نتایج جستجو برای: sex chromosome aberrations
تعداد نتایج: 329977 فیلتر نتایج به سال:
Two general types of clonal chromosome abnormality are observed in de novo acute myeloid leukemia (AML): the unbalanced aberrations with visible gain or loss of chromosome material and the balanced aberrations without such visible gain or loss. AML can be induced by therapy with cytostatic drugs and radiation. The alkylating agents reacting directly with DNA induce AML which often presents as m...
introduction: the prevalence of somatic chromosomal abnormalities in infertile male individuals has been reported to vary in different literatures. the aim of this study was to investigate the frequency of chromosomal aberrations among infertile men referred to the cytogenetic laboratory of iran blood transfusion organization research centre (ibto). materials and methods: chromosomal analysis w...
Two general types of clonal chromosome abnormality are observed in de novo acute myeloid leukemia (AML): the unbalanced aberrations with visible gain or loss of chromosome material and the balanced aberrations without such visible gain or loss. AML can be induced by therapy with cytostatic drugs and radiation. The alkylating agents reacting directly with DNA induce AML which often presents as m...
BACKGROUND The mechanism of sex determination in zebrafish is largely unknown and neither sex chromosomes nor a sex-determining gene have been identified. This indicates that sex determination in zebrafish is mediated by genetic signals from autosomal genes. The aim of this study was to determine the precise timing of expression of six genes previously suggested to be associated with sex differ...
Sex dimorphism in recombination is widespread on both sex chromosomes and autosomes. Various hypotheses have been proposed to explain these dimorphisms. Yet no theoretical model has been explored to determine how heterochiasmy--the autosomal dimorphism--could evolve. The model presented here shows three circumstances in which heterochiasmy is likely to evolve: (i) a male-female difference in ha...
This study tested some predictions of the local-resource-competition hypothesis and localresource-enhancement hypothesis of sex-biased maternal investment in a population of pigtail macaques (Macaca nemestrina leonina). Offspring sex ratios in highand lowranking matrilines were biased in opposite directions as predicted. Sex ratio in the middleranking matriline was female biased similar to the ...
We describe the trajectory of the human sex ratio from conception to birth by analyzing data from (i) 3- to 6-d-old embryos, (ii) induced abortions, (iii) chorionic villus sampling, (iv) amniocentesis, and (v) fetal deaths and live births. Our dataset is the most comprehensive and largest ever assembled to estimate the sex ratio at conception and the sex ratio trajectory and is the first, to ou...
Overview of Five-Years of Experience Performing Non-Invasive Fetal Sex Assessment in Maternal Blood.
Since the discovery of the presence of fetal DNA in maternal blood, non-invasive fetal sex determination has been the test most widely translated into clinical practice. To date there is no agreement between the different laboratories performing such tests in relation to which is the best protocol. As a consequence there are almost as many protocols as laboratories offering the service, using d...
Many separate-sexed organisms have sex chromosomes controlling sex determination. Sex chromosomes often have reduced recombination, specialized (frequently sex-specific) gene content, dosage compensation and heteromorphic size. Research on sex determination and sex chromosome evolution has increased over the past decade and is today a very active field. However, some areas within the field have...
Abstract Background Chromosomal abnormalities represent an important cause of human infertility. Little is known about the prevalence chromosomal among Egyptian couples with We estimated cytogenetic profiles and semen analysis patterns infertile couples. analyzed data from medical archives 2150 patients infertility in Mansoura University Children’s Hospital, Egypt 2015 to 2019. The included kar...
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