To analyze:
The activity of RNA polymerase II is inhibited by Actinomycin D. When actinomycin D is present, early development in many vertebrate species, for example frogs, can begin after the formation of a blastula (hollow ball of cells that forms after early cleavage divisions), but development stops before gastrulation. Question asked to discuss the activity of maternal gene in contrast to activity of zygotic gene in early frog development.
Introduction:
Drosophila is the model organism of study of development. It is a well studied genome sequence. Multiple genes are involved in the development of drosophila. The gene that directs the development and fate of an organism are known as developmental genes. Bicoid and Nanos are maternal effect genes; the egg receives these from the mother. Bicoid and Nanos play an important role in creating the anterior to posterior axis. The genes are activated in the fertilized egg (Zygote). In contrast to maternal effect genes, these genes are transcribed by zygotic DNA.
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Genetic Analysis: An Integrated Approach (3rd Edition)
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- In the sea urchin, early development may occur even in the presence of actinomycin D, which inhibits RNA synthesis. However, if actinomycin D is present early in development but is removed a few hours later, all development stops. In fact, if actinomycin D is present only between the sixth and eleventh hours of development, events that normally occur at the fifteenth hour are arrested. What conclusions can be drawn concerning the role of gene transcription between hours 6 and 15?arrow_forwardAntibiotics such as chloramphenicol, tetracycline, and erythromycin inhibit protein synthesis in bacteria, but have no effect on the synthesis of proteins encoded by eukaryotic nuclear genes. Cycloheximide inhibits the synthesis of proteins encoded by nuclear genes, but has no effect on bacterial protein synthesis. How might these compounds be used to determine which proteins are encoded by mitochondrial and chloroplast genomes?arrow_forwardAnother way to study the role of proteins (e.g., transcription factors) that function in development is to microinject the mRNA that encodes a protein, or the purified protein itself, into an oocyte or embryo, and then determine how this affects the subsequent development of the embryo, larva, and adult. For example, if Bicoid protein is injected into the posterior region of an oocyte, the resulting embryo will develop into a larva that has anterior structures at both ends. Based on your understanding of the function of each developmental gene, what would be the predicted phenotype if the following proteins or mRNAs were injected into normal oocytes? A. Nanos mRNA injected into the anterior end of an oocyte B. Antp protein injected into the posterior end of an embryo C. Toll mRNA injected into the dorsal side of an early embryoarrow_forward
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