| two neutrality tests of y-linked rdna variation in drosophila melanogaster. | the evolutionary significance of y-chromosomal ribosomal dna sequence variation was tested by two different means. a single sample of males and females was collected from a peach orchard in central pennsylvania. wild-caught males and sons of wild-caught, wild-inseminated females were crossed to virgin females having an x-linked rdna deficiency. genomic dna from male progeny of these crosses was extracted and digested with the single restriction endonuclease, drai. southern blots of these digesti ... | 1990 | 28564442 |
| resistance of genetic correlation structure to directional selection in drosophila melanogaster. | the genetic covariance and correlation matrices for five morphological traits were estimated from four populations of fruit flies, drosophila melanogaster, to measure the extent of change in genetic covariances as a result of directional selection. two of the populations were derived from lines that had undergone selection for large or small thorax length over the preceding 23 generations. a third population was constituted using flies from control lines that were maintained with equivalent popu ... | 1990 | 28564436 |
| the evolution of reproductive isolation as a correlated character under sympatric conditions: experimental evidence. | a set of experiments is described that tests the general hypothesis that sympatric speciation is genetically feasible whenever reproductive isolation evolves indirectly as a correlated character. we specifically test the hypothesis that disruptive selection on habitat preference can lead to sympatric speciation when individuals mate locally within their selected habitat. drosophila melanogaster was used as a model system. a 35-generation experiment using a complex habitat maze led to complete re ... | 1990 | 28563894 |
| genetic components of variation in energy storage in drosophila melanogaster. | one approach to examining the underlying genetic structure of the variation in a continuous phenotype is to measure a set of possibly mechanistically related traits and determine the quantitative genetic aspects of their transmission. in this study the quantities of stored triacylglycerol and glycogen were measured along with the activities of 10 enzymes in related metabolic pathways in a set of 1,157 half-sib families of drosophila melanogaster. the families were structured with each male being ... | 1990 | 28567978 |
| dynamics of p-m hybrid dysgenesis in p-transformed lines of drosophila simulans. | an autonomous p element from drosophila melanogaster was introduced by microinjection into the germ line of its sibling species, drosophila simulans. the invasion kinetics of p elements was studied in seven independent lines over 60 generations, using gel blotting, in situ hybridization, and dysgenic crosses. some of the main phenotypic and molecular characteristics of p-m hybrid dysgenesis were observed, i.e., gonadal dysgenesis (gd sterility), chromosome rearrangements, and the occurrence of d ... | 1990 | 28568199 |
| inbreeding increases genetic variance for viability in drosophila melanogaster. | | 1989 | 28564327 |
| female receptivity to remating and early fecundity in drosophila melanogaster. | | 1989 | 28564506 |
| gene trees and organismal histories: a phylogenetic approach to population biology. | a "gene tree" is the phylogeny of alleles or haplotypes for any specified stretch of dna. gene trees are components of population trees or species trees; their analysis entails a shift in perspective from many of the familiar models and concepts of population genetics, which typically deal with frequencies of phylogenetically unordered alleles. molecular surveys of haplotype diversity in mitochondrial dna (mtdna) have provided the first extensive empirical data suitable for estimation of gene tr ... | 1989 | 28564500 |
| a test of the role of epistasis in divergence under uniform selection. | five populations of drosophila melanogaster have previously been shown to be replicably different in their responses to artificial selection for knockdown resistance to ethanol fumes (cohan and hoffmann, 1986). the present study tests whether this divergence could be attributed to the epistatic mechanism assumed by wright's shifting-balance model of evolution, in which alleles favored in the genetic background of one population are not favored in that of another. if this were the mechanism of di ... | 1989 | 28564195 |
| the association between the polymorphisms at the adh and αgpdh loci and the in(2l)t inversion in drosophila melanogaster in relation to temperature. | substantial allele-frequency changes were observed at the adh and αgpdh loci in a seminatural population of drosophila melanogaster kept in a tropical greenhouse during 1972-1985. further analysis of the changes at the adh and αgpdh loci showed that linkage disequilibrium between these loci occurred for a prolonged period due to the presence of in(2l)t, a long inversion on the left arm of the second chromosome. we observed increases in the frequencies of in(2l)t and of short inversions on the le ... | 1989 | 28564191 |
