scholarly journals Temperature and clinal variation in larval growth efficiency in Drosophila melanogaster

2001 ◽  
Vol 14 (1) ◽  
pp. 14-21 ◽  
Author(s):  
S. J. W. Robinson ◽  
L. Partridge
Keyword(s):  
Drosophila Melanogaster ◽  
Larval Growth ◽  
Growth Efficiency ◽  
Clinal Variation

scholarly journals GENETIC DIFFERENTIATION BETWEEN GEOGRAPHICALLY DISTANT POPULATIONS OF DROSOPHILA MELANOGASTER

Genetics ◽  
1982 ◽  
Vol 101 (2) ◽  
pp. 235-256
Author(s):  
Rama S Singh ◽  
Donal A Hickey ◽  
Jean David
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Differentiation ◽  
Gene Frequency ◽  
Natural Populations ◽  
Allozyme Variation ◽  
Clinal Variation ◽  
Significant Genetic Differentiation ◽  
African Populations ◽  
Latitudinal Clines ◽  
North And South

ABSTRACT We have studied allozyme variation at 26 gene loci in nine populations of Drosophila melanogaster originating on five different continents. The distant populations show significant genetic differentiation. However, only half of the loci studied have contributed to this differentiation; the other half show identical patterns in all populations. The genetic differentiation in North American, European and African populations is correlated with the major climatic differences between north and south. These differences arise mainly from seven loci that show gene-frequency patterns suggestive of latitudinal clines in allele frequencies. The clinal variation is such that subtropical populations are more heterozygous than temperate populations. These results are discussed in relation to the selectionist and neutralist hypotheses of genetic variation in natural populations.

scholarly journals Evolution of reduced pre-adult viability and larval growth rate in laboratory populations of Drosophila melanogaster selected for shorter development time

2000 ◽  
Vol 76 (3) ◽  
pp. 249-259 ◽  
Author(s):  
N. G. PRASAD ◽  
MALLIKARJUN SHAKARAD ◽  
VISHAL M. GOHIL ◽  
V. SHEEBA ◽  
M. RAJAMANI ◽  
...  
Keyword(s):  
Growth Rate ◽  
Drosophila Melanogaster ◽  
Development Time ◽  
Larval Growth ◽  
Dry Weight ◽  
Relative Reduction ◽  
Larval Growth Rate ◽  
Laboratory Populations ◽  
The Difference ◽  
Faster Development

Four large (n > 1000) populations of Drosophila melanogaster, derived from control populations maintained on a 3 week discrete generation cycle, were subjected to selection for fast development and early reproduction. Egg to eclosion survivorship and development time and dry weight at eclosion were monitored every 10 generations. Over 70 generations of selection, development time in the selected populations decreased by approximately 36 h relative to controls, a 20% decline. The difference in male and female development time was also reduced in the selected populations. Flies from the selected populations were increasingly lighter at eclosion than controls, with the reduction in dry weight at eclosion over 70 generations of selection being approximately 45% in males and 39% in females. Larval growth rate (dry weight at eclosion/development time) was also reduced in the selected lines over 70 generations, relative to controls, by approximately 32% in males and 24% in females. However, part of this relative reduction was due to an increase in growth rate of the controls populations, presumably an expression of adaptation to conditions in our laboratory. After 50 generations of selection had elapsed, a considerable and increasing pre- adult viability cost to faster development became apparent, with viability in the selected populations being about 22% less than that of controls at generation 70 of selection.

scholarly journals TheDrosophila melanogasterGut Microbiota Provisions Thiamine to Its Host

mBio ◽  
2018 ◽  
Vol 9 (2) ◽  
pp. e00155-18 ◽  
Author(s):  
David R. Sannino ◽  
Adam J. Dobson ◽  
Katie Edwards ◽  
Esther R. Angert ◽  
Nicolas Buchon
Keyword(s):  
Drosophila Melanogaster ◽  
Egg Production ◽  
Larval Growth ◽  
Auxotrophic Mutant ◽  
Close Relative ◽  
Vitamin B ◽  
Substantial Impact ◽  
Host Health ◽  
Host Development ◽  
Different Levels

