EARLY REQUIREMENTS OF FURRY IN CELL FATE DETERMINATION AND MORPHOGENETIC MOVEMENTS

CERVINO, AILEN; HUKRIEDE, NEIL A.; CIRIO, MARIA CECILIA

CABA, Buenos Aires

Congreso; Reunión conjunta de sociedades de biociencias; 2017

Sociedades Argentina de Biociencias

Vertebrate embryonic axes formation is conducted by a group of cells with morphogenetic and inductive properties, named ?the organizer?. These cells coordinate the formation of the axial mesoderm, gastrulation movements and induction of the nervous system. The furry (fry) gene encodes an evolutionarily conserved protein involved in multiple cellular functions in vertebrates and invertebrates. In Xenopus, Fry acts as a corepressor of microRNAs inducing the expression of axial mesoderm genes. Dorsal depletion of fry produces shortening of the dorsal axis and interferes with head formation, possibly due to gastrulation defects and/or incorrect progenitor cells specification.Since little is known about the role of fry in early development, we investigated its expression pattern by in situ hybridization. In Xenopus, fry is maternally expressed in the animal pole of both dorsal and ventral blastomeres. During gastrulation, fry is found in the axial mesoderm and at tailbud stage, its expression remains in notochord, somites and pronephros. Interestingly, zebrafish fryl1 is also maternally deposited and expressed in the notochord at 12-somite stage. To investigate the nature of the developmental defects associated with fry depletion, we injected Xenopus embryos with a specific morpholino oligonucleotide. Dorsal depletion results in reduced expression domain of the organizer genes goosecoid and chordin, indicating that Fry is required for organizer formation. Fry-depleted embryos exhibit blastopore closure and axial mesoderm convergent extension defects, resulting in abnormal gastrulation movements. When fry is ventrally depleted, expression of dorsal organizer markers is unaffected whereas expression of the ventrolateral mesoderm marker, wnt8 is diminished. Together, our results show that Fry has conserved expression in the axial mesoderm and suggest that it has a dual role in early development: it is required for mesoderm specification and cell movements during gastrulation.