The effect of developmental temperature on population flexibility in Drosophila melanogaster and D. simulans

1978 ◽  
Vol 26 (1) ◽  
pp. 105 ◽  
Author(s):  
JA Mckenzie

Ten strains each of D. melanogaster and D. simulans were derived from single inseminated females of the same population. For each strain the influence of developmental temperatures in the range 12-30�C was considered for developmental time, egg to adult development percentage, sex ratio, longevity of adults, mating speed, fecundity and fertility. The species showed similar responses for all characters, although for the latter four D. simulans was more affected by extreme temperatures. Analyses of variance demonstrated temperature, strain, and temperature x strain effects to be generally significant. For sex ratio, however, temperature effects alone were significant. The results are discussed in relation to the level of genetical integration existing in a population and how such integration allows for considerable population flexibility.

2015 ◽  
Author(s):  
Steven Gregory Kuntz ◽  
Michael B. Eisen

InDrosophilaembryogenesis, increasing either oxygen concentration or temperature accelerates development. Having investigated temperature's impact on embryogenesis, here we characterize the fundamentally different developmental response to oxygen levels. The reactions to temperature and oxygen are not independent, but operate primarily through different mechanisms, with developmental time being inversely proportional to oxygen concentration but logarithmically related to temperature. Changing oxygen concentrations greatly impact survival with developmental rate changes that are dwarfed by those induced by temperature. While extreme temperatures increase early embryo mortality, mild hypoxia increases arrest and death during mid-embryogenesis and mild hyperoxia increases survival over normoxia. Most notably, while development scales uniformly with temperature, modifying oxygen levels drives heterochronic changes. Morphological processes all change with oxygen concentration, but at different rates. Gut formation is more severely slowed by decreases in oxygen, while head involution and syncytial development are less impacted than the rest of development. These data reveal that uniform scaling, seen with changes in temperature, is not the default result of adjusting developmental rate.


2017 ◽  
Vol 312 (2) ◽  
pp. R211-R222 ◽  
Author(s):  
Mads F. Schou ◽  
Torsten N. Kristensen ◽  
Anders Pedersen ◽  
B. Göran Karlsson ◽  
Volker Loeschcke ◽  
...  

The ability of ectotherms to respond to changes in their thermal environment through plastic mechanisms is central to their adaptive capability. However, we still lack knowledge on the physiological and functional responses by which ectotherms acclimate to temperatures during development, and in particular, how physiological stress at extreme temperatures may counteract beneficial acclimation responses at benign temperatures. We exposed Drosophila melanogaster to 10 developmental temperatures covering their entire permissible temperature range. We obtained metabolic profiles and reaction norms for several functional traits: egg-to-adult viability, developmental time, and heat and cold tolerance. Females were more heat tolerant than males, whereas no sexual dimorphism was found in cold tolerance. A group of metabolites, mainly free amino acids, had linear reaction norms. Several energy-carrying molecules, as well as some sugars, showed distinct inverted U-shaped norms of reaction across the thermal range, resulting in a positive correlation between metabolite intensities and egg-to-adult viability. At extreme temperatures, low levels of these metabolites were interpreted as a response characteristic of costs of homeostatic perturbations. Our results provide novel insights into a range of metabolites reported to be central for the acclimation response and suggest several new candidate metabolites. Low and high temperatures result in different adaptive physiological responses, but they also have commonalities likely to be a result of the failure to compensate for the physiological stress. We suggest that the regulation of metabolites that are tightly connected to the performance curve is important for the ability of ectotherms to cope with variation in temperature.


