scholarly journals In Situ Restriction Endonucleases Digestion by on the Nucleolar Organizer Region(NOR) in Neuroblast Mitotic Chromosomes of Bradysia hygida(Diptera: Sciaridae).

CYTOLOGIA ◽  
2002 ◽  
Vol 67 (4) ◽  
pp. 347-354
Author(s):  
Eliana Litsuko Tomimatsu Shimauti ◽  
Maria Aparecida Fernandez
Keyword(s):  
Organizer Region ◽  
Nucleolar Organizer Region ◽  
Nucleolar Organizer ◽  
Restriction Endonucleases ◽  
Mitotic Chromosomes ◽  
Bradysia Hygida

scholarly journals First chromosome analysis of Thai pufferfish Pao cochinchinensis (Steindachner, 1866)

2020 ◽  
Vol 21 (9) ◽  
Author(s):  
MANACHAYA PISSAPARN ◽  
SUMALEE PHIMPHAN ◽  
PATCHARAPORN CHAIYASAN ◽  
ALONGKLOD TANOAMTONG ◽  
THOMAS LIEHR ◽  
...  
Keyword(s):  
Organizer Region ◽  
Nucleolar Organizer Region ◽  
Molecular Cytogenetics ◽  
Nucleolar Organizer ◽  
Chromosome Analysis ◽  
Chromosomal Evolution ◽  
Giemsa Staining ◽  
Heteromorphic Sex Chromosomes ◽  
Almost All

Abstract. Pissaparn M, Phimphan S, Chaiyasan P, Tanoamtong A, Liehr T, Suwannapoom C, Reungsing M, Supiwong W. 2020. First chromosome analysis of Thai pufferfish Pao cochinchinensis (Steindachner, 1866). Biodiversitas 21: 4309-4316. Here first analysis of chromosomes and nucleolar organizer region (NOR) pattern in pufferfish Pao cochinchinensis (Steindachner, 1866) was undertaken. Chromosomal preparations were obtained from kidney of P. cochinchinensis from Chi River basin in Thailand. Chromosomal characteristics were analyzed by Giemsa staining, Ag-NOR banding as well as fluorescence in situ hybridization (FISH) using microsatellites d(CA)15 and d(CGG)10 probes. P. cochinchinensis had 2n = 40 with the fundamental number (NF) 74, both in male and female. The karyotype exhibited 12 metacentric (m), 10 submetacentric (sm), 12 acrocentric (a) and 6 telocentric (t) chromosomes. No differentiated heteromorphic sex chromosomes were observed. NORs were located on short arms adjacent to telomere of the metacentric chromosome pair 4, which coincide with signals of d(CGG)10 probe. FISH with d(CGG)10 sequences were also displayed at the telomeres of most other chromosomes, whereas d(CA)15 repeats highly accumulated throughout almost all entire chromosomes except for centromeric regions. The results of conventional Giemsa staining presented the differentiation even the same genus. The localization of NORs on one pair of chromosomes only is a common characteristic found in many fish groups as well as other vertebrates. Mapping of two distinct microsatellites demonstrated the remarkable chromosomal diversification that characterizes evolution in the genus Pao. Both, conventional and molecular cytogenetics are excellent tools to study, and better understand chromosomal evolution, as well as to uncover biodiversity among fishes.

scholarly journals In situ fluorescent visualization of nucleolar organizer region-associated proteins with a thiol reagent.

1993 ◽  
Vol 41 (9) ◽  
pp. 1413-1417 ◽  
Author(s):  
G Méhes ◽  
E Kálmán ◽  
L Pajor
Keyword(s):  
Silver Staining ◽  
Organizer Region ◽  
Nucleolar Organizer Region ◽  
Nucleolar Organizer ◽  
Nucleolar Organizer Regions ◽  
Thiol Reagent ◽  
Sh Group ◽  
Associated Proteins ◽  
Rnase Digestion

Nucleolar organizer regions (NORs) are nucleolus-forming rDNA loops associated with argyrophil proteins, the amount of which varies according to the proliferative state of the cell. It has been presumed that the nucleolar protein-related thiol groups may have a role in selective silver staining. We investigated the nuclear thiol distribution with a fluorescent thiol reagent, coumarinyl-phenyl-maleimide (CPM) in human K-562 myeloblast cultures and found that SH group-related fluorescence was brightest in the area of nucleoli, which became highly selective after RNAse digestion. A remarkable co-localization of AgNOR silver reaction and CPM fluorescence was observed, although occupation of the SH groups by CPM did not prevent the silver staining. We applied the stain to dual-parameter flow cytometry in combination with DNA content measurements, which provide further information on nucleolar function and changes in experimental and pathological specimens.

