High impact information on btd

• Furthermore, BTD and Sp1 are capable of activating transcription in transfected cultured cells through interaction with the same DNA target sites [1].
• The parasegmental register of col activation is controlled by the combined activities of the head-gap genes buttonhead and empty spiracles and the pair-rule gene even skipped; it therefore integrates inputs from both the head and trunk segmentation systems, which were previously considered as being essentially independent [2].
• The Drosophila dead ringer gene is required for early embryonic patterning through regulation of argos and buttonhead expression [3].
• The control of eve expression by btd in these cells is the first indication of a new level of integrated regulation that interfaces the head and trunk segmentation systems [4].
• The Drosophila gap-like segmentation genes orthodenticle, empty spiracles and buttonhead (btd) are expressed and required in overlapping domains in the head region of the blastoderm stage embryo [5].

Biological context of btd

• The requirement for btd and Sp1 persists during the development of ventral discs: inactivation by RNA interference results in a strong reduction of the size of legs and antennae [6].
• D-Sp1 is located in the same cytological location as btd in chromosome band 9A on the X-chromosome [7].
• The btd protein (BTD) is functionally and structurally related to the human C(2)H(2) zinc finger transcription factor Sp1 [7].
• Re-examination of the btd and eve phenotypes in live embryos indicated that both genes are required for CF formation [4].
• Here we report the pattern of btd expression during embryogenesis. btd is not only expressed and required in the blastoderm anlagen of the antennal, intercalary and mandibular segments as reported previously, but both expression and requirement extend into the anlage of the maxillary segment [8].

Anatomical context of btd

• In fact, analysis of btd mutant embryos revealed that btd participates in the formation of the peripheral nervous system [8].

Regulatory relationships of btd

• Consistent with this model, a synthetic construct containing three tandem copies of the native LDL receptor SREBP site linked to a single Sp1 site was also significantly activated in a buttonhead-independent fashion [9].

Other interactions of btd

• Both ems and btd are required in partially overlapping subsets of neuroblasts of the deuterocerebrum and tritocerebrum [10].
• However, D-Sp1 lacks the specific features of BTD required for embryonic intercalary and antennal segment formation [7].
• Misexpression of btd in the anterior half of the blastoderm embryo directed by the hunchback proximal promoter rescues the btd mutant head phenotype to wild-type [5].

References