| Summary: | 碩士 === 國立臺灣大學 === 漁業科學研究所 === 86 === An integrative plasmid, pSJ04 of 9.6 kilobase pairs under the control
of the AOX1 promoter, was constructed for intracellular expression of
yellowfin porgy growth hormone cDNA in the yeast Pichia pastoris.
Recombinant growth hormone (rGH) of fish was found in the cell lysate of
Pichia pastoris KM71 harboring pSJ04. A 22 kilo-daltons (kDa) protein band
was detected in the cellular proteins extracted from the Pichia transformants.
porgy growth hormone. Using densitometer scanning, the production of rGH was
about 5% of total cellular protein.
Transformants of yeast (Pichia pastoris KM71) containing recombinant
ypGH and containing expression vector with no insert DNA (non-rGH yeast, as
a control) were separately cultured, harvested and freeze dried. Two dosages
(0.04% and 0.16%) and different administration of yeasts were respectively
mixed with fish meal, formed a pellet and fed red tilapia (Oreochromis
niloticus x 0. mossambicus) fingerlings (around 0.45g) twice daily for
4 weeks. Each treatment group was duplicated. The results demonstrated
the groups fed 0.04% and 0.16% of rGH yeasts grew significantly superior
than the groups fed with same dose of non-rGH yeasts. Thus, results prove
that rGH has a biological activity and we suggest that the administration
of rGH yeasts in the diet is the simplest way to make the use of rGH in
aquaculture economically feasible.
|
|---|