ABSTRACTThe microbiota ofDrosophila melanogasterhas a substantial impact on host physiology and nutrition. Some effects may involve vitamin provisioning, but the relationships between microbe-derived vitamins, diet, and host health remain to be established systematically. We explored the contribution of microbiota in supplying sufficient dietary thiamine (vitamin B1) to supportD. melanogasterat different stages of its life cycle. Using chemically defined diets with different levels of available thiamine, we found that the interaction of thiamine concentration and microbiota did not affect the longevity of adultD. melanogaster. Likewise, this interplay did not have an impact on egg production. However, we determined that thiamine availability has a large impact on offspring development, as axenic offspring were unable to develop on a thiamine-free diet. Offspring survived on the diet only when the microbiota was present or added back, demonstrating that the microbiota was able to provide enough thiamine to support host development. Through gnotobiotic studies, we determined thatAcetobacter pomorum, a common member of the microbiota, was able to rescue development of larvae raised on the no-thiamine diet. Further, it was the only microbiota member that produced measurable amounts of thiamine when grown on the thiamine-free fly medium. Its close relativeAcetobacter pasteurianusalso rescued larvae; however, a thiamine auxotrophic mutant strain was unable to support larval growth and development. The results demonstrate that theD. melanogastermicrobiota functions to provision thiamine to its host in a low-thiamine environment.IMPORTANCEThere has been a long-standing assumption that the microbiota of animals provides their hosts with essential B vitamins; however, there is not a wealth of empirical evidence supporting this idea, especially for vitamin B1(thiamine). To determine whether this assumption is true, we usedDrosophila melanogasterand chemically defined diets with different thiamine concentrations as a model. We found that the microbiota does provide thiamine to its host, enough to allow the development of flies on a thiamine-free diet. The power of theDrosophila-microbiota system allowed us to determine that one microbiota member in particular,Acetobacter pomorum, is responsible for the thiamine provisioning. Thereby, our study verifies this long-standing hypothesis. Finally, the methods used in this work are applicable for interrogating the underpinnings of other aspects of the tripartite interaction between diet, host, and microbiota.

scholarly journals A modelling study of the influence of environment and food supply on survival of Crassostrea gigas larvae

2004 ◽  
Vol 61 (4) ◽  
pp. 596-616 ◽  
Author(s):  
Eileen E Hofmann ◽  
Eric N Powell ◽  
Eleanor A Bochenek ◽  
John M Klinck
Keyword(s):  
Genetic Variation ◽  
Food Quality ◽  
Egg Quality ◽  
Larval Growth ◽  
High Growth ◽  
Growth Efficiency ◽  
Food Concentration ◽  
Larval Survival ◽  
Food Concentrations ◽  
Food Content

Abstract A biochemically based model was developed to simulate the growth, development, and metamorphosis of larvae of the Pacific oyster (Crassostrea gigas). The unique characteristics of the model are that it: (1) defines larvae in terms of their protein, neutral lipid, polar lipid, carbohydrate, and ash content; (2) tracks weight separately from length to follow larval condition; and (3) includes genetic variation in growth efficiency and egg quality to better simulate cohort population dynamics. The model includes parameterizations for filtration, ingestion, and respiration, which determine larval growth rate, and processes controlling larval mortality and metamorphosis. Changes in larval tissue composition occur as the larva grows and in response to the biochemical composition of the food. Simulations of larval growth indicate that departures of temperature, salinity, or food content from optimum levels reduce larval cohort survival, either because of metabolic constraints that result in death, unsuccessful metamorphosis, or increased predation resulting from increased larval lifespan. Temperatures and salinities near optimal values improve larval survival at low food concentration by increasing ingestion rate or growth efficiency. Also, survival at a given food concentration can vary widely depending on food composition, which determines food quality. The simulations suggest that the ratio of carbohydrate + lipid-to-protein may best describe the overall food quality, with optimal food compositions being characterized by ratios near 1.2 to 1.4 over a range of food concentrations. In contrast, food compositions containing too much or too little protein reduce larval survival, even at saturating food concentrations. In simulations emphasizing genetic variability within the cohort, larvae with high growth efficiency originating from large eggs out-perform other egg quality–growth efficiency combinations over a wide range of temperature, salinity, and food contents. As a consequence, suboptimal temperature, salinity, or food content compresses genetic variation by uniformly favouring larvae from large eggs with a high growth efficiency. However, the larval survival obtained from simulations that use a range of food qualities is representative of a much broader range of genetic types. Thus, the simulations support the supposition that food quality is an important variable controlling the survival and genetic variability of C. gigas larval cohorts.

scholarly journals Using energy budget data to assess the most damaging life-stage of an agricultural pest Mocis latipes (Guenèe, 1982) (Lepidoptera - Noctuidae)

2010 ◽  
Vol 70 (3) ◽  
pp. 459-463 ◽  
Author(s):  
MJT. Assunção-Albuquerque ◽  
MC. Peso-Aguiar ◽  
FS. Albuquerque
Keyword(s):  
Larval Development ◽  
Energy Budget ◽  
Plant Biomass ◽  
Life Stage ◽  
Larval Growth ◽  
Dry Weight ◽  
Growth Efficiency ◽  
Economic Damage ◽  
Gross Growth Efficiency ◽  
Mocis Latipes

