ABSTRACT
In this paper we report the cloning, sequence and expression analysis of a new Ciona intestinalis hox gene. On the basis of sequence comparison with mammalian and Amphioxus homologues, we called this gene Cihox5. Northern blot analysis reveals a single transcript of about 1.3 kb in length, that is present from neurula until larva stage. Whole-mount in situ hybridization shows restricted expression of this gene in putative blood cells precursors and in a regional domain of the spinal chord. Expression in the spinal cord is attributed to ependymal cells. This result implies a role for this gene in primitive regionalization of spinal cord along the anteroposterior axis in the absence of neuronal bodies.
Subject(s)
Ciona intestinalis/embryology , Ciona intestinalis/genetics , Genes, Homeobox , Homeodomain Proteins/genetics , Transcription Factors , Amino Acid Sequence , Animals , Cloning, Molecular , Drosophila/genetics , Gene Expression , Genes, Insect , Molecular Sequence Data , Sequence Homology, Amino Acid , Spine/embryologyABSTRACT
Commercial bulk products and pharmaceutical drug formulations of aminoglycoside antibiotics obtained by fermentation (kanamycin, gentamicin, sisomicin and tobramycin) or by synthesis (amikacin) were analysed with high-performance liquid chromatography on a C8 reversed-phase column. The method is based on a pre-column derivatization of the aminoglycosides with a 2,4,6-trinitrobenzenesulphonic acid reagent and UV detection (350 nm). The quantitative determination was carried out vs. an external standard; both peak heights and areas were used. A gentamicin mixture was separated into five or four components, depending on the column used. Amikacin was separated from its possible regioisomers and kanamycin A was easily separated from its minor components B and C.
