Proliferations- und Transdeterminationsleistungen der weiblichen Genital-Imaginalscheiben vonDrosophila melanogaster nach Kulturin vivo

Abstract

1. Genital-imaginal discs of femaleDrosophila melanogaster were fragmented or locally damaged and then culturedin vivo in the abdomens of adult flies (technqiue:HADORN, 1963). The proliferation rate of the autotypic anlagen, as well as the frequency and the quality of allotypic differentiation after transplantation in larvae undergoing metamorphosis, were studied. 2. Only the anlagen of the anal plates can he extensively cultured. Blastemas of soft parts and of vaginal plates have a low proliferation capacity. 3. The rate of transdetermination is very high for the anlage of the anal plates. The blastemas of other autotypic elements rarely transdetermine and they only form small allotypic areas. 4. Transdeterminations originating from anlagen of anal plates are correlated with an enlargement of the autotypic blastemas. In contrast, the occurence of transdetermination in anlagen of the vaginal plates is correlated with a multiplication of the entire genitalia. 5. Twenty-four different allotypic structures which are normally derived from the antennae-, leg-, wing- or clypeo-labrum primordia have been observed. 6. After a first transdetermination step (initial cases) the anlagen of the anal plates form new anlagen, namely of the praefrons, the basis of the maxillary palpus (Rostralhaut), femur and tarsus. From these "primary formation centers" successive steps are possible as in normogenesis. The anlagen of the allotypic third antenna segment behaves as a "secondary formation center", which will differentiate leg, wing and possibly palpus after it has passed further secondary transdetermination steps. 7. According to the observed frequencies, the segments of the allotypic antennae are formed one after another. 8. The organisation and the typical pattern of the allotypic organs are identical to those formed in normal development. 9. The daughter cells of a single cell of a determined blastema are able to produce normal anlagen which are competent to form an integrated pattern. Such a cell can form qualitatively different allotypic blastemas which each correspond to a different imaginai disc.

Localization of choline acetyltransferase-expressing neurons inDrosophila nervous system

“…The third segment (funiculus) bears the olfactory sensilla classified into three morphological types: club-shaped basiconic sensilla, spine-shaped trichoid sensilla, and small cone-shaped coeloconic sensilla. These sensilla are arranged in a characteristic pattern on the surface (Mindek, 1968;Stocker et al, 1983;Stocker, 1994). Most, if not all, of the sensory neurons associated with these three types of sensilla are stained with X-gal (Kitamoto et al, 1995).…”

Transdetermination in Drosophila imaginal discs: a model for understanding pluripotency and selector gene maintenance

“…More injury to disc tissue stimulates more blastema growth and results in a greater frequency and larger area of transdetermined tissue [32]. Clonal analyses reveal that imaginal disc regeneration proceeds from blastema cells [28,31] and that transdetermined structures derive from, and are clonally related to, the newly regenerated tissue [23][24][25]. Transdetermination requires cell division because when disc fragments are cultured in conditions in which cell division is inhibited, no transdetermination is observed [33,34].…”

“…found in eye, antenna, leg, labial and genital discs ( Figure 1; [19,[23][24][25][26][27]). Weak points are sites where both increased cell division (see below) and changes in selector gene expression occur.…”

Drosophila as a focus in olfactory research: Mapping of olfactory sensilla by fine structure, odor specificity, odorant receptor expression, and central connectivity

“…A peculiarity of the antennal system is the nonhomogeneous pattern of sensilla on the surface of the funiculus (Link, 1983;Mindek, 1968;Venkatesh and Singh, 1984). The recent re-classification of funicular sensilla (Shanbhag et at., 1999;see above) has allowed the improvement of the previous sensillar maps (Fig.…”

“…The surface of the funiculus bears three major types of sensilla: the conspicuous, sharp-tipped trichoid sensilla, the translucent, club-shaped basiconic sensilla, and the tiny, coeloconic sensilla with prominent sockets (Fig. 1) (Link, 1983;Mindek, 1968;Riesgo-Escovar et al, 1997b;Venkatesh and Singh, 1984). Electrophysiological recordings have assigned an olfactory function to all of them (Clyne et al, 1997;de Bruyne et al, 2001;Siddiqi, , 1991see below).…”