Morphological characteristics of early embryogenesis of human triploid embryos
Keywords:
in vitro fertilization, embryo, genetic diagnosis, diandra, diginiya, dispermy, triploidy.Abstract
In the programs of assisted reproductive technology (ART) is often possible to observe the appearance of triploid zygotes. There are three main mechanisms for the formation of triploid embryos: diandra, diginiya, dispermy. Morphokinetical and genetic features of triploid embryos are still unknown. The ontogenetic development path of these embryos can be different. It depends on mechanism of fertilization and potential of embryos. This article deals with the morphological characteristics of early embryogenesis of triploid embryos compared with diploid in ART programs.
To conduct these studies, 75 cycles of preimplantation genetic diagnosis were analyzed in 75 couples who had undergone various ART programs. Morphological characteristics of development of 183 triploid zygotes in in vitro conditions were studied and the following results were obtained: a comparative evaluation of oocyte fertilization in women of different age range showed a positive correlation between the frequency of abnormal fertilization and the age of women. In particular, a pronounced dependence of the frequency of formation of triploids was found depending on the age of the patients; The ontogenetic path of development of human triploid embryos does not differ from the early embryonic development of diploid embryos at the cleavage stage; The frequency of blastulation on the fifth day of embryo cultivation is significantly higher in the group of diploid human embryos.
References
2 Redline R.W., Hassold T., Zaragoza M.V. Prevalance of the partial molar phenotype in triploidy of maternal and paternal origin // Hum. Pathol. – 1998. – No. 29. – P. 505–511.
3 Lindor N.M., Ney J.A., Gaffey T.A., Jenkins R.B., Thibodeau S.N., Dewald G.W. A genetic review of complete and partial hydatidiform moles and nonmolar triploidy // Mayo. Clin. Proc. – 1992. – No. 67. – P. 791–799.
4 Austin C.R. Anomalies of fertilization leading to triploidy // J. Cell Comp. Physiol., 56 (Suppl. 1). – 1990. – P. 1–15.
5 Rosenbusch B., Schneider M. Predivision of chromosomes in human oocytes: a reappraisal of cytogenetic nomenclature // Cytogenet. Cell Genet. – 2000. – No. 89. – P. 189–191.
6 Munné S., Cohen J. Chromosome abnormalities in human embryos // Hum. Reprod. Update. – 1998. – Vol. 4, No. 6. – P. 842–855.
7 Ducibella T. The cortical reaction and development of activation competence in mammalian oocytes // Hum. Reprod. Update. – 1996. – Vol. 2, No. 1. – P. 29–42.
8 Wassarman P.M., Jovine L., Litscher E.S. A profile of fertilization in mammals // Nat. Cell Biol. – 2001. – No. 3. – P. 59–64.
9 Wassarman P.M., Qi H., Litscher E.S. Mutant female mice carrying a single mZP3 allele produce eggs with a thin zona pellucida, but reproduce normally // Proc. R. Soc. Biol. Sci. – 1997. – No. 264. – P. 323–328.
10 Kline J.T., Kline D. Regulation of intracellular calcium in the mouse egg: evidence for inositol triphosphate-induced calcium release, but not calcium-induced calcium release // Biol. Reprod. – 1994. – No. 50. – P. 193–203.
11 Dale B., DeFelice L., Ehrenstein G. Injection of a soluble sperm extract into sea urchin eggs triggers the cortical reaction // Experimential. – 1985. – Vol. 41, No. 8. – P. 1068–1070.
12 Stice S.L., Robl J.M. Activation of mammalian oocytes by a factor obtained by rabbit sperm // Mol. Reprod. Dev. – 1990. – Vol. 25, No. 3. – P. 272–280.
13 Swann K. A cytosolic sperm factor stimulates repetitive calcium increases and mimics fertilization in hamster eggs // Development. – 1990. – No. 110. – P. 1295–1302.
14 Kline D., Simoncini L., Mandel G. et al. Fertilization events induced by neurotransmitters after injection of mRNA in Xenopus eggs // Science. – 1998. – Vol. 241, No 4864. – P. 464–467.
15 Miyazaki S., Ito M. Calcium signals for egg activation in mammals // J Pharmacol Sci. – 2006. – No. 100. – P. 545–552.
16 Williams C.J., Schultz R.M., Kopf G.S. Role of G-proteins in mouse egg activation: stimulatory effects of acetylcholine on the ZP2 to ZP2f conversion and pronuclear formation in eggs expressing a functional m1 muscarinic receptor // Dev. Biol. – 1992. – Vol. 151, No. 1. – P. 288– 296.
17 Grossmann M., Calafell J.M., Brandy N., Vanrell J.A., Rubio C., Pellicer A., Egozcue J., Vidal F., Santaló J. Origin of tripronucleate zygotes after intracytoplasmic sperm injection // Hum. Reprod. – 1997. – No. 12. – P. 2762–2765.
18 Veeck L.L. An atlas of Human Gametes and Conceptuses // Parthenon Publishing Group. – 1999. – P. 150–157.
19 American Society for Reproductive Medicine. Definition of ‘‘infertility’’ // Fertil Steril. – 2006. – No. 86. – P. 228.
20 De Vos A., Van Steirteghem A. Aspects of biopsy procedures prior to preimplantation genetic diagnosis // Prenat. Diagn. – 2001. – No. 21. – P. 767–780.
