Gestational diabetes occurs when a pregnant woman has high levels of blood sugar. Cells in the pancreas usually keep blood sugar levels normal, but hormones produced during pregnancy deactivate the cells. After pregnancy, hormone levels return to normal, and so do the pancreas cells. Is this an example of DNA or the environment controlling gene expression? Explain your answer

Gestational diabetes generally occurs in pregnant women. The sugar level in the bloodstream becomes little high than the normal range during pregnancy. But the glucose level returns to normal after child birth.

The pancreas secrets insulin which helps to lower the blood sugar level in the body. But during pregnancy, the placenta releases some of the hormones which dilutes the effect of insulin. This is known as insulin resistance. So now the pancreas secretes more of insulin to overcome this insulin resistance for the body. Now if a woman during pregnancy does secrete more insulin, the glucose level increases in the body and the woman develops gestational diabetes.

Gestational diabetes greatly depends upon obesity and the ethnicity of the women, but a definite genetic link has not been identified.

This it is a result of the environment control gene expression.