ToxSci Advance Access originally published online on October 20, 2008
Toxicological Sciences 2009 107(1):281-292; doi:10.1093/toxsci/kfn215
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Age-Dependent Variability in Gene Expression in Male Fischer 344 Rat Retina
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* Department of Biostatistics, Carolina Environmental Bioinformatics Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
Neurotoxicology Division (MD-B105-05), National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27712
1 To whom correspondence should be addressed. Fax: (919) 541-4849. E-mail: royland.joyce{at}epa.gov.
Received July 29, 2008; accepted October 1, 2008
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Abstract |
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Recent evidence suggests that older adults may be a sensitive population with regard to environmental exposure to toxic compounds. One source of this sensitivity could be an enhanced variability in response. Studies on phenotypic differences have suggested that variation in response does increase with age. However, few reports address the question of variation in gene expression as an underlying cause for increased variability of phenotypic response in the aged. In this study, we utilized global analysis to compare variation in constitutive gene expression in the retinae of young (4 months), middle-aged (11 months), and aged (23 months) Fischer 344 rats. Three hundred and forty transcripts were identified in which variance in expression increased from 4 to 23 months of age, while only 12 transcripts were found for which it decreased. Functional roles for identified genes were clustered in basic biological categories including cell communication, function, metabolism, and response to stimuli. Our data suggest that population stochastically induced variability should be considered in assessing sensitivity due to old age.
Key Words: genomic variability; statistical analysis; retina; significance analysis of microarrays.
Disclaimer: The research described in this article has been reviewed by the National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, and approved for publication. Approval does not signify that the contents necessarily reflect the views and policies of the Agency nor does mention of trade names or commercial products constitute endorsement or recommendation for use.