The Assessment of Polyploidy on Cell Size, Auditory Morphology, and Tuning in Gray Treefrogs
Poster Number
20
Format
Poster Presentation
Faculty Mentor Name
Marcos Gridi-Papp
Faculty Mentor Department
Biological Sciences
Abstract/Artist Statement
Polyploidy, the acquisition of additional sets of chromosomes, often yields increased cell size. Such alterations may generate physiological changes that affect the fitness of the individuals. The gray treefrogs Hyla chrysoscelis and H. versicolor look identical, but the latter is tetraploid. A change in cell size could affect the tuning of the auditory system, but the calls and the hearing of these two species are tuned to the same frequencies. We are attempting to explain their tuning by using histological techniques to determine how polyploidy affected the sizes of erythrocytes and auditory cartilages. Tetraploid erythrocytes were larger (as shown in previous studies), but we found no significant difference in cartilaginous cells regardless of their involvement in hearing. Since the main element transmitting sound in the middle ear is highly cartilaginous, the lack of a change in cell size for cartilage explains the matched auditory tuning. We are also currently expanding the comparison by using serial sections to assess the auditory transducers (hair cells) and 3D models of the middle and inner ears to test alternative explanations for the lack of difference in auditory tuning. To quantify the differences in middle and inner ear structures, excised ears were embedded in paraffin blocks, then cut into thin sections. The histological sections were photographed and computerized, resulting in a 3D model and volume measurements of the middle ear structures and inner ear, which permit a more comprehensive assessment of structural differences between H. chrysoscelis and H. versicolor.
Location
DeRosa University Center, Ballroom
Start Date
26-4-2014 2:00 PM
End Date
26-4-2014 4:00 PM
The Assessment of Polyploidy on Cell Size, Auditory Morphology, and Tuning in Gray Treefrogs
DeRosa University Center, Ballroom
Polyploidy, the acquisition of additional sets of chromosomes, often yields increased cell size. Such alterations may generate physiological changes that affect the fitness of the individuals. The gray treefrogs Hyla chrysoscelis and H. versicolor look identical, but the latter is tetraploid. A change in cell size could affect the tuning of the auditory system, but the calls and the hearing of these two species are tuned to the same frequencies. We are attempting to explain their tuning by using histological techniques to determine how polyploidy affected the sizes of erythrocytes and auditory cartilages. Tetraploid erythrocytes were larger (as shown in previous studies), but we found no significant difference in cartilaginous cells regardless of their involvement in hearing. Since the main element transmitting sound in the middle ear is highly cartilaginous, the lack of a change in cell size for cartilage explains the matched auditory tuning. We are also currently expanding the comparison by using serial sections to assess the auditory transducers (hair cells) and 3D models of the middle and inner ears to test alternative explanations for the lack of difference in auditory tuning. To quantify the differences in middle and inner ear structures, excised ears were embedded in paraffin blocks, then cut into thin sections. The histological sections were photographed and computerized, resulting in a 3D model and volume measurements of the middle ear structures and inner ear, which permit a more comprehensive assessment of structural differences between H. chrysoscelis and H. versicolor.