Adult ; Chromatids/genetics* ; Chromosome Aberrations ; Humans ; Infertility, Male/genetics* ; Male ; Meiosis ; Metaphase/genetics* ; Spermatocytes/physiology*

Aneuploidy is an important point at issue in human reproductive biology, accounting for both a major proportion of miscarriages and various congenital malformation syndromes among newborns. Despite its high incidence and severe clinical consequences, very little is known about how aneuploidy originates in human. On the other hand, remarkable progress has been made in the research of meiosis. The failure of any process in meiosis can result in chromosome mal-disjunction. The alteration in recombination and the premature separation of sister chromatids are two important processes on which more intensive researches have been done. In addition, mtDNA mutation and sexual dimorphism in aneuploidy genesis have also attracted more and more researchers' attention.
Aneuploidy ; Animals ; Chromatids ; metabolism ; DNA, Mitochondrial ; genetics ; Humans ; Recombination, Genetic ; Sex Characteristics

OBJECTIVETo study the impact of postovulatory ageing to balanced predivision of oocyte sister chromatid.

METHODSThe mouse oocytes were cultured 0-72 h. Then chromosome 16 was detected by fluorescence in situ hybridization (FISH). The oocyte spindle and chromosome configuration were examined by immunocytochemistry.

RESULTSFor freshly ovulated mouse oocyte, the balanced predivision of sister chromatid occurred only at 7%. However, for oocytes cultured for 24 h, 48 h and 72 h in vitro, the balanced predivision of sister chromatid occurred up to at 32%, 51% or 62% respectively (P< 0.01). The abnormal cell spindle and chromosome configuration occurred at 9% of freshly ovulated oocytes, but it increased to 63%, 83% and 98% when the oocytes were cultured in vitro for 24 h, 48 h or 72 h respectively (P< 0.01).

CONCLUSIONThe occurrence of balanced predivision of oocyte sister chromatid may result during postovulatory ageing, and may be related to change of oocyte spindle and chromosome configuration.

Aging ; physiology ; Animals ; Cells, Cultured ; Chromatids ; genetics ; Chromosomes, Mammalian ; genetics ; Female ; Immunohistochemistry ; In Situ Hybridization ; Mice ; Oocytes ; cytology ; metabolism

OBJECTIVETo evaluate the four techniques for clonal analysis in the early diagnosis of myelodysplastic syndromes (MDS).

METHODSFour techniques for clonal analysis were performed in bone marrow samples from fifty patients with suspected MDS: (1) Conventional cytogenetics (CC) for clonal chromosomal abnormalities; (2) BrdU-sister chromatid differentiation (BrdU-SCD) for cell cycle analysis; (3) Fluorescence in situ hybridization (FISH) for trisomy 8; (4) PCR-SSCP for N-ras mutation.

RESULTSThe diagnosis of forty-five patients was compatible with FAB criteria of MDS, the other five patients didn't fully meet the FAB criteria. They had either only one lineage dyspoiesis or no any obvious dysplastic features and two of them were diagnosed as suspicious refractory anemia (RA), one as anemia with hypercellular bone marrow and two as chronic aplastic anemia. The results of the four techniques performed in them showed that four patients had clonal karyotype abnormalities, two had prolonged cell cycle, three had trisomy 8 of different proportions, and one had N-ras mutation. Thus, they were all diagnosed as RA.

CONCLUSIONThe untypical MDS patients can be diagnosed early by examination with combining several clonal analysis techniques.

Adolescent ; Adult ; Aged ; Bromodeoxyuridine ; Child ; Child, Preschool ; Chromatids ; Chromosome Aberrations ; Cytogenetic Analysis ; methods ; Female ; Genes, ras ; Humans ; In Situ Hybridization, Fluorescence ; methods ; Male ; Middle Aged ; Mutation ; Myelodysplastic Syndromes ; diagnosis ; genetics