An unusual karyotype with low chromosome number in Megacephalini, a basal group of tiger beetles (Coleoptera, Cicindelidae): cytogenetic characterisation by C-banding and location of rDNA genes

Artemisia herba-alba is a largely-distributed and often landscape-dominating taxon in arid areas of the Mediterranean and Irano-Turanian regions. In Algeria, in 2010 its communities covered 10% of the steppe territory, but its populations have been subjected to overgrazing. A karyological study based on 22 populations together with a cytogenetic characterisation of this species has been performed for the first time in Algerian materials, through genome size and chromosome number determination. Fluorescence in situ hybridisation (FISH) was also used to assess the rDNA loci number and distribution in the two ploidy levels detected. The studied accessions are diploid (2n = 2x = 18 chromosomes, 6 populations) or tetraploid (2n = 4x = 36 chromosomes, 15 populations). One population, occupying a more or less central geographic position among the studied area, presented both cytotypes. Genome size reflects well the two ploidy levels, with no evidence of downsizing with polyploidy. The karyotypes are rather symmetric (2A Stebbins’ class). FISH analyses detected four signals (2 loci) in diploid and eight signals (4 loci) in tetraploid cytotypes for both ribosomal DNA genes, which present an L-type (linked) organisation, i.e. with loci from both rDNA genes colocalised. The presence of two ploidy levels suggest a genomic dynamism and even a possible differentiation underlying the morphological uniformity and despite the dramatic decrease experienced by this plant in Algeria in terms of surface coverage.

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Karyotype characterization of Trigona fulviventris Guérin, 1835 (Hymenoptera, Meliponini) by C banding and fluorochrome staining: report of a new chromosome number in the genus

Genetics and Molecular Biology ◽

10.1590/s1415-47572005000300009 ◽

2005 ◽

Vol 28 (3) ◽

pp. 390-393 ◽

Cited By ~ 6

Author(s):

Alayne Magalhães Trindade Domingues ◽

Ana Maria Waldschmidt ◽

Sintia Emmanuelle Andrade ◽

Vanderly Andrade-Souza ◽

Rogério Marco de Oliveira Alves ◽

...

Keyword(s):

Chromosome Number ◽

Fluorochrome Staining ◽

C Banding ◽

Trigona Fulviventris

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Chromosome studies in 2n = 14 and 2n = 16 types of Medicago murex

Genome ◽

10.1139/g90-026 ◽

1990 ◽

Vol 33 (2) ◽

pp. 159-163 ◽

Cited By ~ 5

Author(s):

A. Mariani ◽

E. Falistocco

Keyword(s):

Chromosome Number ◽

Plant Morphology ◽

C Banding ◽

Morphological Studies ◽

Staining Techniques

Karyological and morphological studies of Medicago murex with 2n = 16 and 2n = 14 chromosomes were undertaken. Analysis of the somatic chromosomes, using both conventional staining techniques and C-banding, showed that the 2n = 14 karyotype derived from the 2n = 16 karyotype. Plant morphology of the two types differs in relation to the characters of the leaves, florets, and pods. Attempts to obtain hybrids between the two types were completely unsuccessful. From these results it appears that the two M. murex types are not as closely related as has been usually considered and that they should be regarded as two different species.Key words: Medicago murex, chromosome number, C-banding.

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A new species of Urostreptus (Diplopoda, Spirostreptidae): description and chromossome number

Iheringia Série Zoologia ◽

10.1590/s0073-47212006000200011 ◽

2006 ◽

Vol 96 (2) ◽

pp. 209-212 ◽

Cited By ~ 6

Author(s):

Pedro H. B. Pierozzi ◽

Carmem S. Fontanetti

Keyword(s):

New Species ◽

Chromosome Number ◽

Constitutive Heterochromatin ◽

Sao Paulo ◽

São Paulo ◽

Meiotic Analysis ◽

Paulo State ◽

C Banding ◽

São Paulo State ◽

A New Species

This work presents the description and chromosome number of Urostreptus atrobrunneus sp. nov. The genus until now had not been registered yet in the São Paulo State, Brazil. The meiotic analysis showed that the species presents 2n=24, XY. The C-banding revealed large blocks of constitutive heterochromatin and two heteromorphic chromosomal pairs, one of them corresponding to the sexual pair.

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First chromosome data on Steindachneridion doceanum (Siluriformes: Pimelodidae): a critically endangered catfish endemic of the Doce River basin, Brazil

Neotropical Ichthyology ◽

10.1590/1982-0224-20180066 ◽

2018 ◽

Vol 16 (4) ◽

Cited By ~ 1

Author(s):

Ana Claudia Swarça ◽

Mário Luis Orsi ◽

Fábio Hiroshi Takagui ◽

Ana Lucia Dias ◽

Jorge Abdala Dergam ◽

...

Keyword(s):

Secondary Constriction ◽

Extinction Risk ◽

Present Report ◽

5S Rdna ◽

Rdna Genes ◽

C Banding ◽

Endemic Taxon ◽

Acrocentric Chromosomes ◽

Doce River ◽

Submetacentric Pair

ABSTRACT The present report represents the first cytogenetic description of Steindachneridion doceanum, great catfish which is currently at high extinction risk and it is listed as threatened on the red list of the Brazilian Ministry of the Environment, also are suggested karyotype relationships with other species of the same genus endemic from other river basins. The results revealed a diploid number of 2n = 56 and the karyotype composed of 18 metacentric, 20 submetacentric, 10 subtelocentric and 8 acrocentric chromosomes (NF = 104). The AgNORs and CMA3 signals were coincident in location occupying the short arm of an acrocentric chromosome pair (25th), in a secondary constriction. The 5S rDNA genes were localized on the short arms of one subtelocentric pair. C-banding revealed terminal blocks on the short arms on many chromosomes as well as terminal positive bands at the both ends of a submetacentric pair. C banding also revealed a large heterochromatic block in the secondary constriction (25th) region that was coincident with the AgNORs sites and CMA3+ bright bands. In spite S. doceanum represent an endemic taxon, in spite their geographic isolation their cytogenetic characteristics show similarities with other species of the genus.

