The relationship between lipid peroxidation and life span in Drosophila melanogaster

Using Drosophila lines pre-selected for adaptive characters, studies have been made on the relationship between the intensity of lipid peroxidation and life span in flies of different genotype, age and physiological condition. It was shown that the intensity of lipid peroxidation depends mainly on different factors (sex, age, virginity) in different lines. No expected negative correlation was found between the level of lipid peroxidation and life span in hybrids between two inbred lines. The intensity of lipid peroxidation was inherited like a dominant character, the dynamics of aging--like a codominant one in females and superdominant in males. Both the level of lipid peroxidation and life span appeared to be sex-dependent characters.     

Geographic variations of life history strategies in Drosophila melanogaster. III. New data

A crucial assumption of evolutionary theories of aging is that age-specific differences of life history traits may have genetic causes. The present study focuses on the existence of such differences between eight freshly caught populations of Drosophila melanogaster. A highly significant differentiation of the populations is observed, yet it accounts for a relatively small part of the variance. It is also shown that large discrepancies may be found between the estimations of fitness based, on the one hand, on data for egg production and, on the other hand, on fertility data. This stresses the need for accurate measurements of fitness for the assessment of evolutionary theories. Finally, the results suggest that neither of the current evolutionary theories of aging is generally valid. Indeed, the age-specific differences that are found between the populations match either the antagonistic pleiotropy mechanism, or the concordant pleiotropy mechanism, or none of them.     

A comparative genetic analysis of interlinear differences in intensity of lipid peroxidation and life span in Drosophila melanogaster. Inbred lines and hybrids

The interrelationship between the level of peroxidation lipid and longevity was studied as based on highly inbred lines of Drosophila melanogaster, bred for adaptively important characters. The concepts of the free-radical theory proved valid for the lines and failed to be supported for the crosses. The dominant role of heterosis in the protecting against the "aging action" of free radicals is postulated.     

FLP recombinase-mediated induction of Cu/Zn-superoxide dismutase transgene expression can extend the life span of adult Drosophila melanogaster flies

Yeast FLP recombinase was used in a binary transgenic system ("FLP-OUT") to allow induced overexpression of catalase and/or Cu/Zn-superoxide dismutase (Cu/ZnSOD) in adult Drosophila melanogaster. Expression of FLP recombinase was driven by the heat-inducible hsp70 promoter. Once expressed, FLP catalyzed the rearrangement and activation of a target construct in which expression of catalase or Cu/ZnSOD cDNAs was driven by the constitutive actin5C promoter. In this way a brief heat pulse (120 or 180 min, total) of young adult flies activated transgene expression for the rest of the life span. FLP-OUT allows the effects of induced transgene expression to be analyzed in control (no heat pulse) and experimental (heat pulse) populations with identical genetic backgrounds. Under the conditions used, the heat pulse itself always had neutral or slightly negative effects on the life span. Catalase overexpression significantly increased resistance to hydrogen peroxide but had neutral or slightly negative effects on the mean life span. Cu/ZnSOD overexpression extended the mean life span up to 48%. Simultaneous overexpression of catalase with Cu/ZnSOD had no added benefit, presumably due to a preexisting excess of catalase. The data suggest that oxidative damage is one rate-limiting factor for the life span of adult Drosophila. Finally, experimental manipulation of the genetic background demonstrated that the life span is affected by epistatic interactions between the transgene and allele(s) at other loci.     

Influence of photosensitizers and light on the life span of Drosophila

The life span of adult Drosophila melanogaster fruit flies changed when they were fed two different photosensitizers. Methylene blue decreased the median life span by 49% when present in the food at a concentration of 0.001 M. Another photosensitizer, riboflavin, produced no changes in life span under the same conditions of a 12:12 h light/dark cycle at a daytime light intensity of 1000 lux. Flies exposed to constant darkness lived 43.2% longer than those exposed to constant light at a light intensity of 2000 lux. Under these conditions, riboflavin increased the life span of the flies exposed to constant light by as much as 25%. We conclude that riboflavin confers some degree of protection against the effects of constant light exposure. The completely different results obtained with riboflavin and methylene blue suggest a possible mechanism for photoageing involving photodynamic action mediated through the production of singlet oxygen.     

