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.
IN THIS ARTICLE. Stretch Marks Signs and Symptoms. Stretch marks do not generally produce any symptoms but have a characteristic visual appearance no matter when they appear or what the cause. They initially appear as raised pink to purple lines longitudinally arranged over the abdomen, lateral upper thighs, inner arms, or upper breasts.