Regulation and function of Spalt proteins during animal development

Abstract

The genes of the spalt (sal) family play fundamental roles during animal development. The two members of this family in Drosophila, spalt (sal) and spalt-related (salr) encode Znfinger transcription factors that link the Decapentaplegic (Dpp)/BMP signalling pathway to the patterning of the wing. They are regulated by the Dpp pathway in the wing disc, and they were shown to mediate some of the morphogenetic activities of the Dpp/BMP4 secreted ligand. The sal genes were initially found by virtue of mutations that produce homeotic transformations in the head and tail of the Drosophila embryo. Since then, a number of other requirements have been associated to these genes in Drosophila, including morphogenesis of the respiratory system, cell fate specification of sensory organs and the differentiation of several photoreceptor cells, among others. Vertebrate sal orthologues (spalt-like/sall) have also important developmental roles during neural development and organogenesis, and at least two human sall genes are linked to the genetic diseases Townes Brocks Syndrome (TBS; SALL1 ) and Okihiro Syndrome (OS; SALL4). In this review, we will summarize the main characteristics of the sall genes and proteins, pointing out to the similarities in their developmental roles during Drosophila and vertebrate development.

Sall4-Gli3 system in early limb progenitors is essential for the development of limb skeletal elements

“…They play diverse roles in embryonic development, including the development of limbs (12,13). Among four Sall genes in mammals, Sall4 is a key regulator of stemness in stem cells and progenitor cells, such as embryonic stem cells, induced pluripotent stem cells, spermatogenial progenitor cells and cancer cells (14)(15)(16)(17)(18)(19).…”

The LIF/STAT3 Pathway in ES Cell Self-renewal

“…Sall4 is a zinc-finger transcription factor that was originally cloned based on sequence homology to Drosophila spalt (sal), which is a homeotic gene essential for the development of posterior-head and anterior-tail segments (de Celis & Barrio, 2009). In humans, mutations in SALL4 cause an autosomal dominant disorder known as Okihiro syndrome or Duane-radial ray syndrome.…”

Does therapeutic angiogenesis overcome CKD?

“…13,14 At later stages, spalt is involved in the development of the wing disk, trachea and sensory organs. 15,16 Humans and mice have four functional spalt-related genes, SALL1 to SALL4 (Sall1 to Sall4 in mice). The human SALL1 gene encodes transcription factors with a characteristic structure of evenly distributed zinc-finger domains.…”

“…Human SALL1 has been described as a transcriptional repressor in a number of experimental settings, most of them involving the regulation of heterologous promoters fused to reporter genes. 10 SALL1 gene expression is related to some human congenital diseases 11,12,15,[17][18][19] (Figure 2). In particular, mutations in SALL1 result in Townes-Brocks syndrome, a rare autosomal-dominant malformation syndrome characterized by dysplastic ears, pre-axial polydactyly and/or triphalangeal thumbs, imperforate anus, renal malformations and cardiac anomalies.…”