Subcortical Maternal Complex in Female Infertility: A Transition from Animal Models to Human Studies

Female infertility is a significant healthcare burden that is frequently encountered among couples globally. While environmental factors, comorbidities, and lifestyle determine reproductive health, certain genetic variants in key reproductive genes can potentially cause unsuccessful pregnancies. Such crucial proteins have been identified within the subcortical maternal complex (SCMC) and play an integral role in the early stages of embryogenesis before embryo implantation. SCMC proteins are associated with crucial pathways during embryogenesis, causing changes that are necessary for the transition of an oocyte to an embryo. These vital processes include the formation of cytoplasmic spindles and lattices, accurate positioning of meiotic spindles, regulatory roles in various gene translations, organelle redistribution, and zygotic genome reprogramming. While these genes are well studied in animal models, often mice, translation to clinical studies is comparatively less. The present study elucidates the transition in genetic studies from animal to human models of SCMC proteins. The present literature review shows that the expression of various SCMC proteins impairs embryo development at different stages. The clinical translation of SCMC occurs via various pathways. Therefore, females experiencing multiple unsuccessful pregnancies after natural or assisted conception techniques are candidates for underlying SCMC mutations. Although the phenotype of affected individuals has been identified, the molecular mechanisms that lead to impaired pathways still require investigation. Therefore, the present study paves the way for future research leading to the early diagnosis of lethal variants and possible subsequent management.