Neurological Effects of Fos B Gene on Behavior of Mice Essay -- Biolog

The purpose of this study is to gain an understanding of the fos B gene and it's neurological effects on the behavior of mice through the analysis of "A Defect in Nurturing in Mice Lacking the Immediate Early Gene fos B" appearing in the July 26 issue of Cell. Through various chemical and behavioral tests it is found that fos B mothers demonstrate an inability to nurture their young. It was shown that the lack of expression of the fos B gene in certain areas of the brain was the probable cause of the lack of the nurturing response in the mutant mice. Background Immediate Early Genes (IEGs) When the central nervous system of an organism receives a stimulus, such as light, visual images, odors, etc., programs of gene expression are initiated. This expression of genes can start within minutes of receipt of the stimulus, and last for many hours in certain parts of the brain. The very first genes to be expressed are called the Immediate Early Genes. These genes can be transcribed almost immediately without the formation of new proteins. fos B: A Member of the fos Family The fos B gene belongs to a group of genes known as the fos family. The fos family has four members: c-fos, fos B, fra-1, and fra-2. The members of the fos family work in conjunction with a group called the Jun family. The protein that is produced as a result of fos gene expression can be dimerized with Jun prodeits utilizing a leucine zipper domain. This unit then binds to a certain region of DNA. The fos family of genes are expressed during a variety of adaptive neural responses. It has been found that fos related proteins are activated in areas of the nervous system that are needed for nurturing behavior. Creating a fos B lacking Population In or... ...e results of these tests point to a defect in a region of the brain that is specific for nuturing. So, areas of the brain were fos B was expressed were analyzed. It was seen that the fos B gene was expressed in the preoptic area of the hypothalamus and in the main and accessory olfactory bulbs, as well as the pyriform cortex. All of these areas have been shown, in previous studies, to be related to the nuturing response. As a result, the lack of expression of the fos B gene is directly related to the lack of nuturing behavior in mutants, probably due to a lack of gene expression in one, or more of these areas. Bibliography 1. Brown, J.R., Ye, H., Bronson, R. T., Dikkes, P., Greenberg, M. E. "A Defect in Nurturing in Mice Lacking the Immediate Early Gene fosB." Cell 86 (1996): 297 - 309. 2. Cohen, John. "Does Nature Drive Nurture?" Science 273 (1996): 577