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bioRxiv · 10.1101/2023.02.18.529081

Maturation and Refinement of the Maculae and Foveae in the Anolis sagrei lizard

Wahle, M. A.·Kim, H. Q.·Menke, D. B.·Lauderdale, J. D.·Rasys, A. M.
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Abstract

In primates, the fovea is a pit in the center of the macula, which is a region of the retina with a high concentration of cone photoreceptor cells that accounts for a large degree of visual acuity in primates. The maturation of this primate visual acuity area is characterized by the shallowing and widening of the foveal pit, a decrease in the diameter of the rod-free zone, and packing of photoreceptor cells more densely into this area of the retina, which occurs sometime after birth. Maturation occurs concurrently with progressing age and development, which further correlates with increasing eye size, retinal length, and retinal area. These observations have led to the hypothesis that the maturation of the fovea might be a function of mechanical variables that remodel the retina. However, this has never been explored outside of primates. Here, we take advantage of the Anolis sagrei lizard, which has a bifoveated retina, to study maturation of the fovea and macula. Eyes were collected from male and female lizards from five different age groups - hatchling, 2-month, 4-month, 6-month, and adult. We found that Anolis maculae undergo a maturation process somewhat different than what has been observed in primates. Anole macular diameters actually increase in size and undergo minimal photoreceptor cell packing, possessing a near complete complement of these cells at the time of hatching. As the anole eye expands, foveal centers experience little change in overall retina cell density with most cell redistribution occurring at the macular borders and peripheral retina areas. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/529081v1_ufig1.gif" ALT="Figure 1"> View larger version (73K): org.highwire.dtl.DTLVardef@effd8dorg.highwire.dtl.DTLVardef@1ef65b3org.highwire.dtl.DTLVardef@1fde14dorg.highwire.dtl.DTLVardef@d2c0b2_HPS_FORMAT_FIGEXP M_FIG C_FIG Highlights- Foveal and retinal refinement occurs post-hatching into adulthood in anoles. - The temporal pit shallows and widens, whereas central pit morphology remains relatively constant with age. - Retina cell number within a section decreases as the eye grows larger with age. - Anole macular diameter increases from hatching to adult but does not increase proportionately to overall eye growth.

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Wahle, M. A., Kim, H. Q., Menke, D. B., Lauderdale, J. D., Rasys, A. M.. 2023-02-19. Maturation and Refinement of the Maculae and Foveae in the Anolis sagrei lizard. https://doi.org/10.1101/2023.02.18.529081

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