Mating frequency in male Japanese quail: crosses among selected and unselected lines

1983 ◽  
Vol 25 (5) ◽  
pp. 450-456 ◽  
Author(s):  
D. E. Bernon ◽  
P. B. Siegel
Keyword(s):  
Genetic Variation ◽  
Mating Behavior ◽  
Japanese Quail ◽  
Mating Frequency ◽  
Base Population ◽  
Selected Lines ◽  
Gland Size ◽  
Parental Lines ◽  
Selection For ◽  
Cloacal Gland

The genetics of mating behavior in Japanese quail was investigated in replicated lines selected for high or low number of completed matings and the random bred control which served as the base population for the selected lines. Comparisons involved the parental lines, F1, F2, and backcross generations. Results indicate that mating frequency is influenced by additive and nonadditive genetic variation with the former being the primary heritable influence. The relationships between mating behavior, cloacal gland size, and relative aggressiveness suggest that selection for mating frequency influences factors commonly affecting these traits.

Color Preferences in Quail Chicks: Generalization of the Effects of Genetic Selection

Behaviour ◽  
1978 ◽  
Vol 65 (1-2) ◽  
pp. 263-269 ◽  
Author(s):  
Kovach Joseph K.
Keyword(s):  
Japanese Quail ◽  
Genetic Selection ◽  
Coturnix Japonica ◽  
Selected Lines ◽  
Color Preferences ◽  
Selection For ◽  
Different Color ◽  
Color Combinations

Japanese quail (C. coturnix japonica) were artificially selected for early preferences of blue over red and red over blue. Subjects were drawn from the 2nd and 8th generations of the selected lines and were tested for color choices by five different color pairs, in addition to the blue-red pair used for selection. Eight generations of selection for choices between blue and red modified choice responses to all color combinations. Maximum preferences were not shown in the selected choices between blue and red, but in the choice of green over red in the subjects from the line selected for preference of blue and in the choice of yellow over blue in the subjects from the line selected for preference of red.

scholarly journals The effects of inbreeding and artificial selection on reproductive fitness

1962 ◽  
Vol 3 (1) ◽  
pp. 110-138 ◽  
Author(s):  
B. D. H. Latter ◽  
Alan Robertson
Keyword(s):  
Artificial Selection ◽  
Large Population ◽  
Theoretical Models ◽  
Base Population ◽  
Selected Lines ◽  
Index Method ◽  
Competitive Index ◽  
Sib Mating ◽  
Selection For ◽  
Rate Of Decline

The competitive-index method of measurement of over all fitness in Drosophila has been used to measure the effect of inbreeding and of artificial selection for metric characters in a large population of Drosophila melanogaster. The technique itself was examined in detail with particular reference to its repeatability and to the effect on it of the modification of various environmental variables.With continued full-sib mating the decline in the competitive index was very rapid (it was reduced to a half by a single generation of full-sib mating) and there were no indications that interactions between deleterious genes at different loci were important in determining the rate of decline of fitness as inbreeding increased. Other unselected lines with ten pairs of parents in each generation were carried to serve as a control for the lines under artificial selection. At the same theoretical degree of inbreeding the control lines had a much higher average fitness than the lines produced by continued full-sib mating.From the base population lines were selected in both directions for abdominal bristles, sternopleural bristles and for wing length, there being two replicates in all cases. Four control lines were kept with the same number of parents as the selected lines. In all cases the selected lines declined in fitness below the value for the base population. However, in three of the lines the fitness was not significantly below the value for the control lines. The effect of artificial selection on fitness was asymmetrical, the decline being greater with down selection for all characters.The relevance of these results to various theoretical models is discussed. If the variation in these characters is actively maintained in the base population by the selection of heterozygotes then the results are consistent with an average selection disadvantage of homozygotes relative to heterozygotes of about 0·5%.

scholarly journals The quantitative relations between variation in red eye pigment and related pteridine compounds inDrosophila melanogaster

1970 ◽  
Vol 15 (1) ◽  
pp. 65-86 ◽  
Author(s):  
Ilse B. Barthelmess ◽  
Forbes W. Robertson
Keyword(s):  
Genetic Variation ◽  
Biochemical Properties ◽  
Pigment Content ◽  
Red Pigment ◽  
Base Population ◽  
Stock Selection ◽  
Metabolic Pattern ◽  
Red Eye ◽  
Genetic Behaviour ◽  
Selection For

