Genetic and environmental effects on the expression of peptidases and larval viability in Drosophila melanogaster.

Genetics ◽  
1992 ◽  
Vol 131 (3) ◽  
pp. 625-642 ◽  
Author(s):  
K Hiraizumi ◽  
P A Tavormina ◽  
K D Mathes
Keyword(s):  
Amino Acids ◽  
Enzyme Activity ◽  
Drosophila Melanogaster ◽  
Osmotic Stress ◽  
Genetic Background ◽  
Aminopeptidase Activity ◽  
Osmotic Concentration ◽  
Isogenic Lines ◽  
Activity Variation ◽  
Enzyme Activity Variation

Abstract The peptidase system in Drosophila melanogaster, consisting of dipeptidase-A, dipeptidase-B, dipeptidase-C and the leucine aminopeptidases, was used as a model to study the adaptive significance of enzyme activity variation. The involvement of the peptidases in osmoregulation has been suggested from the ubiquitous distribution of peptidase activities in nearly all tissues and the high concentration of amino acids and oligopeptides in the hemolymph. Under this hypothesis, larvae counteract increases in environmental osmotic stress by hydrolyzing peptides into amino acids both intra- and extracellularly to increase physiological osmotic concentration. The expression of the peptidases was studied by assaying for peptidase activities in third instar larvae of isogenic lines, which were reared under increasing levels of environmental osmotic stress using either D-mannitol or NaCl. Second and third chromosome substitution isogenic lines were used to assess the relative contribution of regulatory and structural genes in enzyme activity variation. Results indicate that: (1) genetic variation exists for peptidase activities, (2) the effect of osmotic stress is highly variable among peptidases, (3) changes in peptidase activities in response to osmotic stress depend on both genetic background and osmotic effector and (4) peptidase activities are correlated with each other, but these phenotypic correlations depend on genetic background, osmotic effector, and level of osmotic stress. Osmotic concentration in the larval hemolymph is correlated with leucine aminopeptidase activity, but changes in hemolymph osmotic concentration in response to environmental osmotic stress depend on the osmotic effector in the environment. Although these findings suggest that genetic and environmental factors contribute significantly toward the expression of enzymes with similar functions, a relative larval viability study of genotypes that differed significantly in dipeptidase-B (DIP-B) activity revealed that low DIP-B activity did not confer any measurable reduction in larval viability under increasing levels of environmental osmotic stress. These negative results suggest that, either DIP-B does not play a major role in osmoregulation or differential osmoregulation is not related to egg to adult viability in these tests.

scholarly journals Causes and consequences of esterase 6 enzyme activity variation in pre-adult Drosophila melanogaster

Heredity ◽  
1994 ◽  
Vol 73 (2) ◽  
pp. 160-169 ◽  
Author(s):  
John G Oakeshott ◽  
Marlene Saad ◽  
Anne Y Game ◽  
Marion J Healy
Keyword(s):  
Enzyme Activity ◽  
Drosophila Melanogaster ◽  
Activity Variation ◽  
Esterase 6 ◽  
Enzyme Activity Variation ◽  
Adult Drosophila

scholarly journals Associations between restriction site polymorphism and enzyme activity variation for esterase 6 in Drosophila melanogaster.

Genetics ◽  
1990 ◽  
Vol 126 (4) ◽  
pp. 1021-1031 ◽  
Author(s):  
A Y Game ◽  
J G Oakeshott
Keyword(s):  
Drosophila Melanogaster ◽  
Ejaculatory Duct ◽  
Allozyme Polymorphism ◽  
Nucleotide Polymorphisms ◽  
Adult Males ◽  
Coding Region ◽  
Activity Variation ◽  
Esterase 6 ◽  
Enzyme Activity Variation ◽  
Male Activity

