DIGESTIVE ACID PROTEASE ACTIVITY
AND GENE EXPRESSION OF PEPSINOGEN DURING THE LARVAL DEVELOPMENT OF RED PORGY
M.J. Darias,
H.M. Murray, G.
Martinez-Rodriguez, S. Cardenas, F.J.
Moyano, M. Yúfera
Ontogeny of stomach functionality
during the larval development of the red porgy, Pagrus
pagrus,
was
studied from morphological, physiological and molecular perspectives. The
aim of
this study is to advance our understanding of the sequence of events
occurring during the transition from alkaline to acid digestion in sparids.
Gastric gland histological development was examined using haematoxylin-eosin staining.
Pepsinogen mRNA was localized using in situ
hybridization
on 5-7 pm sections of paraffin embedded samples. Gastric pH in the lumen of
the stomach was measured using a pH microelectrode. The first signs of
gastric glands were apparent by 15 days after hatching (dah) and were
fully morphologically developed at approximately 26 dah. Pepsinogen
expression was evidenced in the gastric glands from 30-35 dah.
A decrease in gastric pH was detected in larvae above 30 dah. The presence
of pepsin will be examined by SDS-PAGE zymograms.
(Instituto de Ciencias
Marinas de Andalucia (CSIC), Apartado Oficial E-11510, Puerto Real, Cadiz,
Spain)