FIG. 1.

Oocyte-specific deletion of the Mgat1 gene coding exon. (A) Diagram of wild-type, floxed, and neo-disrupted alleles of the Mgat1 gene and the ZP3Cre transgene with locations of primers used for PCR genotyping. The Mgat1 and Cre recombinase coding exons are shaded, and the ZP3 promoter region is an open box. (B) PCR genotyping identified the various alleles. The intermediate band in +/F heterozygotes was due to hybrid formation during PCR. Lane M, 1-kb plus markers. (C) Mgat1 genotypes of females and their respective oocytes after deletion (Δ) of the Mgat1 gene by Cre recombinase. The Mgat1 gene deletion abolishes the synthesis of complex N-glycans so that mature glycoproteins express the oligomannosyl substrate (Man₅GlcNAc₂Asn) of GlcNAc-TI. ▪, GlcNAc; •, Man; ○, Gal; ▿, Fuc; and ⧫, sialic acid.