Abstract Thirty-five nucleotide polymorphisms were found in a 21.5-kbp region including the Est6 locus among 42 isoallelic lines extracted from a single natural population of Drosophila melanogaster. The heterozygosity per nucleotide pair was estimated to be 0.010 overall, but was lower in sequences hybridizing to transcripts than in those not hybridizing to transcripts. Eleven of 36 pairwise comparisons among the nine most common polymorphisms showed significant gametic disequilibrium. Four of these polymorphisms were also significantly associated with the major EST6-F/EST6-S allozyme polymorphism. Significant disequilibrium was generally restricted to polymorphisms less than 1-2 kbp apart. Previously reported measures of EST6 activity in virgin adult females proved not to be significantly associated with any of the six most common nucleotide polymorphisms located in the Est6 coding region or the 1.5 kbp immediately 5'. However, the 11 haplotypes for five of these polymorphisms that lie in the 1.5-kbp 5' region could explain about half of the previously reported variation among the lines for both EST6 activity and the amount of EST6 protein in virgin adult males. One particular polymorphism, for a RsaI site 530 bp 5' of the initiation codon, could explain 21% of the male activity variation among lines. This site is embedded in a large palindrome and we suggest that sequences including or close to this site may be involved in the regulation of EST6 synthesis in the ejaculatory duct of the adult male.

scholarly journals Aminopeptidase activity is related to the amino acids composition of the food in passerine birds

2017 ◽  
Author(s):  
Cintia Garro ◽  
Antonio Brun ◽  
Enrique Caviedes-Vidal
Keyword(s):  
Amino Acids ◽  
Enzyme Activity ◽  
Feeding Habits ◽  
Adaptive Modulation ◽  
Aminopeptidase N ◽  
Enzyme Hydrolysis ◽  
The Other ◽  
Aminopeptidase Activity ◽  
Passerine Birds ◽  
Natural Diet

Background. Passerine birds exploit different kinds of feeding habits and they have to face seasonal changes in food availability. Therefore, the composition of the principal nutrient in their food differs from the usual. In consequence the digestive function – enzyme hydrolysis and absorption – have to adapt to these nutrients. These changes in digestive physiology could respond to the adaptive modulation hypothesis which postulated that the activities of digestive enzymes should match the levels of their substrates in their diet so energy is not wasted on enzymes that are no need. Thus, we decide to measure intestinal enzymes activities of two species of passerine birds that differ in natural diet. Overall we hypothesized that species with different feeding habits present enzyme activity according to the mainly component of the diet (e.g., carbohydrates, proteins). Our prediction is that the individuals will present enzyme activity proportionally to the primary components of the diets. Methods. We select for study: red ovenbirds (Furnarius rufus), which are strict insectivores and zebra finches (Taeniopygia guttata), which are specialist granivores. We complete the analysis with publish data for house sparrows (Passser domesticus) feed on high starch from the literature. To examine intestinal enzyme activities, we measured the activity of two disaccharidases (sucrase-isomaltase and maltase-glucoamilase) and one dipeptidase (aminopeptidase-N). Results. The average intestinal activity of sucrase shows that the omnivorous P. domesticus presents almost 4 times more activity than the granivorous T. guttata and more than 11 times than the insectivorous F. rufus. This difference is also reflected in the total sucrase hydrolytic capacity where P. domesticus has roughly 10 times more than the other two birds. Surprisingly in F. rufus we found maltase and aminopeptidase activity while sucrase activity was close to zero. In the case of the average activity of maltase for the omnivorous P. domesticus is approximately 40 % more than the granivorous T. guttata and more than 5 times than the insectivorous F. rufus. Although the total maltase hydrolytic capacity of P. domesticus is 5 times more than T. guttata and F. rufus. The average of aminopeptidase-N activity for F. rufus and T. guttata almost doubled the P. domesticus ones. Also F. rufus roughly doubles the other two birds in total aminopeptidase hydrolytic capacity. Discussion. This study has shown that exist a relationship between the levels of amino acids in the diet and the total aminopeptidase capacity, but in the case of carbohydrates this relationship is not evident.

scholarly journals NATURALLY OCCURRING ENZYME ACTIVITY VARIATION IN DROSOPHILA MELANOGASTER. I. SOURCES OF VARIATION FOR 23 ENZYMES

