GM-CSF is not essential for optimal fertility or for weight control.

Independent studies with GM-CSF-/- mice have concluded that GM-CSF is necessary for normal reproductive outcome and for the maintenance of normal weight. In contrast to the literature we report that GM-CSF-/- and wild type (C57Bl/6) mice over a continuous 12 month period had similar litter size and neonatal survival. Likewise, unlike a literature observation, for the two mouse strains both male and female mice had similar weight gain when fed on a normal chow diet and monitored until 30 weeks of age. It is concluded that GM-CSF is not necessary for an optimal fertility outcome or for normal weight maintenance during development.