NUCLEOCYTOPLASMIC RELATIONS 

 IN EARLY INSECT DEVELOPMENT* 



R. C. VON BORSTEL: biology division, oak ridge 



NATIONAL LABORATORY, OAK RIDGE, TENNESSEE 



Experimental study of interaction between the nucleus and 

 cytoplasm in development had its origin in the analyses of Boveri 

 (1907) on sea urchins, which showed that alteration of the 

 chromosome complement disrupted development. The role of the 

 cytoplasm has been heavily emphasized by such studies as the 

 classical research of Conklin on ascidian embryos (1931). Fank- 

 hauser (1952, 1955) has comprehensively reviewed nucleocyto- 

 plasmic relations in development of animals other than insects. 

 Since certain aspects of development are revealed with greatest 

 clarity in the insect embryo, and since the genetic background is 

 so well known in certain species, it would seem that information 

 of general interest would be derived from an experimental study 

 of insect development. The work described here is confined for 

 the most part to the parasitic wasp Habrobmcon; the results are 

 used wherever possible to illustrate general principles of develop- 

 ment. The embryology of the young system is presented prima- 

 rily from cytogenetic and cytochemical points of view. Some of 

 the conclusions drawn from the work described depend on a 

 study of gynandromorphs and genetic mosaics, and most of the 

 remainder rely on interpretations of the action of radiation. 



In insects as in other animals, the fust mitotic divisions are 

 rapid and result in many nuclei within many cells, which consti- 

 tute a pool utilized during tissue formation. As in all animals, 

 much depends on the particular code within the genome at the 

 outset of embryogeny, by which a wild-type Drosophila can be 

 mutated into a mottled peach, a Mormoniella into an oyster, or 



' Work performed under USAEC contract No. W-7405-eng-26. 



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