Human oocyte proteome and secretome

The proteome and secretome of human oocytes was studied by shotgun LCMSMS, starting from pools of 100 cells. Exploiting SP3, a novel technology for proteomic sample preparation using magnetic beads, we scaled down proteome analysis to single cells. Despite the low protein content of only ~100ng per cell, we consistently identified ~450 proteins from individual oocytes. When comparing proteomes of individual oocytes at the germinal vesicle (GV) and metaphase II (MII) stage by label-free quantification, we found several proteins preferentially expressed in matuare and immature cells. This study demonstrates that an innovative proteomics workflow facilitates analysis of single human oocytes to investigate human oocyte biology and pre-implantation development. The approach presented here paves the way for quantitative proteomics in other quantity-limited tissues and cell types.