The molecular characterization of the genome of Muraena helena L. I. Isolation and hybridization of two MboI-restricted DNA fractions

Genome ◽  
1995 ◽  
Vol 38 (4) ◽  
pp. 809-813 ◽  
Author(s):  
G. Pichiri ◽  
M. Nieddu ◽  
R. Mezzanotte ◽  
P. P. Coni ◽  
S. Salvadori ◽  
...  
Keyword(s):  
Repetitive Dna ◽  
Organizer Region ◽  
Nucleolar Organizer Region ◽  
Electrophoretic Pattern ◽  
Nucleolar Organizer ◽  
Fish Chromosomes ◽  
Highly Repetitive Dna ◽  
Total Dna

To investigate the genome of the anguilliform fish Muraena helena at the molecular level we characterized total DNA by agarose gel electrophoresis after cleavage with AluI, HaeIII, MboI, and DdeI restriction endonucleases. Subsequently, we isolated the DNA from two specific electrophoretic fractions to be used as probes for Southern and in situ hybridization experiments. One such fraction showed an electrophoretic pattern typical of highly repetitive DNA localized in the centromeres of many chromosomes. The other fraction was shown to be located in the nucleolar organizer region, partially coincident with 45S rDNA, and to be composed of highly repetitive sequences.Key words: fish chromosomes, rDNA, highly repetitive DNA.

scholarly journals First report of karyological analysis and heteromorphic nucleolar organizer region of Black Surgeonfish (Acanthurus gahhm, Acanthuridae) in Thailand

Caryologia ◽  
2021 ◽  
Vol 74 (1) ◽  
pp. 83-88
Author(s):  
Sitthisak Jantarat ◽  
Sarun Jumrusthanasan ◽  
Sarawut Kaewsri ◽  
Praween Supanuam ◽  
Alongklod Tanomtong
Keyword(s):  
Organizer Region ◽  
Nucleolar Organizer Region ◽  
Nucleolar Organizer ◽  
Andaman Sea ◽  
Nucleolar Organizer Regions ◽  
Mitotic Chromosomes ◽  
Karyological Analysis ◽  
First Report ◽  
Telocentric Chromosomes ◽  
Karyotype Formula

This research was the first report on karyological analysis and heteromorphic nucleolar organizer region of black surgeonfish (Acanthurus gahhm, Acanthuridae) in Thailand. The 10 male and 10 female specimens were collected from Phuket Marine Biological Center, and Phang Nga Coastal Research and Development Center, Andaman Sea, Thailand. Mitotic chromosomes were directly prepared from gill and kidney tissues. The chromosomes were stained by conventional Giemsa staining and Ag-NOR banding techniques. Results showed that the diploid chromosomes number of A. gahhm was 2n=48, the fundamental numbers (NF) was 54 in both male and female. The karyotype consist of 6 large acrocentric, 20 large telocentric, 18 medium telocentric and 4 small telocentric chromosomes. None of strange size chromosomes related to sex was found. The heteromorphic nucleolar organizer regions (NORs) were observed on telomeric short arm of first acrocentric which can defined as 1a1b. There is NOR in 1a and not in 1b. The karyotype formula of black surgeon fish was as follows: 2n (48) = La6+Lt20+Mt18+St4

