Identification and developmental expression pattern of van gogh-like 1, a second zebrafish strabismus homologue

Cell movement plays a central role in both normal embryogenesis and the development of diseases such as cancer. Therefore, identification and analysis of proteins controlling cell movement is of special importance. The zebrafish trilobite locus encodes a Van Gogh/Strabismus homologue, which regulates diverse cell migratory behaviors during embryogenesis. Trilobite is most similar to human Van Gogh-like 2 (VANGL2)/Strabismus 1 and mouse Loop-tail associated protein/Lpp1. Both human and mouse genomes encode a second Strabismus homologue referred to as VANGL1/Strabismus 2 and Lpp2, respectively. This prompted us to ask whether another van gogh/strabismus gene, one more closely related to human VANGL1, exists in the zebrafish genome. This paper describes the identification of zebrafish vangl1 and provides the first spatiotemporal expression and functional analysis of a vertebrate vangl1 homologue. Our data indicate that vangl1 and trilobite/vangl2 are expressed in largely non-overlapping domains during embryogenesis. Injection of synthetic vangl1 RNA partially suppressed the gastrulation defect in trilobite mutant embryos, suggesting that Vangl1 and Trilobite/Vangl2 have similar biochemical activities.     

No tail co-operates with non-canonical Wnt signaling to regulate posterior body morphogenesis in zebrafish

The vertebrate posterior body is formed by a combination of the gastrulation movements that shape the head and anterior trunk and posterior specific cell behaviors. Here, we investigated whether genes that regulate cell movements during gastrulation [no tail (ntl)/brachyury, knypek (kny) and pipetail (ppt)/wnt5] interact to regulate posterior body morphogenesis. Both kny;ntl and ppt;ntl double mutant embryos exhibit synergistic trunk and tail shortening by early segmentation. Gene expression analysis in the compound mutants indicates that anteroposterior germ-layer patterning is largely normal and that the tail elongation defects are not due to failure to specify or maintain posterior tissues. Moreover, ntl interacts with ppt and kny to synergistically regulate the posterior expression of the gene encoding bone morphogenetic protein 4 (bmp4) but not of other known T-box genes, fibroblast growth factor genes or caudal genes. Examination of mitotic and apoptotic cells indicates that impaired tail elongation is not simply due to decreased cell proliferation or increased cell death. Cell tracing in ppt;ntl and kny;ntl mutants demonstrates that the ventral derived posterior tailbud progenitors move into the tailbud. However, gastrulation-like convergence and extension movements and cell movements within the posterior tailbud are impaired. Furthermore, subduction movements of cells into the mesendoderm are reduced in kny;ntl and ppt;ntl mutants. We propose that Ntl and the non-canonical Wnt pathway components Ppt and Kny function in parallel, partially redundant pathways to regulate posterior body development. Our work initiates the genetic dissection of posterior body morphogenesis and links genes to specific tail-forming movements. Moreover, we provide genetic evidence for the notion that tail development entails a continuation of mechanisms regulating gastrulation together with mechanisms unique to the posterior body.     

Transparent things: Cell fates and cell movements during early embryogenesis of zebrafish

Development of an animal embryo involves the coordination of cell divisions, a variety of inductive interactions and extensive cellular rearrangements. One of the biggest challenges in developmental biology is to explain the relationships between these processes and the mechanisms that regulate them. Teleost embryos provide an ideal subject for the study of these issues. Their optical lucidity combined with modern techniques for the marking and observation of individual living cells allow high resolution investigations of specific morphogenetic movements and the construction of detailed fate maps. In this review we describe the patterns of cell divisions, cellular movements and other morphogenetic events during zebrafish early development and discuss how these events relate to the formation of restricted lineages.     

Impact of Potential Blockers on Ru(III) Complex Binding to Human Serum Albumin

The effects of aspirin, vitamin B2 and warfarin as potential blockers of the ruthenium binding sites in HSA were investigated through UV/visible, circular dichroism (CD), fluorescence spectroscopy and the inductively coupled plasma-atomic emission spectroscopy ICP(AES). The studies on the interactions of several biologically relevant molecules with HSA have shown that drugs like aspirin or warfarin may strongly influence the interaction of serum protein with anticancer drugs. It can derive from the influence of the drug on protein conformation or binding close to binding site of anticancer drug. Aspirin, vitB2 and warfarin bind to IIA subdomain leading to partial blocking of the ruthenium binding site in HSA.