Finkelstein R, Smouse D, Capaci TM, Spradling AC, Perrimon N.
The orthodenticle gene encodes a novel homeo domain protein involved in the development of the Drosophila nervous system and ocellar visual structures. Genes Dev. 1990;4 (9) :1516-27.
Abstract
The orthodenticle (otd) locus of Drosophila is required for embryonic development, and null mutations of otd cause defects in head development and segmental patterning. We show here that otd is necessary for the formation of the embryonic central nervous system (CNS). otd mutations result in the formation of an abnormal neuropil and in the disappearance of identified neurons associated with the midline of the CNS. In addition, otd is allelic to ocelliless (oc), a mutation that causes the deletion of the ocelli of the adult fly. We have identified a transcription unit corresponding to the otd locus and find that it is expressed early in a stripe near the anterior pole of the cellular blastoderm and later in the region of the CNS from which these neurons normally arise. The predicted otd protein contains a well-conserved homeo domain and is therefore likely to be a transcriptional regulator involved in specifying cell fate both in the embryonic CNS and in the ocelli.
1990_Genes Dev_Finkelstein.pdf Finkelstein R, Perrimon N.
The orthodenticle gene is regulated by bicoid and torso and specifies Drosophila head development. Nature. 1990;346 (6283) :485-8.
Abstract
In the Drosophila embryo, cell fate along the anterior-posterior axis is determined by maternally expressed genes. The activity of the bicoid (bcd) gene is required for the development of larval head and thoracic structures, and that of maternal torso (tor) for the development of the unsegmented region of the head (acron). In contrast to the case of thoracic and abdominal segmentation, the hierarchy of zygotically expressed genes controlling head development has not been clearly defined. The bcd protein, which is expressed in a gradient, activates zygotic expression of the gap gene hunchback (hb), but hb alone is not sufficient to specify head development. Driever et al. proposed that at least one other bcd-activated gene controls the development of head regions anterior to the hb domain. We report here that the homeobox gene orthodenticle (otd), which is involved in head development, could be such a gene. We also show that otd expression responds to the activity of the maternal tor gene at the anterior pole of the embryo.
1990_Nat_Finkelstein.pdf