Sex Determination in Vertebrates

Cover
Book content
Series Page
Copyright
Contributors
Preface
References
Evolution and meiotic organization of heteromorphic sex chromosomes
Introduction
Differentiation of autosomes into heteromorphic sex chromosomes
Friend or foe: Pairing and synapsis of heteromorphic sex chromosomes
Pairing without homology: The dense plate of the marsupial XY
The dynamic nature of heteromorphic sex chromosome generation: Meiotic multiples
A role for SMCs in sex chromosome organization: Cohesins are key players in the regulation of meiotic pairing dynamics
Nucleolar association and its role in heterochromatin formation
Meiotic consequences of sex chromosome differentiation: Activation of pathways and mechanisms to identify and manage u ...
Conserved mechanisms act to silence unpaired DNA in meiosis
The recombination pathway machinery is utilized in the management of the unpaired DNA response
The evolutionary history of meiotic silencing
Birds and monotremes use alternative meiotic silencing mechanisms to deal with the unpaired DNA of heteromorphic sex ...
Anything goes: MSCI of pseudo-heteromorphic sex chromosomes in an XX male mammal
Escape from meiotic silencing and the transcriptional regulation of sex chromosome linked genes beyond meiosis I
How do genes on the silenced sex chromosomes reactivate after MSCI while in the PMSC environment?
Outstanding questions and future perspectives
References
Environmental regulation of sex determination in fishes: Insights from Atheriniformes
Introduction
Environmental and temperature-dependent sex determination in fishes
Genotypic sex determination and sex-determining genes in fishes
Environmental effects on sex determination in wild populations
Conclusions and perspectives
Acknowledgments
References
Natural sex change in fish
Introduction
Why change sex?
Size advantage and the evolution of sequential hermaphroditism
Protogyny
Protandry
Bidirectional sex change
The anatomy of sex change
The possible cellular origins of gonadal restructuring in protogynous species
The endocrine regulation of sex change
Neuroendocrine regulation of sex change
The stress response may mediate sex change
The molecular regulation of sex change
Aromatase appears to trigger gonadal sex change in protogynous species
Protandrous sex change and the role of dmrt1, amh and sox8
The role of epigenetics in sex change
Epigenetic barriers separate the sexes
A new model of sex change
Conclusions
Acknowledgments
References
Genetic regulation of sex determination and maintenance in zebrafish (Danio rerio)
Introduction to zebrafish sexual phenotypes
Wild zebrafish, but not domesticated lines, utilize a ZZ/ZW chromosomal sex determination mechanism
Overview of zebrafish gonad development and timing of sex determination and differentiation
Embryogenesis to 8 dpf
The larval bipotential/undifferentiated gonad (8-20 dpf)
Sex-specific differentiation (20-25 dpf)
Oocytes are required for primary female sex determination
Maintenance of the sexual phenotype
Zebrafish sex determination can be influenced by environmental factors
Temperature
Dissolved oxygen content
Food availability
Genetic analysis of zebrafish sex determining pathway
Male-promoting genes
Double-sex and Mab-3 related transcription factor 1 (Dmrt1)
Anti-Müllerian Hormone (Amh)
Gonadal soma derived factor (Gdsf)
Androgen receptor (Ar)
Female-promoting genes
Nr0b1
Wnt4a
Cyp19a1a, Aromatase
Genes required for maintenance of female sex differentiation
FoxL2a and FoxL2b
Bone morphogenetic protein 15 (Bmp15)
Loose ends
Concluding remarks
Acknowledgments
References
Regulation of germ cell sex identity in medaka
Introduction
Timing of acquisition of sex identity in germ cells
sdgc
Conventional view of sex differentiation of gonads in medaka
Switch gene for sexual fate decision in germ cells
Mechanism of sexual fate switch in germ cells
Default state of germ cell sex
Regulation of foxl3
Another pathway for determining germ cell sex?
Acknowledgments
References
Further reading
Characterizing the bipotential mammalian gonad
Introduction
Beginnings: Formation of the adreno-genital primordium (AGP)
Genital ridge formation
Reconstructing developmental lineage trajectories and cell fate in the developing gonad by single-cell RNA sequencing ...
Specification of the somatic lineages in the developing gonads
Molecular control of gonadal cell fate choice: Gene networks and signaling events
SRY and SOX9: Initiating testis determination
Early events: Cell proliferation
Regulation of Sry expression
Testis determination: Opposing the ovarian genetic program
Ovary development: Granulosa cell heterogeneity, germ cells and XX gonadal sex reversal
Comparisons between human and mouse sex determination
Future research perspectives
Acknowledgments
References
Role of epigenetic regulation in mammalian sex determination
Introduction
Transcriptional regulation of the Sry gene
Epigenetic regulation of mammalian sex determination
Histone modification in the regulation of gene transcription
Role of histone methylation and demethylation in sex development
Histone acetylation in sex development
Gene regulation by polycomb group proteins
DNA methylation
ATP-dependent chromatin remodeling
Chromosomal structure
Non-coding RNA and transcriptional gene silencing
Environmental cues for epigenetic regulation
Transcriptional links with intermediary metabolism
The role of metabolism in sex determination
Summary
References
The regulation of Sox9 expression in the gonad
Introduction
The Sox9 gene
The role of Sox9 in gonadal development
The regulatory genomic locus of Sox9
Lessons from human patients
Lessons from mouse models
Gonadal enhancers of Sox9
The TES enhancer
The Enh13 enhancer and other novel enhancers of Sox9
Higher order of chromatin organization at the Sox9 locus
Perspectives
Acknowledgments
References
Sexually dimorphic germ cell identity in mammals
Introduction
Getting to the point of sexual divergence
PGC specification, survival and migration
The new environment of the gonad
Epigenetic reprogramming
Adopting the female fate, in the ovary
Retinoic acid triggers the onset of meiosis
Induction of Stra8 expression by RA is strictly time and cell type specific
The molecular function of STRA8 remains obscure
Other extrinsic factors that may impact on meiotic progression
Adopting the male fate in the testis
Avoidance of meiosis
Controlling pluripotency regulators in testicular germ cells
Mitotic arrest
Active induction of the male fate
Conclusions
References
Rethinking sex determination of non-gonadal tissues
Introduction
The classic vs. revised theories of sex determination and sexual differentiation
Evolution of sex chromosomes: Balance and inequality of X and Y
Categories of X and Y genes causing phenotypic differences between XX and XY cells
Mouse models and methods that separate effects of sex chromosomes vs. gonadal hormones
Sex differences caused by sex chromosome effects
Independent sex-biasing factors interact to cause sex differences in physiology and disease
Metabolism and body weight
Sex differences in volumes of brain regions
Sex chromosome regulation of brain sensitivity to gonadal hormones
Cardiovascular and pulmonary disease
Immune and autoimmune function
Interaction of sex chromosome effects and age
Sex differences in the germline
Y chromosome-mediated sex differences in physiology and disease
Comparison to birds
Conclusions
References
Translating genomics to the clinical diagnosis of disorders/differences of sex development
Introduction
Disorders/differences of sex development, challenges in diagnosis and management
Genetics of DSD
Chromosomal microarrays (CMA)
Exome sequencing
Gene-testing panels
Evaluation of genes on the DSD gene list
Whole genome sequencing
Long-read sequencing
Optical genome mapping
Epigenetics
References
Further reading
Book blurb