Reversal of genetic homeostasis in laboratory populations of Drosophila melanogaster under long-term selection for geotaxis and estimates of gene correlates: Evolution of behavior-genetic systems.

Among Drosophila melanogaster, divergently selected for geotaxis intermittently over 600 generations (28 years), about 80,000 animals have been analyzed behavior-genetically. Each major chromosome pair from two lines was isogenized on an unselected isogenic background. Measurement of their behavioral effects revealed the relative magnitudes II?>?III?>?X for the negatively geotactic (high) line and X?>?III?>?II for the positively geotactic (low) line. When reversing selection for the now phenotypically stable high and low lines and then repeatedly relaxing the reversals, a new genetic homeostasis in the low line was indicated by the return of the reversed-line average scores towards the low extreme; that is, the low line has attained a stable equilibrium for positive geotaxis, an uncharacteristic behavior and an effect not seen before 1979. This change suggests the recent evolution of a new coadaptation among genes. Although not as conclusive, a similar genetic interpretation is suggested for the high line. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A gene correlate of geotaxis near Adh (2-50.1) in Drosophila melangoster.

As part of a long-term study (38+ years) to identify genetic correlates of geotaxis in Drosophila melanogaster, the investigators report the results of allozyme-level analyses of 2 lines derived from hybridizing high- and low-selected lines that have evolved stable, extreme expressions of geotaxis. Allele variation at Adh was associated with geotactic performance in 1 hybrid-derived line, but not in another, after 66 free-mating generations beyond the F? generation. A second-chromosome gene correlate of geotaxis may lie within 1 map unit of Adh. Population genetic analyses suggest that there were different selection pressures on the hybrid-derived lines and that the fixation of PGD-A in the high-geotaxis line was probably due to a founder-effect event. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Analyzing correlations of three types in selected lines of Drosophila melanogaster that have evolved stable extreme geotactic performance.

The behavior–genetic analysis of Drosophila melanogaster with geotactic performance as the phenotype is an ideal model system with which to investigate the complex relations between heredity and behavior. As part of a long-term, 38-year study, we report 4 experiments that identify and analyze trait correlations in the selected high- and low-geotaxis lines. We performed F2 correlational analyses and backcrosses to examine 3 types of correlations: (a) genotype–genotype (alcohol dehydrogenase [Adh]–amylase [Amy]), (b) genotype–phenotype (Adh and Amy–geotaxis), and (c) phenotype–phenotype (mate preference–geotaxis). Only the Adh-geotaxis correlation survived meiosis and reappeared in the F2 generation, which indicates a genotype-phenotype correlation, whereas the others did not. The importance of hybrid correlational analysis to the behavior–genetic analysis of a species is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of alcohol-preferring and nonpreferring selectively bred rat lines. I. Ethanol initiation and limited access operant self-administration

Several lines of alcohol-preferring and alcohol-nonpreferring rats have been developed using selective breeding based on 24-hr homecage ethanol consumption. However, it remains unclear if the selection based on two-bottle choice resulted in similar ethanol self-administration when measured using an operant procedure. In this paper, we compare our previous work using alcohol-accepting (AA) and alcohol-nonaccepting (ANA) rats with data obtained using the identical procedures in the (P) and (NP) rat lines, and both replicate lines of the high alcohol drinking (HAD1 and HAD2) and low alcohol drinking (LAD1 and LAD2) lines. All rats from each line were initiated to self-administer 10% ethanol using the sucrose fading procedure. After initiation, increasing concentrations of ethanol up to 30% ethanol were tested. The results indicated that only in the LAD1 and LAD2 lines was ethanol presentation not able to maintain lever pressing after initiation. Compared with the AA line, the P, HAD1, HAD2, and NP lines all self-administered more ethanol in the operant paradigm after initiation. The ANA line self-administered less ethanol than the AA line, but more than the LAD lines. Correlational analysis of homecage consumption with operant ethanol self-administration suggested that approximately 62% of the genetic variance in operant self-administration resulted from genes selected for the homecage drinking. At the same time, it was clear that there were genetic influences on operant self-administration that were not selected for by homecage ethanol drinking.     

