Abstract Dr. B. Finley
Title Developmental programs robust to niche and scale: examples from primate vision
The eye, with its multiple and multi-level requirements for adaptive function, has long been a defining problem for evolutionary biology. The scale and niche variations of New World monkeys offer the opportunity to compare mature visual system variation to the organizational properties of the developmental mechanisms that produce them. We have collected a number of measures of retinal cell number and conformation for five diurnal species of New World monkeys, including Saguinus midas niger, Callicebus moloch, Saimiri sciureus, Alouatta caraya and Cebus apella, and one nocturnal monkey, Aotus azarae. In diurnal monkeys, eye size, rod, cone and retinal ganglion cell numbers scale with brain size, but rod number increases at a much greater slope. A conserved order of retinal neurogenesis (cones first, rods last) may automatically produce relatively greater proliferation of rods in larger eyes, serving the separate adaptive requirements of cones and rods to maintain acuity and sensitivity respectively.
Compared to diurnal monkeys, owl monkeys have fewer cones and ganglion cells but
many more rods, and consequently greater photoreceptor convergence. The same
order of neurogenesis that automatically adapts rod and cone numbers to eye size
may also permit a coordinated alteration of proliferation for nocturnality and
diurnality produced by shifting the onset and termination of cell proliferation
with respect to the schedule of cell specification.
Updated 08/24/2006
The Arkansas INBRE is Supported by a grant from the
National Institutes of Health
and the
National Center
for Research Resources (P20 RR-16460).
Please contact Caroline Miller Robinson regarding questions or comments about this site or our program. For more information about the University of Arkansas for Medical Sciences visit http://www.uams.edu.
