DELETION OF Y CHROMOSOME INVOLVING THE DAZ (DELETED IN AZOOSPERMIA) GENE IN XX MALES

1999 ◽  
Vol 42 (3) ◽  
pp. 179-183 ◽  
Author(s):  
T. TATENO ◽  
I. SASAGAWA ◽  
J. ASHIDA ◽  
T. NAKADA
Keyword(s):  
Y Chromosome ◽  
Deleted In Azoospermia ◽  
Xx Males

scholarly journals Common Spontaneous Sex-Reversed XX males of the Medaka Oryzias latipes

Genetics ◽  
2003 ◽  
Vol 163 (1) ◽  
pp. 245-251 ◽  
Author(s):  
Indrajit Nanda ◽  
Ute Hornung ◽  
Mariko Kondo ◽  
Michael Schmid ◽  
Manfred Schartl
Keyword(s):  
Y Chromosome ◽  
Oryzias Latipes ◽  
Fish Analysis ◽  
Normal Phenotype ◽  
Dmrt1 Gene ◽  
Male Development ◽  
Female Bias ◽  
Male Sex ◽  
Xx Males ◽  
Number Of Males

Abstract In the medaka, a duplicated version of the dmrt1 gene, dmrt1bY, has been identified as a candidate for the master male sex-determining gene on the Y chromosome. By screening several strains of Northern and Southern medaka we identified a considerable number of males with normal phenotype and uncompromised fertility, but lacking dmrt1bY. The frequency of such males was >10% in some strains and zero in others. Analysis for the presence of other Y-linked markers by FISH analysis, PCR, and phenotype indicated that their genotype is XX. Crossing such males with XX females led to a strong female bias in the offspring and also to a reappearance of XX males in the following generations. This indicated that the candidate male sex-determining gene dmrt1bY may not be necessary for male development in every case, but that its function can be taken over by so far unidentified autosomal modifiers.

Up-regulation of SOX9 in human sex-determining region on the Y chromosome (SRY)-negative XX males

2008 ◽  
Vol 68 (5) ◽  
pp. 791-799 ◽  
Author(s):  
Yoshiyuki Kojima ◽  
Yutaro Hayashi ◽  
Kentaro Mizuno ◽  
Shoichi Sasaki ◽  
Yuko Fukui ◽  
...  
Keyword(s):  
Y Chromosome ◽  
Xx Males

scholarly journals Gene-level, but not chromosome-wide, divergence between a very young house fly proto-Y chromosome and its homologous proto-X chromosome

2020 ◽  
Author(s):  
Jae Hak Son ◽  
Richard P. Meisel
Keyword(s):  
Gene Expression ◽  
Y Chromosome ◽  
Chromosome Evolution ◽  
Sex Chromosome ◽  
House Fly ◽  
Evolutionary Divergence ◽  
Y Chromosomes ◽  
Mitochondrial Functions ◽  
Xx Males ◽  
Y Chromosome Evolution

AbstractX and Y chromosomes are usually derived from a pair of homologous autosomes, which then diverge from each other over time. Although Y-specific features have been characterized in sex chromosomes of various ages, the earliest stages of Y chromosome evolution remain elusive. In particular, we do not know whether early stages of Y chromosome evolution consist of changes to individual genes or happen via chromosome-scale divergence from the X. To address this question, we quantified divergence between young proto-X and proto-Y chromosomes in the house fly, Musca domestica. We compared proto-sex chromosome sequence and gene expression between genotypic (XY) and sex-reversed (XX) males. We find evidence for sequence divergence between genes on the proto-X and proto-Y, including five genes with mitochondrial functions. There is also an excess of genes with divergent expression between the proto-X and proto-Y, but the number of genes is small. This suggests that individual proto-Y genes, but not the entire proto-Y chromosome, have diverged from the proto-X. We identified one gene, encoding an axonemal dynein assembly factor (which functions in sperm motility), that has higher expression in XY males than XX males because of a disproportionate contribution of the proto-Y allele to gene expression. The up-regulation of the proto-Y allele may be favored in males because of this gene’s function in spermatogenesis. The evolutionary divergence between proto-X and proto-Y copies of this gene, as well as the mitochondrial genes, is consistent with selection in males affecting the evolution of individual genes during early Y chromosome evolution.

