Recent advances in assessing genetic variation: genetics & breeding

摘要

When one looks at the tremendous progress breeders of cattle, poultry, and other domesticated species have made over the centuries, and especially in recent decades, it becomes clear that most of the "improvement" to be made in cultured aquatic species still lies in the future. Modem aquaculture geneticists have a number of novel techniques and tools available to them that would have been inconceivable to animal, breeders just a few decades ago. Nonetheless, as was the case with cattle, poultry, hogs and other domesticated animals, the fundamental basis for genetic improvement in most aquatic species will be the amount of natural variation found in traits that impact performance under commercial production. Two basic areas of investigation in aquaculture genetics involve the determination of genetic variation and evaluating the relationship between genetic variation and performance in production systems. While good old fashioned animal breeding and performance evaluation may be overshadowed in many circles within modem aquaculture genetics, it still has its place. In fact, new approaches to this traditional line of investigation still continue to emerge. One example involves the development of new ways to measure genetic variation as it relatesto production performance, such as growth versus feed intake. Silverstein et al. (2001) examined the relationship between feed intake and growth in channel catfish (Ictalurus punctatus) and the underlying genetic variation in voluntary feed intake. In one experiment, 10 fish from each of 31 full-sib families were marked with passive integrated transponder tags, stocked into replicated tanks, and fed to satiation with feed that contained an X-ray opaque marker.