Expression of olfactory receptor genes in non-olfactory tissues in the developing and adult zebrafish.

Since the discovery of olfactory receptor (OR) genes, their expression in non-olfactory tissues have been reported in rodents and humans. For example, mouse OR23 (mOR23) is expressed in sperm and muscle cells and has been proposed to play a role in chemotaxis and muscle migration, respectively. In addition, mouse mesencephalic dopaminergic neurons express various ORs, which respond to corresponding ligands.

Use of the chromosomal co-location of the minor 5S and the major 28S rDNA as a cytogenetic marker within the genus Leuciscus (Pisces, Cyprinidae).

The chromosomes of three species from the genus Leuciscus (the ide L. idus, the European chub L. cephalus and the common dace L.

Genetic and physical mapping of sex-linked AFLP markers in Nile tilapia (Oreochromis niloticus).

Identification of the sex-determining genes of the Nile tilapia (Oreochromis niloticus) has important implications for commercial aquaculture. We previously identified an XX/XY sex-determining locus in this species within a 10-cM interval between markers GM201 and UNH995 on linkage group one (LG1). In order to refine this region, we developed new AFLP markers using bulked segregant analysis of the mapping families.

Cytogenetic mapping of immunoglobulin heavy chain genes in Antarctic fish.

The chromosomal location of the IgH locus has been analyzed in several bony fish of the Antarctic perciform group Notothenioidei. Two IgH probes were prepared from the species Trematomus bernacchii (family Nototheniidae, tribe Trematominae) and mapped onto the chromosomes of ten species belonging to the same genus (Trematomus) and in two outgroups, through one-color and two-color FISH. A single location of the IgH locus was found in the majority of the species examined, including the outgroups, whereas in four of them the IgH genes splited to two chromosomal loci.

Are Cirripedia hopeful monsters? Cytogenetic approach and evidence for a Hox gene cluster in the cirripede crustacean Sacculina carcini.

The "hopeful monster" has haunted evolutionary thinking since Richard Goldschmidt coined the phrase in 1933. The phrase is directly related to genetic mechanisms in development and evolution. Cirripedes are peculiar crustaceans in that they all lack abdomens as adults.

Contrast between extensive variation of 28S rDNA and stability of 5S rDNA and telomeric repeats in the diploid-polyploid Squalius alburnoides complex and in its maternal ancestor Squalius pyrenaicus (Teleostei, Cyprinidae).

The diploid-polyploid Squalius alburnoides complex resulted from interspecific hybridization. The chromosomal mapping of 28S and 5S ribosomal genes and of (TTAGGG)n telomeric repeats was performed on specimens from the complex and from the sympatric bisexual species S. pyrenaicus (the complex maternal ancestor) as part of an investigation of the evolutionary relationships between genomic constitutions and the consequences of the ongoing polyploidization process in terms of chromosome reshaping.

Gene mapping of 28S and 5S rDNA sites in the spined loach Cobitis taenia (Pisces, Cobitidae) from a diploid population and a diploid-tetraploid population.

We compare the chromosomal 28S and 5S rDNA patterns of the spined loach C. taenia (2n = 48) from an exclusively diploid population and from a diploid-polyploid population using 28S and 5S rDNA probe preparation and labelling, and fluorescence in situ hybridization (FISH). The 5S rDNA was located in two to three chromosome pairs, and separated from the 28S loci for the males and one female (F1) from the diploid population.

Genome duplication in the teleost fish Tetraodon nigroviridis reveals the early vertebrate proto-karyotype.

Tetraodon nigroviridis is a freshwater puffer fish with the smallest known vertebrate genome. Here, we report a draft genome sequence with long-range linkage and substantial anchoring to the 21 Tetraodon chromosomes. Genome analysis provides a greatly improved fish gene catalogue, including identifying key genes previously thought to be absent in fish.

Global heterochromatic colocalization of transposable elements with minisatellites in the compact genome of the pufferfish Tetraodon nigroviridis.

Because of its unusual high degree of compaction and paucity of repetitive sequences, the genome of the smooth pufferfish Tetraodon nigroviridis is the subject of a well-advanced sequencing project. An astonishing diversity of transposable elements not found in the human and the mouse has been observed in the genome of T. nigroviridis.

An active non-LTR retrotransposon with tandem structure in the compact genome of the pufferfish Tetraodon nigroviridis.

The fish retrotransposable element Zebulon encodes a reverse transcriptase and a carboxy-terminal restriction enzyme-like endonuclease, and is related phylogenetically to site-specific non-LTR retrotransposons from nematodes. Zebulon was detected in the pufferfishes Tetraodon nigroviridis and Takifugu rubripes, as well as in the zebrafish Danio rerio. Structural analysis suggested that Zebulon, in contrast to most non-LTR retrotransposons, might be able to retrotranspose as a partial tandem array.