Genetics ◽  
1982 ◽  
Vol 102 (2) ◽  
pp. 191-206
Author(s):  
C C Laurie-Ahlberg ◽  
A N Wilton ◽  
J W Curtsinger ◽  
T H Emigh
Keyword(s):  
Enzyme Activity ◽  
Drosophila Melanogaster ◽  
Geographic Origin ◽  
Natural Populations ◽  
Genetic Component ◽  
Activity Levels ◽  
Substitution Lines ◽  
Show Evidence ◽  
Sources Of Variation ◽  
Enzyme Activity Variation

ABSTRACT The genetic component of variation of enzyme activity levels in Drosophila melanogaster was investigated by using 48 second- and 48 third-chromosome isogenic substitution lines derived from natural populations. The results confirm those of our earlier experiments with the same lines and extend them to a number of additional enzymes. All 23 enzymes show a significant genetic component to the variation in one or both sets of lines and only a small part of this variation is accounted for by variation among the lines in the amount of tissue per fly. The magnitude of line effects is, in most cases, considerably larger than the magnitude of environmental and measurement error effects, and the line effects are approximately continuous in distribution. Variation in the geographic origin and karyotype of the chromosomes generally does not contribute to the line component of variation, but allozymes provide an important source of variation for a few of the enzymes. Many of the enzymes show evidence for variation of activity modifiers that are not linked to the structural locus of the enzyme.

scholarly journals Models of quantitative variation of flux in metabolic pathways.

Genetics ◽  
1989 ◽  
Vol 121 (4) ◽  
pp. 869-876 ◽  
Author(s):  
P D Keightley
Keyword(s):  
Enzyme Activity ◽  
Enzyme Activities ◽  
Metabolic Pathways ◽  
Quantitative Character ◽  
Wild Type ◽  
Gene Frequencies ◽  
Activity Variation ◽  
Enzyme Activity Variation ◽  
Interaction Component ◽  
Interaction Variance

Abstract As a model of variation in a quantitative character, enzyme activity variation segregating in a population is assumed to affect the flux in simple metabolic pathways. The genetic variation of flux is partitioned into additive and nonadditive components. An interaction component of flux variance is present because the effect of an allelic substitution is modified by other substitutions which change the concentrations of shared metabolites. In a haploid population, the the proportion of interaction variance is a function of the gene frequencies at the loci contributing to the flux variation, enzyme activities of mutant and wild type at variable loci and activities at nonvariable loci. The proportion of interaction variance is inversely related to the ratio of mutant to wild-type activities at the loci controlling the enzyme activities. The interaction component as a function of gene frequencies is at a maximum with high mutant allele frequencies. In contrast, the dominance component which would apply to a diploid population is maximal as a proportion of the total when mutant alleles are at low frequencies. Unless there are many loci with large differences in activity between the alleles, the interaction component is a small proportion of the total variance. Data on enzyme activity variation from natural and artificial populations suggest that such variation generates little nonadditive variance despite the highly interactive nature of the underlying biochemical system.

scholarly journals Aminopeptidase activity is related to the amino acids composition of the food in passerine birds

2017 ◽  
Author(s):  
Cintia Garro ◽  
Antonio Brun ◽  
Enrique Caviedes-Vidal
Keyword(s):  
Amino Acids ◽  
Enzyme Activity ◽  
Feeding Habits ◽  
Adaptive Modulation ◽  
Aminopeptidase N ◽  
Enzyme Hydrolysis ◽  
The Other ◽  
Aminopeptidase Activity ◽  
Passerine Birds ◽  
Natural Diet

