Abstract
In a strain of flies with a lethal tumor, i.e., a tumor occurring in one half of the males and causing their death, another tumor has appeared as a mutation. The new tumor differs from the lethal one in that it is not sex-linked, i.e., it appears in females as well as males, and further in that it does not cause the death of the flies in which it occurs. Linkage experiments show that one at least of the genes essentially for tumor development is in the third chromosome closely linked to dichaete.
The tumor may occur in any segment of the larva but seems to occur more often in the twelfth and thirteenth segments. When the tumor occurs in the thoracic region, there may be an ingrowth of tumor cells into the imaginal discs of the appendages checking the development of these parts.
The cells of the tumor are rounded or polygonal in shape and show the presence of pigment.
Get full access to this article
View all access options for this article.