Abstract
Purpose: :
Hyaluronan (HA) is known to be synthesized by three hyaluronan synthases (HAS–1, HAS–2 and HAS–3), which are distinct gene products. In our continuing analysis of the role of HA in the IPM, we have evaluated the distribution of HA in HAS–1 and HAS–3 single and double knockout mice.
Methods: :
HAS–1 and HAS–3 knockout lines were obtained from John McDonald, University of Utah. These were bred to generate homozygous HAS–1 (–/–), HAS–3 (–/–) and double knockout lines. Retinas were isolated from each line and rinsed prior to fixation in mixed aldehydes and prepared for microscopy and analysis of HA distribution using a biotynilated fragment of aggrecan which shows high specificity for HA binding in tissue sections.
Results: :
We observed HA in the IPM surrounding inner and outer segments of photoreceptors in virtually identical distribution as previously reported for the wild type distribution of HA in the IPM in each of the knockout combinations studied.
Conclusions: :
We conclude that neither HAS–1 or HAS–3 are involved in the synthesis of HA present in the IPM of the mouse. Further studies are focused on the cell specific knockout of HAS–2, a technology required for analysis of the role of HAS–2 since HAS–2 knockouts are embryonic lethal. Floxed HAS–2 mice are available and these studies are in progress.
Keywords: retina • immunohistochemistry • extracellular matrix