Gerald Franz

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In the medfly Ceratitis capitata, the Y chromosome is responsible for determining the male sex. We have mapped the region containing the relevant factor through the analysis of Y-autosome translocations using fluorescence in situ hybridization with two different probes. One probe, the clone pY114, contains repetitive, Y-specific DNA sequences from C.(More)
In embryos the maternal-to-zygotic transition (MTZ) integrates post-transcriptional regulation of maternal transcripts with transcriptional activation of the zygotic genome. Although the molecular mechanisms underlying this event are being clarified in Drosophila melanogaster, little is know about the embryogenic processes in other insect species. The(More)
The sterile insect technique (SIT) is an environment-friendly method used in area-wide pest management of the Mediterranean fruit fly Ceratitis capitata (Wiedemann; Diptera: Tephritidae). Ionizing radiation used to generate reproductive sterility in the mass-reared populations before release leads to reduction of competitiveness. Here, we present a first(More)
The present study constitutes the first attempt to construct a polytene chromosome map of an Anastrepha species, Anastrepha ludens (Loew), a major agricultural pest. The mitotic karyotype has a diploid complement of 12 acrocentric chromosomes, including five pairs of autosomes and an XX/XY sex chromosome pair. The analysis of salivary gland polytene(More)
The sex chromosomes of the tephritid fruit fly Ceratitis capitata (Wiedemann) are heteromorphic. The male-determining region was located on the Y chromosome by deletion mapping using unbalanced offspring from several translocation strains. In addition, we showed that only 15% of the Y chromosome is required for male determination and male fertility. Based(More)
Two experiments are presented studying interrelations between spatial properties of environments and both experience and spatial behavior. In order to systematically study such interrelations, a generic description of space is required that provides comparability between arbitrarily shaped environments and captures behaviorally relevant properties of space.(More)
In the existing genetic sexing strains for the medfly, Ceratitis capitata, male recombination leads to breakdown of the sexing mechanism under mass rearing conditions. The rate of breakdown depends on the recombination frequency and on the fitness of the recombinants. We have tested two different sexing genes, white pupa and a temperature sensitive lethal,(More)
The Oriental fruit fly, Batrocera dorsalis s.s. (Hendel) is one of the most destructive agricultural pests, belonging to a large group of difficult to distinguish morphologically species, referred as the B. dorsalis complex. We report here a cytogenetic analysis of two laboratory strains of the species and provide a photographic polytene chromosome map from(More)
BACKGROUND Diptera have an extraordinary variety of sex determination mechanisms, and Drosophila melanogaster is the paradigm for this group. However, the Drosophila sex determination pathway is only partially conserved and the family Tephritidae affords an interesting example. The tephritid Y chromosome is postulated to be necessary to determine male(More)
While experiential qualities of rectangular architectural spaces can be effectively predicted from their proportions and area (Franz, von der Heyde, & Bülthoff, 2003), these factors obviously cannot be directly transferred on open-plan indoor spaces. We introduce an approach that relates experiential qualities of arbitrarily shaped architectural spaces to(More)