CHARACTERIZATION OF NITRIC OXIDE SYNTHASE IN SPECIALIST AND PARASITIC SOLITARY BEES

GALVANI GL; DE BENEDICTIS M; CANAVOSO LE; SETTEMBRINI, BP

La Falda, Cordoba

Jornada; XIX Reunion Anual de la Sociedad de Biología de Córdoba; 2013

Sociedad de Biología de Córdoba

Nitric oxide (NO) is recognized as a signaling molecule in the insectnervous system. Several experiments in Apis mellifera suggest animportant role of this molecule in the processing of olfactoryinformation as well as in learning and memory formation. To localizethe presence of NO synthase (NOS), we carried outimmunocytochemistry, histochemistry and western blot (WB)experiments in pollen collecting (NP) and parasitic (P) bees. Usingan antibody directed to the C-terminal sequence of the enzyme,WB experiments revealed a band at approximately 130 kDa in bothNP and P species. NOS activity was evaluated in brain homogenatesby following spectrophotometrically the oxidation ofoxyhemoglobin to methemoglobin. This activity varies from 40,3to 27,9 nmol/min/mg protein in NP bees whereas in P insects, itranged from 7,8 to 16,9 nmol/min/mg protein. NADPH diaphorasehistochemistry allowed detection of positive somata and fibers inthe mushroom body calices and the antennal lobes. These resultssuggest that NO production is mainly present in olfactory brainareas. NP females showed higher levels of NOS activity than Pfemales. In conclusion, NO might be related with the detection andprocessing of olfactory information during foraging.