Goosecoid and HNF-3beta genetically interact to regulate neural tube patterning during mouse embryogenesis

Area of Science:

• Developmental Biology
• Genetics
• Molecular Biology

Background:

• Goosecoid (gsc) and Hepatic Nuclear Factor-3beta (HNF-3beta) are co-expressed during mouse gastrulation.
• Understanding the interplay between these genes is crucial for deciphering early embryonic patterning.

Purpose of the Study:

• To investigate the functional synergy or redundancy between gsc and HNF-3beta during embryogenesis.
• To identify the downstream effects of combined gsc and HNF-3beta mutations on embryonic development.

Main Methods:

• Generation of double-mutant mice with targeted mutations in gsc and HNF-3beta genes (gsc(-/-);HNF-3beta(+/-)).
• Analysis of embryonic phenotypes at day 8.75.
• Examination of gene expression patterns, including Sonic hedgehog (Shh), in mutant embryos.

Main Results:

• Double-mutant embryos exhibited a novel phenotype by embryonic day 8.75.
• Loss of Sonic hedgehog (Shh) and HNF-3beta expression was observed in the notochord and ventral neural tube.
• Forebrain development was severely affected, with growth defects and absent optic vesicles, potentially due to altered Shh and fibroblast growth factor-8 (FGF8) expression.

Conclusions:

• gsc and HNF-3beta genetically interact to regulate Shh expression, which is critical for dorsal-ventral patterning of the neural tube.
• This interaction also influences the expression of other signaling molecules essential for foregut, branchial arch, and heart development.
• The study highlights a complex regulatory network involving gsc and HNF-3beta in early mouse embryogenesis.