Using sequencing and other techniques, a team of Carnegie Mellon researchers has identified multiple unique cell populations within breast milk, providing insights that may support future research into the biologic, prophylactic, and therapeutic contexts of these cell types. Despite evidence pointing to an important role for maternal cells in breast milk, the cells remain understudied. In a new study, which appears in this week's Science Advances, the investigators used a combination of flow cytometry, RT-PCR, and single-cell RNA sequencing to analyze fresh mature-stage breast milk from healthy donors. They identified epithelial lactocytes as the most abundant cell population in breast milk, a small percentage of which are stem-like, along with smaller populations of macrophages and T cells. The scientists also uncovered six distinct epithelial lactocyte subpopulations, including three previously unidentified subpopulations programmed toward mucosal defense and intestinal development. "Future work will determine the role of the subpopulations identified here in healthy and sick infants and apply those learnings to the development of novel, oral therapeutic interventions for gastrointestinal and other infantile diseases," they write.
Aiming to better understand the cellular diversity of the human cerebral cortex, scientists from Harvard University used multiplexed error-robust fluorescence in situ hybridization, or MERFISH, to perform spatially resolved single-cell profiling of 4,000 genes in frozen neurosurgical and postmortem brain samples. As described in Science this week, they found more than 100 transcriptionally distinct neuronal and non-neuronal cell populations and used the data to build a molecularly defined and spatially resolved cell atlas of the human middle and superior temporal gyrus. The investigators also used the resource for comparison studies in mice, revealing conservation in the laminar organization of cells and differences in somatic interactions across species.
By comparing ancient and modern DNA, a group led by Harvard University scientists has gained new insights into the population history of Micronesia. Located in the western Pacific Ocean, Micronesia is composed of thousands of small islands known to have been populated earlier than other parts of Remote Oceania. To better understand the origins of Micronesia's inhabitants, the researchers generated genome-wide ancient DNA data for 164 individuals from five archaeological sites in the region and co-analyzed them with published data from 112 current day people from Guam. An analysis of the data, reported in this week's Science, shows five migratory streams into Micronesia including three that are East Asian related and one that is Polynesian The other is a Papuan source related to mainland New Guineans that is different from the New Britain-related Papuan source for southwest Pacific populations but is similarly derived from male migrants between 2500 to 2000 years ago, the study's authors write. "Our results show that people in Micronesia have a diversity of ancestral origins even within the same geographic region, implying that the term Micronesian should be used as a geographic label without implying a specific biological profile," they conclude. GenomeWeb has more on this, here.