RNAs are the direct products of genes, and these small RNAs can bind to other specific messenger RNA (mRNA) molecules and either increase or decrease their activity, for example by preventing an mRNA from producing a protein.
What causes stretch marks? Stretch marks are caused when the skin rapidly stretches as a result of sudden growth or weight gain. The stretching causes the middle layer of skin (dermis) to tear, allowing the deeper skin layers to show through, forming stretch marks. The dermis contains strong, inter-connected fibres that allow your skin to stretch as your body grows.
Stretch marks typically appear as bands of parallel lines on your skin. These lines are a different color and texture than your normal skin, and they range from purple to bright pink to light gray. When you touch stretch marks with your fingers, you might feel a slight ridge or indentation on your skin. Sometimes, stretch marks feel itchy or sore. These lines commonly appear during or after pregnancy or after a sudden change in your weight. They also tend to occur in adolescents who are rapidly growing. Stretch marks arenât dangerous, and they often disappear over time.