Cytogenetic studies in gomphocerine grasshoppers. II. Chromosomal location of active nucleolar organizing regions

1986 ◽  
Vol 28 (4) ◽  
pp. 540-544 ◽  
Author(s):  
Josefa Cabrero ◽  
Juan Pedro M. Camacho
Keyword(s):  
Chromosomal Location ◽  
Nucleolar Organizer ◽  
X Chromosomes ◽  
Nucleolar Organizing Regions ◽  
Nucleolar Organizing Region ◽  
Primary Activity ◽  
Cytogenetic Studies ◽  
Almost All ◽  
Active Nors

Nucleolar organizing region (NOR) location has been studied in 20 species of gomphocerine grasshoppers. In the 17 species with 2n (♀) = 17, the largest number carry an active NOR on the L2, L3, and X chromosomes. The M4, M5, M6, and S8 show NOR activity in some species, but the L1 and M7 do not carry a NOR in any. While almost all NORs on L2, L3, and X show primary activity, a majority of these on the M4, M5, M6, and S8 are secondary and express a nucleolus only in a minority of male meiocytes. The NORs are located preferentially at particular chromosomal sites; primary active NORs prevail in interstitial locations, while secondary active NORs predominate in paracentromeric locations. In the majority of the species analyzed in this report, primary and secondary active NORs coincide with C-bands. Euchorthippus pulvinatus is an exception; here NORs do not seem to be related to C-bands. However, the nucleolar-associated heterochromatin in this species can be demonstrated by a N-banding technique.Key words: nucleolar organizer, NOR (primary), C-bands, heterochromatin, NOR (secondary).

Karyotypes, C-banding, and chromosomal location of active nucleolar organizing regions in Tapinoma (Hymenoptera, Formicidae)

Genome ◽  
1988 ◽  
Vol 30 (2) ◽  
pp. 277-280 ◽  
Author(s):  
T. Palomeque ◽  
E. Chica ◽  
M. A. Cano ◽  
R. Díaz de la Guardia
Keyword(s):  
Chromosomal Location ◽  
Nucleolar Organizer ◽  
The Other ◽  
Chromosome Differentiation ◽  
Nucleolar Organizing Regions ◽  
C Banding ◽  
Secondary Activity ◽  
Primary Activity ◽  
Tapinoma Erraticum ◽  
Tapinoma Nigerrimum

The haploid and diploid karyotypes of Tapinoma erraticum (n = 8) and Tapinoma nigerrimum (n = 9) were analyzed using C-banding and observation of NOR sites. C-banding showed the existence of heterochromatin in the paracentromeric regions of all chromosomes. The analysis of NOR sites in these species proved the existence of primary activity NOR in one or two chromosomes, respectively, whereas the other chromosomes showed secondary activity NOR, expressed only in a minority of cells. In both species the NOR were located in paracentromeric regions. These results are discussed in relation to a hypothesis of chromosome differentiation of these species.Key words: C-bands, nucleolar organizer, NOR (primary), NOR (secondary), Formicidae.

Karyotype, C-banding, chromosomal location of active nucleolar organizing regions, and B-chromosomes in Lasius niger (Hymenoptera, Formicidae)

Genome ◽  
1990 ◽  
Vol 33 (2) ◽  
pp. 267-272 ◽  
Author(s):  
T. Palomeque ◽  
E. Chica ◽  
R. Díaz de la Guardia
Keyword(s):  
Germ Cells ◽  
Chromosomal Location ◽  
Ganglion Cells ◽  
Cerebral Ganglion ◽  
B Chromosomes ◽  
Lasius Niger ◽  
Nucleolar Organizing Regions ◽  
Nucleolar Organizing Region ◽  
C Banding ◽  
Numerical Variation

The karyotype of Lasius niger (n = 15) was analysed using C-banding and observation of nucleolar organizing region (NOR) sites. C-banding showed the existence of heterochromatin in the paracentromeric regions of all chromosomes. Two sites with primary NORs were found in chromosomes 6 and 8. Chromosome 13 showed a secondary NOR. In both cases, the NORs were located in the paracentromeric region. B-chromosomes were found in male and female germ cells. They exhibited intra- and inter-individual numerical variation. No B-chromosomes were observed in somatic cells (cerebral ganglion cells) of all castes. The Bs are telocentric, small, and clearly distinguishable from the regular members of the complement. They show positive heteropycnosis in meiotic prophase and they are highly C-band positive. The activity of NORs does not change when Bs are present. Several aspects of the behaviour of these Bs are examined.Key words: C-bands, nucleolar organizing region (primary), nucleolar oganizing region (secondary), B-chromosomes, Formicidae.

scholarly journals Effects of B chromosomes on the activity of nucleolar organizer regions in the grasshopper Eyprepocnemis plorans: activation of a latent nucleolar organizer region on a B chromosome fused to an autosome

