Eleven Y-specific DNA probes hybridizing with DNA from one or more 46,XX males were isolated from a recombinant phage DNA library constructed from flow sorted human Y chromosomes. Two probes hybridized with DNA from nine out of eleven, i.e. greater than 80% of these 46,XX males. The relative frequency of hybridization of the probes in the 46,XX males and in a 46,X,dic(Y) female, together with i...

XX maleness is a rare syndrome with a frequency of 1 in 20,000-25,000 males. XX males exist in different clinical categories with ambiguous genitalia or partially to fully mature male genitalia, in combination with complete or incomplete masculinization. In this study, we report a case of SRY-negative XX male with complete masculinization but infertility. The patient had fully mature male genit...

Human XX maleness is often due to the presence of Y-specific DNA, resulting from abnormal interchange of terminal parts of the short arms of the X and Y chromosomes. In an XX male, a rearrangement is observed at locus DXYS5, the most proximal Yp locus detected in this patient. Cloning and analysis of the rearranged DNA fragment revealed pseudoautosomal sequences located beyond the breakpoint. W...

The nematode C. elegans naturally develops as either an XO male or XX hermaphrodite. The sex-determining gene, tra-2, promotes hermaphrodite development in XX animals. This gene encodes a predicted membrane protein, named TRA-2A, which has been proposed to provide the primary feminising activity of the tra-2 locus. Here, we show that transgenic TRA-2A driven from a heat shock promoter can fully...

What is sex determination? Sex determination is the mechanism by which sexual organisms direct gonad development towards distinct but reproductively compatible outcomes. Molecular signaling cascades in the developing gonad provide instructions to the tissue to develop as male or female (or in some cases hermaphrodite), and these signals can be initiated in different ways. Sex can be determined ...

Using molecular chromosomal analyses, we discovered night monkey hybrids produced in captivity from matings between a female Aotus azarae boliviensis (2n = 50) and a male Aotus lemurinus griseimembra (2n = 53). The parents produced seven offspring in total, including one male and six females-a pattern consistent with Haldane's rule. Chromosomal studies were conducted on four of the hybrid offsp...

Sexual ambiguity commonly known as intersexuality, is a condition of imperfect sexual differentiation between male and female. The present study was aimed at analyzing the chromosomal abnormalities of intersex subjects in Coimbatore city, India Of the 30 intersex cases studied, 10 of them were genetically male (46,XY) but phenotypically females, 8 of them were genetically female (46,XX) with ma...

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1. Of 30 mice born from aggregation of embryos from a multiple recessive strain with F1 embryos carrying the contrasting alleles, 4 females and 20 males proved to be overtly chimaeric. 2. Three XX/XX females, five XY/XY males and eight XY/XX males were identified by chromosome analysis. Thus 50% of the population analysed were sex chimaeras, and all of these developed as phenotypic males, thoug...