Research article

Genetic determinants of hyaloid and retinal vasculature in zebrafish

Yolanda Alvarez¹ , Maria L Cederlund¹ , David C Cottell² , Brent R Bill³ , Stephen C Ekker³ , Jesus Torres-Vazquez⁴ , Brant M Weinstein⁵ , David R Hyde⁶ , Thomas S Vihtelic⁶ and Breandan N Kennedy¹

¹UCD School of Biomolecular, and Biomedical Sciences, University College Dublin, Dublin 4, Ireland

²Electron Microscopy Laboratory, UCD Conway Institute, University College Dublin, Dublin 4, Ireland

³Center for Transposon Research. Department of Genetics, Cell Biology and Development. University of Minnesota, Minneapolis, MN 55455, USA

⁴Skirball Institute of Biomolecular Medicine. New York University School of Medicine, New York, NY 10016, USA

⁵Laboratory of Molecular Genetics, NICHD, NIH, Building 6B, Room 309, 6 Center Drive, Bethesda, MD 20892, USA

⁶Center for Zebrafish Research. Department of Biological Sciences. University of Notre Dame, Notre Dame, IN 46556, USA

author email corresponding author email

BMC Developmental Biology 2007, 7:114doi:10.1186/1471-213X-7-114

Published:	15 October 2007

Abstract

Background

The retinal vasculature is a capillary network of blood vessels that nourishes the inner retina of most mammals. Developmental abnormalities or microvascular complications in the retinal vasculature result in severe human eye diseases that lead to blindness. To exploit the advantages of zebrafish for genetic, developmental and pharmacological studies of retinal vasculature, we characterised the intraocular vasculature in zebrafish.

Results

We show a detailed morphological and developmental analysis of the retinal blood supply in zebrafish. Similar to the transient hyaloid vasculature in mammalian embryos, vessels are first found attached to the zebrafish lens at 2.5 days post fertilisation. These vessels progressively lose contact with the lens and by 30 days post fertilisation adhere to the inner limiting membrane of the juvenile retina. Ultrastructure analysis shows these vessels to exhibit distinctive hallmarks of mammalian retinal vasculature. For example, smooth muscle actin-expressing pericytes are ensheathed by the basal lamina of the blood vessel, and vesicle vacuolar organelles (VVO), subcellular mediators of vessel-retinal nourishment, are present. Finally, we identify 9 genes with cell membrane, extracellular matrix and unknown identity that are necessary for zebrafish hyaloid and retinal vasculature development.

Conclusion

Zebrafish have a retinal blood supply with a characteristic developmental and adult morphology. Abnormalities of these intraocular vessels are easily observed, enabling application of genetic and chemical approaches in zebrafish to identify molecular regulators of hyaloid and retinal vasculature in development and disease.