Insect axis formation is best understood in Drosophila melanogaster, where rapid anteroposterior patterning of zygotic determinants is directed by maternal gene products. The earliest zygotic control is by gap genes, which determine regions of several contiguous segments and are largely conserved in insects. We have asked genetically whether early zygotic patterning genes control similar antero...

ABNORMALITIES of thoracic configuration cani alter the iniformation derived from clinical assessment of the heart. Altlhouigh these alterations may he subtle, occasionally they may be sufficiently overt to produice signs that closely mimic organic heart disease. Pecttus excavatumn' 2 is a wvellrecognized thoracic deformity in this category. On the, other hand, absence, of normal thoracic kyphos...

We investigate a mechanism for the robust identification of the center of a developing biological system. We assume the existence of two morphogen gradients, an activator emanating from the anterior, and a corepressor from the posterior. The corepressor inhibits the action of the activator in switching on target genes. We apply this system to Drosophila embryos, where we predict the existence o...

Most of the thoracic and abdominal segments of Drosophila are specified early in embryogenesis by the overlapping activities of the hunchback (hb), Krüppel, knirps, and giant gap genes. The orderly expression of these genes depends on two maternal determinants: bicoid, which activates hb transcription anteriorly, and nanos, which blocks translation of hb transcripts posteriorly. Here we provide...

Drosophila segmentation is governed by a well-defined gene regulation network. The evolution of this network was investigated by examining the expression profiles of a complete set of segmentation genes in the early embryos of the mosquito, Anopheles gambiae. There are numerous differences in the expression profiles as compared with Drosophila. The germline determinant Oskar is expressed in bot...

Anterior-posterior (AP) patterning in the Drosophila embryo is dependent on the Bicoid (Bcd) morphogen gradient. However, most target genes of Bcd also require additional inputs to establish their expression domains, reflective of the operation of a cross-regulatory network and contributions of other maternal signals. This is in contrast to hunchback (hb), which has an anterior expression domai...

Understandably describe historical and current spinal deformity classifications. Spinal deformities can be divided into three main categories: congenital, idiopathic, secondary deformities. Secondary is by far the largest group. Congenital are generally seen in very early ages may accompanied neural with systemic organ pathologies. Different classification systems based on clinical radiological...

Hemivertebra is a rare congenital spinal malformation, where only one side of the vertebral body develops, resulting in deformation of the spine, such as scoliosis, lordosis, or kyphosis. We present the ultrasonographic features of a fetus with hemivertebra at 20 weeks' gestation confirmed by post mortem radiography and pathological examination. The prenatal literature on this disorder is also ...

The Bicoid-based anterior patterning system of Drosophila embryogenesis appears to be unique to higher dipterans. A new study suggests how this may have evolved out of an alternative mechanism based on cooperating Orthodenticle and Hunchback proteins, the two mechanisms intersecting at the level of downstream target genes.

The Drosophila morphogen gradient of Bicoid (Bcd) initiates anterior-posterior (AP) patterning; however, it is poorly understood how its ability to activate a target gene may have an impact on this process. Here we report an F-box protein, Dampened (Dmpd) as a nuclear cofactor of Bcd that can enhance its activating potency. We establish a quantitative platform to specifically investigate two pa...