scholarly journals NATURALLY OCCURRING ENZYME ACTIVITY VARIATION IN DROSOPHILA MELANOGASTER. II. RELATIONSHIPS AMONG ENZYMES

Genetics ◽  
1982 ◽  
Vol 102 (2) ◽  
pp. 207-221
Author(s):  
A N Wilton ◽  
C C Laurie-Ahlberg ◽  
T H Emigh ◽  
J W Curtsinger

ABSTRACT This report describes an investigation of the specificities of the genetic effects, caused by whole chromosome substitution, on the activities of 23 enzymes in Drosophila melanogaster. Two types of correlation estimates are examined, the product-moment correlation over the chromosome substitution line means and the corresponding correlation of line effects, which is a standardized covariance component estimate. The two types of correlations give very similar results. Although there is ample evidence for specific line effects on individual enzyme activities, there are extensive intercorrelations among many of the enzymes for both second- and third-chromosome substitution lines. The pattern of correlations with respect to the metabolic functions or other properties of the enzymes is difficult to visualize by inspection of the correlation matrix, so a multivariate graphical technique, the biplot (Gabriel 1971), was employed to obtain a two-dimensional view of relationships among the enzyme activities. The second and third chromosome lines show similar patterns. Four of the five mitochondrial enzymes form one highly intercorrelated group whereas another highly intercorrelated group contains several cytosolic enzymes. Within the cytosolic group, particularly high correlations are observed between enzymes that have glucose 6-phosphate as a substrate or product and between enzymes that are NADP-dependent. Although the pattern of intercorrelations is not clearly explicable in terms of metabolic relationships among the enzymes, there is some tendency for enzymes that catalyze sequential reactions or share a substrate or product to have correlated activity levels.

1984 ◽  
Vol 43 (3) ◽  
pp. 307-321 ◽  
Author(s):  
Billy W. Geer ◽  
Cathy C. Laurie-Ahlberg

SUMMARYGenetic variation in the modulating effect of dietary sucrose was assessed in Drosophila melanogaster by examining 27 chromosome substitution lines coisogenic for the X and second chromosomes and possessing different third isogenic chromosomes derived from natural populations. An increase in the concentration of sucrose from 0·1% to 5% in modified Sang's medium C significantly altered the activities of 11 of 15 enzyme activities in third instar larvae, indicating that dietary sucrose modulates many, but not all, of the enzymes of D. melanogaster. A high sucrose diet promoted high activities of enzymes associated with lipid and glycogen synthesis and low activities of enzymes of the glycolytic and Krebs cycle pathways, reflecting the physiological requirements of the animal. Analyses of variance revealed significant genetic variation in the degrees to which sucrose modulated several enzyme activities. Analysis of correlations revealed some relationships between enzymes in the genetic effects on the modulation process. These observations suggest that adaptive evolutionary change may depend in part on the selection of enzyme activity modifiers that are distributed throughout the genome.


Genetics ◽  
1986 ◽  
Vol 113 (4) ◽  
pp. 919-938
Author(s):  
Glenn C Bewley ◽  
William J Mackay ◽  
Julia L Cook

ABSTRACT Two variants that alter the temporal expression of catalase have been isolated from a set of third chromosome substitution lines. Each variant has been mapped to a cytogenetic interval flanked by the visible markers st (3-44.0) and cu (3-50.0) at a map position of 47.0, which is within or near the interval 75D-76A previously identified as containing the catalase structural gene on the bases of dosage responses to segmental aneuploidy. Each variant operates by modulating the rate of enzyme synthesis and the level of translatable catalase-mRNA.


1997 ◽  
Vol 70 (2) ◽  
pp. 97-103 ◽  
Author(s):  
YOSHINORI MATSUO ◽  
TSUNEYUKI YAMAZAKI

Using second- or third-chromosome substitution lines of Drosophila melanogaster, the genetic variation of inducibility and amylase specific activities in three media (starch, normal and glucose) were investigated. Genetic factors on both the second and third chromosomes were responsible for the variation in amylase specific activity and inducibility. In glucose medium, the genetic variance of amylase specific activity estimated for the second-chromosome substitution lines was larger than that for the third-chromosome substitution lines; however, for starch medium and inducibility, the variance was larger for the third-chromosome substitution lines. High correlations for the second-chromosome substitution lines and low correlations for the third-chromosome substitution lines were observed for amylase specific activities in different media. These results suggest that the genetic factor(s) responsible for inducibility or amylase activity variation in an induced medium such as starch should be on the third chromosome and those in the non-induced medium such as glucose should be on the second chromosome. The functional roles of the factors on the second and third chromosomes would be the repression and induction of amylase, respectively.


