Msb069 primer pairs encompassed region is believed to be associated with a quantitative trait loci (QTL) of dorsal fin length in subgenus Poecilia. However, detailed investigation on Msb069 which originated from Xiphophorus on subgenus Poecilia remains unexplored. In this study, full sequence of Msb069 was characterized by sequencing bioinformatics analysis and gene expression. The sequence analysis of Msb069 primer pairs encompassed region on three species of Poecilia revealed higher number of microsatellite tandem repeats in Poecilia latipinna (ATG 16 ) compared to P. sphenops (ATG 13-14 ). There is no notable pattern of ATGtandem repeats discovered in the hybrids. The full sequence of Msb069 is 734 bp in length and showed a 233 bp conserved region between Xiphophorus and Poecilia. BLAST search performed on this sequence revealed no significant similarities. Nonquantitative RT-PCR exhibited the presence of Msb069 transcripts in three different tissues in subgenus Poecilia. Meanwhile, quantitative RTPCR expression on two different tissues showed relatively higher expression of Msb069 transcript in P. latipinna dorsal fin tissues in both male and female fishes, suggesting a repressive function of this transcript with respect to dorsal fin length. However the exact gene expression event of Msb069 is still unknown and requires further investigation.
Teleosts are useful vertebrate model species for understanding copper toxicity due to the dual entry route for copper intake via the gills and intestine. In this present study, we utilized the differential display reverse transcription-polymerase chain reaction to isolate potential novel hepatic genes induced by sublethal copper exposure in the freshwater swordtail fish, Xiphophorus helleri. Full length cloning of a cDNA fragment induced by copper exposure to 1 μg/ml during 24 h resulted in the positive identification of a hepatic ribosomal protein L19 (RPL19) gene. Further characterization of this gene revealed that its transcriptional expression was dependent on dosage and time of copper exposure. This study describes for the first time the involvement of RPL19 in copper toxicity, probably as a result of increase in ribosome synthesis rate to support activities such as cellular protein translation, transcriptional activation and mRNA stabilization during sublethal copper exposure.