Major histocompatibility complex class IV restriction fragment length polymorphism markers in replicated meat-type chicken lines divergently selected for high or low early immune response

Information on MHC may improve the efficiency of selection for immunological traits via the application of marker assisted selection or by selecting directly for a specific restriction fragment length polymorphism (RFLP) band or MHC haplotype. An experimental procedure is presented here for identifying MHC genes that are related to early immune response. A Class IV cDNA clone was used to probe Southern blots of erythrocyte genomic DNA from chickens. Chickens were taken from the second (S2) and third (S3) generations of replicated lines divergently selected for high antibody response (HC1, HC2) or low antibody response (LC1, LC2) to Escherichia coli vaccination at 10 days of age. These selection criteria have been found to be associated with other immunological parameters. The hypothesis that these selected lines differ in their MHC loci was evaluated by comparing the frequencies of MHC RFLP markers (single RFLP bands) and haplotypes (patterns of RFLP bands). The significant differences between LC and HC in the frequency of many MHC RFLP bands and of five MHC haplotypes indicate that early antibody production is influenced by MHC genes. The reliability of the association between the selection and frequency differences was tested and proven in most cases by analysis of the replicated lines. These differences in RFLP markers represent a change in allelic frequencies in MHC genes, probably due to selection. The results imply a connection between the Class IV genes and early antibody production, and they show the potential of prospective breeding not only by immunological phenotype but also by genotype (i.e., using RFLP markers of the MHC).     

Measurement of genetic variation within and between Japanese quail lines using DNA fingerprinting

The objective of the present experiment was to study genetic variation within and among well-defined Japanese quail lines by DNA fingerprinting. The Japanese quail lines included a randombred control line (R1) and lines developed from R1 by divergent selection over 30 generations for 4-wk BW (HW, LW) and total plasma phosphorus (TPP) (HP, LP), a measure of yolk precursor in the blood. In addition, two sublines (HW-HP, HW-LP) of HW, developed in the ninth generation, were included in the analysis. Males of the sublines were selected for increased 4-wk BW whereas females were selected for increased (HW-HP) or decreased (HW-LP) TPP. Sixteen individual DNA samples per line were digested with HaeIII restriction enzyme and hybridized with Jeffreys' 33.6 probe. The DNA fingerprints were analyzed with computer programs designed to measure band sharing (BS). Within lines, BS ranged from 0.384 to 0.525. The BS within the R1 line was less than that of all selected lines, except for the HP and LP lines, indicating that, in general, selection had increased genetic homogeneity within the selected lines. Between lines, BS was less than within lines and the R1 line had the highest average level of BS (0.278) with the other lines. The BS between lines for the selected lines ranged from 0.230 to 0.308 with an average of 0.265. In the comparison of the R1 line with the selected lines, it appeared that selection for increased TPP or decreased BW may have influenced BS levels. The relationships of the HW line with its sublines (HW-HP and HW-LP) were not accurately predicted by the DNA fingerprinting technique used. All lines were separated, as indicated by the genetic distance between lines.     

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)     

Food-search behavior and its relation to the central excitatory state in the genetic analysis of the blow fly Phormia regina..

Tested the hypothesis, derived from the work of V. G. Dethier (see record 1958-01228-001), that dance behavior in the blowfly might be an ethologically relevant manifestation of the central excitatory state (CES). Dance duration in lines selected for high- and low-CES levels was measured. As predicted, Ss from the high-CES line danced longer than those from the low-CES line, and the CES–dance correlation in individual Ss was high. This phenotypic correlation disappeared in the F? generation of a cross between the high- and low-CES lines, a result indicating that the observed variations in CES and dance duration were not caused by the same set of genes. Further characterization of the underlying genetic system showed that several linked autosomal genes with digenic epistatic interactions and a complex pattern of maternal inheritance were responsible for the difference in dance durations between the high- and low-CES lines. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Developmental-behavioral initiation of evolutionary change.

