Exam 18: Development of the Ears and Eyes

What are the key protein constituent(s) of the lens?

The prosensory region in the saccule forms which structure(s)?

During retinal differentiation,the various cell types differentiate in sequence.Which cell type is the last to be born?

Which growth factor signaling pathway initiates retinal differentiation in the fovea?

Branchio-oto-renal syndrome,characterized by kidney and hearing defects,is due to mutation of which gene?

The number of hair and supporting cells in the inner ear is determined by which signaling pathway?

Mutations in the gene encoding the FOXC2 transcription factor would be expected to cause which anomaly?

Which signaling pathway controls the orientation and arrangement of the stereocilia on the inner hair cells?

Protanopes lack which cell type?

Development of the sensory regions of the inner ear involves the formation of hair cells and supporting cells by the process of lateral inhibition controlled by Notch signaling.How would overexpression of the transcription factors Hes1 and 5,which are modulated by Notch signaling,be expected to affect the number of hair cells or supporting cells?

Which is the most frequent genetic syndrome that affects the retina?

The inner ear arises from which structure?

Coloboma results from failure of which development event?

Researchers have shown that the various regions of the developing eye are specified by different transcription factors whose expression is induced by the adjacent tissues.Which region of the eye requires the transcription factor Chx10?

Microtia/anotia can be associated with other birth defects as a component of a syndrome.What percentage of children with microtia/anotia would be expected to have additional congenital abnormalities?

Hereditary deafness can result from mutations in many genes.Which gene is mutated most frequently in nonsyndromic congenital deafness?

Researchers have shown that the various regions of the developing eye are specified by different transcription factors whose expression is induced by the adjacent tissues.Chx10 is one such factor that is required for the development of the neural retina.What growth factor regulates its expression?

The cristae detect which modality?

Would mutation in genes that encode cytoskeletal components such as ACTIN,ESPSIN,and HARMONIN be expected to result in sensorineural or conductive hearing loss?

Goldenhar syndrome is characterized by a spectrum of defects.What eye abnormality is the cardinal finding of this syndrome?