Chromosome banding in salmonid fish: nucleolar organizer regions in Salmo and Salvelinus

1985 ◽  
Vol 27 (4) ◽  
pp. 433-440 ◽  
Author(s):  
Ruth Phillips ◽  
Peter E. Ihssen
Keyword(s):  
Atlantic Salmon ◽  
Brown Trout ◽  
Brook Trout ◽  
Chromosome Banding ◽  
Lake Trout ◽  
Nucleolar Organizer ◽  
Nucleolar Organizer Regions ◽  
Banding Patterns ◽  
Single Chromosome ◽  
Secondary Constrictions

Chromosome banding patterns obtained by silver staining (Ag-NORs) were analyzed in three species of Salmo (rainbow, brown trout, and Atlantic salmon) and three species of Salvelinus (brook trout, lake trout, and arctic char). In rainbow trout and Atlantic salmon the Ag-NORs were found at the secondary constrictions of a single chromosome pair, while in brown trout the Ag-NORs were found on the short arms of one or two of the two longest subtelocentric or acrocentric chromosome pairs. The location of the Ag-NORs was multichromosomal in the three Salvelinus species, occurring on one or both members of four to six different chromosome pairs in different individuals. The Ag-NOR sites were on the short arms of some acrocentric pairs and at the telomeres of other acrocentric pairs and one or two metacentric pairs. Chromomycin A3 positive bands were found at the same sites as the Ag-NORs in all species. In the species with multichromosomal location of Ag-NORs, polymorphisms in the size and location of the NORs were extremely common, so that almost every individual fish had a different pattern of Ag-NOR sites.Key words: banding, Salmo, Salvelinus, Ag-NORs, polymorphisms, nucleolar organizer.

Chromosome banding in salmonid fishes: nucleolar organizer regions in Oncorhynchus

1986 ◽  
Vol 28 (4) ◽  
pp. 502-510 ◽  
Author(s):  
Ruth B. Phillips ◽  
Kerry D. Zajicek ◽  
Fred M. Utter
Keyword(s):  
Chromosome Pair ◽  
Chromosome Banding ◽  
Acrocentric Chromosome ◽  
Nucleolar Organizer ◽  
Nucleolar Organizer Regions ◽  
Salmonid Fishes ◽  
Chromomycin A3 ◽  
Banding Patterns ◽  
Submetacentric Chromosome ◽  
Single Chromosome

Chromosome banding patterns obtained by silver staining and chromomycin a3 (CMA3) staining were analyzed in six species of Oncorhynchus: O. tshawytscha, O. kisutch, O. keta, O. nerka, and O. gorbuscha from North America and O. masou from Japan. Four different chromosomal locations of the nucleolor organizer regions (NORs) were found in different species. In O. tshawytscha, O. kisutch, and O. masou the NORs comprised the entire short arms of one medium-sized acrocentric chromosome pair. In O. nerka the NORs were found in an interstitial band on the short arms of one submetacentric chromosome pair and in O. gorbuscha proximal to the centromere on one metacentric chromosome pair. In O. keta the NORs were found on the telomeres of one small submetacentric chromosome pair. As in the related genera Salmo and Salvelinus chromomycin A3 positive bands were found at the same sites as the AgNORs in all species. Salmonid fish are assumed to be ancestral tetraploids and the considerable differences in chromosome number between different species are thought to be the result of chromosomal fusions after tetraploidization. In all members of the genus Oncorhynchus the rearrangements have resulted in the consolidation of the NORs on a single chromosome pair. The possible significance of intra- and inter-species NOR polymorphisms is discussed.Key words: nucleolar organizer regions, salmon, Oncorhynchus, chromosomes.