The traditional approach to evolutionary psychology relies entirely on natural selection as the cause of the evolution of adaptations. Exclusive reliance on natural selection overlooks the fact that changes in development are a necessary prerequisite for evolutionary change. These developmental changes provide the material for natural selection to work on. In the neo-Darwinian scenario, the mechanisms of evolution are mutation or genetic. In the spirit of evolutionary pluralism, the author describes a different 3-stage scenario in which migration (the invasion of new niches or habitats) may occur without mutation or genetic recombination and selection first initiating a change in genes or gene frequencies. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Relationship of Onodi cell to optic neuritis--radiological anatomy on coronal CT scanning

Previous somatic cell hybridization studies have assigned many human cell lines to one of four complementation groups (A-D) for immortalization. We report here that the A1698DM cell line, which contains selectable markers and has previously been defined as the immortalization group D representative, was derived from T24 cells rather than A1698. A1698DM did not undergo senescence when fused with cell lines assigned to groups A, B, or C. This raises the possibility that this cell line has undergone further evolution and lost multiple putative senescence genes so that it is now unable to complement any, or most, other cell lines for senescence. Cell lines previously assigned to group D may, therefore, be heterogeneous with respect to the genetic changes that resulted in their immortalization. This has important implications for strategies to clone senescence genes based on complementation groups.     

Cyclin D1/PRAD1 as a central target in oncogenesis

Understanding the genetic elements controlling the process of tumor metastasis to distant organ sites such as the liver may be the key to improving survivorship from colon cancer. By using standard cytogenetic techniques in combination with comparative genomic hybridization, multiple genetic imbalances within three human colon cancer cell lines previously selected for differences in liver-metastatic behavior were identified. The entire genome of one poorly metastatic cell line (KM12C) was compared directly with that of two highly metastatic cell lines (KM12SM, KM12L4A) derived from it. A number of chromosomal gains (8q, 12q15, 20q11.2) and losses (5p13, 6p21.3, 18) were common to all three cell lines and are likely related to early tumor development rather than to the selection process used to generate cell lines of increased metastatic potential. Chromosomal imbalances detected only in the highly metastatic cell lines were also observed. KM12SM showed losses of portions of 2p22, 2q24.3--> 2q32.2, 4p15.3--> cen, 4q24 without the 13q and 15q22.3 gains noted for KM12C. Both gains (1p31.3--> 1p21, 2q22--> 2q33, 3cen--> 3q26.2, 5q14--> 5q23, 6cen--> 6q23) and losses (16p, 17p, 17q 19p, 19q 22q) were observed for KM12L4A but not for the other two cell lines. Identification of these alterations provides valuable insight into the process of experimental liver metastasis and is a first step towards mapping genes linked to the terminal phases of human colon cancer progression.     

Constitutional biases in early perceptual learning: I. Preferences between colors, patterns, and composite stimuli of colors and patterns in genetically manipulated and imprinted quail chicks (C. coturnix japonica).

Bidirectional genetic selection of quail for early color preferences, for 18 generations, resulted in nearly perfect choices of blue over red in one and red over blue in the other selected line. It also enhanced the preference of a grated over a dotted black-and-white pattern. Color and pattern preferences in hybrids of selected and control lines fell back to about halfway between parental values. Choices between composite stimuli of colors and patterns indicated summation of the respective, genetically influenced preference values, with partial dominance of color over pattern effects. Exposure to colors modified color choices. Exposure to colored patterns likewise modified color choices, but it did not change, or only marginally changed, choices between patterns. The phenotypic expression of this selective learning, however, was influenced by the genetically manipulated preference values and preference combinations of colors and patterns in the stimuli with which postexposure performances were tested. Overall, data highlight the need for concepts that would discriminate between the developmental and the episodic expression of genetic influences and genotype–environment interactions in behavior. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Analysis of FHIT transcripts in cervical and endometrial cancers

