Question

State two methods to visualize where a gene is expressed in an embryo and describe how they work with drawing. This method uses a whole embryo (or sections) as a specimen. Do not use any reporter genes.

Subject: Developmental Biology

Answer 1

Gene expression of a gene can be studied by various method

1. Gene expression by RT-PCR

a. To study gene expression in the embryo, embryo tissue is removed and stored in triazole. Extract RNA from the tissue and prepared complementary DNA by process of reverse transcription. This is done by Reverse transcription PCR.

b. After preparation of complementary DNA, primers for specific gene should be designed and Real-time PCR should be performed. This will give us the information of upregulation or downregulation of gene by different drugs. This method can use a whole embryo or specific section to study.

2. Gene expression by Immunohistochemistry

a. Another method such as Immunohistochemistry can also be used to determine gene regulation. The embryo tissue sample is fixed by formalin fixation and later tissue blocks are prepared using paraffin. Sections of the tissue blocks are taken and IHC is performed.

b.Immunohistochemistry is a process of selectively identifying antigens (proteins) in cells of a tissue section by applying the principle of antibodies binding specifically to antigens in biological tissues. This method uses tissue sections.

3.Gene expression by western blotting

a. To study gene expression in the embryo, embryo tissue is removed and treated with collagenase to form a tissue suspension.

b. Protein is isolated from a tissue sample and western blotting is carried out. Western blotting method to dentify and locate specific proteins in a sample of tissue based on their ability to bind to specific antibodies.