Erez Raz

..Our results indicate that zebrafish PGCs are guided by attraction towards two signaling centers, one of which may represent the somatic tissues of the gonad...

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..In all of these stages, zebrafish germ cells respond as individual cells to alterations in the shape of the sdf-1a expression domain, by directed migration towards their target - the position where the gonad develops...

..This review summarizes studies aimed at understanding the development of this cell population in zebrafish and compares these results with those obtained in other model organisms...

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..The ability to visualize chemokine-guided migration at a high resolution in vivo in these model organisms provides a unique opportunity to study this process, which is relevant for many events in normal development and disease...

..These distinctive morphological and molecular alterations could represent a general occurrence in similar processes critical for development and disease...

..Little is known about the structure of these granules as well as their segregation in mitosis during early germ-cell development...

..The biased formation of new protrusions in a particular region of the cell in response to SDF-1 defines the leading edge and the direction of cell migration...

..Together, these behavioral modes allow the cells to arrive at specific destinations with high fidelity and remain at their target site...

..Finally, we show that the PGCs can be attracted toward an ectopic source of the chemokine, strongly suggesting that this molecule provides a key directional cue for the PGCs...

..Based on molecular modeling, we identify the putative RNA binding domain of Dnd as a canonical RRM and propose that this domain is important for protein subcellular localization and function...

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..We have identified dead end orthologs in other vertebrates including Xenopus, mouse, and chick, where they are expressed in germ plasm and germ-line cells, suggesting a role in germ-line development in these organisms as well...

..We therefore conclude that Gi-dependent signaling is essential for directional migration, whereas the PI3K pathway is important for the actual motility of PGCs...

..Our results demonstrate an unexpected role for the germ line in promoting female development because PGC-ablated fish invariably developed as males...

..These findings suggest that SDF-1 is required for the PGCs to execute the final migration steps as they transmigrate through the blood vessel endothelium of the chick or the gut epithelium of the mouse...

..In addition, these studies underscore the different functions a single signaling pathway can have in controlling cell survival, cell proliferation, and cell migration during different phases of development...

..H1M transcripts are uniformly distributed during blastula stages, but become restricted to the PGCs during gastrulation and remain visible in PGCs as they migrate towards the region of the gonad...

..In conclusion, we show that posttranscriptional degradation-protection mechanisms acting on RNA and protein function in a vertebrate to enrich for specific molecules in the PGCs...

..Screening for genes mediating EMT and cancer metastasis, Waerner, Alacakaptan, and colleagues identified ILEI, a cytokine-like protein that plays an essential role in EMT, tumor growth, and late steps of metastasis...

..Furthermore, we show that piRNAs are Dicer independent and that their 3' end likely carries a 2'O-Methyl modification...

..The mouse Blimp1 gene encodes a transcriptional repressor that is essential for B-cell development. Recent studies have shown that the Blimp1 protein also plays a critical role in the specification of mouse primordial germ cells...

..In this process both SDF1 co-orthologues show only partly overlapping expression pattern and cooperate in the correct positioning of the PGCs...

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..These effects of Dnd1 are mediated through uridine-rich regions present in the miRNA-targeted mRNAs. Thus, our data unravel a novel role of Dnd1 in protecting certain mRNAs from miRNA-mediated repression...

..Our analysis reveals a role of SDF1/CXCR4 signaling in the development of migrating muscle progenitors and shows that a threshold number of progenitor cells is required to generate muscle of appropriate size...

..This demonstrates a high degree of evolutionary conservation of part of the mechanism, but also an area of evolutionary divergence...

..However, a mutation of the Pax6 site did not abolish reporter activity from an electroporated vector. We conclude that Otx2 and Pax6 are key molecules involved in conserved mechanisms of ANF gene regulation...

..Furthermore, the ability to generate large clutches of purely mutant embryos will greatly facilitate embryological, genetic, genomic, and biochemical studies...