divergence among the populations in anti-predator traits (behaviour and morphology) at different rearing conditions in the laboratory (factorial combinations of acid or neutral pH and the presence or the absence of a caged predator). Second, we evaluated relative fitness (survival) of the populations by exposing tadpoles from the different rearing conditions to predation by free-ranging dragonfly larvae. We found that morphological defences (relative tail depth) as well as survival of tadpoles under predation increased with increasing pond acidity (under most experimental conditions). Tail depth and larval size mediated survival differences among populations, but the contribution of trait divergence to survival was strongly dependent on prior rearing conditions. Our results indicate that R. arvalis populations are adapted to the elevated predator pressure in acidified ponds and emphasize the importance of multifarious selection via both direct (here: pH) and indirect (here: predators) environmental changes.

scholarly journals Changes in relative fitness with temperature among second chromosome arrangements in Drosophila melanogaster.

Genetics ◽  
1991 ◽  
Vol 127 (3) ◽  
pp. 507-514
Author(s):  
W van Delden ◽  
A Kamping
Keyword(s):  
Drosophila Melanogaster ◽  
Development Time ◽  
Relative Fitness ◽  
Significant Excess ◽  
Chromosome Arrangements ◽  
Different Temperatures ◽  
Latitudinal Clines ◽  
Frequency Changes ◽  
Weight Decrease ◽  
Increasing Temperature

Abstract Development time and body weight of In(2L)t, R (a putative short inversion on the left arm of the second chromosome) and ST (standard) karyotypes of Drosophila melanogaster were measured at different temperatures. Frequency changes were followed in populations polymorphic for In(2L)t and ST and kept under different environmental conditions. These experiments were carried out in order to explain the worldwide latitudinal clines for In(2L)t and other inversions. To avoid interactions with the Adh and alpha Gpdh loci, which also have latitudinal clines, all karyotypes were homozygous AdhS alpha GpdhF. In(2L)t homokaryotypes had a longer development time and a lower weight than the other karyotypes at all temperatures. R/ST heterokaryotypes had the shortest development time and ST/ST had the smallest weight decrease with increasing temperature. The differences among the In(2L)t and ST karyotypes in development time were further analyzed in an experiment where the age at which 50% of the larvae were able to become adults, without further food ingestion, was determined. In polymorphic populations at 20 degrees and 25 degrees a significant decline of In(2L)t frequencies was observed. At 29.5 degrees and 33 degrees there was no change in In(2L)t frequencies but a significant excess of heterokaryotypes occurred. On ethanol-supplemented food the most drastic decline in In(2L)t frequency was observed. Populations transferred at 2- and 3-week intervals at 25 degrees exhibited large differences in final In(2L)t frequencies. The frequency changes could in part be attributed to the differences in development time and to previously observed differences in high temperature resistance. The experiments prove that the karyotypes are under selection. The results are discussed in relation to the geographic distribution of In(2L)t.

Parental effect of diapause in relation to photoperiod and temperature in the cabbage beetle, Colaphellus bowringi (Coleoptera: Chrysomelidae)

2018 ◽  
Vol 108 (6) ◽  
pp. 773-780
Author(s):  
H.-M. He ◽  
H.-J. Xiao ◽  
F.-S. Xue
Keyword(s):  
Low Temperatures ◽  
Negative Relationship ◽  
Summer Temperature ◽  
Continuous Darkness ◽  
Parental Effect ◽  
The Third ◽  
Rearing Conditions ◽  
Different Temperatures ◽  
The Mean ◽  
Diapause Incidence

AbstractIncreasing evidence has demonstrated that the environmental conditions experienced by parents can shape offspring phenotypes. Here, we examined the effects of the photoperiod and temperature experienced by parents on the incidence of diapause in their progeny in the cabbage beetle, Colaphellus bowringi, using three experiments. The first experiment examined parental diapause incidence under different photoperiods at 25°C and the incidence of diapause in progeny from both non-diapausing and diapausing parents under the same rearing conditions. The results revealed that the incidence of diapause among progeny was exactly opposite to that of their parents, i.e., higher parental diapause incidence led to lower progeny diapause incidence, showing a negative relationship in diapause incidence between the parental generation and the progeny generation. The incidence of diapause among progeny produced by diapausing parents was higher than that in progeny produced by non-diapausing parents. The second experiment examined parental diapause incidence at different temperatures under LD 12:12 and the incidence of diapause in progeny from both non-diapausing and diapausing parents under the same rearing conditions. Similarly, the incidence of diapause in progeny was also opposite to that of their parents. However, the incidence of diapause in progeny produced by non-diapausing parents was different from that in progeny produced by diapausing parents. In the third experiment, naturally diapausing adults were maintained at a constant temperature of 9, 28°C or the mean daily summer temperature of 27.84°C under continuous darkness for 3 months of dormancy. After dormancy, the progeny of these post-diapause parents were reared under different photoperiods at 25°C. The results showed that the incidence of diapause among progeny was higher when their parents experienced high temperatures than when they experienced low temperatures. All results demonstrate that the photoperiod and temperature experienced by parents may significantly affect the diapause incidence among progeny.