| intra- and extracellular electrical fields of vitellogenic polytrophic insect follicles. | dye-coupling of lucifer yellow between follicle cells and germ cells of the vitellogenic polytrophic follicles of sarcophaga bullata, drosophila melanogaster, and manduca sexta does not always occur. the electrical field around the follicles of sarcophaga bullata can be modified by altering the ionic composition of the ringer solution. we propose general model that suggests possible pathways for both intracellular and extracellular current loops. | 1989 | 29300572 |
| charge-dependent molecular movement through intercellular bridges in drosophila follicles. | the steady-state membrane potentials of the nurse cells of drosophila melanogaster incubated in a ringer's solution containing 2.5 mm k+ averaged 5.2 mv more negative than those of oocytes to which they were attached by intercellular bridges (n = 159; p < 0.001, paired t-test). in sodium azide, the resting potentials of the two cells diminished from a range of -50 to -70 mv to an average of -10 mv, and the transbridge difference disappeared. therefore, the transbridge difference is dependent upo ... | 1989 | 29300569 |
| density-dependent evolution of life-history traits in drosophila melanogaster. | populations of drosophila melanogaster were maintained for 36 generations in r- and k-selected environments in order to test the life-history predictions of theories on density-dependent selection. in the r-selection environment, populations were reduced to low densities by density-independent adult mortality, whereas populations in the k-selection environment were maintained at their carrying capacity. some of the experimental results support the predictions or r- and k-selection theory; relati ... | 1989 | 28568549 |
| molecular analysis of the alleles of alcohol dehydrogenase along a cline in drosophila melanogaster. i. maine, north carolina, and florida. | clinal variation in natural populations is often assumed to be due to the operation of natural selection. however, for many clines there exist plausible neutralist explanations which suggest that aspects of population structure maintain differences among subpopulations for particular traits. we used a restriction-mapping technique to investigate the contributions of population subdivision and selection to the maintenance of the allozyme polymorphism at the alcohol dehydrogenase (adh) locus of dr ... | 1989 | 28568543 |
| effects of parental photoperiod on development time and density sensitivity of progeny in drosophila melanogaster. | | 1988 | 28581076 |
| analysis of the genetic structure of life history of drosophila melanogaster using recombinant extracted lines. | a model for the evolution of senescence known as "antagonistic pleiotropy" makes the specific prediction that there should be a negative genetic correlation between early- and late-age traits associated with fitness. this model has previously been tested by classical quantitative-genetic means including sib-analysis and artificial selection. we used the approach of chromosome extraction, which has both advantages and disadvantages compared to classical techniques, to test the model further. from ... | 1988 | 28581074 |
| adaptations to temperate climates and evolution of overwintering strategies in the drosophila melanogaster species group. | the drosophila melanogaster species group is considered to have originated in the tropics and only recently invaded temperate habitats. the temperate species of this group that were studied here may be subdivided into the warm-temperate species (d. lutescens and d. rufa) and the cool-temperate species (species of the auraria complex). the warm-temperate species were more cold-hardy than were their tropical relatives (d. takahashii or d. melanogaster) at the larval and imaginal stages, and the co ... | 1988 | 28581072 |
| multiple genetic mechanisms for the evolution of senescence in drosophila melanogaster. | we present the results of selection experiments designed to distinguish between antagonistic pleiotropy and mutation accumulation, two mechanisms for the evolution of senescence. reverse selection for early-life fitness was applied to laboratory populations of drosophila melanogaster that had been previously selected for late-life fitness. these populations also exhibited reduced early-age female fecundity and increased resistance to the stresses of starvation, desiccation, and ethanol, when com ... | 1988 | 28563863 |
| environmental effects on remating in drosophila melanogaster. | the effects of density and food on remating were investigated using drosophila melanogaster. the frequency of remating was unaffected by density for some combinations of fly strains but was reduced at low relative densities for other combinations. until females had used most of their stored sperm, remating was less likely when food was absent or contact with food was prevented. food availability had little effect on the incidence of remating once stored sperm were depleted and had no effect on i ... | 1988 | 28567838 |
| sexual selection in a natural population of drosophila melanogaster. | | 1988 | 28563853 |
| evolutionary steps and transposable elements in drosophila melanogaster: the missing rp type obtained by genetic transformation. | the i-r and p-m hybrid dysgenesis systems in drosophila melanogaster have been interpreted as due to recent invasions of the genome by the i and p mobile genetic elements. temporal and geographical surveys have never shown individuals harboring p sequences but devoid of active i elements. we describe here the successful genetic transformation by autonomous p elements of embryos initially devoid of active i elements and any p sequences. the results demonstrate that p elements may invade the genom ... | 1987 | 28564366 |