Mapping the Y chromosome

Development ◽  
1987 ◽  
Vol 101 (Supplement) ◽  
pp. 39-39
Author(s):  
P. N. Goodfellow
Keyword(s):  
Sex Determination ◽  
Y Chromosome ◽  
X Chromosome ◽  
Dna Probes ◽  
Genetic Maps ◽  
Variable Amount ◽  
Regional Localization ◽  
Y Chromosomes ◽  
Xx Males ◽  
Human Y Chromosome

DNA probes isolated from the human Y chromosome have been used to resolve two fundamental problems concerning the biology of sex determination in man. Coincidentally, resolution of these problems has generated genetic maps of the short arm of the human Y chromosome and has allowed the regional localization of TDF. The first problem to be solved was the origin of XX males (de la Chapelle, this symposium): the majority of XX males are caused by a telomeric exchange between the X and Y chromosomes that results in TDF and a variable amount of Y-derived material being transferred to the X chromosome. The differing amounts of Y-derived material present in XX males has been used as the basis of a ‘deletion’ map of the Y chromosome (Müller; Ferguson-Smith & Affara; this symposium).

scholarly journals Analysis of DAZ gene expression in a partial AZFc deletion of the human Y chromosome

2014 ◽  
Vol 26 (2) ◽  
pp. 307 ◽  
Author(s):  
Byunghyuk Kim ◽  
Wonkyung Lee ◽  
Kunsoo Rhee ◽  
Soo Woong Kim ◽  
Jae-Seung Paick
Keyword(s):  
Y Chromosome ◽  
Pcr Assay ◽  
Azfc Region ◽  
Azoospermia Factor ◽  
Azfc Deletion ◽  
Deleted In Azoospermia ◽  
Polymerase Chain ◽  
Factor C ◽  
Human Y Chromosome ◽  
Daz Gene

The azoospermia factor c (AZFc) region of the Y chromosome consists of repetitive amplicons and is therefore highly susceptible to structural rearrangements, such as deletions and duplications. The b2/b3 deletion is a partial AZFc deletion that is conventionally determined by the selective absence of sY1191 in sequence-tagged site polymerase chain reaction (PCR) and is generally believed to retain two of the four deleted in azoospermia (DAZ) genes on the Y chromosome. In the present study we determined the copy number and expression of DAZ genes in sY1191-negative individuals. Using a DAZ dosage PCR assay and Southern blot analysis we evaluated the expression of four DAZ genes in five of six sY1191-negative individuals. Furthermore, cloning and immunoblot analyses revealed that three or more DAZ genes are expressed in sY1191-negative testes with germ cells. The results indicate that the selective absence of sY1191 not only means b2/b3 deletion with two DAZ genes, but also includes another AZFc configuration with four DAZ genes. These results exemplify the prevalence of variations in the AZFc region of the human Y chromosome.

Localization of Y chromosome sequences and X chromosomal replication studies in XX males

1989 ◽  
Vol 81 (2) ◽  
pp. 144-148 ◽  
Author(s):  
W. Schempp ◽  
G. M�ller ◽  
G. Scherer ◽  
S. K. Bohlander ◽  
W. Rommerskirch ◽  
...  
Keyword(s):  
Y Chromosome ◽  
Chromosomal Replication ◽  
Replication Studies ◽  
Xx Males

scholarly journals Y-chromosome haplotypes of varying differentiation to the X are not associated with male fitness in common frogs

