Disclosed herein are novel nucleic acid and protein sequences that are essential to fertility. In particular, human Mater cDNA and protein sequences are provided. Functional MATER is required for female fertility; zygotes that arise from Mater null oocytes do not progress beyond the two-cell stage. Methods are described for using Mater molecules in diagnoses, prognosis, and treatment of infertility and reduced fertility. Also provided are methods for using MATER as a contraceptive agent. The disclosure also describes compounds involved in such methods, and the identification of such compounds.