Genome variation in the trophoblast cell lifespan: Diploidy, polyteny, depolytenization, genome segregation  

作　　者：Tatiana G Zybina Eugenia V Zybina 

机构地区：[1]Laboratory of Cell Pathology,Institute of Cytology,Russian Academy of Sciences,194064 St.-Petersburg,Russian Federation

出　　处：《World Journal of Medical Genetics》2014年第4期77-93,共17页世界医学遗传学杂志

基　　金：Supported by The Program "Molecular and Cell Biology" of the Russian Academy of Sciences

摘　　要：The lifespan of mammalian trophoblast cells includes polyploidization, its degree and peculiarities are, probably, accounted for the characteristics of placenta development. The main ways of genome multiplication-endoreduplication and reduced mitosis-that basically differ by the extent of repression of mitotic events, play, most probably, different roles in the functionally different trophoblast cells in a variety of mammalian species. In the rodent placenta, highly polyploid(512-2048c) trophoblast giant cells(TGC) undergoing endoreduplication serve a barrier with semiallogenic maternal tissues whereas series of reduced mitoses allow to accumulate a great number of low-ploid junctional zone and labyrinth trophoblast cells. Endoreduplication of TGC comes to the end with formation of numerous low-ploid subcellular compartments that show some signs of viable cells though mitotically inactive; it makes impossible their ectopic proliferation inside maternal tissues. In distinct from rodent trophoblast, deviation from(2n)c in human and silver fox trophoblast suggests a possibility of aneuploidy and other chromosome changes(aberrations, etc.). It suggests that in mammalian species with lengthy period of pregnancy, polyploidy is accompanied by more diverse genome changes that may be useful to select a more specific response to stressful factors that may appear occasionally during months of intrauterine development.The lifespan of mammalian trophoblast cells includes polyploidization, its degree and peculiarities are, probably, accounted for the characteristics of placenta development. The main ways of genome multiplication-endoreduplication and reduced mitosisthat basically differ by the extent of repression of mitotic events, play, most probably, different roles in the functionally different trophoblast cells in a variety of mammalian species. In the rodent placenta, highly polyploid （512-2048c） trophoblast giant cells （TGC） undergoing endoredupli-cation serve a barrier with semiallogenic maternal tissues whereas series of reduced mitoses allow to accumulate a great number of low-ploid junctional zone and labyrinth trophoblast cells. Endoreduplication of TGC comes to the end with formation of numerous low-ploid subcellular compartments that show some signs of viable cells though mitotically inactive; it makes impossible their ectopic proliferation inside maternal tissues. In distinct from rodent trophoblast, deviation from （2n）c in human and silver fox trophoblast suggests a possibility of aneuploidy and other chromosome changes （aberra-tions, etc. ）. It suggests that in mammalian species with lengthy period of pregnancy, polyploidy is accompanied by more diverse genome changes that may be useful to select a more specific response to stressful factors that may appear occasionally during months of intrauterine development.

关 键 词：Cell cycle Endocycle POLYPLOIDY GENOME ANEUPLOIDY TROPHOBLAST Placenta 

分 类 号：R1[医药卫生—公共卫生与预防医学]