The fetal brain undergoes rapid changes in late gestation, when waves of neurogenesis and gliogenesis shape cortical circuitry. The periventricular proliferative region and adjacent white matter are enriched in neuroprogenitor cells, newborn neurons, and interneurons, which is challenging to study in the late gestation human fetal brain. The nonhuman primate (NHP) provides a powerful translational model to overcome this limitation, given its close similarity to human neurodevelopmental trajectories. The study objective was to construct a single-cell RNA-Seq (scRNA-Seq) atlas of the late-gestation fetal brain of the pigtail macaque (Macaca nemestrina), focused on the periventricular proliferative zone. A sample of the lateral ventricular wall, subventricular zone, and overlying white/gray matter was dissociated into single cells and processed through the 10X Genomics pipeline, followed by SoupX removal of ambient RNA, and the Seurat pipeline to aggregate, cluster, and annotate single-cell populations. Monocle3 was used to determine pseudotime and map lineage progression. This analysis captured diverse populations of neuroprogenitors, newborn neurons, developing lineages of excitatory and inhibitory neurons, oligodendrocyte and astrocyte lineages, and resident immune and endothelial cells. In summary, single-cell populations from the third-trimester nonhuman primate fetal brain are highly similar to those in the human fetus. This late-gestation single-cell atlas of the periventricular proliferative zone provides a unique reference for progenitor, neuronal, glial, vascular, and immune cell states during a critical window of primate neurodevelopment, enabling mechanistic interrogation of how inflammatory, infectious, or hypoxic insults disrupt vulnerable neurogenic niches.

Background: In 2020, the World Health Organization declared a Public Health Emergency of International Concern due to the global outbreak of SARS-CoV-2. Recognized as a severe and highly contagious disease, it affected both the adult and pediatric population. However, due to the early timing of the pandemic, limited research was conducted in the perinatal field, leaving many questions regarding the true impact of maternal transmission to fetuses and its consequences during the neonatal period. Methods: In this case series, we reviewed data from ten newborns delivered in the Instituto Nacional de Perinatología (INPer) in Mexico City (tertiary referral institute), all from high-risk pregnancies, between November 2020 and January 2021, all of whom tested positive for SARS-CoV-2 at various points during their hospital stay. Results: Despite showing correct extrauterine adaptation after birth, several of them developed complications such as sepsis, superinfections, inadequate weight gain, and, in some cases, death. Conclusions: These results highlight the urgent need for targeted neonatal care protocols and further research to better understand the impact of persistent viral positivity and immune vulnerability in this population.