Genetic instability in the Drosophila melanogaster lozenge locus: characteristics of the lz75V locus

Genetic properties of lz75V, an unstable allele of the lozenge locus, are described. The lz75V allele appeared in progeny of a male from a Far East natural population of Drosophila melanogaster. Mutation of this allele produces a broad spectrum of mutant derivatives with phenotypes varying from normal to extreme. The arising alleles can be stable or unstable. Some lz75V derivatives continuously preserve their spontaneous mutability in laboratory conditions, whereas other alleles of the same family show progressive stabilization at the intralocus or intrachromosome level. Instability of the lz75V-bearing X chromosome is locus-specific: only the lozenge gene mutates with high frequency, while visible mutations at other loci rarely occur. As shown previously, the lz75V allele appears to be caused by a P-element insertion. The appearance of spontaneous instability is discussed with regard to the general problem of transposition regulation in mobile elements. Different systems of hybrid dysgenesis, and, in particular, P elements are assumed to play an important role in induction of unstable mutations in nature.     

Prolongation of life in an experimental model of aging in Drosophila melanogaster

The mammalian fetus has been perceived, paradoxically, as a successful allograft, a successful tumor, and a successful parasite. Success depends on fetal trophoblast cells, which form the interface with the mother. The maternal immune system is involved in the success of pregnancy and in its failure. The discovery that maternal gammadelta T cells may recognize and react to the fetal trophoblast and the definition of a vascular mechanism whereby their Th1 and Th2/3-type cytokines may abort embryos replaces confusion and debate with a new and simple clarity that enables further research.     

Non-mendelian female sterility in Drosophila melanogaster: quantitative variations in the efficiency of inducer and reactive strains

Crosses between various strains of Drosophila melanogaster lead in some cases to a quite typical female sterility which involves non-mendelian hereditary factors. On the basis of the fertility of F1 females, strains can be divided into three classes: Inducer, Reactive and Neutral. Females showing various degrees of sterility arise when reactive strain females are crossed to inducer males. The degree of sterility depends on the particular reactive and inducer strains used in the cross. Quantitative variations in the efficiency of inducer and reactive strains to produce sterile F1 females are studied in the present paper. The results indicate that the order which can be established within a set of reactive strains for this efficiency is largely independent of the inducer strain which is chosen for the cross.     

Extinction of conservation: A life span investigation.

Tested 8 groups (180 Ss) on measures of continuous and discontinuous quantity conservation. The 8 groups were trained and untrained Grade 2 conservers and Grade 5, Grade 7, young adult, middle-age adult, elderly, and institutionalized elderly Ss. All Ss who reached criterion on quantitative invariance judgments were then tested for resistance to conservation of quantity extinction. Both resistance judgments and explanations were found to develop in a curvilinear fashion, increasing with age until young adulthood and declining thereafter. (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Innate metabolic differences and mutagen sensitivity of Drosophila melanogaster. I. Radiosensitivity of hyperkinetic mutant

The sensitivity to gamma-rays of a hyperkinetic mutant (HK1), characterized by high metabolic activity, has been studied and compared with gamma-ray sensitivity of the wild-type Oregon-K. Radiation damage, as measured by the frequency of induced dominant lethals (DL) and sex-linked recessive lethals (SLRL), was more in HK1 as compared with Or-K. The maximal sensitivity differences for these parameters were observed in the first brood. Translocations, on the contrary, were in general fewer in the HK1 compared with Or-K. These results have been interpreted in terms of reduced repair of mutational lesions in the energy-stressed cells of KH1.     

Gene substitutions and geotaxis in Drosophila melanogaster.

