ABSTRACT Understanding the mechanisms involved in the control of feed intake and regulation of energy balance has increased greatly in recent years, thanks in part to the discovery of leptin, an event that ushered in a renaissance in research in this field. Over the last 5 yr, several other neuropeptides that affect feed intake and energy balance have been discovered, including cocaine- and amphetamine-regulated transcript, melanin-concentrating hormone, orexin/hypocretin, and agouti-related protein. In addition, new roles have been defined for previously discovered factors, such as galanin and neuropeptide Y. These recent advances have been possible because of new technologies, including cloning, transgenics, genomics, and bioinformatics. For example, positional cloning techniques have been used to identify the genes for these peptides and factors and their receptors. Knowledge about specific transcription factor-binding motifs in promoter regions allows development of specific agents that alter gene expression. By using transgenic and cloning techniques, genes can be added or deleted, and transcription can be enhanced or suppressed to produce new animal models for studying interactions among factors. Over the next few years, the combination of microarray techniques and proteomics with sophisticated informatics tools will continue to provide fundamental insights into the complex physiological processes involved in feeding behavior and metabolism.
Implications
New technologies being developed in genomics and proteomics are bringing about revolutionary changes in animal agriculture. Genomic research is providing information necessary for better understanding the physiology of feed intake and growth regulation and for developing customized genetics. As much as 50% of the variation in important traits, such as control of feed intake, can be accounted for by specific combinations of genes. Once identified, transgenesis can be used to modify genes responsible for growth characteristics, and animals can be selected for specific niche markets for enhanced value capture. In the future, accepted and efficient means of introducing new genes associated with important traits will be used to greatly improve the efficiency of production. As the world faces increasing population growth pressures, these new technologies will be used to develop solutions to the problem of providing sufficient, nutritious, and safe food in environmentally sound ways.
Key Words: Feeding behavior, Transgenic Animals
© 2001, by the American Society of Animal Science. All rights reserved.
J. Anim. Sci. 2001. 79:E171-E179
| Search PubMed MEDLINE and PubMed are registered trademarks of the U.S. National Library of Medicine. |