Improving the Quality of Oocytes with the Help of Nucleolotransfer Therapy.

Michal Benc,Florina Popovska Percinic,Frantisek Strejcek,Jozef Laurincik,Matej Murin,Ahmed Gad,Amelie Bonnet-Garnier,Alexandra Bartkova,Martin Morovic

doi:10.3390/ph14040328

Abstract

The nucleolus is an important nucleus sub-organelle found in almost all eukaryotic cells. On the one hand, it is known as a differentiated active site of ribosome biogenesis in somatic cells, but on the other hand, in fully grown oocytes, zygotes, and early embryos (up to the major embryonic genome activation), it is in the form of a particular homogenous and compact structure called a fibrillar sphere. Nowadays, thanks to recent studies, we know many important functions of this, no doubt, interesting membraneless nucleus sub-organelle involved in oocyte maturation, embryonic genome activation, rRNA synthesis, etc. However, many questions are still unexplained and remain a mystery. Our aim is to create a comprehensive overview of the recent knowledge on the fibrillar sphere and envision how this knowledge could be utilized in further research in the field of biotechnology and nucleolotransfer therapy.

Highlights

Nucleoli in somatic and stem cells, and in growing oocytes and early embryos after the major genome activation, have a typical structure composed of fibrillar centres, dense fibrillar components, and granular components [1,2]
The fibrillar sphere is first visible in the germinal vesicle (GV) stage, and disappears during the progress of oocyte maturation
Since the discovery of enucleolation, a new era has begun in terms of understanding the various new functions of this structure, which strengthen its role in early embryonic development

Summary

Introduction

Nucleoli in somatic and stem cells, and in growing oocytes and early embryos after the major genome activation, have a typical structure composed of fibrillar centres, dense fibrillar components, and granular components [1,2]. These differentiated nucleoli are involved in many cell processes, i.e., ribosomal RNA synthesis [3], chromosome segregation, cell cycle regulation, and many others [4,5]. It can be said that NLBs and NPBs are very similar in many ways This opinion is supported by studies with NLB transfer, when a previously enucleolated oocyte was unable to re-build NPBs in PNs [13]. It is appropriate to note that many functions are still unknown, and could be studied with the help of proteomic and transcriptomic profiling or with functional nucleolotransfer studies

Fibrillar Sphere Handling

Key Findings

Conclusions