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 are a normal part of puberty for most girls and guys. When a person grows or gains weight really quickly (like during puberty), that person may get fine lines on the body called stretch marks. Stretch marks happen when the skin is pulled by rapid growth or stretching. Although the skin is usually fairly elastic, when it's overstretched, the normal production of collagen (the major protein that makes up the connective tissue in your skin) is disrupted. As a result, scars called stretch marks may form. If you're noticing stretch marks on your body, you're not alone. Most girls and women have them, usually on their breasts, thighs, hips, and butt. Many women get them during pregnancy. Stretch marks are more common in girls, but guys can get them, too. People who are obese often have stretch marks.