Histone variant macroH2A confers resistance to nuclear reprogramming

Gurdon and collaborators report reversible X chromosome inactivation in epiblast stem cells (EpiSCs) that seems to be determined by macroH2A1 deposition. These findings are of rather general interest as they highlight the epigenetic state of repressed loci as determinant for reprogramming efficiency

The Specification and Global Reprogramming of Histone Epigenetic Marks during Gamete Formation and Early Embryo Development in C. elegans

In addition to the DNA contributed by sperm and oocytes, embryos receive parent-specific epigenetic information that can include histone variants, histone post-translational modifications (PTMs), and DNA methylation. However, a global view of how such marks are erased or retained during gamete formation and reprogrammed after fertilization is lacking. To focus on features conveyed by histones, we conducted a large-scale proteomic identification of histone variants and PTMs in sperm and mixed-stage embryo chromatin from C. elegans, a species that lacks conserved DNA methylation pathways. The fate of these histone marks was then tracked using immunostaining. Proteomic analysis found that sperm harbor ?2.4 fold lower levels of histone PTMs than embryos and revealed differences in classes of PTMs between sperm and embryos. Sperm chromatin repackaging involves the incorporation of the sperm-specific histone H2A variant HTAS-1, a widespread erasure of histone acetylation, and the retention of histone methylation at sites that mark the transcriptional history of chromatin domains during spermatogenesis. After fertilization, we show HTAS-1 and 6 histone PTM marks distinguish sperm and oocyte chromatin in the new embryo and characterize distinct paternal and maternal histone remodeling events during the oocyte-to-embryo transition. These include the exchange of histone H2A that is marked by ubiquitination, retention of HTAS-1, removal of the H2A variant HTZ-1, and differential reprogramming of histone PTMs. This work identifies novel and conserved features of paternal chromatin that are specified during spermatogenesis and processed in the embryo. Furthermore, our results show that different species, even those with diverged DNA packaging and imprinting strategies, use conserved histone modification and removal mechanisms to reprogram epigenetic information

In the Supreme Court of the United States, Pierre Yassue Nashun Riley, petitioner, v. Merrick B. Garland, United States Attorney General, respondent ::on writ of certiorari to the United States Court of Appeals for the Fourth Circuit : brief for American Immigration Lawyers Association and American Immigration Council as amici curiae in support of petitioner /

The case concerns requirements for judicial review of orders of removal, specifically: (1) whether the 30-day statutory deadline for filing a petition for review is jurisdictional or can be waived or forfeited, and (2) whether a person can obtain review of the Board of Immigration Appeals' decision in a withholding-only proceeding by filing a petition within 30 days of that decision

In the Supreme Court of the United States, Pierre Yassue Nashun Riley, petitioner, v. Merrick Garland, Attorney General, respondent ::on writ of certiorari to the United States Court of Appeals for the Fourth Circuit : brief of Constitutional Accountability Center & National Immigration Litigation Alliance as amici curiae in support of petitioner /

The case concerns requirements for judicial review of orders of removal, specifically: (1) whether the 30-day statutory deadline for filing a petition for review is jurisdictional or can be waived or forfeited, and (2) whether a person can obtain review of the Board of Immigration Appeals' decision in a withholding-only proceeding by filing a petition within 30 days of that decision

In the Supreme Court of the United States, Pierre Yassue Nashun Riley, petitioner, v. Merrick B. Garland, Attorney General, respondent ::on writ of certiorari to the U.S Court of Appeals for the Fourth Circuit : brief of amici curiae immigration legal service providers supporting petitioner /

The case concerns requirements for judicial review of orders of removal, specifically: (1) whether the 30-day statutory deadline for filing a petition for review is jurisdictional or can be waived or forfeited, and (2) whether a person can obtain review of the Board of Immigration Appeals' decision in a withholding-only proceeding by filing a petition within 30 days of that decision

22q11.2 rearrangements found in women with low ovarian reserve and premature ovarian insufficiency

International audienceOvarian reserve represents the number of available follicles/oocytes within ovaries and it can be assessed by follicle stimulating hormone levels, anti-Müllerian hormone levels, and/or antral follicle count determined by ultrasounds. A low ovarian reserve is defined by an abnormal ovarian reserve test. This condition can be considered premature if it occurs before the age of 40, leading to premature ovarian insufficiency. Despite the growing knowledge concerning the genetic basis of ovarian deficiency, the majority of cases remain without a genetic diagnosis. Although 22q11.2 deletions and duplications have been associated with genitourinary malformations, ovarian deficiency is not a commonly reported feature. We report here four patients bearing a 22q11.2 rearrangement, identified during the clinical assessment of their low ovarian reserve or premature ovarian insufficiency, and discuss the molecular basis of the ovarian defects