نتایج جستجو برای: y chromosome
تعداد نتایج: 603865 فیلتر نتایج به سال:
BACKGROUND In most mammals, sex is determined at the beginning of gestation by the constitution of the sex chromosomes, XY in males and XX in females. CASE Here we report an interesting case characterized by ambiguous genitalia and ovotestis in a newborn carrying an apparently female karyotype (46 XX). Array Comparative Genomic Hybridization (Array-CGH) revealed an unbalanced rearrangement re...
Currently, the gradual introduction and routine application of validated Y chromosomal STR systems in stain analysis is being experienced. These systems are powerful forensic tools especially for the area of sexual assault evidence and are superior to autosomal systems for two reasons: the differential cell lysis step prior to the PCR is replaced by a sex chromosome selection during PCR and the...
Using the data on five diallellic Y-chromosome loci ( DYS199 , 92R7 , SRY1532 , RBF5 , and DYS287 ) polymorphism, genetic structures of the five Turkic-speaking ethnic groups of the Altai–Sayan upland (Tuvinians, Sojots, Shorians, Khakassians, and Southern Altaians (Altai-Kizhi), were described. The gene pools of the populations examined were characterized by the presence of pronounced paleo-Ca...
Several studies based on a variety of genetic markers have attempted to establish the origins of horse domestication. Thus far a discrepancy between the results of mitochondrial DNA analysis, which show high levels of diversity, and results from the Y-chromosome, with almost no genetic variability, has been identified. Most previous work on the horse Y-chromosome has focused on widespread, popu...
Three unique sequences derived from the Y chromosome have been mapped within the human genome. A Y specific sequence DYS20 is localised to Yq11.2. DXYS25 and DXYS27 are both X-Y homologous sequences which map to the Y short arm and to Xq21. DXYS25 maps more distally than DXYS27, on the Y short arm and on the X long arm. Y specific restriction fragments for these two sequences are shown to be pr...
Sex chromosome translocations are unique and must be considered separately from translocations between autosomes. Here, we describe the first prenatal case of one twin fetus with an unbalanced translocation between chromosome Y and chromosome 15, presenting a 46,XY,der(15)t(Y;15) karyotype. The other twin had a normal 46,XY karyotype. Cytogenetic analysis of the parental chromosomes revealed th...
A mentally retarded female child with multiple congenital abnormalities had an abnormal X chromosome and a Y chromosome; the karyotype was interpreted as 46,dup(X)(p21 leads to pter)Y. Prenatal chromosome studies in a later pregnancy indicated the same chromosomal abnormality in the fetus. The fetus and proband had normal female genitalia and ovarian tissue. H--Y antigen was virtually absent in...
Haldane's rule states that in organisms with differentiated sex chromosomes, hybrid sterility or inviability is generally expressed more frequently in the heterogametic sex. This observation has been variously explained as due to either genic or chromosomal imbalance. The fixation probabilities and mean times to fixation of sex-chromosome translocations of the type necessary to explain Haldane'...
We investigated the frequency and types of Y-chromosome microdeletions and chromosomal anomalies in non-obstructive azoospermic and severely oligozoospermic infertile males in northeastern China. The sample consisted of 519 infertile males (456 azoospermic, 63 severely oligozoospermic). PCR assays for Y-chromosome microdeletions and chromosome analysis were performed on all patients and co...
A 13-year-old male pseudohermaphrodite (mixed gonadal dysgenesis, unilateral testicular differentiation) was found to be a chromosomal mosaic of the 45, X0/46, XY type, the Y chromosome being a symmetrical dicentric chromosome. Presumed ¥ chromosomes similar to this one have been observed before, but their identification was not supported by autoradiographic data. In the present study the ident...
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