Abstract
Purpose: :
A transgenic rat line harboring CAG-EGFP (Chicken beta-actin promotor -Enhanced Green Fluorescent Protein) transgene (Japan SLC, Inc.) exhibited an abnormal early open eyelid (EOEL) at birth through normal breeding process. In this study, we established this EOEL sub-line in order to understand the genetic base of this mutation.
Methods: :
We regularly mate between EOEL and normal progeny in every generation of the EOEL rat strain. The eyelid phenotypes were examined in all progenies of first (F1), second (F2), and backcross generations with ACI/N, as normal rat strain. Histological studies were used to examine phenotypes in eyelid and cornea.
Results: :
In mating experiments, no EOEL rats appear out of 8 F1 progenies, 31 EOEL rats appear out of 135 F2 progenies, and 38 EOEL rats appear out of 83 backcross progenies. Therefore, EOEL gene is a single autosomal ressesive gene. All of 31 F2 EOEL progenies carry EGFP gene, suggesting that the putatitve "EOEL" gene is closely linked to EGFP transgene. By linkage analysis eoel gene is mapped on 10th chromosome. The eyelids of the EOEL rat never fused to each other throughout the embryonic development and the cornea is exposed at birth. At P10, this matter comes off and eyelids blinking are normal. The corneas of EOEL are associated with neovascularization. K12 protein was detected in the corneal epithelium of EOEL.
Conclusions: :
The putative EOEL gene is a single ressesive autosomal and mapped on 10th chromosome in rat. The EOEL rat could be a useful animal model for research on eyelid development and cornea with dry eye syndrome.
Keywords: development • eyelid • neovascularization