Background: The present study has been carried out to investigate the effects of preovulatory stage gamma-irradiation of female mice in the absence or presence of vitamin E on numerical chromosome abnormalities in 8-cell embryos after mating with non-irradiated males. Materials and Methods: The 8-11 weeks adult female NMRI mice were whole body irradiated at preovulatory stage (post PMSG inject...

Excesses of sex chromosome abnormalities in patients with psychiatric diseases have recently been observed. It remains unclear whether sex chromosome abnormalities are related to sex differences in some psychiatric diseases. While studies showed evidence of susceptibility loci over many sex chromosomal regions related to various mental diseases, others demonstrated that the sex chromosome aneup...

background: induction of radioadaptive responses in cells pretreated with a low dose radiation before exposure to a high dose is well documented by many investigators. the aim of this study is to determine the frequency of chromosomal aberration in peripheral blood lymphocytes of patients treated by radioiodine (131i) for hyperthyroidism, with or without previous thyroid scan with 99mtc. materi...

Sex chromatin studies in institutions for mentally handicapped children show a considerably higher frequency of abnormalities as compared with observations on the general population. The published material is summarized in Table I. The present research was undertaken in order to determine the frequency of possible X chromosome numerical aberrations, by means of a sex chromatin study, in a group...

Veterinary cytogenetics is an area of genetics that deals with normal or abnormal chromosomes of animals. Chromosome abnormalities in cattle can cause significant adverse effects on fertility through failure of production of viable gametes or early embryonic death that consequently leads to great economic loss. Chromosomal aberrations can occur as numerical errors or structural rearrangements u...

The importance of chromosomal abnormalities in etiology of premature ovarian failure (POF) is well known but in many cases, POF still remains idiopathic. We investigated the frequency and type of chromosomal aberrations in Iranian women diagnosed with idiopathic POF. Standard cytogenetic analysis was carried out in a total of 179 patients. Karyotype analysis of these patients revealed that 161 ...

We conducted a cytogenetic study on 865 individuals with idiopathic mental retardation (MR) who were admitted to the Cytogenetics Department of the Iran Blood Transfusion Organisation (IBTO) Research Centre, Tehran, Iran; these were performed on blood samples using conventional staining methods. Chromosome anomalies were identified in 205 of the patients (23.6%). The majority were Down's syndro...

background: cytogenetic study of reproductive wastage is an important aspect in determining the genetic background of early embryogenesis. approximately 15 to 20% of all pregnancies in humans are terminated as recurrent spontaneous abortions (rsas). the aim of this study was to detect chromosome abnormalities in couples with rsas and to compare our results with those reported previously. materi...

Sex determination in flies relies on the different ratio of X chromosomes to autosomes in XX females and XY males. Mammals have a male-determining Y-linked gene, but may retain dosage-related elements.

Sex determination is a fundamental process governed by diverse mechanisms. Sex ratio selection is commonly implicated in the evolution of sex-determining systems, although formal models are rare. Here, we argue that, although sex ratio selection can induce shifts in sex determination, genomic conflicts between parents and offspring can explain why single-factor systems (e.g. XY/XX or ZW/ZZ) are...