THE UNIVERSITY OF CALGARY

FACULTY OF SCIENCE

FINAL EXAMINATION

BIOLOGY 403

April, 1993 TIME: 2 hours

TOTAL POINTS: 100

(VALUE) QUESTION

(20) 1. When Drosophila females are homozygous for the mutant gene eggnog (egn), cellularization of the blastoderm does not occur in their progeny. However, all progeny of a mating between egn+/egn- males and egn+/egn- females cleave normally. A transgenic Drosophila strain was produced in which the 100 nucleotides upstream of egn+ were fused to the luciferase reporter gene. What experiments would you perform to identify the trans-acting factors that regulate transcription of egn+?

(20 ) 2. Discuss the roles of the pair-rule genes in patterning of the Drosophila embryo. Identify the genes involved and discuss their individual roles in as much detail as you can. Cite experimental evidence where relevant.

(60) 3. Reconstruct the series of events beginning with oogenesis that leads to muscle cell determination and differentiation in mesoderm of Xenopus. Be complete. If in doubt, include all regulatory events that might bear upon development of muscle in this organism.