| variations in cuticular hydrocarbons among the eight species of the drosophila melanogaster subgroup. | in addition to protecting against desiccation, some of the hydrocarbons of the waxy cuticle have previously been shown to be mating pheromones in drosophila melanogaster and d. simulans. therefore, cuticular hydrocarbons were compared among the eight species in the d. melanogaster subgroup. for the two cosmopolitan species and several geographic strains that were studied, all males are quite similar with very abundant monoenes. the major compound in most cases is 7-tricosene. only three exceptio ... | 1987 | 28568760 |
| equilibrium analysis of sexual selection in drosophila melanogaster. | several models for sexual selection, both by male-male competition and female choice, predict that a character which covaries with mating success should be near an equilibrium where the intensity of sexual selection opposes viability selection. this prediction was used to design experiments for estimating the intensity of sexual and viability selection on wing length in a recently captured population of drosophila melanogaster. observations of matings by males color-marked for wing length indica ... | 1987 | 28563750 |
| continuing studies on the south amherst drosophila melanogaster natural population during the 1970's and 1980's. | continuing investigations on the south amherst drosophila melanogaster natural population following the significant decline and recovery of lethal (le) and semilethal (sle) frequencies in the late 1960's (ives, 1970) show that the population has been remarkably stable although it contains mr (male recombination) and/or p dna elements (kidwell et al., 1977a; green, 1980). a 13-year study affirms that the lethals present are nonrandomly distributed along the second chromosome and deficient on the ... | 1986 | 28563498 |
| inhibition of female drosophila melanogaster remating by a seminal fluid protein (esterase 6). | recent experiments have indicated that est 6 transferred to d. melanogaster females during copulation mediates a large decrease in their attractiveness within the first six hours after mating. this decrease in attractiveness could increase the male's fitness if it were associated with less frequent remating by their mates, because a large proportion of the first male's sperm is lost if a female remates within one day. here, i confirm a strong est 6 influence on the receptivity of mated females; ... | 1986 | 28556223 |
| the reproductive relationships of drosophila sechellia with d. mauritiana, d. simulans, and d. melanogaster from the afrotropical region. | hybridization tests among the four sibling species of the drosophila melanogaster complex were made to determine the reproductive status of the recently discovered d. sechellia (which is endemic to a few islands and islets of the seychelles archipelago) with regard to its three close relatives, d. mauritiana (endemic to mauritius) and afrotropical strains of the two cosmopolitan species d. melanogaster and d. simulans. interstrain variation in the ability to hybridize with other species was also ... | 1986 | 28556049 |
| disruptive selection on body weight in drosophila melanogaster. | disruptive selection can have two consequences in a population: the rise of polymorphism or the divergence of the population. divergence creates subpopulations which can be sexually isolated. previous studies have shown that these consequences depend on the pattern of mate choices by the individuals. we have studied the effects of different patterns of mating (free mating, enforced random mating and enforced assortative mating) in a population of drosophila melanogaster subjected to disruptive s ... | 1986 | 28556042 |
| mating preference and its relevance to adaptation in drosophila melanogaster: inversion polymorphism and ddt resistance. | the importance of adult mating success as a component of fitness influencing inversion polymorphism in two ddt-resistant populations of drosophila melanogaster was investigated. the polymorphism involved in(3r)p and the standard (st) gene arrangement. in population 731r the st/st females showed greater mating propensity than in/in females, while in population j2 the in/in females showed a significant positive association between mating propensity and the percentage of st/st males present. mating ... | 1985 | 28561499 |
| a molecular approach to the role of historicity in evolution. i. experimental design with enzyme polymorphism in drosophila melanogaster. | i investigate the role of the past history (characterized by two inverse sequences of three environments) experienced by drosophila melanogaster populations, on the allozyme frequencies at four loci (α-gpdh, adh, est-6, pgm) in a common and constant final environment. the only locus for which an effect of past history was detected is adh. although not unambiguous, this result is discussed in terms of interactions between this locus and other polymorphic loci. for est-6 and pgm, no influence of p ... | 1985 | 28561367 |
