PI3K/AKT signaling controls ICM maturation and proper epiblast and primitive endoderm specification in mice.

The inner cell mass (ICM) of early mouse embryos is specified into epiblast (Epi) and primitive endoderm (PrE) lineages during blastocyst formation. The antagonistic transcription factors (TFs) NANOG and GATA-binding protein 6 (GATA6) in combination with fibroblast growth factor (FGF)/extracellular-signal-regulated kinase (ERK) signaling are central actors in ICM fate choice. However, what initiates the specification of ICM progenitors into Epi or PrE and whether other factors are involved in this process has not been fully understood yet.

Comprehensive alpha, beta, and delta cell transcriptomics reveal an association of cellular aging with MHC class I upregulation.

Objectives: This study aimed to evaluate the efficacy of a purification method developed for isolating alpha, beta, and delta cells from pancreatic islets of adult mice, extending its application to islets from newborn and aged mice. Furthermore, it sought to examine transcriptome dynamics in mouse pancreatic endocrine islet cells throughout postnatal development and to validate age-related alterations within these cell populations.

Methods: We leveraged the high surface expression of CD71 on beta cells and CD24 on delta cells to FACS-purify alpha, beta, and delta cells from newborn (1-week-old), adult (12-week-old), and old (18-month-old) mice.

A conserved NR5A1-responsive enhancer regulates SRY in testis-determination.

The Y-linked SRY gene initiates mammalian testis-determination. However, how the expression of SRY is regulated remains elusive. Here, we demonstrate that a conserved steroidogenic factor-1 (SF-1)/NR5A1 binding enhancer is required for appropriate SRY expression to initiate testis-determination in humans.

Learning trauma surgery through cytoreductive surgery.

Objectives: Regarding war surgery (WS), the initial and continuing education of French military gastrointestinal surgeons (FMGIS) is considered flawed and inappropriate. This results from the low incidence of gastrointestinal (GI) trauma, its predominantly non-surgical management, and a daily surgical practice that strongly differs from WS. Conversely, cytoreductive surgery (CRS) of peritoneal metastases has similarities with WS which led us to assess its potential contribution to the initial and continuing education of FMGIS in WS.