I have performed some pilot experiments in male and female C57BL/6 mice and think I might see differences based on sex of the mice. Does anyone know if sex plays a role in disease onset and/or severity as it does in humans?
Dear Dunja,
yes, there are minor differences, also described in the literature. They are, however, not as severe as they are in humans. Thus, if possible use only mice from one gender. For this, it does not matter which one, as long as you stay with the one. If not (e.g. due to rare genotypes) one can also use mixed groups provided the male/female ratio is about the same in the different observation groups.
Good luck with your experiements,
Fred
Why use male mice for anything? You end up with one or two dominant males in a cage that beat up the rest of the mice - loss of fur - stress, etc. So, males are inherently more variable than females who all just get along in a cage. Seems like an ancient no-brainer. And, surprised not know.
I would recommend using females over males - partly due to what Charles said above re: aggression, but also, if the EAE progresses to the severe end of the scale where the hind legs are paralyzed, you will have to express the bladders of the mice - this is easier in females, and you don't have to worry about the possibility of penile prolapse, and the males then dragging their extended penises through the bedding (which could lead to necrosis of the tissue, on top of likely urine scalding).