Feeding, Growth, and Survival of Atlantic Cod (Gadus morhua) Larvae Reared in Replicate Plastic Enclosures

1993 ◽  
Vol 50 (5) ◽  
pp. 913-924 ◽  
Author(s):  
Håkon Otterå
Keyword(s):  
Gadus Morhua ◽  
Atlantic Cod ◽  
Brachionus Plicatilis ◽  
Larval Mortality ◽  
Larval Density ◽  
Larval Growth ◽  
Stocking Density ◽  
Gut Content ◽  
Growth And Survival ◽  
Rearing Conditions

Feeding, growth, and survival of Atlantic cod (Gadus morhua) larvae were examined during their first 2 mo of life. The experiment was carried out in eight plastic enclosures of 10 m3 volume each. Larval cod, at an initial stocking density of 10 larvae/L, were fed rotifers (Brachionus plicatilis) and natural zooplankton collected from the sea. The enclosures replicated well with regard to hydrography, feeding conditions, and larval growth and survival. Larval mortality was low during the first month, with a mean mortality rate (Z) of 0.02/d. Growth, however, was very slow and mortality increased significantly after about 4 wk, possibly due to starvation. Brachionus plicatilis dominated the gut content during the first 3–4 wk. The zooplankton concentration averaged 15–80 rotifers/L during the first 2 wk, which seemed to be insufficient under the present rearing conditions. Most of the larvae were distributed in the upper parts of the rearing enclosures, while rotifers were distributed deeper. This, together with the high larval density, inadequate rotifer enrichment, and low temperature probably amplified the unfavourable feeding conditions.

scholarly journals Deep Hypothermic Circulatory Arrest Does Not Show Better Protection for Vital Organs Compared with Moderate Hypothermic Circulatory Arrest in Pig Model

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Yang Liu ◽  
Zining Wu ◽  
Lu Dai ◽  
Haiyang Li ◽  
Ming Gong ◽  
...  
Keyword(s):  
Circulatory Arrest ◽  
Deep Hypothermic Circulatory Arrest ◽  
Hypothermic Circulatory Arrest ◽  
Pig Model ◽  
Control Group ◽  
Standard Laboratory ◽  
Organ Protection ◽  
Type A Aortic Dissection ◽  
Different Temperatures ◽  
Aortic Arch Repair

Background. Continued debates exist regarding the optimal temperature during hypothermic circulatory arrest in aortic arch repair for patients with type A aortic dissection. This study seeks to examine whether the use of moderate hypothermic circulatory arrest in a pig model provides comparable vital organ protection outcomes to the use of deep hypothermic circulatory arrest. Methods. Thirteen pigs were randomly assigned to 30 minutes of hypothermic circulatory arrest without cerebral perfusion at 15°C (n = 5), 25°C (n = 5), and a control group (n = 3). The changes in standard laboratory tests and capacity for protection against apoptosis in different vital organs were monitored with different temperatures of hypothermic circulatory arrest management in pig model to determine which temperature was optimal for hypothermic circulatory arrest. Results. There were no significant differences in the capacity for protection against apoptosis in vital organs between 2 groups (p > 0.05, respectively). Compared with the moderate hypothermic circulatory arrest group, the deep hypothermic circulatory arrest group had no significant advantages in terms of the biologic parameters of any other organs (p > 0.05). Conclusions. Compared with deep hypothermic circulatory arrest, moderate hypothermic circulatory arrest is a moderate technique that has similar advantages with regard to the levels of biomarkers of injury and capacity for protection against apoptosis in vital organs.

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