The Y Chromosome That Lost the Male-Determining Function Behaves as an X Chromosome in the Medaka Fish, Oryzias latipes

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.

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Roles of Anti-Müllerian hormone (Amh) and its duplicates in sex determination and germ cell proliferation of Nile tilapia

Genetics ◽

10.1093/genetics/iyab237 ◽

2021 ◽

Author(s):

Xingyong Liu ◽

Shengfei Dai ◽

Jiahong Wu ◽

Xueyan Wei ◽

Xin Zhou ◽

...

Keyword(s):

Cell Proliferation ◽

Sex Determination ◽

Germ Cell ◽

Y Chromosome ◽

X Chromosome ◽

Nile Tilapia ◽

Critical Period ◽

Sex Reversal ◽

Homozygous Mutation ◽

Germ Cell Proliferation

Abstract Duplicates of amh are crucial for fish sex determination and differentiation. In Nile tilapia, unlike in other teleosts, amh is located on X chromosome. The Y chromosome amh (amh△-y) is mutated with 5 bp insertion and 233 bp deletion in the coding sequence, and tandem duplicate of amh on Y chromosome (amhy) has been identified as the sex determiner. However, the expression of amh, amh△-y and amhy, their roles in germ cell proliferation and the molecular mechanism of how amhy determines sex is still unclear. In this study, expression and functions of each duplicate were analyzed. Sex reversal occurred only when amhy was mutated as revealed by single, double and triple mutation of the three duplicates in XY fish. Homozygous mutation of amhy in YY fish also resulted in sex reversal. Earlier and higher expression of amhy/Amhy was observed in XY gonads compared with amh/Amh during sex determination. Amhy could inhibit the transcription of cyp19a1a through Amhr2/Smads signaling. Loss of cyp19a1a rescued the sex reversal phenotype in XY fish with amhy mutation. Interestingly, mutation of both amh and amhy in XY fish or homozygous mutation of amhy in YY fish resulted in infertile females with significantly increased germ cell proliferation. Taken together, these results indicated that up-regulation of amhy during the critical period of sex determination makes it the sex-determining gene, and it functions through repressing cyp19a1a expression via Amhr2/Smads signaling pathway. Amh retained its function in controlling germ cell proliferation as reported in other teleosts, while amh△-y was nonfunctionalized.

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Y-Chromosome Microdeletions Patients Display an Increased Incidence of X-Chromosome Duplications and Deletions.

10.1210/endo-meetings.2010.part2.or.or17-5 ◽

2010 ◽

pp. OR17-5-OR17-5

Author(s):

CJ Jorgez ◽

JW Weedin ◽

A Sahin ◽

LI Lipshultz ◽

DJ Lamb

Keyword(s):

Y Chromosome ◽

X Chromosome ◽

Y Chromosome Microdeletions

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Clues from other animals and theoretical considerations

Development ◽

10.1242/dev.101.supplement.3 ◽

1987 ◽

Vol 101 (Supplement) ◽

pp. 3-4

Author(s):

Anne McLaren

Keyword(s):

Sex Determination ◽

Genetic Control ◽

Y Chromosome ◽

X Chromosome ◽

X Chromosomes ◽

The Third ◽

Mouse Species ◽

Primary Male ◽

Theoretical Considerations ◽

State Of Activity

In the first two papers of this volume, the genetic control of sex determination in Caenorhabditis and Drosophila is reviewed by Hodgkin and by Nöthiger & Steinmarin-Zwicky, respectively. Sex determination in both cases depends on the ratio of X chromosomes to autosomes, which acts as a signal to a cascade of règulatory genes located either on autosomes or on the X chromosome. The state of activity of the last gene in the sequence determines phenotypic sex. In the third paper, Erickson & Tres describe the structure of the mouse Y chromosome and the polymorphisms that have been detected in different mouse species and strains. As in all mammals, the Y carries the primary male-determining locus; autosomal genes may also be involved in sex determination, but they must act down-stream from the Y-linked locus.

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No influence of parental origin of intact X chromosome and/or Y chromosome sequences on three-year height response to growth hormone therapy in Turner syndrome

Annals of Pediatric Endocrinology & Metabolism ◽

10.6065/apem.2014.19.3.127 ◽

2014 ◽

Vol 19 (3) ◽

pp. 127 ◽

Cited By ~ 4

Author(s):

Hye Jin Lee ◽

Hae Woon Jung ◽

Gyung Min Lee ◽

Hwa Young Kim ◽

Jae Hyun Kim ◽

...

Keyword(s):

Growth Hormone ◽

Hormone Therapy ◽

Turner Syndrome ◽

Y Chromosome ◽

X Chromosome ◽

Growth Hormone Therapy ◽

Parental Origin

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A second X chromosome contributes to resilience in a mouse model of Alzheimer’s disease

Science Translational Medicine ◽

10.1126/scitranslmed.aaz5677 ◽

2020 ◽

Vol 12 (558) ◽

pp. eaaz5677 ◽

Cited By ~ 7

Author(s):

Emily J. Davis ◽

Lauren Broestl ◽

Samira Abdulai-Saiku ◽

Kurtresha Worden ◽

Luke W. Bonham ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Y Chromosome ◽

X Chromosome ◽

Sex Chromosome ◽

Testicular Development ◽

X Chromosomes ◽

Model Of Alzheimer’S Disease ◽

Preclinical Ad ◽

Brain Expression

A major sex difference in Alzheimer’s disease (AD) is that men with the disease die earlier than do women. In aging and preclinical AD, men also show more cognitive deficits. Here, we show that the X chromosome affects AD-related vulnerability in mice expressing the human amyloid precursor protein (hAPP), a model of AD. XY-hAPP mice genetically modified to develop testicles or ovaries showed worse mortality and deficits than did XX-hAPP mice with either gonad, indicating a sex chromosome effect. To dissect whether the absence of a second X chromosome or the presence of a Y chromosome conferred a disadvantage on male mice, we varied sex chromosome dosage. With or without a Y chromosome, hAPP mice with one X chromosome showed worse mortality and deficits than did those with two X chromosomes. Thus, adding a second X chromosome conferred resilience to XY males and XO females. In addition, the Y chromosome, its sex-determining region Y gene (Sry), or testicular development modified mortality in hAPP mice with one X chromosome such that XY males with testicles survived longer than did XY or XO females with ovaries. Furthermore, a second X chromosome conferred resilience potentially through the candidate gene Kdm6a, which does not undergo X-linked inactivation. In humans, genetic variation in KDM6A was linked to higher brain expression and associated with less cognitive decline in aging and preclinical AD, suggesting its relevance to human brain health. Our study suggests a potential role for sex chromosomes in modulating disease vulnerability related to AD.

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Nearly Complete Genome Sequence of Brugia pahangi FR3

Microbiology Resource Announcements ◽

10.1128/mra.00479-20 ◽

2020 ◽

Vol 9 (27) ◽

Cited By ~ 1

Author(s):

John Mattick ◽

Silvia Libro ◽

Benjamin C. Sparklin ◽

Matthew Chung ◽

Robin E. Bromley ◽

...

Keyword(s):

Y Chromosome ◽

Genome Sequence ◽

X Chromosome ◽

Complete Genome Sequence ◽

Complete Genome ◽

Brugia Pahangi ◽

Content Type ◽

Filarial Nematodes ◽

Zoonotic Parasite

ABSTRACT Brugia pahangi is a zoonotic parasite that is closely related to human-infecting filarial nematodes. Here, we report the nearly complete genome of Brugia pahangi, including assemblies of four autosomes and an X chromosome, with only seven gaps. The Y chromosome is still not completely assembled.

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