We show that mammalian cells can be stably transfected by a mechanical loading procedure in which cells are forced through a small opening in the presence of DNA. A suspension of cells and plasmid DNA in growth medium was passed up and down through a 30-gauge needle attached to a 1-ml syringe. Cells were immediately plated at appropriate densities for subsequent selection for stable expression of a marker gene. Two rodent cell lines, Chinese hamster ovary and mouse Ltk- cells, were successfully transfected with an efficiency of about one transfectant per 5 x 10(4) cells. The human HeLa cell line was transfected with a somewhat lower efficiency. Pluronic F-68, a detergent believed to aid in healing of membrane injuries, had no beneficial effect when present during the loading procedure. Successful transfection was accomplished using three different genes as selectable markers. Southern blotting analysis revealed that transfectants contained one or very few copies of the introduced DNA construct integrated into the genome. Several transfectants were demonstrated to remain stable for more than 20 generations of growth in the absence of selection. This procedure is fast, economical, and of general utility.     

Constitutional biases in early perceptual learning: III. Similarities and differences between artificially selected and imprinted color preferences in quail chicks (Coturnix coturnix japonica).

Tested color preferences and preference generalization in naive and imprinted Japanese quail chicks drawn from the 20th generation of a genetic control line and 2 genetic lines that were bidirectionally selected for preferences between blue and red. 12 hrs of imprinting to blue or red on the 1st posthatch day resulted in large preference changes in the genetic controls, and these Ss exhibited no or only small additional changes from 3 more days of imprinting (for the total of 66 hrs of exposure time). By contrast, 12 hrs of imprinting of artificially selected Ss did not change or only marginally changed their genetically manipulated preferences, but 66 hrs of imprinting changed them by magnitudes as large as or larger than those in genetic controls. Reciprocal imprinting partially mimicked the phenotypic effects of bidirectional selection. Differences between transfer and generalization of phenotypically similar but genetically and experientially different preferences indicated dissimilar mediation of the implicit gene effects and learning effects. (13 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Positive Geotaxis in Infant Rats (Rattus norvegicus) : A Natural Behavior and a Historical Correction.

Infant rats (Rattus norvegicus) placed on a shallow incline (2°, 4°, or 8°) oriented and moved downhill within 1 min; that is, they displayed positive geotaxis. Their downhill translocation increased with angle of inclination. A variety of possible behavioral elements (e.g., initial orientation, rotational movements, ambulatory velocities) were eliminated as explanations of the geotaxis. Wall contact was recognized as a determinative event: Pups on the inclines showed no orientation with respect to the geogravitational stimulus before contacting a wall. The event of wall contact, however, evoked reliable downhill orientation and more linear movements. Positive geotaxis was created by pups' orientation against walls and an associated increase in movement velocity. This is a distinct perspective on a behavioral response that replaces a traditionally misinterpreted phenomenon. The authors discuss the ecological validity and historical context of these findings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A nonparametric bootstrap method for testing close linkage vs. pleiotropy of coincident quantitative trait loci

A novel method using the nonparametric bootstrap is proposed for testing whether a quantitative trait locus (QTL) at one chromosomal position could explain effects on two separate traits. If the single-QTL hypothesis is accepted, pleiotropy could explain the effect on two traits. If it is rejected, then the effects on two traits are due to linked QTLs. The method can be used in conjunction with several QTL mapping methods as long as they provide a straightforward estimate of the number of QTLs detectable from the data set. A selection step was introduced in the bootstrap procedure to reduce the conservativeness of the test of close linkage vs. pleiotropy, so that the erroneous rejection of the null hypothesis of pleiotropy only happens at a frequency equal to the nominal type I error risk specified by the user. The approach was assessed using computer simulations and proved to be relatively unbiased and robust over the range of genetic situations tested. An example of its application on a real data set from a saline stress experiment performed on a recombinant population of wheat (Triticum aestivum L. ) doubled haploid lines is also provided.     

The developmental basis of evolutionary change.

