We performed RNAseq analysis to determine the effect of MFN1 deletion on oocyte global gene expression profile. RNAseq revealed a total of 982 genes were significantly differentially expressed (p<0.05) in Mfn1-/- oocytes compared to WT (654 up-regulated and 337 down-regulated). Pathway analysis indicated significant over-representation of elements involved in regulation of ceramide biosynthesis, death receptor signaling and adherens junction signaling. Differential expression of these genes (Bad, G2e3, Cdh17 and Myh2) was also confirmed by qRT-PCR.Our findings provide new insight into the role of MFN1 in the oocytes, and may help understand the potential mechanism of infertility and reproductive aging associated with MFN1-deficiency. Overall design: Secondary follicle-enclosed oocytes were collected from 8-week-old Mfn1-/- and WT mice (n=3 for each group) and 5 oocytes from each group were pooled for RNA sequencing analysis.