Click
here to close Hello! We notice that
you are using Internet Explorer, which is not supported by Echinobase
and may cause the site to display incorrectly. We suggest using a
current version of Chrome,
FireFox,
or Safari.
???displayArticle.abstract???
Small micromeres of the sea urchin are believed to be primordial germ cells (PGCs), fated to give rise to sperm or eggs in the adult. Sea urchin PGCs are formed at the fifth cleavage, undergo one additional division during blastulation, and migrate to the coelomic pouches of the pluteus larva. The goal of this chapter is to detail classical and modern techniques used to analyze primordial germ cell specification, gene expression programs, and cell behaviors in fixed and live embryos. The transparency of the sea urchin embryo enables both live imaging techniques and in situ RNA hybridization and immunolabeling for a detailed molecular characterization of these cells. Four approaches are presented to highlight small micromeres with fluorescent molecules for analysis by live and fixed cell microscopy: (1) small molecule dye accumulation during cleavage and blastula stages, (2) primordial germ cell targeted RNA expression using the Nanos untranslated regions, (3) fusing genes of interest with a Nanos2 targeting peptide, and (4) EdU and BrdU labeling. Applications of the live labeling techniques are discussed, including sorting by fluorescence-activated cell sorting for transcriptomic analysis, and, methods to image small micromere behavior in whole and dissociated embryos by live confocal microscopy. Finally, summary table of antibody and RNA probes as well as small molecule dyes to label small micromeres at a variety of developmental stages is provided.
Campanale,
Migration of sea urchin primordial germ cells.
2014,
Pubmed
,
Echinobase
Campanale,
Programmed reduction of ABC transporter activity in sea urchin germline progenitors.
2012,
Pubmed
,
Echinobase
Essodaigui,
Kinetic analysis of calcein and calcein-acetoxymethylester efflux mediated by the multidrug resistance protein and P-glycoprotein.
1998,
Pubmed
Ettensohn,
Lessons from a gene regulatory network: echinoderm skeletogenesis provides insights into evolution, plasticity and morphogenesis.
2009,
Pubmed
,
Echinobase
Extavour,
Mechanisms of germ cell specification across the metazoans: epigenesis and preformation.
2003,
Pubmed
Foltz,
Echinoderm eggs and embryos: procurement and culture.
2004,
Pubmed
,
Echinobase
Fresques,
Selective accumulation of germ-line associated gene products in early development of the sea star and distinct differences from germ-line development in the sea urchin.
2014,
Pubmed
,
Echinobase
Fujii,
Role of the nanos homolog during sea urchin development.
2009,
Pubmed
,
Echinobase
Hamdoun,
Activation of multidrug efflux transporter activity at fertilization in sea urchin embryos (Strongylocentrotus purpuratus).
2004,
Pubmed
,
Echinobase
Hara,
Exclusive expression of hedgehog in small micromere descendants during early embryogenesis in the sea urchin, Hemicentrotus pulcherrimus.
2005,
Pubmed
,
Echinobase
HORSTADIUS,
The mechanics of sea urchin development.
1950,
Pubmed
,
Echinobase
Juliano,
A conserved germline multipotency program.
2010,
Pubmed
,
Echinobase
Juliano,
Germ line determinants are not localized early in sea urchin development, but do accumulate in the small micromere lineage.
2006,
Pubmed
,
Echinobase
Juliano,
Nanos functions to maintain the fate of the small micromere lineage in the sea urchin embryo.
2010,
Pubmed
,
Echinobase
Juliano,
Developmental biology. Versatile germline genes.
2010,
Pubmed
Lehmann,
Germline stem cells: origin and destiny.
2012,
Pubmed
Luo,
Opposing nodal and BMP signals regulate left-right asymmetry in the sea urchin larva.
2012,
Pubmed
,
Echinobase
Martik,
Deployment of a retinal determination gene network drives directed cell migration in the sea urchin embryo.
2015,
Pubmed
,
Echinobase
Materna,
Notch and Nodal control forkhead factor expression in the specification of multipotent progenitors in sea urchin.
2013,
Pubmed
,
Echinobase
Materna,
A comprehensive analysis of Delta signaling in pre-gastrular sea urchin embryos.
2012,
Pubmed
,
Echinobase
McClay,
Methods for embryo dissociation and analysis of cell adhesion.
2004,
Pubmed
,
Echinobase
Minokawa,
Timing of the potential of micromere-descendants in echinoid embryos to induce endoderm differentiation of mesomere-descendants.
1999,
Pubmed
,
Echinobase
Oulhen,
Transient translational quiescence in primordial germ cells.
2017,
Pubmed
,
Echinobase
Oulhen,
The 3'UTR of nanos2 directs enrichment in the germ cell lineage of the sea urchin.
2013,
Pubmed
,
Echinobase
Oulhen,
Retention of exogenous mRNAs selectively in the germ cells of the sea urchin requires only a 5'-cap and a 3'-UTR.
2013,
Pubmed
,
Echinobase
Oulhen,
Differential Nanos 2 protein stability results in selective germ cell accumulation in the sea urchin.
2016,
Pubmed
,
Echinobase
Pehrson,
The fate of the small micromeres in sea urchin development.
1986,
Pubmed
,
Echinobase
Raz,
Guidance of primordial germ cell migration.
2004,
Pubmed
Roepke,
Increase in multidrug transport activity is associated with oocyte maturation in sea stars.
2006,
Pubmed
,
Echinobase
Santos,
Germ cell specification and migration in Drosophila and beyond.
2004,
Pubmed
Swartz,
Deadenylase depletion protects inherited mRNAs in primordial germ cells.
2014,
Pubmed
,
Echinobase
Tanaka,
Study of the Lineage and Cell Cycle of Small Micromeres in Embryos of the Sea Urchin, Hemicentrotus pulcherrimus: (small micromeres/cell cycle/cell lineage/unequal cleavage/sea urchin).
1990,
Pubmed
,
Echinobase
Tarbashevich,
The nuts and bolts of germ-cell migration.
2010,
Pubmed
Tokuoka,
Specification and differentiation processes of secondary mesenchyme-derived cells in embryos of the sea urchin Hemicentrotus pulcherrimus.
2002,
Pubmed
,
Echinobase
Voronina,
Vasa protein expression is restricted to the small micromeres of the sea urchin, but is inducible in other lineages early in development.
2008,
Pubmed
,
Echinobase
Wessel,
The biology of the germ line in echinoderms.
2014,
Pubmed
,
Echinobase
Wu,
Asymmetric localization of germline markers Vasa and Nanos during early development in the amphioxus Branchiostoma floridae.
2011,
Pubmed
Yajima,
Small micromeres contribute to the germline in the sea urchin.
2011,
Pubmed
,
Echinobase
Yajima,
Autonomy in specification of primordial germ cells and their passive translocation in the sea urchin.
2012,
Pubmed
,
Echinobase