A role for upstream binding factor in organizing ribosomal gene chromatin

2006 ◽  
Vol 73 ◽  
pp. 77-84 ◽  
Author(s):  
Jane E. Wright ◽  
Christine Mais ◽  
José-Luis Prieto ◽  
Brian McStay
Keyword(s):  
Nucleolar Organizer ◽  
Ribosomal Gene ◽  
Rna Polymerase I ◽  
Nucleolar Organizer Regions ◽  
Binding Factor ◽  
Upstream Binding Factor ◽  
Acrocentric Chromosomes ◽  
Polymerase I ◽  
Secondary Constrictions ◽  
Active Nors

Human ribosomal genes are located in NORs (nucleolar organizer regions) on the short arms of acrocentric chromosomes. During metaphase, previously active NORs appear as prominent chromosomal features termed secondary constrictions, which are achromatic in chromosome banding and positive in silver staining. The architectural RNA polymerase I transcription factor UBF (upstream binding factor) binds extensively across the ribosomal gene repeat throughout the cell cycle. Evidence that UBF underpins NOR structure is provided by an examination of cell lines in which large arrays of a heterologous UBF binding sequences are integrated at ectopic sites on human chromosomes. These arrays efficiently recruit UBF even to sites outside the nucleolus, and during metaphase form novel silver-stainable secondary constrictions, termed pseudo-NORs, that are morphologically similar to NORs.

Effects of Proposed Passamaquoddy Power Project on Anadromous Fishes in Canadian Waters

1960 ◽  
Vol 17 (5) ◽  
pp. 713-720 ◽  
Author(s):  
C. J. Kerswill
Keyword(s):  
Atlantic Salmon ◽  
Brown Trout ◽  
Brook Trout ◽  
High Potential ◽  
Bay Of Fundy ◽  
Tidal Power ◽  
Potential Production ◽  
Sport Fishery ◽  
Potential Value ◽  
Power Project

Atlantic salmon, smelt, alewives, shad, eastern brook trout, and introduced brown trout occur in waters that will be affected by the Passamaquoddy power project. The first four species are taken occasionally in herring weirs but total annual landed values did not exceed $6,000 in the period 1937 to 1956. Salmon and trout have high potential value for angling, subject to improvements in local river management.Construction of tidal power dams should overcome the present lack of typical estuarine conditions in the Passamaquoddy area and favour production of anadromous species. An improved sport fishery for sea-run trout could develop. Realization of the potential production of Atlantic salmon, alewives and shad, but possibly not sea-run trout, would depend on satisfactory access from the Bay of Fundy to the impounded areas.

scholarly journals Physical and Genetic Mapping in the GrassesLolium perenneandFestuca pratensis

Genetics ◽  
2002 ◽  
Vol 161 (1) ◽  
pp. 315-324 ◽  
Author(s):  
J King ◽  
I P Armstead ◽  
I S Donnison ◽  
H M Thomas ◽  
R N Jones ◽  
...  
Keyword(s):  
Large Scale ◽  
Physical Map ◽  
Rice Chromosome ◽  
Nucleolar Organizer ◽  
Physical Distance ◽  
Chromosome 1 ◽  
Grass Species ◽  
Nucleolar Organizer Regions ◽  
Single Chromosome ◽  
Large Scale Analysis

AbstractA single chromosome of the grass species Festuca pratensis has been introgressed into Lolium perenne to produce a diploid monosomic substitution line (2n = 2x = 14). In this line recombination occurs throughout the length of the F. pratensis/L. perenne bivalent. The F. pratensis chromosome and recombinants between it and its L. perenne homeologue can be visualized using genomic in situ hybridization (GISH). GISH junctions represent the physical locations of sites of recombination, enabling a range of recombinant chromosomes to be used for physical mapping of the introgressed F. pratensis chromosome. The physical map, in conjunction with a genetic map composed of 104 F. pratensis-specific amplified fragment length polymorphisms (AFLPs), demonstrated: (1) the first large-scale analysis of the physical distribution of AFLPs; (2) variation in the relationship between genetic and physical distance from one part of the F. pratensis chromosome to another (e.g., variation was observed between and within chromosome arms); (3) that nucleolar organizer regions (NORs) and centromeres greatly reduce recombination; (4) that coding sequences are present close to the centromere and NORs in areas of low recombination in plant species with large genomes; and (5) apparent complete synteny between the F. pratensis chromosome and rice chromosome 1.

