Cytogenetic and molecular studies in a lungfish, Protopterus annectens (Osteichthyes, Dipnoi)

Morescalchi, M. A.; Rocco, Lucia; Stingo, Vincenzo

doi:10.1016/s0378-1119(02)00755-2

Cited by 10 publications

(9 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Slight changes in the telomeric sequences have occurred during vertebrate evolution (Mayne et al 1990); the average rates of the DNA sequences differ between taxonomic groups, but the conservation of the (TTAGGG) n sequence and its telomeric location, also in species that are believed to have a common ancestor dating back to 400 million years BP, strongly suggests that this molecular ''fossil'' is the functional vertebrate telomere (Morescalchi et al 2002). The presence of additional (TTAGGG) n interstitial sites seems to be related with taxa undergoing an active evolution.…”

Section: Discussionmentioning

confidence: 99%

“…Metaphases were obtained from cephalic kidney, gills and gonads cell, according to Morescalchi et al (2002). NOR locations, identified by Ag-staining and CMA 3 /methylgreen were examined according to Howell and Black (1980) and Sola et al (1992) respectively.…”

Section: Chromosome Preparation and Fluorescent In Situ Hybridizationmentioning

confidence: 99%

“…For localization of telomeric (TTAGGG) n sequences and (GATA) 7 repeats, digoxigenin-labelled probes were purchased by Roche Diagnostics and in situ hybridization was performed following the manufacturer's suggestion. For 5S and 18S rDNA, the whole 5S and 18S rDNA PCR products were labelled with digoxigenin, by nick translation; hybridization was performed as previously described (Morescalchi et al 2002). Slides with metaphases were incubated with 0.004% Rnase, in a moist chamber at 37°C.…”

Section: Chromosome Preparation and Fluorescent In Situ Hybridizationmentioning

confidence: 99%

See 2 more Smart Citations

Karyotypic characterization and genomic organization of the 5S rDNA in Polypterus senegalus (Osteichthyes, Polypteridae)

et al. 2007

Self Cite

View full text Add to dashboard Cite

Polypteridae (Cladistia) is a family of archaic fishes, confined to African freshwaters. On account of their primitiveness in anatomical and morphological characters and mosaic relationships among lower Osteichthyans fishes, they constitute an important subject for the study of evolution in vertebrates. Very little is known about the karyological structure of these species. In this article, a cytogenetic analysis on twenty specimens of Polypterus senegalus (Cuvier, 1829) was performed using both classical and molecular techniques. Karyotype (2n=36; FN=72), chromosome location of telomeric sequences (TTAGGG)(n), (GATA)(7) repeats and ribosomal 5S and 18S rRNA genes were examined by using Ag-NOR, classical C-banding, CMA(3) staining and FISH. Staining with Ag-NOR showed the presence of two GC rich NORs on the p arm of the chromosome pair no. 1. CMA(3) marked all centromerical and some (no. 1 and no. 14) telomeric regions. FISH with 5S rDNA marked the subtelomeric region of the q arm of the chromosome pair no. 14. FISH with 18S rDNA marked the telomeric region of the p arm of the chromosome pair no. 1, previously marked by Ag-NOR. (GATA)(7) repeats marked the subtelomeric regions of all chromosome pairs, with the exclusion of the no. 1, 3 and 14. Hybridization with telomeric probes (TTAGGG)(n) showed bright signals at the end of all chromosomes. After cloning, the 5SrDNA alignment revealed an organization of sequences made up of two different classes of tandem arrays (5S type I and 5S type II) of different lengths.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Chromosome Preparation and Fluorescent In Situ Hybridizationmentioning

confidence: 99%

Section: Chromosome Preparation and Fluorescent In Situ Hybridizationmentioning

confidence: 99%

See 1 more Smart Citation

Karyotypic characterization and genomic organization of the 5S rDNA in Polypterus senegalus (Osteichthyes, Polypteridae)

et al. 2007

Self Cite

View full text Add to dashboard Cite

show abstract

“…Metaphases were obtained from cephalic kidney, gills and gonad cells, according to Morescalchi et al (2002). NOR locations, identified by CMA 3 /methyl-green, DAPI and Ag-staining were examined according to Sola et al (1992) and Howell and Black (1980) respectively.…”

Section: Chromosome Preparation and Fluorescent In Situ Hybridizationmentioning

confidence: 99%

Cytogenetic analysis in Polypterus ornatipinnis (Actinopterygii, Cladistia, Polypteridae) and 5S rDNA

2011

Self Cite

View full text Add to dashboard Cite

“…Chromosome preparation and fluorescent in situ hybridization (FISH) Metaphases were obtained from cephalic kidney, gills and gonads cell, according to Morescalchi et al (2002). NOR locations, identified by CMA 3 /methyl-green, DAPI and Ag-staining were examined according to Howell and Black (1980) and Sola et al (1992) respectively.…”

Section: Animalsmentioning

confidence: 99%

Karyotypic characterization and genomic organization of the 5S rDNA in Erpetoichthys calabaricus (Osteichthyes, Polypteridae)

et al. 2006

Self Cite

View full text Add to dashboard Cite

Polypterids are a group of Osteichthyan fish whose evolutionary relationships with closer basal ray-finned and lobe-finned fish have been disputed since their discovery. Very little is known about the evolutive karyology in the whole Polypteriformes group. In order to fill this gap, a cytogenetic analysis of Erpetoichthys calabaricus species was performed, using both classical and molecular techniques. Karyotype structure (2n = 36; FN = 72), chromosome location of telomeric sequences (TTAGGG)n and ribosomal 5S and 18S rRNA genes were examined in twenty specimens of E. calabaricus by using Ag-NOR, classical C-banding, sequential CMA3/4',6-diaminidino-2-phenylindole (DAPI) staining and fluorescent in situ hybridization (FISH). CMA3 marked all centromerical and some (no. 1 and no. 15) telomeric regions. Staining with Ag-NOR and CMA3 showed the presence of two NORs on the p arm of the chromosome pair no. 1. Hybridization with telomeric probes (TTAGGG)n showed signals at the end of all chromosomes. 5S rDNA was cloned and sequenced. After the alignment, the 5S rRNA sequences revealed an organization made up of two different classes of tandem arrays (type I and type II). FISH with 5S rDNA marked the telomeric regions of the small chromosome pair no. 15, while FISH with 18S rDNA marked the telomeric region of the pair no. 1. The results obtained were compared with cariological data on closer species now available in literature.

show abstract

Cytogenetic and molecular studies in a lungfish, Protopterus annectens (Osteichthyes, Dipnoi)

Cited by 10 publications

References 34 publications

Karyotypic characterization and genomic organization of the 5S rDNA in Polypterus senegalus (Osteichthyes, Polypteridae)

Karyotypic characterization and genomic organization of the 5S rDNA in Polypterus senegalus (Osteichthyes, Polypteridae)

Cytogenetic analysis in Polypterus ornatipinnis (Actinopterygii, Cladistia, Polypteridae) and 5S rDNA

Karyotypic characterization and genomic organization of the 5S rDNA in Erpetoichthys calabaricus (Osteichthyes, Polypteridae)

Contact Info

Product

Resources

About