Genetics ◽  
1997 ◽  
Vol 147 (3) ◽  
pp. 1191-1201 ◽  
Author(s):  
Hope Hollocher ◽  
Chau-Ti Ting ◽  
Mao-Lien Wu ◽  
Chug-I Wu

The collection of Drosophila melanogaster from Zimbabwe and nearby regions (the Z-type) yield females who would not mate with the cosmopolitan D. melanogaster males (the M-type). To dissect the genetic basis of this sexual isolation, we constructed 16 whole-chromosome substitution lines between two standard Z- and M-lines. The results were as follows: (1) All substitution lines appear normal in viability and fertility in both sexes, indicating no strong postmating isolation. (2) The genes for the behaviors are mapped to all three major chromosomes with the same ranking and comparable magnitude of effects for both sexes: III > II ⪢ X ≥ 0 (III, II and X designate the effects of the three chromosomes). The results suggest less evolution on the X than on autosomes at loci of sexual behavior. (3) The genes for “Z-maleness” are many and somewhat redundant. Whole-chromosome effects for Z-maleness appear nearly additive and show little dominance. (4) In contrast, “Z-femaleness” has less redundancy as partial genotypes never exhibit full phenotypic effects. Epistatic interactions and incomplete dominance can sometimes be detected. (5) The extensive genetic divergence underlying sexual isolation has evolved in the absence of detectable reduction in hybrid fitnesses. Sexual selection has apparently been a driving force of multiple facets of speciation at the nascent stage without reinforcement.


Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1158
Author(s):  
Nacer Bellaloui ◽  
Sukumar Saha ◽  
Jennifer L. Tonos ◽  
Jodi A. Scheffler ◽  
Johnie N. Jenkins ◽  
...  

Nutrients, including macronutrients such as Ca, P, K, and Mg, are essential for crop production and seed quality, and for human and animal nutrition and health. Macronutrient deficiencies in soil lead to poor crop nutritional qualities and a low level of macronutrients in cottonseed meal-based products, leading to malnutrition. Therefore, the discovery of novel germplasm with a high level of macronutrients or significant variability in the macronutrient content of crop seeds is critical. To our knowledge, there is no information available on the effects of chromosome or chromosome arm substitution on cottonseed macronutrient content. The objective of this study was to evaluate the effects of chromosome or chromosome arm substitution on the variability and content of the cottonseed macronutrients Ca, K, Mg, N, P, and S in chromosome substitution lines (CS). Nine chromosome substitution lines were grown in two-field experiments at two locations in 2013 in South Carolina, USA, and in 2014 in Mississippi, USA. The controls used were TM-1, the recurrent parent of the CS line, and the cultivar AM UA48. The results showed major variability in macronutrients among CS lines and between CS lines and controls. For example, in South Carolina, the mean values showed that five CS lines (CS-T02, CS-T04, CS-T08sh, CS-B02, and CS-B04) had higher Ca level in seed than controls. Ca levels in these CS lines varied from 1.88 to 2.63 g kg−1 compared with 1.81 and 1.72 g kg−1 for TM-1 and AMUA48, respectively, with CS-T04 having the highest Ca concentration. CS-M08sh exhibited the highest K concentration (14.50 g kg−1), an increase of 29% and 49% over TM-1 and AM UA48, respectively. Other CS lines had higher Mg, P, and S than the controls. A similar trend was found at the MS location. This research demonstrated that chromosome substitution resulted in higher seed macronutrients in some CS lines, and these CS lines with a higher content of macronutrients can be used as a genetic tool towards the identification of desired seed nutrition traits. Also, the CS lines with higher desired macronutrients can be used as parents to breed for improved nutritional quality in Upland cotton, Gossypium hirsutum L., through improvement by the interspecific introgression of desired seed nutrient traits such as Ca, K, P, S, and N. The positive and significant (p ≤ 0.0001) correlation of P with Ca, P with Mg, S with P, and S with N will aid in understanding the relationships between nutrients to improve the fertilizer management program and maintain higher cottonseed nutrient content.


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