Tightly linked gene markers at the white locus of Drosophila were placed, by repeated backcrossing, on each of 2 genetic backgrounds. 10 genotypes representing various combinations of homo- and heterozygosity were studied in a Hirsch-type geotactic maze. In general, the effects of genetic background, dominance, and epistasis were found to exceed the additive effects of gene substitutions. Results demonstrate the feasibility of analyzing the contributions of single genes to behaviors known to be polygenically determined. (29 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Emotional experience in everyday life across the adult life span.

Age differences in emotional experience over the adult life span were explored, focusing on the frequency, intensity, complexity, and consistency of emotional experience in everyday life. One hundred eighty-four people, age 18 to 94 years, participated in an experience-sampling procedure in which emotions were recorded across a 1-week period. Age was unrelated to frequency of positive emotional experience. A curvilinear relationship best characterized negative emotional experience. Negative emotions declined in frequency until approximately age 60, at which point the decline ceased. Individual factor analyses computed for each participant revealed that age was associated with more differentiated emotional experience. In addition, periods of highly positive emotional experience were more likely to endure among older people and periods of highly negative emotional experience were less stable. Findings are interpreted within the theoretical framework of socioemotional selectivity theory. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Management of burnout: Training psychologists in professional life span perspectives.

Describes a keen awareness developing in psychology and other professions, supported by research findings, that many professionals are psychologically impaired and considerably underproductive in their work environment. A 4-stage theory of professional development is presented to highlight important developmental issues experienced by psychologists. It is proposed that the growing research on burnout in professionals may be better understood in the context of a developmental theory. Pertinent suggestions are offered for graduate school education. (42 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Left-handedness and life span: A reply to Harris.

L. J. Harris's (see record 1994-00697-001) critique of the authors' hypothesis that left-handedness is associated with a shorter life span (S. Coren and D. F. Halpern; see record 1991-11914-001) ignores the supporting statistical evidence, which virtually always shows an increased incidence of left handedness (or other left-sided laterality) associated with a wide range of health risk factors, including serious accidents, immune disorders, early onset breast cancer, alcoholism, smoking, some types of mental retardation, homosexuality, birth-related complications (e.g., resuscitation at birth, extremely low birth weight, Rh incompatibilities, multiple birth, breech birth, and older maternal age), and selected categories of mental disorders. Given that there are no known risk factors that are elevated in right-handed populations, the longevity hypothesis remains supported. Harris's arguments against the authors' hypothesis are based on studies that show nonsignificant results, which can be explained by these studies' low statistical power. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A life span model of successful aging.

To lay the foundation for our model, we first describe existing conceptions of successful aging, underlying assumptions of development, and criteria for success. The model presented extends the discourse on this topic in three directions: (a) It frames the discussion of successful aging in the broader context of life course development; (b) it accounts for both normative and nonnormative (i.e., exceptional) success; and (c) it integrates motivational processes into a theory of successful aging. Successful aging is equated with the development and maintenance of primary control throughout the life course, which is achieved through control-related processes that optimize selection and failure compensation functions. Selection processes regulate the choice of action goals so that diversity is maintained and positive and negative trade-offs between performance domains and life stages are taken into account. Compensation mechanisms serve to maintain, enhance, and remediate competencies and motivational resources after failure experiences. Both compensation and selection processes are motivated by desires for primary control and can be characterized in terms of primary and secondary control processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conceptualizations of sex roles: A life span developmental study.

Investigated the proposition that sex role development is a life span process. It was predicted that late adolescence and adulthood would be characterized by a relative degree of relaxation of sex role specialization. At each of 3 age levels (7th grade, 12th grade, and adult) 40 male and 40 female Ss indicated on the Attitude Check List which traits they considered desirable in a male or female target ideal. Two major results were found: (a) Male and female Ss gave stereotyped responses primarily when rating an opposite-sex target, but responses were less stereotyped when judging a same-sex target figure. (b) The expected stereotype relaxation was not observed; instead, the age-related patterns primarily reflected an increased endorsement of socially desirable traits. The latter finding is in disagreement with previous research, and possible reasons for this discrepancy are explored. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)