Question

A mouse model for type 1 diabetes, the NOD mouse, has a well-described sex bias in the incidence and rate of diabetes onset. Female NOD mice are about twofold more likely to become diabetic, and do so on average about six-weeks earlier than male NOD mice. Recent studies have shown that a large component of this sex bias is due to differences in the intestinal microbiota between male and female NOD mice. In fact, colonization of young female NOD mice with male microbiota reduced the incidence and time to onset of diabetes in the transplanted mice, resulting in a disease course resembling that of the typical male NOD mice. These data indicate that:

A.        Male mice are genetically resistant to type 1 diabetes.

B.        Sex-based differences in microbiota have a substantial impact on immune system regulation.

C.       Differences in microbiota between male and female mice affect the regulation of pancreatic insulin-producing cells.

D.       Environmental factors are more important than genetic factors in determining which individuals acquire an autoimmune disease.

E.        Antibiotic treatment to eliminate intestinal microbiota would be a useful treatment for most autoimmune diseases.

Answer 1

Type 1 diabetes is a condition in which your immune system destroys insulin-making cells in your pancreas.It is said in the above statements that the onset of diabetes is slower in males compared to the female mice not that they are genetically resistant to type 1 diabetes.From the above statements we cannot conclude that sex-based differences in microbiota have a "substantial impact" on immune system regulation.But it can be said that the differences in microbiota between male and female mice does indeed in some way affect the regulation of pancreatic insulin-producing cells (maybe due to some impacts on its immune system).There is no evidence that environmental factors are more important than genetic factors in determining which individuals acquire an autoimmune disease.Antibiotic treatment to eliminate intestinal microbiota might infact be harmful for the individual and not a useful treatment for most autoimmune diseases.Thus the correct statement according to the data is:

Option C: Differences in microbiota between male and female mice affect the regulation of pancreatic insulin-producing cells,