| oviposition site selection by drosophila melanogaster and drosophila simulans. | the effects of texture and larval residues in the medium on oviposition site selection (oss) by drosophila melanogaster and drosophila simulans were studied. drosophila melanogaster laid over 95% of its eggs in sieved medium (vs. unsieved medium); d. simulans laid all of its eggs in sieved medium. surgical removal of antennal segments, and of fore-, mid-, or hindtarsi did not affect this result, indicating that sense organs involved in discriminating between sieved and unsieved medium are not co ... | 1985 | 28561364 |
| male effects on fecundity in drosophila melanogaster. | effects of male drosophila melanogaster on female fecundity and productivity were examined, considering both females held in containers with males and females exposed to male effects not involving contact. females were more fecund when male effects were present, and the largest increase was recorded when vials were previously conditioned by males. this effect was probably due to the growth of transmitted microorganisms, which were observed on the laying surface, as further experiments with vials ... | 1985 | 28561980 |
| disruptive selection on habitat preference and the evolution of reproductive isolation: an exploratory experiment. | a. pair of replicate experiments was carried out to examine the role of habitat specialization in the process of sympatric speciation. the rationale of the experimental design was that disruptive selection for habitat preference can facilitate the process of sympatric speciation by reducing an antagonistic interaction between the processes of recombination and selection. replicate populations of drosophila melanogaster were subjected to disruptive selection for habitat preference and simultaneou ... | 1985 | 28561974 |
| latitudinal cline in drosophila melanogaster for knockdown resistance to ethanol fumes and for rates of response to selection for further resistance. | we have introduced a device for selecting drosophila for increased resistance to very high concentrations of ethanol fumes. this device has enabled us to: 1) select quickly and easily over a thousand flies at a time, and 2) score the knockdown time of every fly in the distribution, while causing very little injury to the flies. a sample of nine west coast populations of drosophila melanogaster showed a significant trend toward higher knockdown resistance in more northern populations. a populatio ... | 1985 | 28564212 |
| the effect of experimental design on female receptivity to remating and its impact on reproductive success in drosophila melanogaster. | | 1984 | 28563780 |
| sperm dependence of female receptivity to remating in drosophila melanogaster. | | 1984 | 28563774 |
| laboratory evolution of postponed senescence in drosophila melanogaster. | | 1984 | 28555803 |
| selection for delayed senescence in drosophila melanogaster. | | 1984 | 28555795 |
| interactions between the amylase and adipose chromosomal regions of drosophila melanogaster. | | 1984 | 28555787 |
| evolutionary change of the chromosomal polymorphism in drosophila melanogaster populations. | | 1984 | 28555818 |
| artificial selection on a fitness-component in drosophila melanogaster. | | 1984 | 28555975 |
| increased density does not increase remating frequency in laboratory populations of drosophila melanogaster. | | 1984 | 28555909 |
| genetic divergence under uniform selection. i. similarity among populations of drosophila melanogaster in their responses to artificial selection for modifiers of cid. | | 1984 | 28556075 |
| rare male mating disadvantage in drosophila melanogaster. | | 1983 | 28556018 |
| polymorphism of alcohol dehydrogenase (adh) in a winery cellar population of drosophila melanogaster: gene frequency association with temperature and genotypic differences in progeny production. | | 1983 | 28568122 |
| genetic studies on sexual isolation and hybrid sterility in long-term cage populations of drosophila melanogaster. | | 1982 | 28581106 |
| alcohol dehydrogenase and glycerol-3-phosphate dehydrogenase clines in drosophila melanogaster on different continents. | | 1982 | 28581103 |
| genes affecting courtship song and mating preference in drosophila melanogaster, drosophila simulans and their hybrids. | | 1981 | 28563392 |
| studies of esterase 6 in drosophila melanogaster. v. progeny production and sperm use in females inseminated by males having active or null alleles. | | 1981 | 28563460 |
| multigenic response to ethanol in drosophila melanogaster. | | 1981 | 28563446 |
| selection for amylase allozymes in drosophila melanogaster: some questions. | | 1980 | 28581136 |
| a multifactorial genetic investigation of speciation theory using drosophila melanogaster. | | 1980 | 28563991 |
| selection for amylase allozymes in drosophila melanogaster: a reply. | | 1980 | 28568700 |
| altered competition between two reproductively isolated strains of drosophila melanogaster. | | 1980 | 28568691 |
| male mating discrimination in drosophila melanogaster, d. simulans and their hybrids. | | 1980 | 28563423 |
| evolution of competitive ability in mixtures of drosophila melanogaster: populations with an initial asymmetry. | | 1979 | 28563924 |
| selection on amylase allozymes in drosophila melanogaster: selection experiments using several independently derived pairs of chromosomes. | | 1979 | 28563906 |
| mutual facilitation between larvae of drosophila melanogaster cultured on sterol mutant yeast. | | 1979 | 28563938 |
| aldehyde oxidase allozymes, inversions and ddt resistance in some laboratory populations of drosophila melanogaster. | | 1979 | 28568195 |