SUMMARYThe relations between the quantity of red eye pigment and related pteridine compounds ofDrosophila melanogasterhave been studied in a variety of genotypes, which include strains selected for high or low pigment content, various derivatives of these lines and also lines in which one or other of the major autosome pairs were represented by homozygous chromosome pairs, derived by random sampling from the base population and also inbred lines. The quantity of red pigment was defined by the optical density when whole heads were extracted in a suitable solvent, while the pteridines were separated by chromatography and their amounts estimated by means of their characteristic fluorescence.The evidence from selection, inbreeding and chromosome sampling from the base population demonstrated the presence of substantial genetic variation for pigment content and amounts of related pteridines.The genetic and biochemical properties of the selected lines differed according to the direction of selection. High lines remained heterozygous after many generations of selection and displayed dominance and epistasis in favour of higher pigment content in crosses to the unselected stock. Selection for low pigment content led to fixation of recessive effects, attributable to particular chromosomes. The dominance-recessive relationship in red pigment differences was also applicable to the associated pteridines.The metabolic pattern in all lines with reduced pigment content is compatible with the assumption of reduced enzyme activity at particular steps of the pathway leading to the drosopterins (red eye pigments). The two steps accessible to study are subject to genetic variation in the base population, while inbreeding or selection for low pigment content leads to genetically fixed alterations at one or other of these steps. The genetic analysis was consistent with the biochemical evidence.Increase in pigment content above the normal level, either by selection or chance fixation, is accompanied by correlated increase in all the precursors. Several alternatives are possible but it is suggested that this may be due to an increase in early precursors, before the stages which have been altered in the low pigment lines.Attention is drawn to the similarity in genetic behaviour between pigment content and body size. Particular emphasis is laid on the value of selection as a means of creating biochemical differences which offer a basis for relating biochemical function and genetic behaviour.

TWO-WAY SELECTION ON PUPAL WEIGHT WITH DIFFERENT DEGREES OF INBREEDING IN TRIBOLIUM CASTANEUM

1974 ◽  
Vol 16 (4) ◽  
pp. 765-775 ◽  
Author(s):  
P. Y. Jui ◽  
G. W. Friars
Keyword(s):  
Tribolium Castaneum ◽  
Linear Response ◽  
Significant Interaction ◽  
Pupal Weight ◽  
Base Population ◽  
Significant Progress ◽  
Selected Lines ◽  
Selection Limit ◽  
Selection For ◽  
Seven Generations

Responses to selection for high and low pupal weight in Tribolium castaneum under four different inbreeding systems and two different relative humidities (40 and 70%) were observed for seven generations. By the seventh generation, the coefficients of inbreeding ranged from 0.79 in the full sib lines to 0.12 in the control lines.Heritability of pupal weight estimated by mid-parent offspring regression from the base population was around 0.30 which is lower than the estimates obtained by Bell (1969). However, realized heritabilities were around 0.50. Significant progress was observed for both upward and downward selection. A linear response in pupal weight was observed for most of the selected lines, suggesting that the selection limit had not been reached.Inbreeding caused a reduction of approximately two offspring per 10% increment in the inbreeding coefficient.Asymmetric responses were noted in conjunction with the significant interaction of the degree of inbreeding and the direction of selection.

EFFECT OF SELECTION FOR GROWTH AND FOR BREAST DEVELOPMENT ON KEEL DEFECTS IN BROILERS

1962 ◽  
Vol 42 (2) ◽  
pp. 203-210 ◽  
Author(s):  
E. S. Merritt ◽  
M. Zawalsky ◽  
R. D. Crawford ◽  
S. B. Slen
Keyword(s):  
Lower Incidence ◽  
Breast Development ◽  
Base Population ◽  
Control Strain ◽  
Selected Lines ◽  
The Third ◽  
Definite Relationship ◽  
Rate Of Growth ◽  
Selection For

Data from the third and fourth generations of a number of lines selected exclusively for growth, and of a number selected solely for breast angle, showed that selection for these traits had an effect on the incidence of crooked keels and breast blisters in 63-day-old broilers. The base population of these selected lines was a meat-control strain and a sample of this strain was reared with each hatch of the selected lines.Lines selected for growth had the highest incidence of both crooked keels and breast blisters. The lines selected for breast angle had a lower incidence of these defects than the controls, even though they did not differ from the controls in 63-day weight. It was concluded that there is a definite relationship between rate of growth, breast development and the incidence of keel defects. Market grading data on a sample of birds from these lines reflected these differences in keel defects. The market grades for conformation were lowest in the growth lines and highest in the breast lines.

scholarly journals The number of loci affecting a quantitative trait in Drosophila melanogaster revealed by artificial selection

1983 ◽  
Vol 42 (2) ◽  
pp. 137-149 ◽  
Author(s):  
Araceli Gallego ◽  
Carlos López-Fanjul
Keyword(s):  
Initial Response ◽  
Selection Method ◽  
Base Population ◽  
Response To Selection ◽  
Family Selection ◽  
Selected Lines ◽  
Additive Variance ◽  
Bristle Number ◽  
Selection Limit ◽  
Selection For

SUMMARYIndividual and within-full-sib family selection for low sternopleural bristle number was carried out for 17 generations, with six replicate lines for each selection method. Our results can be summarized as follows: (1) the response to selection was exhausted very quickly, (2) the additive variance of the selected lines declined rapidly, (3) the variation in response to selection decreased as selection progressed, (4) genetic differences among replicates at the selection limit were small, (5) individual selection resulted in a higher initial response than within-family selection, but similar limits were achieved with both procedures. These observations are consistent with the hypothesis that the pattern of response to selection is due to the segregation in the base population of only a few loci with large effects, at intermediate frequencies.

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