Production of androgenetic Nile tilapia, Oreochromis niloticus L.: Optimization of heat shock duration and application time to induce diploidy

Citation

Karayucel I, Karayucel S, Penman D & McAndrew B (2002) Production of androgenetic Nile tilapia, Oreochromis niloticus L.: Optimization of heat shock duration and application time to induce diploidy. Israeli Journal of Aquaculture -Bamidgeh, 54 (4), pp. 145-156. http://aquaculture.ocean.org.il/ija/54/54-4_145-156.htm

Abstract
Diploid androgenetic Nile tilapia, Oreochromis niloticus, were produced using 5 min UV irradiation at 150 µW/cm and heat shock at 42.5°C for 3:30 min applied 25 min after fertilization. The survival rates to morula, pigmentation, hatching and yolk sac resorption stages were 42.84±4.73%, 10.69±2.24%, 2.03±0.60% and 0.07±0.07% (relative to controls), respectively. A significant female, but not male, effect on the survival was confirmed. Multilocus DNA finger-printing produced by hypervariable 33.15 DNA probe verified the all-paternal inheritance in the androgens. The sex ratio of the androgenetic tilapia was not significantly different from the expected ratio of 1:0 (male:female), indicating that O.niloticus has a monofactorial sex-determining mechanism with female homogamety and male heterogamety. This study confirmed that the YY genotype is viable and fertile in O.niloticus.

Keywords
androgenesis; diploidy; tilapia

Journal
Israeli Journal of Aquaculture -Bamidgeh: Volume 54, Issue 4