Others discuss shelterin-mediated telomere protection, the genetic basis of C4 Kranz anatomy, brain aging and age-related neurodegenerative diseases, chromosome dynamics in response to DNA damage, ribosome hibernation, chemical modifications in the lifecycle of mRNA transcripts, calcium channelopathies and disorders of the muscle excitation-contraction complex, somatic mutagenesis in mammals and its implications for human disease and aging, crop quantitative genomics, phage-encoded anti-CRISPR (clustered regulatory interspaced short palindromic repeat) defenses, unique archaeal small RNAs, behavioral epigenetics in eusocial insects, mitonuclear coregulation, X-chromosome
inactivation, and immunoglobin-like receptors and their impact on wiring of brain synapses.
Epigenetic inactivation of one X-chromosome
in embryonic female cells functions to equalize the dosage of X-linked genes with that of male cells.
XLRP is most commonly caused by a mutation on the RPGR gene on the X-chromosome
that causes blindness in about one in 15,000 men.
It is an inherited disorder caused by mutations (alterations) in the alpha-galactosidase A gene located on the X-chromosome
Long noncoding RNA X-chromosome
inactive specific transcript
However, an early onset progressive muscular dystrophy could be seen in carriers with 45 X, 46 XY, and mosaic Turner karyotypes, apparently balanced X/autosome translocations with breakpoints in Xp21 within the dystrophin gene, and preferential inactivation of the normal X and nonrandom (skewed) X-chromosome
inactivation that leads to diminished expression of the normal dystrophin allele [17, 22, 23].
It is thought that the development of NDI in female carriers is due to skewed X-chromosome
inactivation of the normal allele.
In the nematode Caenorhabditis elegans, sex determination is a direct function of X-chromosome
dosage, with XX being hermaphrodites if the ratio of X-chromosomes
to autosomes (A) is balanced (2X/2A = 1), and X0 being male (Hodgkin 2002).
When breed-specific X-chromosome
regional gene expression differences were determined, the chromosomal band Xq13, which contains 13 genes including OGT and X inactivation-specific transcript (XIST), ranked highest by criteria of placental gene expression and chromosomal location .
Sex chromatin seen as darkly staining mass at the nucleus of all non-dividing cells of genotypically females represents the heterochromatin of the inactivated X-chromosome
. It is also found in polymorphonuclear leukocytes of normal females as a drumstick-shaped mass attached to one end of the nuclear lobes.
Although X monosomy is the most frequent chromosomal finding, in some patients with the Turner syndrome the karyotype shows variants of X-chromosome
abnormalities such as deletions, duplications, inversions, X/autosomal balanced translocations, and rings.
The amelogenin genes, which are present on both the X-chromosome
(AMELX) and the Y-chromosome (AMELY), have been used to determine sex in cattle , sheep, and deer  as well as in other species of the Bovidae family .