Background. Passerine birds exploit different kinds of feeding habits and they have to face seasonal changes in food availability. Therefore, the composition of the principal nutrient in their food differs from the usual. In consequence the digestive function – enzyme hydrolysis and absorption – have to adapt to these nutrients. These changes in digestive physiology could respond to the adaptive modulation hypothesis which postulated that the activities of digestive enzymes should match the levels of their substrates in their diet so energy is not wasted on enzymes that are no need. Thus, we decide to measure intestinal enzymes activities of two species of passerine birds that differ in natural diet. Overall we hypothesized that species with different feeding habits present enzyme activity according to the mainly component of the diet (e.g., carbohydrates, proteins). Our prediction is that the individuals will present enzyme activity proportionally to the primary components of the diets. Methods. We select for study: red ovenbirds (Furnarius rufus), which are strict insectivores and zebra finches (Taeniopygia guttata), which are specialist granivores. We complete the analysis with publish data for house sparrows (Passser domesticus) feed on high starch from the literature. To examine intestinal enzyme activities, we measured the activity of two disaccharidases (sucrase-isomaltase and maltase-glucoamilase) and one dipeptidase (aminopeptidase-N). Results. The average intestinal activity of sucrase shows that the omnivorous P. domesticus presents almost 4 times more activity than the granivorous T. guttata and more than 11 times than the insectivorous F. rufus. This difference is also reflected in the total sucrase hydrolytic capacity where P. domesticus has roughly 10 times more than the other two birds. Surprisingly in F. rufus we found maltase and aminopeptidase activity while sucrase activity was close to zero. In the case of the average activity of maltase for the omnivorous P. domesticus is approximately 40 % more than the granivorous T. guttata and more than 5 times than the insectivorous F. rufus. Although the total maltase hydrolytic capacity of P. domesticus is 5 times more than T. guttata and F. rufus. The average of aminopeptidase-N activity for F. rufus and T. guttata almost doubled the P. domesticus ones. Also F. rufus roughly doubles the other two birds in total aminopeptidase hydrolytic capacity. Discussion. This study has shown that exist a relationship between the levels of amino acids in the diet and the total aminopeptidase capacity, but in the case of carbohydrates this relationship is not evident.

scholarly journals Aminopeptidase activity is related to the amino acids composition of the food in passerine birds

2017 ◽  
Author(s):  
Cintia Garro ◽  
Antonio Brun ◽  
William Karasov ◽  
Enrique Caviedes-Vidal
Keyword(s):  
Amino Acids ◽  
Enzyme Activity ◽  
Feeding Habits ◽  
Adaptive Modulation ◽  
Aminopeptidase N ◽  
Enzyme Hydrolysis ◽  
The Other ◽  
Aminopeptidase Activity ◽  
Passerine Birds ◽  
Natural Diet

Background. Passerine birds exploit different kinds of feeding habits and they have to face seasonal changes in food availability. Therefore, the composition of the principal nutrient in their food differs from the usual. In consequence the digestive function – enzyme hydrolysis and absorption – have to adapt to these nutrients. These changes in digestive physiology could respond to the adaptive modulation hypothesis which postulated that the activities of digestive enzymes should match the levels of their substrates in their diet so energy is not wasted on enzymes that are no need. Thus, we decide to measure intestinal enzymes activities of two species of passerine birds that differ in natural diet. Overall we hypothesized that species with different feeding habits present enzyme activity according to the mainly component of the diet (e.g., carbohydrates, proteins). Our prediction is that the individuals will present enzyme activity proportionally to the primary components of the diets. Methods. We select for study: red ovenbirds (Furnarius rufus), which are strict insectivores and zebra finches (Taeniopygia guttata), which are specialist granivores. We complete the analysis with publish data for house sparrows (Passser domesticus) feed on high starch from the literature. To examine intestinal enzyme activities, we measured the activity of two disaccharidases (sucrase-isomaltase and maltase-glucoamilase) and one dipeptidase (aminopeptidase-N). Results. The average intestinal activity of sucrase shows that the omnivorous P. domesticus presents almost 4 times more activity than the granivorous T. guttata and more than 11 times than the insectivorous F. rufus. This difference is also reflected in the total sucrase hydrolytic capacity where P. domesticus has roughly 10 times more than the other two birds. Surprisingly in F. rufus we found maltase and aminopeptidase activity while sucrase activity was close to zero. In the case of the average activity of maltase for the omnivorous P. domesticus is approximately 40 % more than the granivorous T. guttata and more than 5 times than the insectivorous F. rufus. Although the total maltase hydrolytic capacity of P. domesticus is 5 times more than T. guttata and F. rufus. The average of aminopeptidase-N activity for F. rufus and T. guttata almost doubled the P. domesticus ones. Also F. rufus roughly doubles the other two birds in total aminopeptidase hydrolytic capacity. Discussion. This study has shown that exist a relationship between the levels of amino acids in the diet and the total aminopeptidase capacity, but in the case of carbohydrates this relationship is not evident.

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