Microarray analysis of retinal gene expression in Egr-1 knockout mice

Area of Science:

• Genetics and Molecular Biology
• Developmental Biology
• Ophthalmology

Background:

• Egr-1 knockout mice exhibit increased eye length and myopia by postnatal day 42.
• Understanding the genetic basis of this altered axial eye growth is critical.

Purpose of the Study:

• To identify genes responsible for enhanced axial eye growth in Egr-1 knockout mice.
• To analyze gene expression differences between knockout and wild-type mice at postnatal days 30 and 42 using microarray analysis.

Main Methods:

• Retinal RNA was isolated from Egr-1 knockout and wild-type mice at 30 and 42 days.
• Microarray analysis (Affymetrix GeneChip Mouse Genome 430 2.0) was performed, with differential expression defined by FC ≥ 1.5 and p < 0.05.
• Ten candidate genes were validated using semiquantitative real-time RT-PCR.

Main Results:

• 73 genes were differentially expressed at day 30 and 135 at day 42 in knockout mice compared to wild-types.
• Significant gene expression changes were also observed between the two ages in both genotypes.
• Four genes, Pcdhb9, Narf, Ogdh, and Selenbp1, were validated by RT-PCR, with Pcdhb9 being most consistently regulated.

Conclusions:

• Differential gene expression during postnatal development (days 30-42) in Egr-1 knockout mice provides insights into axial eye growth control.
• Pathway analysis suggests potential involvement of key regulators like VEGF and retinoic acid, despite unchanged mRNA levels.
• Identifying these genes and pathways may offer targets for pharmacological interventions to manage myopia.