2.0 ADVANCES IN FISH GENETICS
Fish genetics has provides researchers with information on how best to improve, in the various areas of fisheries and in the studies of fish population advances in fish genetics are to be discussed below
It is defined as the introduction of exogenous gene/ DNA into host genome resulting in its stable maintenance, transmission and expression. The technology offers an excellent opportunity for modifying or improving the genetic traits of commercially important fishers, mollusks and crustaceans for aquaculture.This idea of producing transgenic animals became popular when palmitter et al. (1982), first produced transgenic mouse by introducing metallothionaum human growth hormone fusion gene (Mt-hGH) into mouse egg, resulting in dramatic increase in growth. This triggered a series of attemptson gene transfer in economically important animals including fish. The first transgenic fish was produced zhu et al. (1988) in china, who claimed the transient expression putative transgenic, although they gave no molecular evidence for the integration of the transgenics. The techniques has now been successfully applied to a number of fish species. Dramatic growth enhancement has been shown using this technique especially in salmonids (Devlin et al. 1994). The introduction of transgenic techniques has simultaneously put more emphasis on the need for production of sterile progeny in order to minimize the risk of transgenic stock mixing in the wild populations. Although significant progress has been made in several laboratories around the world, there are numerous problems to be resolved before the successful commercialization of the transgenic brood stock for aquaculture. To realize the full potential of the transgenic fish technology, several important scientific break through are required. These include;
- i. More efficient technological mass gene transfer.
- ii. Targeted gene transfer technologies such as embryonic stem cell gene transfer.
- iii. Suitable promoters to direct the expression of transgenic at optimal levels during the desired development stages.
- iv. Information on the physiological, nutritional, immunological and environmental factors that maximize the performance of the transgenics.
- v. Safely and environmental impact of transgenic fish.