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On sex determination in the Turkish desert woodlouse Hemilepistus elongatus (Crustacea, Isopoda, Oniscidea): searching for sex chromosomes and for sex-specific differences in simple DNA repeats

Genome ◽

10.1139/g96-103 ◽

1996 ◽

Vol 39 (4) ◽

pp. 818-821 ◽

Cited By ~ 3

Author(s):

G. Röder ◽

K. E. Linsenmair ◽

I. Nanda ◽

M. Schmid

Keyword(s):

Chromosome Number ◽

Sex Determination ◽

Sex Chromosomes ◽

Genomic Dna ◽

Constitutive Heterochromatin ◽

Dna Repeats ◽

Male And Female ◽

General Morphology ◽

C Banding ◽

Heteromorphic Sex Chromosomes

The karyotype of male and female Hemilepistus elongatus was investigated by means of C-banding. The diploid chromosome number in both sexes is 2n = 50. By scrutinizing general morphology and localization of the constitutive heterochromatin, no heteromorphic sex chromosomes were found. All chromosome pairs in males are well paired during diakinesis. Hybridization of genomic DNA with (GACA)4 and (GATA)4 oligonucleotides revealed no sex-specific patterns. Key words : karyotype, C-banding, sex determination, simple DNA-repeats, Isopoda.

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Chromosomes of the Parasitic Isopod Anilocra Physodes

Crustaceana ◽

10.1163/156854096x00079 ◽

1996 ◽

Vol 69 (1) ◽

pp. 56-62

Author(s):

Maria Stella Colomba ◽

Roberto Vitturi ◽

Lorenzo Pellerito ◽

Eliodoro Catalano

Keyword(s):

Chromosome Number ◽

Diploid Number ◽

Centromeric Region ◽

Banding Technique ◽

Robertsonian Fusion ◽

Mitotic Chromosomes ◽

C Banding ◽

Parasitic Isopod

AbstractCounts of mitotic chromosomes have allowed to determine 2n = 12 as the modal diploid number of Anilocra physodes. Application of the C-banding technique reveals that two hetero-chromatic blocks bordering the centromeric region occur in each chromosome. This supports the notion that the actual low chromosome number of A. physodes may have been derived through a process of Robertsonian fusion.

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C-Banded Karyotype and Cytotaxonomy of Mertensiella caucasica (WAGA, 1876) (Caudata: Salamandridae)

Amphibia-Reptilia ◽

10.1163/156853882x00022 ◽

1982 ◽

Vol 3 (4) ◽

pp. 303-307 ◽

Cited By ~ 1

Author(s):

Matilde Ragghianti ◽

Stefania Bucci-Innocenti ◽

Giorgio Mancino

Keyword(s):

Chromosome Number ◽

Banding Pattern ◽

Related Form ◽

C Banding ◽

Structural Character ◽

Chromosomal Banding

AbstractChromosome number, karyotype and chromosomal banding pattern of Mertensiella caucasica were studied in differentially stained mitotic preparations. The main feature of the C-banded appearance concerns the centromere regions, which are heavily stained by the Giemsa and are outlined by proximal C-bands. This morpho-structural character seems to be peculiar of the genome of M. caucasica, when compared with the C-banding pattern shown by the chromosomes of Salamandra, considered the most closely related form. Therefore, a preliminary cytotaxonomic survey seems to support the opinion that the Caucasian salamander can be referred to a well defined genus Mertensiella rather than a subgenus of Salamandra.

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Chromosomal Analysis of Ctenolucius hujeta Valenciennes, 1850 (Characiformes): A New Piece in the Chromosomal Evolution of the Ctenoluciidae

Cytogenetic and Genome Research ◽

10.1159/000515456 ◽

2021 ◽

pp. 1-8

Author(s):

José Souza ◽

Erika Guimarães ◽

Vanessa Pinheiro-Figliuolo ◽

Marcelo B. Cioffi ◽

Luiz A.C. Bertollo ◽

...

Keyword(s):

Chromosome Number ◽

5S Rdna ◽

Chromosomal Evolution ◽

Freshwater Fishes ◽

Rdna Genes ◽

Telomeric Sequences ◽

Generic Status ◽

Cytogenetic Studies ◽

Chromosomal Markers ◽

Unusual Phenomenon

Ctenoluciidae (Characiformes), a family of freshwater fishes, comprises 2 genera, Ctenolucius and Boulengerella, with 7 recognized species. Up to now, only species of the genus Boulengerella have been subjected to cytogenetic studies. Here, we investigated the karyotype and other cytogenetic features of pike characin, Ctenolucius hujeta, using conventional (Giemsa staining, C-banding, Ag-NOR staining) and molecular (rDNA, telomeric sequences, and fiber-FISH mapping) procedures. This species has a diploid chromosome number of 2n = 36, and a karyotype composed of 12m + 20sm + 4a and FN = 68, similar to that found in Boulengerella species. However, differences regarding the number and distribution of several chromosomal markers support a distinct generic status. Colocalization of the 18S and 5S rDNA genes is an exclusive characteristic of the C. hujeta genome, with an interspersed distribution in the chromosomal fiber, an unusual phenomenon among eukaryotes. Additionally, our results support the view that Ctenoluciidae and Lebiasinidae families are closely related.

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