• BM-MSCs enhance oocyte survival and promote follicle growth in reconstituted ovaries.
• BM-MSCs do not contribute to follicle formation or proliferate, but localize around growing follicles.
• BM-MSCs may direct theca cell differentiation, as indicated by CYP17a1 co-staining.
• Artificial ovary with BM-MSCs supports normal folliculogenesis and oocyte maturation after transplantation.