GENETIC-CHARACTERIZATION OF TUBE AND PELLE, GENES REQUIRED FOR SIGNALING BETWEEN TOLL AND DORSAL IN THE SPECIFICATION OF THE DORSAL-VENTRALPATTERN OF THE DROSOPHILA EMBRYO
Pm. Hecht et Kv. Anderson, GENETIC-CHARACTERIZATION OF TUBE AND PELLE, GENES REQUIRED FOR SIGNALING BETWEEN TOLL AND DORSAL IN THE SPECIFICATION OF THE DORSAL-VENTRALPATTERN OF THE DROSOPHILA EMBRYO, Genetics, 135(2), 1993, pp. 405-417
tube and pelle are two of the maternally transcribed genes required fo
r dorsal-ventral patterning of the Drosophila embryo. Females homozygo
us for strong alleles of tube or pelle produce embryos that lack all v
entral and lateral embryonic pattern elements. By analyzing the phenot
ypes caused by 24 pelle and 9 tube alleles, we have defined characteri
stic features of the two genes, including the extremely variable pheno
types of a number of tube alleles and the antimorphic character of a n
umber of pelle alleles. Double mutant females carrying dominant ventra
lizing alleles of Toll and dorsalizing alleles of tube or pelle produc
e dorsalized embryos, suggesting that tube and pelle act downstream of
the membrane protein Toll in the signaling pathway that defines the e
mbryonic dorsal-ventral pattern. Both tube and pelle are also importan
t zygotically for survival: at least 30% of the zygotes lacking either
tube or pelle die before adult stages, while 90-95% of tube- pelle-do
uble mutant zygotes die. We discuss the phenotypes of tube-pelle doubl
e mutants in the context of whether the two proteins interact directly
.