Monster Seminar Jam - Are Fish Swimbladders Modified Lungs?
Dr. Amy McCune, Professor and Chair, Department of Ecology and Evolutionary Biology, Cornell University
Early anatomical studies indicated that the gasbladders of ray-finned fishes are evolutionary modifications of lungs of bony vertebrates. We are examining the predictions of this hypothesized transition through studies of gene expression and modern imaging techniques. One prediction of the lung-to-gasbladder transition is that the same genes deployed during the early development of mouse lungs would also be involved in the early development of the zebrafish gasbladder. Our studies show this is the case, although the relative timing of gene expression differs during mouse lung development and zebrafish gasbladder development. We are also using modern micro-CT imaging techniques to examine comparatively, the gross morphology of lungs and gasbladders. A previously unresolved anatomical prediction is that the vascular patterning associated with swimbladders would be the same as that for lungs. Increased acuity stemming from micro-CT studies of barium-injected vasculature have revealed vestigial vessels, not previously recognized, and confirm the similarity of the vasculature supplying both gas bladders and lungs.
Date and Time:
October 20, 2011,
10:30 am - 1:00 pm