Given the success of Volume I of this Research Topic, and how rapidly the subject area is evolving, we are pleased to announce the launch of The Fertilization Success from the Oocyte's Perspective, Volume II. The entire fertilization process is extremely delicate and precise. Normal fertilization involves the fusion of a capacitated and reacted sperm with an ovulated oocyte. During this process, several sperm go through the zona pellucida and attempt to fuse with the oocyte's plasma membrane (oolema), however, only one sperm will be accepted by the oocyte in most mammals.Contrary to a passive role, the oocyte has a very active participation in fertilization and preimplantatory embryo. First, the oocyte prepares both the nucleus and cytoplasm during their maturation. During nuclear maturation, genetic material is carefully split in the meiotic division; thus, any error in this division will be fatal for the embryo's life. During cytoplasmic maturation, all organelles are prepared for supporting fertilization and preimplantatory embryo development. For instance, mature and correctly located cortical granules are essential to avoid polyspermy during cortical reaction. Similarly, healthy mitochondria are indispensable for ensuring the cellular energy required for the oocyte and embryo metabolism.When all processes, known and unknown, involved in the oocyte biology occur normally, we define the female gamete as a “competent oocyte”, even in those species of mammals that have polyspermic fertilization such as pigs. Although today we have a lot of evidence to describe a good quality oocyte, the oocyte is still the “black box” of fertilization. An in-depth understanding of the mechanisms that define a competent oocyte is necessary considering that the oocyte is an essential part of the assisted reproductive techniques. In addition, finding molecular markers for oocyte selection is the main goal for assisted reproduction in humans and animals.This Research Topic aims to develop an integrative view of all mechanisms involved in oocyte maturation and oocyte fertilization such as meiotic maturation of oocytes (meiosis), cytoplasmic oocyte maturation (organelles and receptors maturation), in vivo and in vitro oocyte maturation, cumulus cells, monospermic and polyspermic fertilization, oocyte activation (physiological or parthenogenetic), calcium signaling, cell polarity establishment, and cortical reaction.Various article types, including Original Research and Reviews, are welcomed. More information on article types accepted by the journal can be found here.
Given the success of Volume I of this Research Topic, and how rapidly the subject area is evolving, we are pleased to announce the launch of The Fertilization Success from the Oocyte's Perspective, Volume II. The entire fertilization process is extremely delicate and precise. Normal fertilization involves the fusion of a capacitated and reacted sperm with an ovulated oocyte. During this process, several sperm go through the zona pellucida and attempt to fuse with the oocyte's plasma membrane (oolema), however, only one sperm will be accepted by the oocyte in most mammals.Contrary to a passive role, the oocyte has a very active participation in fertilization and preimplantatory embryo. First, the oocyte prepares both the nucleus and cytoplasm during their maturation. During nuclear maturation, genetic material is carefully split in the meiotic division; thus, any error in this division will be fatal for the embryo's life. During cytoplasmic maturation, all organelles are prepared for supporting fertilization and preimplantatory embryo development. For instance, mature and correctly located cortical granules are essential to avoid polyspermy during cortical reaction. Similarly, healthy mitochondria are indispensable for ensuring the cellular energy required for the oocyte and embryo metabolism.When all processes, known and unknown, involved in the oocyte biology occur normally, we define the female gamete as a “competent oocyte”, even in those species of mammals that have polyspermic fertilization such as pigs. Although today we have a lot of evidence to describe a good quality oocyte, the oocyte is still the “black box” of fertilization. An in-depth understanding of the mechanisms that define a competent oocyte is necessary considering that the oocyte is an essential part of the assisted reproductive techniques. In addition, finding molecular markers for oocyte selection is the main goal for assisted reproduction in humans and animals.This Research Topic aims to develop an integrative view of all mechanisms involved in oocyte maturation and oocyte fertilization such as meiotic maturation of oocytes (meiosis), cytoplasmic oocyte maturation (organelles and receptors maturation), in vivo and in vitro oocyte maturation, cumulus cells, monospermic and polyspermic fertilization, oocyte activation (physiological or parthenogenetic), calcium signaling, cell polarity establishment, and cortical reaction.Various article types, including Original Research and Reviews, are welcomed. More information on article types accepted by the journal can be found here.