Lucille Joly

Screen for genes differentially expressed during regeneration of the zebrafish caudal fin

The zebrafish caudal fin constitutes an important model for studying the molecular basis of tissue regeneration. The cascade of genes induced after amputation or injury, leading to restoration of the lost fin structures, include those responsible for wound healing, blastema formation, tissue outgrowth, and patterning. We carried out a systematic study to identify genes that are up‐regulated during “initiation” (1 day) and “outgrowth and differentiation” (4 days) of fin regeneration by using two complementary methods, suppression subtraction hybridization (SSH) and differential display reverse transcriptase polymerase chain reaction (DDRT‐PCR). We obtained 298 distinct genes/sequences from SSH libraries and 24 distinct genes/sequences by DDRT‐PCR. We determined the expression of 54 of these genes using in situ hybridization. In parallel, gene expression analyses were done in zebrafish embryos and early larvae. The information gathered from the present study provides resources for further investigations into the molecular mechanisms of fin development and regeneration. Developmental Dynamics 231:527–541, 2004.

Zebrafish/mouse somatic cell hybrids for the characterization of the zebrafish genome.

Publisher Summary This chapter overviews the techniques pertinent to the production and the characterization of zebrafish/mouse cell hybrids. Transfer of zebrafish chromosomes to cells of a foreign species has been accomplished successfully with three different fish cell lines-ZF4, LFF, and AB9—as donor cells, and with the mouse B78 cells or hamster Wg3H cells as recipients. The mouse B78 melanoma cell line was chosen as recipient in whole-cell fusion experiments because it was previously shown to fuse very easily with other cell lines. Furthermore, the cells have a fast growth rate and are easy to maintain, characteristics that were often retained after fusion. Zebrafish chromosomes are tagged with the neo resistance gene. Mouse B78 cells are not deficient in any enzyme—therefore, the aminoglycoside phosphotransferase (neo) gene, conferring resistance to the aminoglycoside drug G418, is introduced into zebrafish chromosomes to select against unfused recipient mouse cells and to ensure retention of zebrafish chromosomes in hybrids.

Linkage Mapping of the [Pro2]Somatostatin-14 Gene in Zebrafish: Evolutionary Perspectives

Abstract: Radiation hybrid mapping assigned the zebrafish [Pro2]somatostatin‐14 (also termed somatostatin 2; SS2) gene to linkage group 23 of the zebrafish genome, close to the marker nadl1.2. Comparative genomic analysis revealed conserved syntenies of the SS2 gene locus with part of the human 1p36 region, where the cortistatin gene is located. This observation strongly suggests that the SS2 gene in nonmammalian species and the cortistatin gene in mammals are orthologous.

Patterning of the Zebrafish Embryo along the Anteroposterior Axis

Publisher Summary This chapter describes how different regional identities may be assigned along the anteroposterior (AP) body axis of the developing zebrafish embryo, namely in the head, trunk, and tail regions. It provides a description on the isolation of the Hox cluster genes in zebrafish. Although the characterization of this family of genes in the frog, chick, mouse, and human has often been dogmatically reported in the literature and textbooks as applicable to all vertebrates, this chapter describes important differences in the genomic organization and expression patterns of the zebrafish Hox cluster genes relative to the Hox cluster genes in tetrapods. It has been found that the zebrafish Hox cluster genes are useful markers for regions of the zebrafish hindbrain and trunk; however, as in tetrapods, the genes which are studied here to date do not appear to have unique expression patterns within the tail region. To show how different regional identities may be specified in the vertebrate tail region, this chapter describes cell marking and cell movement analyses of the developing tail bud in the living zebrafish embryo. It was found that although the tail bud region of the zebrafish, like most vertebrates, appears initially as a homogeneous blastema without easily recognizable germ layer distinctions, it is actually a very ordered tissue with distinct fate-map regions of cell fate identity. In addition, this chapter provides a set of cell movements that appear to be unique to the tail bud region.