Table 2. Summary of mouse Y chromosome genes and their known functions.
A gene is classified as ‘ancestral’ if it is predicted to have been present in the last common eutherian ancestor. The list of animals where each gene is conserved only includes organisms where a high-quality Y chromosome sequence is available, and the presented list is not exhaustive. *Rbmy was initially thought to be important in spermatid morphogenesis, but this was later questioned (Szot et al., 2003).
| Y gene | Sequence class | X-homologue | Y copy number | Conserved in | Reported functions in the testis | Key gene ontology process | Expression pattern |
|---|---|---|---|---|---|---|---|
| Sry | Ancestral | Sox3 | 1 | Opossum, bull, rat, mouse, marmoset, rhesus, chimp, human |
Testis determination | DNA-binding transcription factor activity | Somatic cells in genital ridge, germ cell specific in adult |
| Rbmy array | Ancestral | Rbmx | ~30 | Opossum, bull, rat, mouse, marmoset, rhesus, chimp, human | Unknown * | RNA splicing | Testis biased |
| Zfy1, Zfy2 | Ancestral | Zfx | 2 | Bull, rat, mouse, marmoset, rhesus, chimp, human |
Apoptotic elimination of univalent spermatocytes at metaphase I, meiosis II completion, MSCI initiation and maintenance, spermatid head and tail morphogenesis | Transcription activator | Spermatogenic cells specific |
| Kdm5d | Ancestral | Kdm5c | 1 | Opossum, rat, mouse, marmoset, rhesus, chimp, human |
Unknown | Histone demethylase that specifically demethylates 'Lys-4' of histone H3 | Ubiquitous |
| Uty | Ancestral | Utx | 1 | Bull, rat, mouse, marmoset, rhesus, chimp, human | Unknown | Histone demethylase activity (H3-K27 specific) | Ubiquitous |
| Ddx3y | ancestral | Ddx3x | 1 | Bull, rat, mouse, marmoset, rhesus, chimp, human |
Unknown | ATP-dependent RNA helicase | Ubiquitous |
| Usp9y | Ancestral | Usp9x | 1 | Bull, rat, mouse, marmoset, rhesus, chimp, human | Unknown | Ubiquitination regulator, peptidase C19 | Testis biased |
| Uba1y | Ancestral | Uba1x | 1 | Opossum, bull, rat, mouse | Unknown | U1 ubiquitin activator | Testis biased, mostly spermatogonia and round spermatid |
| Eif2s3y | Ancestral | Eif2s3x | 1 | Bull, rat, mouse | Spermatogonial proliferation and differentiation | Translation initiation | Ubiquitous |
| Teyorf | Acquired | – | 1 | Mouse | Unknown | Claudin transmembrane | Testis specific |
| Prslly | Acquired | – | 1 | Mouse | Unknown | Serine-type endopeptidase activity | Testis specific |
| H2al2b, H2al2c | Acquired | H2al1 | 2 | Mouse | Unknown | DNA packaging, pericentric heterochromatin regulation | Testis specific, expressed from round spermatid stage |
| Sly | Acquired | Slx, Slxl1 | 126 | Mouse | Interacts with SSTY to recruit SMRT/N-Cor in turn mediating spermatid-specific gene expression | Chromatin remodelling | Testis biased |
| Srsy | Acquired | Srsx | 197 | Mouse | Unknown | Unknown | Testis biased |
| Ssty1&2 | Acquired | Sstx | 85&221 | Mouse | H3K4me3-reader at the promoter of spermatid-specific genes, recruits SLY and SLX/SLX1 | Methylated histone binding | Testis biased |
| Rbm31y | Acquired | Rbm31x | 2 | Mouse | Unknown | RNA binding | Testis biased |