DOI: 10.5061/dryad.n5tb2rbvx
title: Size data for transgenic coho salmon from 5 rivers

description: Experiments examining potential impacts of growth hormone (GH)
 transgenesis in fish typically use a single source strain, and do not
 address potential differential impacts in strains of different genetic
 backgrounds. Here, we examine the effects of differing genetic backgrounds
 on the growth of transgenic and non-transgenic coho salmon produced by
 mating sires from different rivers with transgenic dams from a single
 origin. We found a significant difference in size between offspring of
 sires originating from various river systems in British Columbia. This
 difference was independent of differences between transgenotypes (i.e.,
 transgenic vs. non-transgenic offspring). However, the effects of strain
 or sire were relatively small compared to the effects of the transgene,
 which were consistent regardless of sire origin. Thus, results derived
 from studies of GH transgenic fish from a single source pouplation could
 provide useful information for assessments of GH transgenic salmon from
 other systems. This has important implications for examining potential
 risks from introgression of a transgene into different populations.
description: Three experimental groups
 of coho salmon were established: Experiment 1 (<i>Exp 1: sire
 effect</i>s) examined the effects of a wild-type sire on size of
 transgenic offspring.  Experiment 2 (<i>Exp 2: strain
 effects</i>) was used to examine the effect of sire length and river
 of origin (strain) on lengths and weights of transgenic offspring over a
 1.5 year period. Experiment 3 (<i>Exp 3: transgenotype</i>)
 compared the effects of sire length and strain over a shorter timeframe on
 weights and lengths of both transgenic and non-transgenic offspring.
 Experiments were carried out under permitting from the Pacific Region
 Animal Care Committee (AUP#11-020 and 15-001) and following Canadian
 Council on Animal Care guidelines. <i>Exp 1: sire
 effects</i>: Twenty –four wild-type males were collected from the
 Chehalis River, British Columbia, Canada in 2004; all males were crossed
 with a single homozygous growth hormone (GH) transgenic female from
 experimental line strain M77 (Devlin RH, Biagi CA, Yesaki TY. 2004.
 Growth, viability and genetic characteristics of GH transgenic coho salmon
 strains. Aquaculture 236:607–632. doi: 10.1016/j.aquaculture.2004.02.026)
 maintained at the Department of Fisheries and Oceans Canada’s Pacific
 Science Enterprise Centre in West Vancouver, BC. This transgenic line was
 derived from the Chehalis River, BC strain. All progeny resulting from
 this cross carried the transgene. Fertilized eggs were divided into 2
 rearing replicates of approximately 50 eggs each in order to account for
 tank effects (replicates are termed A and B in the dataset). Replicates
 were randomly assigned to hatchery trays, and after hatching they were
 maintained in separate 5L buckets randomly assigned to the larger tanks;
 buckets were re-assigned at each sampling date. For all experiments, fish
 were fed to satiation 5 times per day using stage-appropriate commercial
 diets (Skretting Canada, Vancouver, BC); feeding was reduced to 3 times a
 day after 3.5 months. Weights and fork lengths of 25 randomly collected
 fish from each replicate were measured at ponding (April 6, 2004) and all
 fish from each cross were measured 1.5 months after ponding (June 1, 2004)
 and 3 months after ponding (July 19, 2004). For<i> Exp 2</i> and
 <i>Exp 3</i>, sires included wild male coho collected in 2015
 from five river systems within British Columbia, Canada (Chehalis River
 (Ch), Kitimat River (K), Robertson Creek (R), Capilano River (Ca) and Big
 Qualicum River (BQ)). Fork length of sire was recorded. Eggs were
 collected from GH transgenic females from experimental line strain
 M77.<i> Exp 2: strain effects</i> involved crossing 115
 individual wild-type males (N per strain: BQ =25; Ca=18; Ch=24; K=23;
 R=24) with females that were homozygous for the GH transgene. A random mix
 of eggs from 25 females was subdivided for fertilization by each male,
 resulting in 115 families in which all offspring were transgenic. In
 <i>Exp 3: transgenotype </i>the same 115 males were crossed
 with a mix of eggs from 9 females that were hemizygous for the transgene,
 resulting in 115 families that were a mix of transgenic and non-transgenic
 offspring; approximately 50% of the offspring from each family were
 transgenic. For all families, eggs and hatched-out alevin were incubated
 in Heath trays until yolk sacs were absorbed at which time fish were
 ponded into individual 5L floating buckets within 200L tanks (5 buckets
 per tank) with densities of up to 50 fish for <i>Exp 2</i> and
 up to 100 fish for <i>Exp 3</i>. Fish were fed to satiation 5
 times per day using stage-appropriate commercial diets (Skretting Canada,
 Vancouver, BC); feeding was reduced to 3 times a day after 3.5
 months. For
 <i>Exp 2: strain effects</i>, weights and fork lengths of 15
 fish from each family, selected at random, were measured at ponding (March
 30, 2015) and 30 fish from each family, selected at random, were measured
 1.5 months after ponding (May 21, 2015). All fish from each family were
 measured 3.5 months after ponding (July 14, 2015) at which time 20 fish
 from each family were tagged using passive integrated transponder (PIT)
 tags for individual identification. PIT tagged fish were combined and
 moved to larger tanks (19,900L) where they were maintained at densities
 below 16g/m<sup>3</sup>. All fish were measured again at 6.5
 months post ponding (October 17, 2015) at which time they were transferred
 to a saltwater mesocosm tank (350,000L) within the same facility.
 Subsequent samplings occurred 9.5 months (January 19, 2016), 12.5 months
 (April 19, 2016) and 15.5 months (July 13, 2016) after initial ponding. 
 At the time of PIT tagging it was noted that, due to high densities for
 some families in the smaller tanks up until that point, there was a
 relationship between the number of fish in the family and the average size
 of the fish in that family (i.e. fish from families that maintained close
 to the 50 fish that were ponded were smaller than those from families that
 had fewer fish due to mortalities since ponding). For <i>Exp 3:
 transgenotype</i>, fish were measured 1.5 months after ponding (May
 13, 2016) and 2.5 months after ponding (June 18, 2016); at both time
 points 30 fish were sampled at random from each family and weights (g) and
 lengths (cm) were measured. All sampled fish were tested for the presence
 of the transgene using a transgene-specific qPCR test (Fitzpatrick et al.
 2011). At each sampling period, approximately 15 transgenic and 15
 non-transgenic fish were sampled from each family. Sire and offspring weights and
 length are reported here.
description: Table 1 contains size data
 for sires from each experiment. MaleID can be used to match males with
 offspring in other tables from this dataset. Table 2 contains ffspring weights
 (g) and lengths (cm) from Exp 1: sire effects collected on 3 sampling
 dates. There are two replicates (Group A or B) for each sire.
 Table 3 contains size data
 for Exp 2: strain effects. Offspring weights (g) and lengths (cm)
 collected over 7 sample dates. River of sire origin is given along with
 the sire ID for each family. Table 4 contains ize data for Exp
 3: transgenotype. Offspring weights (g) and lengths (cm) were collected on
 2 sample dates. River of sire origin is given along with the sire ID for
 each family. Genotype indicates if offspring were transgenic (T) or
 non-transgenic (NT). Table 5 contains the density of
 fish in tanks held as part of Exp 2: strain effects. Density refers to the
 number of fish in each tank prior sampling in July 2015 (max
 50).