Proteomic Analyses of Songbird (Zebra Finch; Taeniopygia Guttata) Retina

Abstract

Purpose:: To identify the total proteins in cone rich zebra finch (Taeniopygia guttata) retina and to confirm presence of select identified proteins. These studies will be useful for understanding age-related macular degeneration (AMD) in humans where cone rich region of retina or macula undergoes faster differential degeneration compared to relatively rod rich peripheral retina.

Methods:: Male zebra finch retina (n=16 eyes) were carefully dissected and proteins were extracted in Tris-Cl buffer containing 1% SDS or 0.1% genapol. Following 1D SDS-PAGE, gel bands were excised, digested in-situ with trypsin and proteins identified by capillary LC MS/MS. Western and analyses were performed with antibodies to Glutamine synthase, recoverin, Gbeta5 and ß-crystallin (research gifts from Drs. V. Slepak and A. Hackam). These studies were performed adhering to the ARVO Statement for the Use of Animals in Ophthalmic and Vision Research.

Results:: Mass spectrometry of zebra finch retinal proteins resulted in the identification of 129 proteins. Comparison of T. guttata retinal proteome with that of chicken found proteins detected in both retinas. Immunohistochemical analyses of T. guttata retinal sections and Western analyses of total retinal protein extract were performed confirming presence of select bona fide retinal proteins.

Conclusions:: Understanding cone rich retinal proteome in zebra finches will provide insight into the etiology of AMD. The results will also be useful for future proteomic comparison of zebra finch retina and brain tissues in different behavioral and pharmacological studies.

Keywords: proteomics • retina • immunohistochemistry