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|Title:||Behavior-Genetic Analysis of the Black Blow Fly, Phormia Regina, Using the Central Excitatory State (Ces)|
|Author(s):||Tully, Timothy Paul|
|Department / Program:||Genetics and Development|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Abstract:||Behavior-genetic analysis of the black blow fly, Phormia regina, using the central excitatory state (CES) has identified two more components of the proboscis-extension response. Now four are known: Conditioning and sucrose-induced CES (s-CES) were described in previous studies, and here evidence is presented for the existence of water-induced CES (w-CES) and base-level water responsiveness. Furthermore, using replicated hybrid crosses between pure breeding lines, a single major-gene correlate of s-CES has been detected.
The stability (i.e., reliability or repeatability) of individual differences for s-CES was demonstrated in an unselected population. Bidirectional selection for CES produced an immediate, asymptotic response to selection, but mean CES scores regressed upon relaxation of selection. Subsequent single-pair breeding analyses revealed the misclassification of genotypes inferred from phenotypic CES scores (i.e., lack of genotype-phenotype isomorphism). However, the genotypic "bottleneck" imposed by single-pair mating served to establish pure breeding high and low CES lines in a single generation.
Results from replicated hybrid crosses between the pure breeding high and low CES lines failed to reject a one-locus model, and a quantitative genetic analysis indicated no intra- (or inter-) locular dominance or maternal inheritance. Accordingly, the autosomal allele, which in double dose is associated with high CES expression, is named ces('H). The alternate allele, associated with low CES expression, is designated ces('L).
The correlation between CES and conditioning scores was measured in an unselected population, and individuals in a hybrid analysis were also tested for conditioning. The correlation between CES and conditioning was high and did not attenuate in the F(,2) generation of replicated hybrid crosses, indicating pleiotropy or tight linkage of the genetic correlates associated with each behavior-trait. This correlation may be the result of common sensory input, motor output and/or central processing systems.
Behavioral control experiments performed with the high and low CES lines detected the presence of the two new components of proboscis extension behavior, base-level water responsiveness and w-CES. In addition, the high CES line was shown to have higher levels of water responsiveness, w-CES and s-CES than the low CES line. A reanalysis of data, from food-deprived but water-satiated flies in nonsegregating generations from hybrid crosses, demonstrated a confounding of proboscis-extension responses due to water responsiveness with scores from the CES test used to infer s-CES levels. Such confounding of the measurement of s-CES can obscure investigations into relations among gene correlates of water responsiveness, s-CES and w-CES. The presence of water responsiveness and w-CES complicate the interpretation of proboscis extension responses during conditioning.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1981.
|Date Available in IDEALS:||2014-12-16|
This item appears in the following Collection(s)
Dissertations and Theses - Genetics and Development
Graduate Dissertations and Theses at Illinois
Graduate Theses and Dissertations at Illinois