It is a hard-won insight that developmental change is essential to evolution, and the issue has received little consideration in the psychological literature. The origin of the concept can be traced to the nineteenth century biologist St. George Mivart, with the more systematic and extensive treatments of the issue in the early twentieth century by Walter Garstang, Gavin de Beer, and Richard Goldschmidt playing an instrumental role in fleshing out the idea and keeping it alive. Garstang and de Beer held that genetic change, either through selective breeding or mutation, could change the timing of ontogenetic events in various defined ways to give rise to a new species. Goldschmidt felt that a developmental macromutation was necessary to produce a genuine evolutionary novelty. In the view of Garstang, de Beer, and Goldschmidt, a genetic change or mutation is necessary to bring about the developmental changes that lead to evolution. In the present article I utilize the developmental change concept in a different manner than the aforementioned writers. In essence, I describe a different evolutionary pathway, one in which developmental changes in behavior lead to evolutionary change. On this view, genetic change is a secondary or tertiary consequence of enduring behavioral changes brought about by nongenetic alterations of species-typical development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hereditary variation in uric acid transport by avian kidney slices

Uric acid transport in renal cortical slices from a selected line of hyperuricemic chickens was investigated. Slices from the hyperuricemic (HUA) line accumulated less than half as much uric acid as slices from a control (LUA) line when uric acid in the medium varied from 0.01 to 5 mM. Uric acid uptake by both lines increased as the uric acid concentration in the medium was raised from 0.1 to 0.5 mM, but was markedly inhibited in the HUA line at 3-5 mM. Omission of sodium or potassium from the incubation medium inhibited uric acid uptake by slices from both lines. Ouabain inhibited uric acid uptake in the LUA line. The sodium and potassium requirements for initiation of uric acid uptake were higher, and the potassium requirement for maximal uptake was lower, for slices of the HUA line. No genetic differences in potassium or sodium contents of slices were observed when the potassium content of the incubation medium was altered or when the medium contained ouabain. These studies indicate that hereditary hyperuricemia in chickens may be due to a qualitative change in renal uric acid transport which involves the interaction of cations in the transport process.     

Genetic differences in avoidance learning by Rattus norvegicus: Escape/avoidance responding, sensitivity to electric shock, discrimination learning, and open-field behavior.

Studied the behaviors of Long-Evans rats selectively bred for either good (SHA line) or poor (SLA line) shuttle box avoidance learning. The results of Exp I indicated that the phenotypic difference in avoidance learning was not associated with differences in speed of escape or avoidance responding. Differences between the lines in frequency of intertrial responses (ITRs), which appeared during training but not during pretest, suggest that ITRs in Ss of the low-avoidance SLA line were more suppressed by electric shock than in Ss of the high-avoidance SHA line. This result suggests that SLA Ss may be more emotionally responsive than SHA Ss. Exp II demonstrated that the Ss of the 2 lines did not differ in absolute sensitivity to electric shock, and Exp III showed that the poor performance of the SLA line was not due to an inability to learn. Ss also provided evidence that the poor avoidance learning by SLA Ss was due to their emotional reactivity. Observations of open-field behavior in Exp IV were consistent with this hypothesis. It is concluded that the major consistent correlate of the phenotypic difference in avoidance learning was greater emotionality or emotional reactivity in SLA than in SHA Ss. (57 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Etiological Contributions to Heavy Drinking From Late Adolescence to Young Adulthood.

The authors examined genetic and environmental contributions to stability and change in heavy drinking from late adolescence to young adulthood in a sample of 1,152 twin pairs. In men, heavy drinking was similarly heritable at ages 17 (h2 = .57) and 20 (h2 = .39), and its stability owed primarily to common genetic factors. In women, heavy drinking was less heritable than in men at ages 17 (h2 = .18) and 20 (h2 = .30) and its stability was primarily due to enduring shared environmental influences. P3 amplitude, an event-related brain potential marker of alcoholism risk, was less predictive of heavy drinking in women than in men, providing further support for the proposition that biological factors have less impact on heavy drinking in young adult women than in young adult men. (PsycINFO Database Record (c) 2010 APA, all rights reserved)