ROLE OF CHROMOSOMES IN EMBRYO DEVELOPMENT
Geraedts JPM*
*Corresponding Author: Professor Dr. Joep P.M. Geraedts, Department of Genetics and Cell Biology, University of Maastricht, P.O. Box 1475, 6201 BL Maastricht, The Netherlands; Tel.: +31-43-3875840; Fax: +31-43-3877877; E-mail: joep.geraedts@gen.unimaas.nl
page: 3

Abstract

Cytogenetic studies can be carried out on metaphase chromosomes or on interphase cells. Besides the classical techniques, many new methods, based on molecular ap­proaches, are now available. About one-third of oocytes are cytogenetically abnormal. This percentage increases with maternal age. Most abnormalities are caused by non disjunction, but premature centromere division at meiosis-I (M-I) has been suggested as an alternative mechanism.. In sperm cells about 7% show abnormalities. This percentage is higher in infertile males. About a third of morphologi­cally normal embryos are chromosomally abnormal at the cleavage stages. In human blastocysts chromosomal mosa­icism arises. During preimplantation development, the percentage of embryos showing chromosomal mosaicism increases to almost 100% at the blastocyst stage. The most common abnormality in miscarriage is trisomy. Trisomy 16 accounts for 30% of all trisomies. Trisomy for all chro­mosomes except chromosome 1 has been observed in spon­taneous abortions. Autosomal monosomies are practically unknown in human miscarriages, but monosomy X is a frequent finding. The abnormality most frequently result­ing from abnormal fertilization is triploidy.

 

Key words: Chromosome abnormalities, Preimplan­tation embryo development, Spontaneous abortion, Non disjunction.

 




Number 19
VOL. 19 (2), 2016
Number 19
VOL. 19 (1), 2016
Number 18
VOL. 18 (2), 2015
Number 18
VOL. 18 (1), 2015
Number 17
VOL. 17 (2), 2014
Number 17
VOL. 17 (1), 2014
Number 16
VOL. 16 (2), 2013
Number 16
VOL. 16 (1), 2013
Number 15
VOL. 15 (2), 2012
Number 15
VOL. 15, 2012 Supplement
Number 15
Vol. 15 (1), 2012
Number 14
14 - Vol. 14 (2), 2011
Number 14
The 9th Balkan Congress of Medical Genetics
Number 14
14 - Vol. 14 (1), 2011
Number 13
Vol. 13 (2), 2010
Number 13
Vol.13 (1), 2010
Number 12
Vol.12 (2), 2009
Number 12
Vol.12 (1), 2009
Number 11
Vol.11 (2),2008
Number 11
Vol.11 (1),2008
Number 10
Vol.10 (2), 2007
Number 10
10 (1),2007
Number 9
1&2, 2006
Number 9
3&4, 2006
Number 8
1&2, 2005
Number 8
3&4, 2004
Number 7
1&2, 2004
Number 6
3&4, 2003
Number 6
1&2, 2003
Number 5
3&4, 2002
Number 5
1&2, 2002
Number 4
Vol.3 (4), 2000
Number 4
Vol.2 (4), 1999
Number 4
Vol.1 (4), 1998
Number 4
3&4, 2001
Number 4
1&2, 2001
Number 3
Vol.3 (3), 2000
Number 3
Vol.2 (3), 1999
Number 3
Vol.1 (3), 1998
Number 2
Vol.3(2), 2000
Number 2
Vol.1 (2), 1998
Number 2
Vol.2 (2), 1999
Number 1
Vol.3 (1), 2000
Number 1
Vol.2 (1), 1999
Number 1
Vol.1 (1), 1998

 

 


 About the journal ::: Editorial ::: Subscription ::: Information for authors ::: Contact
 Copyright © Balkan Journal of Medical Genetics 2006