Vertebrate Sex Chromosomes

1. X chromosome inactivation: theme and variations
2. X chromosome inactivation, differentiation, and DNA methylation revisited, with a tribute to Susumu Ohno
3. ICF syndrome cells as a model system for studying X chromosome inactivation
4. X chromosome inactivation: how human are mice?
5. Escape from X inactivation
6. Spontaneous reactivation of the inactive X chromosome in mouse embryonal carcinoma cells
7. Nonrandom X chromosome inactivation in mouse embryos carrying Searle’s T( X; 16) 16H translocation visualized using X- linked lacZ and GFP transgenes
8. Antisense regulation in X inactivation and autosomal imprinting
9. Differential patterns of histone methylation and acetylation distinguish active and repressed alleles at X- linked genes
10. Integrated kinetics of X chromosome inactivation in differentiating embryonic stem cells
11. Overall DNA methylation and chromatin structure of normal and abnormal X chromosomes
12. Ectopic XIST transcripts in human somatic cells show variable expression and localization
13. Functional analysis of the highly conserved exon IV of Xist RNA
14. Chromatin reprogramming of male somatic cell- derived Xist and Tsix in ES hybrid cells
15. Effect of Tsix disruption on Xist expression in male ES cells
16. Sex chromosome elimination, X chromosome inactivation and reactivation in the southern brown bandicoot Isoodon obesulus (Marsupialia: Peramelidae)
17. The evolution of sex chromosomes
18. Evolution of the human X – a smart and sexy chromosome that controls speciation and development
19. Speculations on the role of natural antisense transcripts in mammalian X chromosome evolution
20. Early origins of the X and Y chromosomes: Lessons from tilapia
21. Chromosome evolution in fish: sex chromosome variability in Eigenmannia virescens (Gymnotiformes: Sternopygidae)
22. Sex determination and sex chromosome evolution in the medaka, Oryzias latipes, and the platyfish, Xiphophorus maculatus
23. Comparative mapping of Z-orthologous genes in vertebrates: implications for the evolution of avian sex chromosomes
24. The prototype of sex chromosomes found in Korean populations of Rana rugosa
25. Cytogenetic studies of Hynobiidae (Urodela)

During the last two decades of the 20th century, the study of chromosomes was enormously stimulated by the availability of various biological resources, valuable databases and new genetic and molecular biological techniques including PCR and fluorescent in situ hybridization. The simultaneous development of new and effective systems for targeting genes and gene transfer led to astonishing advances also in the study of vertebrate sex chromosomes. We now have considerable insight into their evolution, the dosage compensation mechanisms in mammals that involve chromosome-wide chromatin remodeling triggered by noncoding Xist RNA, and the unique properties of the human X chromosome which comprises many genes important for sex determination and reproduction. This thematic issue of "Cytogenetic and Genome Research" presents an excellent and highly authoritative compilation of current research findings related to vertebrate sex chromosomes.