2019 ◽  
Author(s):  
Paris Veltsos ◽  
Nicolas Rodrigues ◽  
Tania Studer ◽  
Wen-Juan Ma ◽  
Roberto Sermier ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Y Chromosome ◽  
Sex Chromosomes ◽  
Chromosome Evolution ◽  
Sex Chromosome ◽  
Sex Chromosome Evolution ◽  
Chromosome Differentiation ◽  
Y Chromosomes ◽  
Male Phenotype ◽  
Xx Males

AbstractThe canonical model of sex-chromosome evolution assigns a key role to sexually antagonistic (SA) genes on the arrest of recombination and ensuing degeneration of Y chromosomes. This assumption cannot be tested in organisms with highly differentiated sex chromosomes, such as mammals or birds, owing to the lack of polymorphism. Fixation of SA alleles, furthermore, might be the consequence rather than the cause of recombination arrest. Here we focus on a population of common frogs (Rana temporaria) where XY males with genetically differentiated Y chromosomes (non-recombinant Y haplotypes) coexist with both XY° males with proto-Y chromosomes (only differentiated from X chromosomes in the immediate vicinity of the candidate sex-determining locus Dmrt1) and XX males with undifferentiated sex chromosomes (genetically identical to XX females). Our study shows no effect of sex-chromosome differentiation on male phenotype, mating success or fathering success. Our conclusions rejoin genomic studies that found no differences in gene expression between XY, XY° and XX males. Sexual dimorphism in common frogs seems to result from the differential expression of autosomal genes rather than sex-linked SA genes. Among-male variance in sex-chromosome differentiation is better explained by a polymorphism in the penetrance of alleles at the sex locus, resulting in variable levels of sex reversal (and thus of X-Y recombination in XY females), independent of sex-linked SA genes.Impact SummaryHumans, like other mammals, present highly differentiated sex chromosomes, with a large, gene-rich X chromosome contrasting with a small, gene-poor Y chromosome. This differentiation results from a process that started approximately 160 Mya, when the Y first stopped recombining with the X. How and why this happened, however, remain controversial. According to the canonical model, the process was initiated by sexually antagonistic selection; namely, selection on the proto-Y chromosome for alleles that were beneficial to males but detrimental to females. The arrest of XY recombination then allowed such alleles to be only transmitted to sons, not to daughters. Although appealing and elegant, this model can no longer be tested in mammals, as it requires a sex-chromosome system at an incipient stage of evolution. Here we focus on a frog that displays within-population polymorphism is sex-chromosome differentiation, where XY males with differentiated chromosomes coexist with XX males lacking Y chromosomes. We find no effect of sex-chromosome differentiation on male phenotype or mating success, opposing expectations from the standard model. Sex linked genes do not seem to have a disproportionate effect on sexual dimorphism. From our results, sexually antagonistic genes show no association with sex-chromosome differentiation in frogs, which calls for alternative models of sex-chromosome evolution.

Ambiguous Genitalia in XX Male Children: Report of Two Infants

PEDIATRICS ◽  
1977 ◽  
Vol 60 (1) ◽  
pp. 55-59
Author(s):  
Thomas F. Roe ◽  
Omar S. Alfi
Keyword(s):  
Y Chromosome ◽  
Blood Group ◽  
High Frequency ◽  
Indirect Evidence ◽  
Ambiguous Genitalia ◽  
Apparent Absence ◽  
Inheritance Patterns ◽  
Genital Ambiguity ◽  
Xx Males ◽  
Xx Male

Two infants with ambiguous genitalia were recognized to have the XX male syndrome. Although most xx males have normal penile development, a review of the reported cases showed that eight of the 14 affected children, diagnosed before age 15 years, had penile abnormalities, most commonly hypospadias and/or chordee. This syndrome should be considered in children with incomplete genital differentiation. The available indirect evidence suggests that deficient testosterone production by the fetal testes accounts for the genital ambiguity. Although no explanation has been established for the presence of testes in the apparent absence of the Y chromosome, studies of the X-linked Xg blood group in XX males demonstrate a high frequency of unusual inheritance patterns. This implies that the abnormality in the transmission of maleness in affected families may also be X-related rather than autosomal.

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