IIB   20738
INSTITUTO DE INVESTIGACIONES BIOLOGICAS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Regulation of the compatible osmolyte inositol in gills of tilapia during salinity stress
Autor/es:
DIETMAR KÜLTZ, DIEGO FIOL, ROMINA SACCHI, ALISON GARDELL
Lugar:
Barcelona
Reunión:
Congreso; 9th International Congress on the Biology of Fish; 2010
Institución organizadora:
American Fisheries Society
Resumen:
Myo-inositol
is a compatible osmolyte utilized by most organisms for maintaining
intracellular ion homeostasis during extreme fluctuations of environmental
salinity. We have recently identified myo-inositol-phosphate synthase (MIPS) - the
key enzyme myo-inositol synthesis - as an immediate early osmotic stress
response gene in gills of euryhaline tilapia (Oreochromis mossambicus). The
tilapia MIPS gene is structurally highly conserved but lacks a short region
that encodes an external loop in other MIPS orthologes. Tilapia MIPS is rapidly
transcriptionally induced in response to hyperosmotic stress and shows a
biphasic mode of upregulation in tilapia gills. The initial induction peaks
between 2 6 h and is transient and the second, long-term induction is
permament and proportional to the degree of salinity change. In contrast to
fish using MIPS for myo-insoitol synthesis during hyperosmotic stress,
mammalian cells primarily accumulate inositol via uptake using
Sodium-myo-inositol co-transporter (SMIT). Evolutionary implications of these
different strategies will be discussed.