Genetics ◽  
2001 ◽  
Vol 157 (3) ◽  
pp. 1257-1265 ◽  
Author(s):  
Hsiao-Pei Yang ◽  
Ana Y Tanikawa ◽  
Wayne A Van Voorhies ◽  
Joana C Silva ◽  
Alexey S Kondrashov

Abstract We induced mutations in Drosophila melanogaster males by treating them with 21.2 mm ethyl methanesulfonate (EMS). Nine quantitative traits (developmental time, viability, fecundity, longevity, metabolic rate, motility, body weight, and abdominal and sternopleural bristle numbers) were measured in outbred heterozygous F3 (viability) or F2 (all other traits) offspring from the treated males. The mean values of the first four traits, which are all directly related to the life history, were substantially affected by EMS mutagenesis: the developmental time increased while viability, fecundity, and longevity declined. In contrast, the mean values of the other five traits were not significantly affected. Rates of recessive X-linked lethals and of recessive mutations at several loci affecting eye color imply that our EMS treatment was equivalent to ∼100 generations of spontaneous mutation. If so, our data imply that one generation of spontaneous mutation increases the developmental time by 0.09% at 20° and by 0.04% at 25°, and reduces viability under harsh conditions, fecundity, and longevity by 1.35, 0.21, and 0.08%, respectively. Comparison of flies with none, one, and two grandfathers (or greatgrandfathers, in the case of viability) treated with EMS did not reveal any significant epistasis among the induced mutations.


Insects ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 925
Author(s):  
Tommaso Manenti ◽  
Anders Kjærsgaard ◽  
Toke Munk Schou ◽  
Cino Pertoldi ◽  
Neda N. Moghadam ◽  
...  

Temperature has profound effects on biochemical processes as suggested by the extensive variation in performance of organisms across temperatures. Nonetheless, the use of fluctuating temperature (FT) regimes in laboratory experiments compared to constant temperature (CT) regimes is still mainly applied in studies of model organisms. We investigated how two amplitudes of developmental temperature fluctuation (22.5/27.5 °C and 20/30 °C, 12/12 h) affected several fitness-related traits in five Drosophila species with markedly different thermal resistance. Egg-to-adult viability did not change much with temperature except in the cold-adapted D. immigrans. Developmental time increased with FT among all species compared to the same mean CT. The impact of FT on wing size was quite diverse among species. Whereas wing size decreased quasi-linearly with CT in all species, there were large qualitative differences with FT. Changes in wing aspect ratio due to FT were large compared to the other traits and presumably a consequence of thermal stress. These results demonstrate that species of the same genus but with different thermal resistance can show substantial differences in responses to fluctuating developmental temperatures not predictable by constant developmental temperatures. Testing multiple traits facilitated the interpretation of responses to FT in a broader context.


Insects ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 697
Author(s):  
Marie-Paule Nawrot-Esposito ◽  
Aurélie Babin ◽  
Matthieu Pasco ◽  
Marylène Poirié ◽  
Jean-Luc Gatti ◽  
...  

Bioinsecticides made from the bacterium Bacillus thuringiensis (Bt) are the bestselling bioinsecticide worldwide. Among Bt bioinsecticides, those based on the strain Bt subsp. kurstaki (Btk) are widely used in farming to specifically control pest lepidopteran larvae. Although there is much evidence of the lack of acute lethality of Btk products for non-target animals, only scarce data are available on their potential non-lethal developmental adverse effects. Using a concentration that could be reached in the field upon sprayings, we show that Btk products impair growth and developmental time of the non-target dipteran Drosophila melanogaster. We demonstrate that these effects are mediated by the synergy between Btk bacteria and Btk insecticidal toxins. We further show that Btk bioinsecticides trigger intestinal cell death and alter protein digestion without modifying the food intake and feeding behavior of the larvae. Interestingly, these harmful effects can be mitigated by a protein-rich diet or by adding the probiotic bacterium Lactobacillus plantarum into the food. Finally, we unravel two new cellular mechanisms allowing the larval midgut to maintain its integrity upon Btk aggression: First the flattening of surviving enterocytes and second, the generation of new immature cells arising from the adult midgut precursor cells. Together, these mechanisms participate to quickly fill in the holes left by the dying enterocytes.


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