Exam 1: PNB 3252

Research on which animal does NOT (currently) require prior approval of an IACUC application?

Fly

What is the common pathophysiological attribute underlying many neuorological disorders (diseases which can be studied in nematodes)?  

Aggregated of misfolded Proteins

What changes would decrease serotonin (5-HT) signaling between neurons?

• decrease in serotonin synthesis

• faulty transport and docking of synaptic vesicles

• decrease of serotonin receptors in the post-synaptic neuron 

• increase in activity of serotonin reuptake transporters

What would be the most reasonable order of model species to experiment on when testing the efficacy of novel compounds for a potential cancer therapy?

1. Baker's Yeast (Saccharomyces cerevisiae)

2. Nematode (Caenorhabditis elegans)

3. Zebrafish (Danio rerio)

4. Rat (Rattus norvegicus)

The "3 R's" of animal research stand for...

Replacement, Reduction, and Refinement.

Chronologically arrange the life stages of a synchronized C. elegans cohort that was food-deprived post-hatching until the researchers returned to feed their worms three months later.

Gastrula, Egg, L1, L2d, Dauer, L4, Young Adult

Chronologically order the events that occur when cells experience and respond to hypertonic stress, as studied in C. elegans.

1. Cell volume shrinkage

2. electrolyte uptake and cell volume increase

3. osmolyte replacement

4. DNA and protein repair

Which molecular tool can reveal upregulation and localization of a specified gene product in a living worm?

GFP reporter assay

What is a limitation in working with the sea urchin as a model system?

Because sea urchins take years to mature, most researchers must collect adults from wild populations. 

What animals can regenerate its head following amputation and can create clones of itself from tail fission?

Planaria

What happens to 131 cells during the development of a C. elegans hermaphrodite into adulthood?

They undergo apoptosis.

What is the sex of a fruit fly that has diploid cells containing XXY sex chromosomes?

female: the ratio of X chromosomes to autosomal sets is 1.0 (or greater)

What are the life history and molecular effects that would be hypothesized for a high-sugar diet in an experiment testing caloric excess in Drosophila?

• TOR is activated

• FOXO is inhibited

• onset of type 2 diabetes like synptoms (insulin resistance)

• shorter lifespan

• higher fecundity

True or false: fruit flies that cannot express timeless lack circadian rhythm

True

How do Cycle (CYC) and Clock (CLK) work together?

they dimerize and form a transcription complex that transcribes period and timeless (mostly during early evening into nightfall).

Chronologically order (1-6) the hierarchical activation of the following regulatory gene groups involved in developing anterior-posterior axis polarity during embryonic development in Drosophila (and in other animals).

1. Maternal Factors

2. Zygotic Genes

3. Gap Genes

4. Pair-rule genes

5. Segment polarity genes

6. homeotic (hox) genes

Maternal Factors

The initial group of genes that are deposited in the egg by the mother, influencing early embryonic development and establishing body axes.

zygotic genes

the first genes expressed from the embryo's own genome after fertilization. They are activated in response to the maternal factor gradients.

gap genes

Genes that define broad segments of the embryo and activate pair-rule genes. They respond to maternal and zygotic regulatory signals.

pair-rule genes

genes that regulate the segmentation of the embryo by establishing alternating bands of expression, crucial for the formation of segments.

segment polarity genes

genes that refine segment boundaries and determine the anterior-posterior characteristics of each segment in the embryo.

homeotic genes

genes that specify the identity of body segments and structures in the developing embryo, ensuring that each segment develops into the appropriate anatomical structures.

Why is Drosophila melanogaster a relevant model of substance abuse disorders? 

• Several fly genes responsible for level of ethanol sensitivity have human orthologs.

• The fruit fly also has neuropeptides secreted by brain cells that influence preference behaviors.

• The fruit fly has a homologous circadian clock, which can be manipulated to investigate changes in physiological responses to drugs.

In a single-locus homology-directed repair (HDR), CRISPR/Cas9 machinery makes ___ breaks in the dsDNA at the target site.

two

Which protein or organelle assists in re-folding denatured proteins?

Heat Shock Proteins / Chaperonins

Which signaling pathway does RAS GTPase activate?

the MAPK/ERK signaling pathway, which is crucial for cell division, differentiation, and survival.

True or false:The level of neuropeptide F (NPF) decreases when fruit flies drink ethanol from capillary tubes.

False.