Genomic relationships between maize and its wild relatives

Genome ◽  
1999 ◽  
Vol 42 (6) ◽  
pp. 1201-1207 ◽  
Author(s):  
C Takahashi ◽  
J A Marshall ◽  
M D Bennett ◽  
I J Leitch
Keyword(s):  
Genomic Dna ◽  
Organizer Region ◽  
Nucleolar Organizer Region ◽  
Diploid Species ◽  
Nucleolar Organizer ◽  
Wild Relatives ◽  
Tripsacum Dactyloides ◽  
Genomic Relationships ◽  
Genome Donors

Recent molecular studies confirm the long-held theory that maize is a tetraploid, but the identity of the ancestral diploid species remains an enigma. The various hypotheses were investigated using genomic in situ hybridization (GISH). Total genomic DNA from 10 wild relatives of maize were used as probes onto maize chromosomes to see if this could identify the ancestral genome donors in maize. While none of the taxa hybridized to a subset of chromosomes, genomic DNA from Zea mays ssp. mexicana, Z. mays ssp. parviglumis, Z. diploperennis, Tripsacum dactyloides and Coix lacryma-jobi all showed a similar hybridization pattern consisting of a dispersed signal over all maize chromosomes. Moreover, the first four species also showed highly localized subtelomeric signal on the long arms of maize chromosomes 5, 6 ,7, and 8. In contrast, three Sorghum species tested (S. bicolor, S. halapense, and S. versicolor) only showed hybridization at the nucleolar organizer region. In light of recent data on retrotransposon occurrence in maize, the results may provide insights into the timing of speciation of Zea, Tripsacum, and Coix. Data obtained from the tetraploid Z. perennis strongly supported its taxonomic separation from the diploid Z. diploperennis.Key words: Zea, GISH, evolution, Tripsacum, Sorghum.

scholarly journals Comparative FISH analysis of Senna tora tandem repeats revealed insights into the chromosome dynamics in Senna

2021 ◽  
Vol 43 (3) ◽  
pp. 237-249 ◽  
Author(s):  
Thanh Dat Ta ◽  
Nomar Espinosa Waminal ◽  
Thi Hong Nguyen ◽  
Remnyl Joyce Pellerin ◽  
Hyun Hee Kim
Keyword(s):  
Tandem Repeats ◽  
Chromosomal Rearrangements ◽  
Organizer Region ◽  
Nucleolar Organizer Region ◽  
Nucleolar Organizer ◽  
Pericentromeric Region ◽  
Its2 Sequence ◽  
Fish Analysis ◽  
Chromosomal Distribution ◽  
Chromosome Dynamics

Abstract Background DNA tandem repeats (TRs) are often abundant and occupy discrete regions in eukaryotic genomes. These TRs often cause or generate chromosomal rearrangements, which, in turn, drive chromosome evolution and speciation. Tracing the chromosomal distribution of TRs could therefore provide insights into the chromosome dynamics and speciation among closely related taxa. The basic chromosome number in the genus Senna is 2n = 28, but dysploid species like Senna tora have also been observed. Objective To understand the dynamics of these TRs and their impact on S. tora dysploidization. Methods We performed a comparative fluorescence in situ hybridization (FISH) analysis among nine closely related Senna species and compared the chromosomal distribution of these repeats from a cytotaxonomic perspective by using the ITS1-5.8S-ITS2 sequence to infer phylogenetic relationships. Results Of the nine S. tora TRs, two did not show any FISH signal whereas seven TRs showed similar and contrasting patterns to other Senna species. StoTR01_86, which was localized in the pericentromeric regions in all S. tora, but not at the nucleolar organizer region (NOR) site, was colocalized at the NOR site in all species except in S. siamea. StoTR02_7_tel was mostly localized at chromosome termini, but some species had an interstitial telomeric repeat in a few chromosomes. StoTR05_180 was distributed in the subtelomeric region in most species and was highly amplified in the pericentromeric region in some species. StoTR06_159 was either absent or colocalized in the NOR site in some species, and StoIGS_463, which was localized at the NOR site in S. tora, was either absent or localized at the subtelomeric or pericentromeric regions in other species. Conclusions These data suggest that TRs play important roles in S. tora dysploidy and suggest the involvement of 45S rDNA intergenic spacers in “carrying” repeats during genome reshuffling.

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