NUCLEOLAR ORGANIZER REGIONS IN THE RABBIT (ORYCTOLAGUS CUNICULUS) AS SHOWN BY SILVER STAINING

1978 ◽  
Vol 20 (3) ◽  
pp. 377-382 ◽  
Author(s):  
Patricia A. Martin-Deleon ◽  
Dorene L. Petrosky ◽  
M. Eileen Fleming
Keyword(s):  
New Zealand ◽  
Silver Staining ◽  
Oryctolagus Cuniculus ◽  
Nucleolar Organizer ◽  
Nucleolar Organizer Regions ◽  
Telomeric Region ◽  
Metaphase Chromosomes ◽  
Domestic Rabbit ◽  
Silver Precipitation ◽  
Secondary Constrictions

Nucleolar organizer regions (NOR's) were demonstrated in metaphase chromosomes of the domestic rabbit, Oryctolagus cuniculus (L.) (New Zealand white strain) using silver staining. Sequential quinacrine banding and a modification of the Ag-AS silver precipitation technique with duplicate photography allowed identification of silver staining NOR's on the short arms of chromosomes 13, 16, and 20, as well as the telomeric region of the long arms of number 21 in some cells. Chromosomes 13, 16 and 20 all have subterminal to terminal centromeres, often showed satellites and secondary constrictions, and were sometimes involved in associations.

DIMORPHIC NUCLEOLAR ORGANIZER REGIONS IN THE FROG RANA BLAIRI

1977 ◽  
Vol 19 (1) ◽  
pp. 51-57 ◽  
Author(s):  
Oscar G. Ward
Keyword(s):  
Species Complex ◽  
Rana Pipiens ◽  
Nucleolar Organizer ◽  
Staining Procedure ◽  
Nucleolar Organizer Regions ◽  
Specific Staining ◽  
Rana Blairi ◽  
Ammoniacal Silver ◽  
Secondary Constrictions ◽  
Unequal Length

The nucleolar organizer-specific staining procedure, ammoniacal silver (Ag-AS), has been used to study the distribution and size of the nucleolar organizer regions (NORs) in chromosomes of the frog Rana blairi (Mecham, Littlejohn, Oldham, Brown and Brown). The somatic metaphase karyotype of this frog is similar to that of other frogs of the Rana pipiens species complex, numerically (2n = 26) and morphologically. Secondary constrictions are detectable in untreated Giemsa-stained metaphase preparations as achromatic gaps in the long arms of a pair of submetacentric chromosomes (no. 10). These constrictions are the only regions which are deeply stained with the Ag-AS method and are thus identified as the nucleolar organizer regions (Ag-NORs). In each of the three individuals, the Ag-NORs as visualized on the homologues are of unequal length.

scholarly journals Cytogenetic analyses in Trinomys (Echimyidae, Rodentia), with description of new karyotypes

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5316 ◽  
Author(s):  
Naiara Pereira Araújo ◽  
Cayo Augusto Rocha Dias ◽  
Rodolfo Stumpp ◽  
Marta Svartman
Keyword(s):  
Chromosome Mapping ◽  
Nucleolar Organizer ◽  
Interspecific Variation ◽  
Nucleolar Organizer Regions ◽  
45S Rdna ◽  
Banding Patterns ◽  
Pericentric Inversions ◽  
Cytogenetic Analyses ◽  
First Time

Trinomys Thomas (1921) is a terrestrial genus of spiny rats endemic to the Brazilian areas of Atlantic Forest and the transitional areas of Cerrado and Caatinga. Although most species have been already karyotyped, the available cytogenetic information is mostly restricted to diploid and fundamental numbers. We analyzed the chromosomes of two Trinomys species: Trinomys moojeni (2n = 56, FN = 106) and Trinomys setosus setosus (2n = 56, FN = 106 and 2n = 56, FN = 108). Our analyses included GTG- and CBG-banding, silver-staining of the nucleolar organizer regions, and chromosome mapping of telomeres and 45S rDNA by fluorescent in situ hybridization (FISH). Comparative GTG- and CBG-banding suggested that the interspecific variation may be due to rearrangements such as pericentric inversions, centromere repositioning, and heterochromatin variation. We report two new karyotypes for T. s. setosus and describe for the first time the banding patterns of the two Trinomys species.

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