The Modification of the Endocrine System of Domestic Animals

Manipulation of the endocrine status of domestic animals was an obvious early target for transgenesis following the pioneering research of Palmiter et al. (6,7) in laboratory mice and, as a consequence, has received considerable attention over the past few years. The results have been reviewed in detail several times in recent years (13-18), so in this section, only the overall conclusions from the work will be summarized, together with some evaluation of the commercial potential of the...

Loss of Function Experiments

Techniques are now available by which specific cell types can be ablated in transgenic animals. This powerful tool has been developed through the use of cytotoxic genes such as the A subunit of diphtheria toxin (DT-A) or ricin, which may be linked in transgene constructs to cell-specific regulatory elements (24,25). Cells expressing such constructs in transgenics are killed. Although the possibilities of this tech nique are exciting, a number of problems may limit its application in studies of...

Future Uses of Transgenic Fish

Fish are good candidates for transgenic studies. It now seems clear that our knowledge of fish genes and fish gene regulation will rapidly advance with the increased use of fish gene libraries and trans- genie induction with sequences derived from them. It also seems probable that, in the near future, transgenic fish with improved disease resistance, delayed sexual maturity, or increased growth rate will make a significant and valuable contribution to commercial aquaculture. Rainbow Trout These...

Injection of Zebra Fish Eggs

1 Fill the microinjection pipet with DNA solution see Section 2. . Place the pipet tip into about 50 pL of DNA solution on wax paper, and suck up into the pipet using the suction of a 6-mL syringe. 2. Inject the DNA using a continuously flowing pipet maintained with air pressure by an electrically driven automatic microinjector Fig. 3 , which maintains the pressure while injection is conducted. Precalibrate the amount injected by counting the number of seconds that the needle stays in the egg...