There is much evidence to support that Mocis latipes larvae (Guenèe, 1852) are the most dangerous pasture pest and usually cause large environmental losses. However, no studies have been carried out to identify the instars during which this moth causes the most damage to the environment. Here we calculate M. latipes larval energy budget to assess its consumption across all instars and estimate the consumption/amount of plant biomass required to complete its larval development. Assimilation, respiration, consumption, excretion, gross growth efficiency and net growth efficiency were calculated. Pearson correlations were used to identify the best predictors that influenced larval growth and weight. Across all instars consumption increased exponentially, especially during the last phase. M. latipes larvae consumed ca 13.8% of total food from the first to the fifth instar, whereas during the sixth instars these larvae consumed ca 72.6%. Results also show that the best gross growth and net growth efficiency were obtained when larvae reached the fifth instar. The results also show that one larva of Mocis latipes consumes 1.02 g (dry weight) of Paspalum maritimum (Trin) in 19 days. Overall, our results indentified the sixth instar as the most destructive instar of this insect. Thus, once we know the most destructive instars of this pest, measures can be taken to disable M. latipes larval development and consequently stop their increase in plant consumption, reducing ecological and economic damage. This knowledge may eventually lead to reduced agricultural damage and contribute to sustainable farming strategies.

scholarly journals Insulin-Like Signalling Influences the Coordination of Larval Hemocyte Number with Body Size in Drosophila melanogaster

2020 ◽  
Vol 10 (7) ◽  
pp. 2213-2220 ◽  
Author(s):  
Daniel Bakopoulos ◽  
Lauren Forbes Beadle ◽  
Katherine M. Esposito ◽  
Christen K. Mirth ◽  
Coral G. Warr ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Body Size ◽  
Larval Growth ◽  
Strong Relationship ◽  
Embryonic Patterning ◽  
Tissue Remodelling ◽  
Larval Phase ◽  
Larval Growth Rate ◽  
Link Type ◽  
Impaired Insulin

Blood cells, known as hemocytes in invertebrates, play important and conserved roles in immunity, wound healing and tissue remodelling. The control of hemocyte number is therefore critical to ensure these functions are not compromised, and studies using Drosophila melanogaster are proving useful for understanding how this occurs. Recently, the embryonic patterning gene, torso-like (tsl), was identified as being required both for normal hemocyte development and for providing immunity against certain pathogens. Here, we report that Tsl is required specifically during the larval phase of hematopoiesis, and that tsl mutant larvae likely have reduced hemocyte numbers due to a reduced larval growth rate and compromised insulin signaling. Consistent with this, we find that impairing insulin-mediated growth, either by nutrient deprivation or genetically, results in fewer hemocytes. This is likely the result of impaired insulin-like signaling in the hemocytes themselves, since modulation of Insulin-like Receptor (InR) activity specifically in hemocytes causes concomitant changes to their population size in developing larvae. Taken together, our work reveals the strong relationship that exists between body size and hemocyte number, and suggests that insulin-like signaling contributes to, but is not solely responsible for, keeping these tightly aligned during larval development.

scholarly journals Evolution of reduced minimum critical size as a response to selection for rapid pre-adult development in Drosophila melanogaster

2020 ◽  
Vol 7 (6) ◽  
pp. 191910 ◽  
Author(s):  
Khushboo Sharma ◽  
Nalini Mishra ◽  
Mallikarjun N. Shakarad
Keyword(s):  
Drosophila Melanogaster ◽  
Adult Development ◽  
Critical Size ◽  
Food Limitation ◽  
Larval Growth ◽  
Critical Duration ◽  
Adult Size ◽  
Time Duration ◽  
Critical Weight ◽  
Selection For

Adult body size in holometabolus insects is directly proportional to the time spent during the larval period. The larval duration can be divided into two parts: (i) pre-critical duration—time required to attain a critical size/critical weight that would result in successful completion of development and metamorphosis even under non-availability of nutrition beyond the time of attainment of critical size, and (ii) post-critical duration—the time duration from the attainment of critical size till pupation. It is of interest to decipher the relative contribution of the two larval growth phases (from the hatching of the egg to the attainment of critical size, and from the attainment of critical size to pupation) to the final adult size. Many studies using Drosophila melanogaster have shown that selecting populations for faster development results in the emergence of small adults. Some of these studies have indirectly reported the evolution of smaller critical size. Using two kinds of D. melanogaster populations, one of which is selected for faster/accelerated pre-adult development and the other their ancestral control, we demonstrate that the final adult size is determined by the time spent as larvae post the attainment of critical size despite having increased growth rate during the second larval instar. Our populations under selection for faster pre-adult development are exhibiting adaptive bailout due to intrinsic food limitation as against extrinsic food limitation in the yellow dung fly.

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