Question

Tissue-specific microarray analysis facilitates the comparison of gene expression in different tissues. In order to prepare a sample for microarray analysis, messenger RNA (mRNA) is extracted from a particular tissue, reverse transcribed to generate complementary DNA (cDNA), and labeled with a fluorescent probe.

The microarray below shows comparison of gene expression in stomach and intestinal tissues. The cDNA from stomach tissue was labeled with red fluorescent probes, whereas the cDNA from the intestinal tissue was labeled with green fluorescent probes. Gene C is primarily expressed only in stomach tissue, whereas gene D is primarily expressed in intestinal tissues. Genes A and B are responsible for basic cellular functions and are equally expressed in stomach and intestinal tissues.

Match the spots on the microarray with the appropriate genes based on the information provided. If there are multiple possible answers for a particular gene, choose any of the possible options.

Genes

Answer 1

According to the given information

CDNA from tumor tissue is labelled with red flouroscence dye

Gene D - expressed in tumor tissue

cDNA from normal tissue is labelled with green flouroscence dye

Gene A - expressed in normal tissue

While gene B and C both are equally involved in functioning in tumor and normal tissue

Based on the information

All gene expressed in tumor tissue - show red flouroscence

Gene expressed in normal tissue - show green flouroscence

If a gene expressed in both tissue than mix color will produce that of yellow color

Red circle present - Gene D

Green circle - Gene A

Yellow circle - GeneB and c

Answer 2