Genetic variation in the Y chromosome and sex-biased DNA methylation in somatic cells in the mouse.

Several lines of evidence suggest that the presence of the Y chromosome influences DNA methylation of autosomal loci. To better understand the impact of the Y chromosome on autosomal DNA methylation patterns and its contribution to sex bias in methylation, we identified Y chromosome dependent differentially methylated regions (yDMRs) using whole-genome bisulfite sequencing methylation data from livers of mice with different combinations of sex-chromosome complement and gonadal sex. Nearly 90% of the autosomal yDMRs mapped to transposable elements (TEs) and most of them had lower methylation in XY compared to XX or XO mice.

Five multicopy gene family genes expressed during the maternal-to-zygotic transition are not essential for mouse development.

Upon fertilization, oocytes transform into totipotent and pluripotent cleavage stage cells through the maternal-to-zygotic transition (MZT), which is regulated by maternal factors and zygotic genome activation (ZGA). Here, we investigated the in vivo function of 16 genes expressed with strong biases in oocytes and cleavage stage embryos by generating knockout (KO) mice. These MZT-associated genes are conserved across many mammalian species and include five multicopy gene family genes: the Nlrp9, Khdc1, Rfpl4, Trim43, and Zscan5 genes.

Prognostic stratification of patients with nasopharyngeal carcinoma based on tumor immune microenvironment.

Background: Little is known about immune-related prognostic factors in patients with nasopharyngeal carcinoma (NPC).

Methods: We retrospectively reviewed 66 patients with NPC. Epstein-Barr virus (EBV) status, programmed cell death-ligand 1 (PD-L1) expression, and tumor-infiltrating lymphocyte (TIL) densities were analyzed, and a prognostic evaluation of these immune-related parameters was performed.