Abstract
Abstract: :
Purpose: To determine differential gene expression associated with cataract in the alphaA-crystallin knockout mouse. Methods: Oligonucleotide microarray analysis of 12,000 genes was performed on lens RNA from two separate litters of 11-day-old alphaA-crystallin knockout (αA-/-), alphaB-crystallin knockout (αB-/-), and wild type 129Sv mice. At this age, αA-/- mice have apparent nuclear opacities, which progress to nearly complete lens opacity by 10 weeks. Cataracts have not been observed in αB-/- mice. Hybridization signals from duplicate chips/samples were normalized, filtered, and data analyzed using Affymetrix microarray suite v5.0. RT-PCR was used for confirmation of the differential gene expression between knockout and control lenses. Results:Eighteen genes were consistently differentially expressed in αA-/- mice when compared to wild type mice. Seven genes were up regulated and 11 genes were down regulated. Confirmations, to date, show that carnitine palmitoyltransferase is down regulated 2-fold, while selenium-dependent glutathione peroxidase and protein disulphide isomerase (RIKEN cDNA 1700015E05) are up regulated 2-fold. Five genes (different than those from αA-/-) were differentially expressed in αB-/- mice compared to wild type. Conclusions:Microarray analysis indicates that both αA-/- and αB-/- mice have differences in gene expression patterns, when compared to wild type. The subset of genes found in αA-/-, which were unchanged in αB-/-, suggest their involvement in cataract formation. The down regulation of carnitine palmitoyltransferase, if reflected at the protein level, may indicate that ATP synthesis is reduced in the αA-/- mouse.
Keywords: cataract • crystallins • gene microarray