CTP:PHOSPHOCHOLINE CYTIDYLYL TRANSFERASE EXPRESSION THROUGHOUT Bufo arenarum (AMPHIBIA) EMBRYOGENESIS

FERNANDEZ-BUSSY, RODRIGO; BANCHIO, CLAUDIA; COUX, GABRIELA

Puerto Madryn

Congreso; XLVI Reunión Anual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2010

Phosphatidylcholine plays fundamental structural and functional roles. In nucleated cells it is synthesized through the Kennedy pathway where the regulatory step isbcatalyzed by CTP: phosphocholine cytidylyl transferase (CT). The CTa isoform expresses in every animal tissue and presents two differential states: a cytosolic-inactive state and a membrane bound-active state. Pcyt1a knock-out mouse fail to form blastocysts demonstrating the essential role of CTa early during embryonic development. Our goals were to:1) detect CTa mRNA and protein in B. arenarum oocytes, 2) study CTa protein expression and distribution between cytosolic and membrane fractions during development. mRNA encoding Cta was analyzed by RT-PCR using mouse-specific primers in B arenarum total ovary RNA. Immunoblotting with anti- CT policlonal antibody confirmed the presence of Cta in oocytes. Total protein samples (ET) from embryos of different stages showed constant levels of CTa until morula. In blastocyst it starts decreasing reaching a minimum at neural plate after which it begins to recover. Immunoblot analysis demonstrated that cytosolic/total CTa protein ratio is constant during embryogenesis. Our results suggest that CTa is present in B. arenarum oocytes and shows sequence similarity to mammalian CTa. Maternal CTa protein seems to fulfil the metabolic requirements during early development.