Cryopreservation of gametes: history and current state of a question

Abstract

Development of reproductive medicine, namely, extracorporal fertilization, set the task of preservation and preserving of biological suitability of female and men's gametes for scientific community. Opening of a method of a vitrification showed its benefit before other methods of a cryopreservation and became the encouraging event in development of cryobank of gametes. In this work the history of emergence of a method of a cryopreservation is described; modern aspects of a cryopreservation of gametes; shortcomings and benefits of various techniques of selection of full-fledged gametes are reflected; some protocols of carrying out a cryo-preservation are provided; short characteristic of separately used cryoprotectors and their various combinations capable more effectively to protect the freezing objects from damage, than, each of cryoprotectors separately is given. It is noted that in modern literature special attention is paid to consideration of mechanisms of cryodamages and cryoprotection during the freezing and a vitrification. Characteristics of the changes happening in gametes after the procedure of freezing and thawing are discussed. Modern techniques of assessment of viability of gametes before and after a cryopreservation are given. It is shown that violation of compaction of chromatin and fragmentation of DNA in morphologically not changed spermiya has negative impact and on quality of embryos. The benefit of a structurally functional condition of oocytes of mammals at a cryopreservation of oocytes in structure is emphasized an oocyte-kumulyusnykh of complexes in comparison with the oocytes which ripened in the kultivatsionny environment.