PT  - JOURNAL ARTICLE
AU  - Gonzalez-Reyes, A.
AU  - Morata, G.
TI  - Organization of the Drosophila head as revealed by the ectopic expression of the Ultrabithorax product
DP  - 1991 Dec 01
TA  - Development
PG  - 1459--1471
VI  - 113
IP  - 4
4099  - http://dev.biologists.org/content/113/4/1459.short
4100  - http://dev.biologists.org/content/113/4/1459.full
SO  - Development1991 Dec 01; 113
AB  - By using a hsp70-Ubx fusion gene, we have ectopically expressed a Ubx product in the embryonic head primordia and studied the developmental effects on the larval head. We find that after high and persistent levels of Ubx product, the head is replaced by three (C1, C2 and C3) abdominal-like denticle belts. The C2 and C3 belts are the homeotic transformations of parasegments 1 and 2, respectively, while the C1 belt probably derives from the transformation and subsequent fusion of the most anterior procephalic primordia. On the basis of their response to the Ubx product and other arguments, we propose that the larval head is made of two genetically distinct components; one is the procephalon and the anterior region of the mandibular lobe, and the other is part of the parasegmental trunk and includes parasegments 1 and 2. Our results also indicate that most or all the larval head structures derive from precursor cells of ventral origin.