CHEMICAL AND PHYSICAL METHODS OF TRIPLOIDY INDUCTION IN Crassostrea gigas (THUNBERG, 1793)*

Three methods of triploidy (3N) induction were tested in diploid (2N) oysters Crassostrea gigas: two chemical methods cytochalasin-B (CB) and 6-dimethylaminopurine (6-DMAP), and one physical method with temperature shock. The objective was to evaluate the triploidy induction technology using flow cytometry as a tool to check the results of induction. The experiments were performed in separate and a seawater temperature in the tanks was maintained at 25 °C for all experiments. In the experiment I, the efficacy of triploidy induction was evaluated using CB (0.5 mg L-1) and 6DMAP (390 μmols L-1). In the experiment II, the efficiency of triploidy induction was tested using CB (0.5 mg L-1) and 6-DMAP (450 μmols L-1). In the experiment III, the efficiency of triploidy induction was evaluated using CB (0.5 mg L-1) and temperature shock (25 to 36 °C). In all three experiments, viable triploid larvae were obtained. However, in the experiments I and II (with chemical methods), high mortality of larvae was observed, especially for the treatment CB. From these results, it is suggested the replacement of CB by other methods of triploidy induction, due to its high cost and high toxicity to humans and to the environment.

[1]  J. Matt,et al.  Heteroploid mosaic tetraploids of Crassostrea virginica produce normal triploid larvae and juveniles as revealed by flow cytometry , 2014 .

[2]  L. Colombo,et al.  Polyploid fish and shellfish: Production, biology and applications to aquaculture for performance improvement and genetic containment , 2009 .

[3]  D. Hedgecock,et al.  Centromere mapping in triploid families of the Pacific oyster Crassostrea gigas (Thunberg). , 2009 .

[4]  R. S. Rasmussen,et al.  Biotechnology in Aquaculture: Transgenics and Polyploidy , 2007 .

[5]  Ximing Guo,et al.  Polyploid induction by heat shock-induced meiosis and mitosis inhibition in the dwarf surfclam, Mulinia lateralis Say , 2006 .

[6]  P. Muthiah,et al.  Induced triploidy in the edible oyster, Crassostrea madrasensis by temperature shock , 2006 .

[7]  P. Thompson,et al.  Studies on triploid oysters in Australia: XIII. Performance of diploid and triploid Sydney rock oyster, Saccostrea glomerata (Gould, 1850), progeny from a third generation breeding line , 2004 .

[8]  Jonathan M. P. Davis,et al.  Optimal chemical triploid induction in geoduck clams, Panopea abrupta, by 6-dimethylaminopurine , 2004 .

[9]  J. Nell.  Farming triploid oysters , 2002 .

[10]  Ximing Guo,et al.  All-triploid Pacific oysters (Crassostrea gigas Thunberg) produced by mating tetraploids and diploids , 1996 .

[11]  G. Maguire,et al.  Studies on triploid oysters in Australia. I. The farming potential of triploid Sydney rock oysters Saccostrea commercialis (Iredale and Roughley) , 1994 .

[12]  Y. Naciri,et al.  Optimization of triploid induction by the use of 6-DMAP for the oyster Crassostrea gigas (Thunberg) , 1994 .

[13]  Jorge E. Toro,et al.  Direct comparison of six methods to induce triploidy in bivalves , 1994 .

[14]  P. Guerrier,et al.  A novel method to produce triploids in bivalve molluscs by the use of 6-dimethylaminopurine , 1993 .

[15]  W. Hershberger,et al.  Genetic Consequences of Blocking Polar Body I with Cytochalasin B in Fertilized Eggs of the Pacific Oyster, Crassostrea gigas: I. Ploidy of Resultant Embryos. , 1992, The Biological bulletin.

[16]  S. Gendreau,et al.  Induced triploidy and tetraploidy in the European flat oyster, Ostrea edulis L. , 1990 .

[17]  N. P. Wilkins.  Hatchery manual for producing triploid oysters: S.K. Allen, S.L. Downing and K.K. Chew. Washington Sea Grant Program, 1989. Price US$8.00, 27 pp., ISBN 0-295-77031-7 , 1990 .

[18]  E. Gosling,et al.  Triploidy induction by thermal shock in the Manila clam, Tapes semidecussatus , 1990 .

[19]  Satoshi Yamamoto,et al.  Induced triploidy in the mussel, Mytilus edulis, by temperature shock , 1988 .

[20]  S. Allen,et al.  Performance of triploid Pacific oysters, Crassostrea gigas (Thunberg). I. Survival, growth, glycogen content, and sexual maturation in yearlings , 1986 .

[21]  E. Quillet,et al.  Triploidy induction by thermal shocks in the Japanese oyster, Crassostrea gigas , 1986 .

[22]  J. G. Stanley,et al.  Polyploidy induced in the American oyster, Crassostrea virginica, with cytochalasin B , 1981 .

[23]  R. Hillman.  The American oyster,Crassostrea virginica gmelin , 1965 .