Review Article

Lu X, Perkins LA, Perrimon N. The torso pathway in Drosophila: a model system to study receptor tyrosine kinase signal transduction. Dev Suppl. 1993;:47-56. Abstract

In the Drosophila embryo, specification of terminal cell fates that result in the formation of both the head (acron) and tail (telson) regions is under the control of the torso (tor) receptor tyrosine kinase. The current knowledge suggests that activation of tor at the egg pole initiates a signal transduction pathway that is mediated sequentially by the guanine nucleotide releasing factor son of sevenless (Sos), the p21Ras1 GTPase, the serine/threonine kinase D-raf and the tyrosine/threonine kinase MAPKK (Dsor1). Subsequently, it is postulated that activation, possibly by phosphorylation, of a transcription factor at the egg poles activates the transcription of the terminal gap genes tailless and huckebein. These gap genes, which encode putative transcription factors, then control the expression of more downstream factors that ultimately result in head and tail differentiation. Also involved in tor signaling is the non-receptor protein tyrosine phosphatase corkscrew (csw). Here, we review the current model and discuss future research directions in this field.

1993_Dev Suppl_Lu.pdf
Perrimon N. The torso receptor protein-tyrosine kinase signaling pathway: an endless story. Cell. 1993;74 (2) :219-22. 1993_Cell_Perrimon.pdf
Finkelstein R, Perrimon N. The molecular genetics of head development in Drosophila melanogaster. Development. 1991;112 (4) :899-912. 1991_Dev_Finkelstein.pdf
Perkins LA, Perrimon N. The molecular genetics of tail development in Drosophila melanogaster. In Vivo. 1991;5 (5) :521-31. Abstract

The formation of the telson in the Drosophila embryo, which encompasses all structures posterior to abdominal segment 7, is under the control of the "terminal class" genes. These maternally expressed genes are organized in a signal transduction pathway which implicates cell-cell interactions between the germ cell derivatives (the nurse cells and oocyte) and the surrounding follicle cell epithelium. Activation of this localized signal transduction pathway at the termini of the embryo is believed to specify the domains of activation and repression of a set of zygotic genes whose interactions specify the various cell states required for the proper formation of tail structures.

1991_In Vivo_Perkins.pdf
Siegfried E, Ambrosio L, Perrimon N. Serine/threonine protein kinases in Drosophila. Trends Genet. 1990;6 (11) :357-62. Abstract

The study of serine/threonine kinases in Drosophila is coming of age. Recently several kinases have been identified and their role in cell determination has been established. This review discusses these recent findings and describes the potential for genetic analyses of kinase activity and signal transduction.

1990_Trends Genet_Siegfried.pdf