Genome ◽  
1987 ◽  
Vol 29 (1) ◽  
pp. 116-121 ◽  
Author(s):  
J. Cabrero ◽  
J. D. Alché ◽  
J. P. M. Camacho
Keyword(s):  
Organizer Region ◽  
Nucleolar Organizer Region ◽  
Centric Fusion ◽  
Nucleolar Organizer ◽  
B Chromosome ◽  
Nucleolar Organizer Regions ◽  
Eyprepocnemis Plorans ◽  
X Chromosomes ◽  
Active Nors ◽  
Do So

Four nucleolar organizer regions (NORs) are active in standard males of the grasshopper Eyprepocnemis plorans. They are located near the centromeric regions of the S9, S10, S11, and X chromosomes. Changes in the pattern of NOR activity have been observed in the presence of a B2 type supernumerary chromosome. Males with one B show a higher mean number of active NORs per cell than do zero B males owing to significant increases in the activity of the NORs on the S11 and the X. Zero B and one B embryos, however, showed similar patterns of activity. In a male carrying a centric fusion between a B and one of the L1 chromosomes, the activation of a latent NOR, present at the telomere of the long arm of the B, parallelled a significant decrease of NOR activity on the S9 and S10 bivalents stemming from a competition between different NORs in the presence of the B. Thus, while in zero B males the activity of the S10 NOR influences that of the NORs on the X and S9 in a negative way, in one B males it does not do so, although such an influence is observed in the B–L1 fusion male where the activity of the S10 NOR again decreases significantly. On the other hand, the activities of the NORs on the S9 and S11 show a significant positive interdependence in both zero B and one B males where S11 NOR activity is increased but do not do so in the B–L1 fusion male, which shows a significant decrease in the S9 NOR activity. Key words: Eyprepocnemis plorans, B chromosome, nucleolus.

Biological aspects of Amazonian fishes. IX. Cytogenetic studies in two species of the genus Semaprochilodus (Pisces, Prochilodontidae)

Genome ◽  
1987 ◽  
Vol 29 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Eliana Feldberg ◽  
Luiz Antonio Carlos Bertollo ◽  
Lurdes Foresti de Almeida Toledo ◽  
Fausto Foresti ◽  
Orlando Moreira Filho ◽  
...  
Keyword(s):  
Diploid Number ◽  
Constitutive Heterochromatin ◽  
Low Frequency ◽  
Nucleolar Organizer ◽  
Hybrid Origin ◽  
Nucleolar Organizer Regions ◽  
Nucleolar Organizing Regions ◽  
Cytogenetic Studies ◽  
Key Words Fish ◽  
Biological Aspects

The karyotype of Semaprochilodus insignis and Semaprochilodus taeniurus were analyzed through the conventional Giemsa staining, C-banding, and the nucleolar organizer regions. The diploid number is the same (2n = 54) in both species, but S. taeniurus shows a chromosomic system of the ZZ/ZW type. This and some other differences between the two karyotypes will be useful in further studies on the possible hybrid origin of the "jaraqui açú," a low frequency form that is observed together with S. insignis and S. taeniurus. Key words: fish, ZZ/ZW system, constitutive heterochromatin, nucleolar organizing regions.

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.

Structure and variability of nucleolar organizer regions in Parodontidae fish

1984 ◽  
Vol 26 (5) ◽  
pp. 564-568 ◽  
Author(s):  
Orlando Moreira-Filho ◽  
Luiz Antonio Carlos Bertollo ◽  
Pedro Manoel Galetti Jr.
Keyword(s):  
Chromosome Pair ◽  
Constitutive Heterochromatin ◽  
Nucleolar Organizer ◽  
Nucleolar Organizer Regions ◽  
Mitotic Chromosomes ◽  
Homozygous Condition ◽  
Nucleolar Organizing Regions ◽  
Nucleolar Chromosome

Nucleolar organizer regions (NORs) were studied in mitotic chromosomes of four species of fish of family Parodontidae: Parodon tortuosus, Apareiodon affinis, Apareiodon ibitiensis, and Apareiodon piracicabae. All four species exhibited only a single nucleolar chromosome pair in their karyotypes. Intraspecific differences were observed in the size of these chromosomes; however, these were not very clear for A. affinis and A. piracicabae, Apareiodon piracicabae exhibited two clearly visible NORs in each of the nucleolar chromosomes, which was the only configuration practically found in this species. This trait therefore predominates in a homozygous condition in the population investigated. Regions of constitutive heterochromatin adjacent to the two NORs were detected. Possible mechanisms that may have originated the two NORs are discussed.Key words: nucleolar organizing regions, fish.

scholarly journals Comparative molecular cytogenetics in Melipona Illiger species (Hymenoptera, Apidae)

Sociobiology ◽  
2018 ◽  
Vol 65 (4) ◽  
pp. 696 ◽  
Author(s):  
Vanderly Andrade-Souza ◽  
Olivia Maria Pereira Duarte ◽  
Cinthia Caroline Cardoso Martins ◽  
Igor Silva Santos ◽  
Márcio Gilberto Cardoso Costa ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Chromosome Number ◽  
Fluorescent In Situ Hybridization ◽  
Molecular Cytogenetics ◽  
Fluorochrome Staining ◽  
Rdna Sites ◽  
Cytogenetic Studies ◽  
Melipona Species ◽  
Almost All

