Plautz CZ, Zirkle BE, Deshotel MJ, Grainger RM. Early stages of induction of anterior head ectodermal properties in Xenopus embryos are mediated by transcriptional cofactor ldb1.
Dev Dyn 2014;
243:1606-18. [PMID:
25258326 DOI:
10.1002/dvdy.24193]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Revised: 09/02/2014] [Accepted: 09/22/2014] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND
Specific molecules involved in early inductive signaling from anterior neural tissue to the placodal ectoderm to establish a lens-forming bias, as well as their regulatory factors, remain largely unknown. In this study, we sought to identify and characterize these molecules.
RESULTS
Using an expression cloning strategy to isolate genes with lens-inducing activity, we identified the transcriptional cofactor ldb1. This, together with evidence for its nuclear dependence, suggests its role as a regulatory factor, not a direct signaling molecule. We propose that ldb1 mediates induction of early lens genes in our functional assay by transcriptional activation of lens-inducing signals. Gain-of-function assays demonstrate that the inductive activity of the anterior neural plate on head ectodermal structures can be augmented by ldb1. Loss-of-function assays show that knockdown of ldb1 leads to decreased expression of early lens and retinal markers and subsequently to defects in eye development.
CONCLUSIONS
The functional cloning, expression pattern, overexpression, and knockdown data show that an ldb1-regulated mechanism acts as an early signal for Xenopus lens induction.
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