A DETAILED FATE MAP OF THE WING DISC OF SARCOPHAGA PEREGRINA

Abstract

In order to construct an anlageplan of the imaginal disc, various fragments of the wing disc from mature larvae of Sarcophaga peregrina were implanted into host larvae of the same age. The implants were metamorphosed with the host and the differentiated adult structures were analyzed.On the basis of the results obtained from the transplanted disc fragments, a fate map of the wing disc was satisfactorily constructed.The fate map of S. peregrina is similar to an earlier study of Drosophila, but the PAA, PWP, and AP are located in different positions from those of Drosophila.In the holometabolous insect, particular parts of the imaginal disc cell develop into corresponding parts of adult structures during metamorphosis. HADORN (4) reported that an imaginal disc, which had been taken from a third instar larva and implanted into a host larva of the same age, metamorphosed with the host and differentiated into the adult structures. This method has been applied to fragments of discs for constructing a fate map of Drosophila (3). Thereafter, fate maps of the wing disc of Calliphora (8) and Zaprionus (9) were described to be highly similar to that of Drosophila. Recently, BRYANT (1) reported a more precise fate map of a Drosophila wing disc using the same method, and revealed the regenerative properties of the fragmented disc.Larvae of Sarcophaga peregrina are useful material for studies in developmental biology because their physiological age can easily controlled by dry-wet treatment as described by OHTAKI (6). Furthermore, the large size of the imaginal discs aids in handling and precision. We constructed a fate map of the wing disc of S. peregrina as a basic study for the further analysis of determination and differentiation of particular parts of the imaginal disc. MATERIALS AND METHODSLarvae of the fleshfly, Sarcophaga peregrina, were reared and maintained as previously described by OHTAKI (6). All experiments were conducted with the use of wing discs which were isolated from mature larvae being kept under wet conditions.Imaginal wing discs were removed from mature larvae and were fragmented in insect Ringer (2) using a pair of fine forceps and iridectomy scissors. Each disc was cut into three parts along two of the levels indicated in Fig. 1. A "V"-shaped incision was made with iridectomy scissors in the abdomen of another mature larva. Either whole wing discs or fragmented discs were picked up with the fine forceps and placed into the body cavity of the host. After metamorphosis, the differentiated implants were removed from the flies and their structures were analyzed. A total of 1168 implants were analyzed in this study.For ease in analyzing the metamorphosed structures derived from wing disc implants, we made a complete list of the epidermal structures normally produced by the disc. Fig. 2 shows a diagram of the wing disc derivatives. Figs. 3 and 4 show in detail, the dorsal and ventral hinge regions. We have principally employed the general terminology; the abbreviations used for the structures are listed in ...

Differentiation Capacities of the Foreleg Imaginal Disc of Sarcophaga ruficornis Fabr (Diptera, Sarcophagidae): I. Fate Map

“…In addition to the different imaginal discs of Drosophila, pattern formation and fate map of the imaginal discs of other insects are also known. The fate maps of wing disc of Zaprionus (6), Calliphora (7), and Sarcophaga (8) have been studied and the concentric arrangements of the anlagen have been more or less confirmed. These studies, therefore, confirm that most discs, at least the thoracic and cephalic ones, present concentric patterns of anlagen.…”

“…Trochanter also possesses some excellent markers viz. 6-8 small bristles (6)(7)(8), borderline (BL), two groups of Fig. 2-3.…”