Through analysis of the infertile phenotype and its underlying mechanisms in female mice harboring either a missense point‐mutant allele or the oocyte‐specific knockout allele of Dpagt1 gene, the indispensable role of protein N‐glycosylation in ensuring the development of high‐quality oocytes competent to complete meiotic division and support embryogesis is revealed. The gene discussed is DPAGT1; the disease is Infertility.