http://pinktentacle.com/2009/06/all-purpose-tanuki-testicles-prints-by-kuniyoshi/ Day 348 has 16 protein-coding genes (browser view) including TSPY1 (testis specific protein, Y-linked 1).
Like all genes that are present on the Y Chromosome without a homolog on the X Chromosome, TSPY genes must have a function only in men. Indeed, they are only found in testes, but is role is unknown (hence their vague name.)
They may be degraded versions of homologous genes on the X Chromosome.
Click here to see all 8175345 letters of Day 348 with TSPY1 underlined.