| estimation of average fitness of populations of drosophila melanogaster and the evolution of fitness in experimental populations. | | 1979 | 28568191 |
| genetic capacity for adaptation to cold resistance at different developmental stages of drosophila melanogaster. | | 1979 | 28568188 |
| average fitness of populations of drosophila melanogaster as estimated using compound-autosome strains. | | 1979 | 28568182 |
| resistance of the sibling species drosophila melanogaster and drosophila simulans to high temperatures in relation to humidity: evolutionary implications. | | 1979 | 28568073 |
| comparative studies on induced mutations with physical & chemical mutagens in drosophila melangaster : part--i. specificity & spectrum of mutations. | | 1979 | 112048 |
| sperm competition, male fitness, and repeated mating by female drosophila melanogaster. | | 1978 | 28567960 |
| selection for amylase allozymes in drosophila melanogaster. | | 1977 | 28563717 |
| mutual facilitation between larvae of the sibling species drosophila melanogaster and d. simulans. | | 1977 | 28563703 |
| the lansing effect revisited. ii.-cumulative and spontaneously reversible parental age effects on fecundity in drosophila melanogaster. | | 1977 | 28563230 |
| presence of the hereditary rhabdovirus sigma and polymorphism for a gene for resistance to this virus in natural populations of drosophila melanogaster. | | 1976 | 28563328 |
| heterosis overdominance and frequency-dependent selection in drosophila melanogaster at the sepia locus. | | 1976 | 28563247 |
| genetic changes in natural populations of drosophila melanogaster. | | 1976 | 28565036 |
| ecological competition and the advantage of the rare type in drosophila melanogaster. | | 1975 | 28563098 |
| high frequency of one element of segregation distorter in natural populations of drosophila melanogaster. | | 1975 | 28563187 |
| changes in mating behavior produced by selection for ethological isolation between ebony and vestigial mutants of drosophila melanogaster. | | 1974 | 28564833 |
| effects of population size and selection intensity on responses to disruptive selection in drosophila melangaster. | disruptive selection for sternopleural bristle number with opportunity for random mating was done in the four treatment combinations of two population sizes (40 pairs and 8 pairs of selected parents) and two selection intensities (1 in 40 and 1 in 2). in each generation, matings among selected parents were observed in a mating chamber, and progeny collected separately from each female parent. in the high number, high selection intensity treatment, divergence between the high and low parts ceased ... | 1974 | 4217303 |
| coadaptation and recessive lethal content in ddt resistant populations of drosophila melanogaster. | | 1974 | 28563273 |
| sexual vigor and sexual selection in drosophila melanogaster. | | 1973 | 28563525 |
| frequency-dependent selection at the payne inversion in drosophila melanogaster. | | 1973 | 28563521 |
| fertility genes in natural populations of drosophila melanogaster. iii. superiority of inversion heterozygotes. | | 1973 | 28564915 |
| propensity for multiple mating in drosophila melanogaster females. | | 1973 | 28564771 |
| effects of population density on the frequency-dependent selection in the esterase-6 locus of drosophila melanogaster. | | 1972 | 28563066 |
| recognition by drosophila melanogaster of individuals from other strains or cultures: support for the role of olfactory cues in selective mating? | | 1972 | 28555743 |
| further evidence of genetic and increased developmental homeostasis in a drosophila melanogaster natural population during a minor climatic shift. | | 1972 | 28555763 |
| coadaptation of the payne inversion with a previously unrelated genetic background in drosophila melanogaster. | | 1971 | 28562943 |
| the distribution of gene frequencies in polymorphic populations of drosophila melanogaster. | | 1970 | 28564948 |
| extrachromosomal element delta in drosophila melanogaster. iv. variation and persistence of delta-associating second chromosomes in a natural population. | | 1970 | 28564939 |
| competition between drosophila melanogaster and d. simulans on media supplemented with saccharomyces and schizosaccharomyces. | | 1970 | 28562993 |
| further genetic studies of the south amherst population of drosophila melanogaster. | | 1970 | 28562987 |
| the interaction between the payne inversion and genetic background in the tumorous-head strain of drosophila melanogaster. | | 1970 | 28563007 |
| selective mating and eye pigmentation: an analysis of the visual component in the courtship behavior of drosophila melanogaster. | | 1969 | 28562876 |
| [isolation, in tissue culture, of drosophila melangaster cell lines]. | | 1969 | 4976834 |
| genetic structure of populations. iv. summer environmental variables and lethal and semilethal frequencies in a natural population of drosophila melanogaster. | | 1968 | 28564770 |
| migration and competition in drosophila i. competition between wild and vestigial strains of drosophila melanogaster in a cage and migration-tube population. | | 1968 | 28564807 |
| relation of infection to population structure in drosophila melanogaster. | | 1968 | 28564803 |
| studies on natural populations of drosophila vi. competition between drosophila melanogaster and drosophila simulans. | | 1967 | 28556108 |
| [lengthy modifications in experiments on temperature effects on larvae of forked mutants of drosophila melangaster]. | | 1966 | 6001569 |