An animal’s reproductive capabilities are established early in development, when a homogeneous embryonic cell population gives rise to two distinct cell types—somatic cells that form the vast majority of body tissues, and primordial germ cells (PGCs) that ultimately yield spermatozoa or ova.
Identifying genes responsible for ‘programming’ PGC development will be essential to fully understand this essential developmental process. Unfortunately, existing techniques for large-scale gene expression profiling are designed for use with multicellular samples—an ineffective strategy for PGC analysis.
“PGCs are small in number—especially at early stages—and are embedded in somatic neighbors,” explains Mitinori Saitou, of the RIKEN Center for Developmental Biology in Kobe. “Therefore, for systematically identifying genes specific to PGCs, single-cell analysis is considered to be essential.” Prior work from Saitou’s team identified several genes potentially important to PGC development. Now, his group has developed a powerful new technique for preparation and amplification of nucleic acids from individual cells, enabling stage-specific genomic profiling of mouse PGCs in unprecedented detail1.
The researchers focused on identifying genes regulated by Blimp1, a gene identified in their earlier work2. After analyzing PGCs from various developmental stages, it became clear that Blimp1 expression specifically increases in these cells over time. They also observed that although early-stage PGCs exhibit expression profiles for certain developmental genes that are similar to those observed in somatic cells, continued expression of Blimp1 leads to reversal of these expression patterns, actively driving development onto a PGC-specific trajectory.
A broader comparison of stage-specific gene expression in PGCs and somatic cells enabled Saitou’s team to assemble clusters of genes that are generally up- or down-regulated by Blimp1, allowing them to be categorized respectively as ‘specification’ or ‘somatic’ genes. Certain gene types were enriched for each category—including cell division regulators for the somatic genes and effectors of germ cell development for the specification genes—and each category also contained distinct sets of genes involved in embryonic development and body pattern formation.
Follow-up analyses confirmed that Blimp1 plays a central role in managing appropriate regulation of both somatic and specification genes for PGC development. “To me, the fact that Blimp1 represses essentially all the genes normally repressed in PGCs in comparison to their somatic neighbors is the most important finding,” says Saitou. Now, having glimpsed the ‘big picture’, Saitou’s team hunting for the primary target genes for Blimp1, and the mechanism by which it switches them on to set PGC development in motion.
1. Kurimoto, K., Yabuta, Y., Ohinata, Y., Shigeta, M., Yamanaka, K. & Saitou, M. Complex genome-wide transcription dynamics orchestrated by Blimp1 for the specification of the germ cell lineage in mice. Genes & Development 22, 1617–1635 (2008).
2. Ohinata, Y., Payer, B., O’Carroll, D., Ancelin, K., Ono, Y., Sano, M., Barton, S.C., Obukhanych, T., Nussenzweig, M., Tarakhovsky, A., et al. Blimp1 is a critical determinant of the germ cell lineage in mice. Nature 436, 207–213 (2005).
The corresponding author for this highlight is based at the RIKEN Laboratory for Mammalian Germ Cell Biology
Interfacial engineering core@shell nanoparticles for active and selective direct H2O2 generation
19.09.2018 | Science China Press
Making better use of enzymes: a new research project at Jacobs University
19.09.2018 | Jacobs University Bremen gGmbH
Thin-film solar cells made of crystalline silicon are inexpensive and achieve efficiencies of a good 14 percent. However, they could do even better if their shiny surfaces reflected less light. A team led by Prof. Christiane Becker from the Helmholtz-Zentrum Berlin (HZB) has now patented a sophisticated new solution to this problem.
"It is not enough simply to bring more light into the cell," says Christiane Becker. Such surface structures can even ultimately reduce the efficiency by...
A study in the journal Bulletin of Marine Science describes a new, blood-red species of octocoral found in Panama. The species in the genus Thesea was discovered in the threatened low-light reef environment on Hannibal Bank, 60 kilometers off mainland Pacific Panama, by researchers at the Smithsonian Tropical Research Institute in Panama (STRI) and the Centro de Investigación en Ciencias del Mar y Limnología (CIMAR) at the University of Costa Rica.
Scientists established the new species, Thesea dalioi, by comparing its physical traits, such as branch thickness and the bright red colony color, with the...
Scientists have succeeded in observing the first long-distance transfer of information in a magnetic group of materials known as antiferromagnets.
An international team of researchers has mapped Nemo's genome, providing the research community with an invaluable resource to decode the response of fish to...
Graphene is considered a promising candidate for the nanoelectronics of the future. In theory, it should allow clock rates up to a thousand times faster than today’s silicon-based electronics. Scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) and the University of Duisburg-Essen (UDE), in cooperation with the Max Planck Institute for Polymer Research (MPI-P), have now shown for the first time that graphene can actually convert electronic signals with frequencies in the gigahertz range – which correspond to today’s clock rates – extremely efficiently into signals with several times higher frequency. The researchers present their results in the scientific journal “Nature”.
Graphene – an ultrathin material consisting of a single layer of interlinked carbon atoms – is considered a promising candidate for the nanoelectronics of the...
03.09.2018 | Event News
27.08.2018 | Event News
17.08.2018 | Event News
19.09.2018 | Life Sciences
19.09.2018 | Physics and Astronomy
19.09.2018 | Information Technology