Cytogenetic studies in Melipona are scarce with only 24 species analyzed cytogenetically. Of these, six species had the rDNA sites physically mapped and characterized by Fluorescent in situ Hybridization (fish). The aim of this study was to perform karyotype analyzes on Melipona species from different regions of Brazil, with a greater sampling representative of the Amazonian fauna and using conventional, fluorochrome staining and FISH with heterologous rDNA probes. The predominant chromosome number was 2n = 18, however, the subspecies M. seminigra abunensis and M. s. pernigra showed 2n = 22 chromosomes. The karyotypes were symmetrical, however M. bicolor, M. quadrifasciata, M. flavolineata, M. fuscopilosa, M. nebulosa presented the first pair heteromorphic in length. CMA3+ blocks also exhibited heteromorphism of size and in almost all cases coincided with rDNA sites, except for M. crinita and M. nebulosa, which presented additional non-coincident CMA3+ blocks. The CMA/ rDNA sites were terminal and interstitial in species with high heterochromatic content, and pericentromeric in those species with low heterochromatic content. In addition to pointing out cytogenetic features of cytotaxonomic importance, the reorganization of the genome in Melipona is discussed.

Chromosome differentiation in the subantarctic Bovichtidae species Cottoperca gobio (Günther, 1861) and Pseudaphritis urvillii (Valenciennes, 1832) (Pisces, Perciformes)

1995 ◽  
Vol 7 (4) ◽  
pp. 381-386 ◽  
Author(s):  
Eva Pisano ◽  
C. Ozouf-Costaz ◽  
J-C. Hureau ◽  
R. Williams
Keyword(s):  
Constitutive Heterochromatin ◽  
Chromosomal Location ◽  
Cytogenetic Study ◽  
Nucleolar Organizer ◽  
Nucleolar Organizer Regions ◽  
Chromosome Differentiation ◽  
Fundamental Number ◽  
Magellan Strait ◽  
Australian Plate ◽  
Acrocentric Chromosomes

A cytogenetic study on the bovichtid species Cottoperca gobio from the Magellan Strait and Pseudaphritis urvillii from Tasmania showed both species have a plesiomorphic number of chromosomes (2n=48). However, C.gobio has a more conservative karyotype composed entirely of acrocentric chromosomes (Fundamental Number=48); the presence of two metacentric pairs in P. urvilli (FN=52) makes this species karyologically more derived. The differences in the number of chromosomal arms, and the chromosomal location of the nucleolar organizer regions indicate karyological divergence in the two separating stocks from which C.gobio and P.urvillii originated. During the diversification of this notothenioid family, probably coincident with the fragmentation of Gondwana, the stock that split off with the Australian Plate gave rise to the Tasmanian species and experienced more chromosomal modifications than the stock from which C. gobio is derived. The pattern of constitutive heterochromatin suggests a possible homology between a pair of chromosomes in bovichtids and other notothenioids.

Genetic analysis of sterility in hybrids from crosses of Glossina morsitans submorsitans and Glossina morsitans centralis (Diptera: Glossinidae)

1993 ◽  
Vol 71 (10) ◽  
pp. 1963-1972 ◽  
Author(s):  
R. H. Gooding
Keyword(s):  
Y Chromosome ◽  
Lower Probability ◽  
Glossina Morsitans ◽  
Hybrid Male ◽  
X Chromosomes ◽  
Glossina Morsitans Submorsitans ◽  
Glossina Morsitans Centralis ◽  
Recurrent Backcrossing ◽  
Almost All ◽  
Glucose 6 Phosphate Dehydrogenase

When genetically marked Glossina morsitans submorsitans Newstead were mated to Glossina morsitans centralis Machado, viable offspring were obtained when using G. m. submorsitans females but not when using G. m. centralis females. The maternally inherited sterility factor, from G. m. submorsitans, that causes this asymmetry was inactivated or replaced during recurrent backcrossing to G. m. centralis. F1 hybrid males were sterile but most F1 hybrid females were fertile. There was little evidence for differential transmission of G. m. submorsitans and G. m. centralis chromosomes by hybrid females. Almost all backcross males were sterile if they had an X and a Y chromosome from two different taxa; the exceptional males had recombinant X chromosomes. The X chromosome locus for X/Y compatibility lies closer to the locus for esterase-X than to the locus for glucose-6-phosphate dehydrogenase. Heterozygosity in linkage group II is also a factor in causing hybrid male sterility; the locus for compatibility is closer to the locus for octanol dehydrogenase than to the locus for esterase-1. Among the backcross males that had an X and a Y chromosome from the same taxon, 12% of those obtained by backcrossing to G. m. centralis were fertile and 65% of those obtained by backcrossing to G. m. submorsitans were fertile. Backcrossing F1 hybrid females to G. m. submorsitans produced females that were equally likely to be fertilized by G. m. submorsitans and G. m. centralis. However, backcrossing to G. m. centralis produced females that had a much lower probability of being fertilized by G. m. submorsitans than by G. m. centralis.

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.

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