Intact feto-placental growth in microRNA-210 deficient mice.

MicroRNA-210 (miR-210) has been implicated in homeostatic adaptation during hypoxia. We hypothesized that miR-210 deficiency impacts feto-placental growth. As expected, mir-210 knockout (ko) mice exhibited markedly reduced placental miR-210 expression, compared to wild-type (wt) mice. Mating of mir-210 heterozygotes resulted in near Mendelian progeny distribution, with insignificant differences between wt and ko animals with regard to embryo or placental weight and gross morphology. Intriguingly, exposure of mice to non-severe hypoxia (O2  = 12%) between E11.5-E17.5 reduced placental miR-210 expression, with slight expression changes of some miR-210 target mRNAs. Thus, miR-210 is likely dispensable for feto-placental growth in normoxia or non-severe hypoxia.