Question

One of the gene variants in the globin family is for myoglobin. While hemoglobin is produced by red blood cells, myoglobin is produced by muscle cells and doesn't circulate. It's function is to store O2 in order to maintain homeostasis of muscle cells, with respect to oxygen Genetic equivelancy holds that all cells in an organism have all the genes needed. regardless of differentiation into cell type. Which of the following best describes why red blood cells don't produce myoglobin, even though they have the gene to do so?
a. None of these answers are correct
b. Chromatin remodeling
c. Alternative splicing
d. RNA interferance
e. Post-transcriptional control

Answer 1

Answer:

b. Chromatin remodeling

Explanation:

During initial stages in RBCs, the myoglobin gene expression is restricted through chromatin remodeling. Chromatin remodelers which belong to CHD family are involved in chromosome condensation which mask the euchromatin portion of chromosomes containing genes for myoglobin expression with the help of histone proteins. This leads to the masking of genes of myoglobin genes in RBCs and their expression does not take place.  

Note: Mature red blood cells (RBCs) are dead cells and their only function is to transport the oxygen and nutrients to various body parts so they don't need to express any other gene than hemoglobin. RBCs become dead during later stages of their maturation, at that time their entire nucleus is degenerated but before doing that RBCs synthesize enough copies of hemoglobin gene product. This process is known as gene diminution.