Suchergebnisse

Not Available ; Dual-color fluorescence in situ hybridization (FISH) was performed to study the simultaneous localization of major (45S) and minor (5S) family ribosomal RNA genes on chromosomes of Neolissochilus hexagonolepis. The partial 45S (18S, ITS 1, 5.8S, ITS 2 and 28S) and complete 5S (coding and NTS) rDNA units were amplified, sequenced, analyzed, and mapped on the metaphase chromosomes. The complete 18S, 5.8S and partial 28S rDNAs were 1849 bp, 157 bp and 1819 bp long, respectively. Internal transcribed spacers, namely ITS 1 (828 bp) and ITS 2 (359 bp), showed significant nucleotide variations from other fish species listed in NCBI database. The 5S rDNA contained an identical coding region of 120 bp and a highly divergent, non-transcribed 81-bp spacer. The specimens of N. hexagonolepis showed six bright fluorescent signals of 18S, while the 5S signals were present only on one pair of chromosomes. Subsequent analyses between conventional Ag-NORs and 18S rDNA FISH strongly suggested the possible inactivation of one pair of NORs that was localized at a telomeric position of a submetacentric chromosome. The sequencing and chromosomal localization of 45S and 5S rDNAs may serve as a useful genetic marker in taxonomic classification as well as in phylogenetic and evolutionary studies. ; Department of Biotechnology, Ministry of Science and Technology, Government of India .

Not Available ; Fish cell line has emerged as an important tool in fishery biotechnology. In recent years, various fish cell lines have been developed by different researchers across the country. National Repository on Fish cell lines, established with the aim to preserve fish cell lines for training and education to stakeholders, has started functioning at National Bureau of Fish Genetic Resources, Lucknow. This repository is supposed to characterize and preserve the fish cell lines developed across the country and serve as a national referral centre for Indian and exotic fish cell lines. Currently, the repository is maintaining 50 fish cell lines deposited by various research institutes in India, including the cell lines developed at cell culture facility of National Bureau of Fish Genetic Resources. The cell lines have been successfully cryopreserved after verifying its authenticity by sequence analysis of two mitochondrial genes, viz. 16S rRNA and cytochrome c oxidase sub-unit I. Chromosomal analysis, transfection efficiency and immunocytochemistry are also being used to characterize the cell lines. The facility is serviceable for the collection, deposition and distribution of fish cell lines. This paper discusses the status as well as the methodology adopted for fish cell lines development, characterization and storage at NRFC. ; Department of Biotechnology, Government of India, New Delhi.