Willem J. Ouweneel

Learn More
The mature labial disc, when implanted into a larva of the same age, undergoes metamorphosis along with the host and produces one lateral half of the medi- and distiproboscis. On the basis of results obtained from transplanted disc halves (including the separate peripodial membrane) a tentative fate map of the labial disc was constructed, which shows most(More)
This paper deals with the influence of environmental factors, particularly those that may be expected to change the rate of growth in the larval period, on the homoeotic wing-like outgrowths in the eyes of the strainloboid-ophthalmoptera (see Ouweneel, 1969a, b). The penetrance of the homoeotic effect increases with maternal age (Table 1); Delcour (1968)(More)
Anterior fragments of mature haltere discs are shown to regenerate missing anlagen when allowed additional growth in adult hosts. It appears that a small part of the scabellum anlage, and perhaps even the metathoracic anlage alone, is capable of regenerating a complete haltere. Posterior fragments are capable of duplicating the anlagen present in them,(More)
1. The wild-type mature eye disc, when implanted into a larva of the same age, undergoes metamorphosis along with the host, and produces exactly one half of the head capsule outside the frontal suture. Implants ofopht eye discs form fewer facets, but many additional vibrissae, and produce homoeotic wing tissue (Fig. 1) in 20% of the cases. 2. On the basis(More)
In a previous paper (Ouweneel, 1969) the genetic basis has been described of a uew homoeotic strain, calledloboid-ophthalmoptera (ld-opht). In the present paper the morphological appearance and the development of the homoeotic effect are dealt with. In the adult fly the eye is often considerably reduced and kidney-shaped (Fig. 2). In the hypodermal part of(More)
describing the origin and na ture of the determined state, and its continuous propagat ion th rough numerous cell generations in in vivo culture, as well as the sudden changes of determinat ion ( t ransdeterminat ion) which occur in cultured clones derived f rom determined cells. These t ransde te rmina t ions are also propagated during cell division, are(More)
A homoeotic strain in which wing-like outgrowths are produced from the eye region was investigated. The actual wing nature of the malformation was confirmed. Genetically, this homoeotic character depends on the presence of an eye-reducing factor,loboid (ld; 3–102), and of modifier genes. One important sex-linked modifier, probably located at 1–5±, is(More)
  • 1