Disease relevance of salm

• Mutations in SALL4, the human homolog of the Drosophila homeotic gene spalt (sal), cause the autosomal dominant disorder known as Okihiro syndrome [1].

High impact information on salm

• Therefore, we conclude that Antp negatively regulates salm [2].
• The time course of the interaction and reporter gene fusion experiments suggests (but does not prove) a direct interaction between Antp and cis-regulatory elements of salm [2].
• spalt encodes an evolutionarily conserved zinc finger protein of novel structure which provides homeotic gene function in the head and tail region of the Drosophila embryo [3].
• Based on P-element mediated germ line transformation and DNA sequence analysis of sal mutant alleles, we identified the transcription unit that carries sal function. sal is located close to the misidentified transcription unit, and it is expressed in similar temporal and spatial patterns during embryogenesis [3].
• Antibodies produced against the sal protein show that sal is first expressed at the blastoderm stage and later in restricted areas of the embryonic nervous system as well as in the developing trachea [3].

Biological context of salm

• Here, we show that the spalt zinc-finger transcription factors (spalt major and spalt-related) are part of the molecular mechanisms regulating R3/R4 specification and planar cell polarity establishment [4].
• The mutants present embryonic or pupal lethality, with phenotypes consistent with the loss of spalt function [5].
• Identification of regulatory regions driving the expression of the Drosophila spalt complex at different developmental stages [5].
• The sal gene encodes a zinc finger protein of novel structure composed of three widely spaced 'double zinc finger' motifs of internally conserved sequences and a single zinc finger motif of different sequence [3].
• Subsequently, sal-dependent SAL upregulation is triggered as part of the oenocyte-specific EGFR response [6].

Anatomical context of salm

• Sal protein is expressed in the dorsal but not lateral ectoderm and acts as a competence modifier to bias the response to Spi ligand in favour of the oenocyte fate [7].

Regulatory relationships of salm

• Finally, kni and knrl are likely to refine the L2 position by positively auto-regulating their own expression and by providing negative feedback to repress salm expression [8].
• spalt-dependent switching between two cell fates that are induced by the Drosophila EGF receptor [6].

Other interactions of salm

• The transcription factor encoded by spalt major (salm) gene, which is expressed in a broad wedge centered over the dpp stripe, is one target of Dpp signaling [9].
• Furthermore, we provide evidence that the border between cells acquiring dorsal branch and dorsal trunk identity is established by the direct interaction of KNIRPS with a spalt cis-regulatory element [10].
• Here, we present the isolation and characterization of novel spalt/spalt-related alleles, which analysis indicates that these genes cannot substitute for each other in the developmental processes studied [5].
• We demonstrate that spalt and senseless are part of a genetic network, which regulates rhodopsin 6 and rhodopsin 1 [11].
• We discuss a recently proposed model that integrates the roles of Sal and the EGFR pathway in oenocyte/chordotonal organ induction [7].

Analytical, diagnostic and therapeutic context of salm

• Sequence analysis of the sal gene of Drosophila virilis, a species which is phylogenetically separated by approximately 60 million years, suggests that the sal function is conserved during evolution, consistent with its proposed role in head formation during arthropod evolution [3].

References