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. MATER-protein specific binding agents, such as antibodies, are described. Methods are described for detecting MATER protein in a subject, including methods for determining whether a subject has a biological condition associated with abnormal Mater expression. Also provided are kits for detecting MATER protein in a subject.