Aquaculture, 99 ( 1991) 249-255 Elsevier Science Publishers B.V., Amsterdam 249 Survival and integration rate of channel catfish and common carp embryos microinjected with DNA at various developmental stages Mohammad Hayata, Christopher P. Joyce”, Tim M. Townesb,Thomas T. Chen’, Dennis A. Powers?dv* and Rex A. Dunham” ‘Department of Fisheries and Allied Aquacultures,Auburn University, AL 36849, USA bDepartme t f n o Biochemistry, University ofAlabama-Birmingham, Birmingham, AL 35294. USA. ‘Center of Marine Biotechnology, The University of Maryland, Baltimore, MD 21202, USA dDepartmentof Biology, The Johns Hopkins University, Baltimore, MD 21218, USA (Accepted 24 February 199 I ) ABSTRACT Hayat, M., Joyce, C.P., Townes, T.M., Chen, T.T., Powers, D.A. and Dunham, R.A., 1991. Survival and integration rate of channel catfish and common carp embryos microinjected with DNA at var- ious developmental stages. Aquaculture, 99: 249-255. Channel catfish, Ictaluruspunctatus, and common carp, Cyprinus carpio, were microinjected with DNA at early, intermediate or late one-cell stage, two-cell stage or four-cell stage to determine the most appropriate developmental stage for maximizing the production of transgenic individuals, a product of survival x integration rate. Survival (hatching rate) decreased (PC 0.05, r= -0.8 1) when channel catfish embryos were microinjected at later stages compared to earlier stages. Survival rela- tive to non-microinjected controls was 65.0,43.6,38.5,27.4, and 35.9Oh and integration rate was 2. I, IS, 15.2, 12.5 and 7.7% for early one-cell, intermediate one-ceil, late one-cell, two-cell and four-cell stages, respectively. Cell stage at time of microinjecticn did not affect (P> 0.05, r= -0.52) survival in common carp and survival of microinjected common carp embryos was higher (PcO.01) than survival for channel catfish embryos. Survival relative to non-microinjected controls was 88.9, 85.3, 91.5, 85.3, and 83.4% and integration rate was 8.3, 1.0, 0.0, Il.5 and I .7% for early one-cell, inter- mediate one-cell, late one-cell, two-ceil and four-cell stages, respectively, of common carp. The late one-cell and the two-cell stage were the most appropriate stages for maximizing production of trans- genie channel catfish and common carp, respectGeT D INTRODUCTION Transgenic fish have been produced for many species including rainbow trout, Oncorhynchus mykiss (formerly Salmo gairdneri) (Chourrout et al., 1986), goldfish, Carassiusauratus (Zhu et al., 1985 ), and channel catfish, Ictalurus punctatus (Dunham et al., 1987 ). Survival and integration rate ap- pear to be high, 50-70%.each, in rainbow trout and goldfish embryos mi- *Present address: Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA 0044-8486/9 l/$03.50 0 199 1 Elsevier Science Publishers B.V. All rights reserved.