scholarly journals Highly divergent karyotypes and barcoding of the East African genus Gonatoxia Karsch (Orthoptera: Phaneropterinae)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Elżbieta Warchałowska-Śliwa ◽  
Beata Grzywacz ◽  
Maciej Kociński ◽  
Anna Maryańska-Nadachowska ◽  
Klaus-Gerhard Heller ◽  
...  

AbstractEast Africa is a hotspot of biodiversity of many orthopteran taxa, including bushcrickets. Gonatoxia Karsch, 1889 species are fully alate Phaneropterinae, which are perfectly adapted to the foliage of forests. We examined five species using combined cytogenetic and molecular data to determine the inter- and intraspecific genetic diversity. The variation in the diploid number of chromosomes in males ranged from 2n = 28 + X0 and 26 + X0 to 2n = 6 + X0. Fluorescence in situ hybridization showed from one to many 18S rDNA loci as well as interstitial sequences, especially in G. helleri. 18S rDNA loci coincided with active NOR and C-banding patterns. The isolation of populations of the species explains differences in the number of chromosomes (G. maculata), chromosomal polymorphism and chromosomal heterozygosity (G. helleri). Our molecular phylogeny based on the COI locus supported the monophyly of the genus Gonatoxia and separateness of the five examined species in accordance with their morphological features and chromosome numbers as well as the species’ distribution.

2010 ◽  
Vol 8 (3) ◽  
pp. 667-671 ◽  
Author(s):  
Rosiley B. Pacheco ◽  
Lucia Giuliano-Caetano ◽  
Horácio F. Julio Junior ◽  
Ana L. Dias

Cytogenetic analyses were performed in Astyanax jacuhiensis from lago Guaíba, Brazil. The diploid number was 50, with a karyotype composed of 8m+30sm+4st+8a chromosomes, FN = 92. The AgNORs were observed in 2 to 5 chromosomes, with intra- and interindividual variation. The sm pair 8 observed always carried NORs on the short arms, presenting size heteromorphism between homologous. Fluorescence in situ hybridization (FISH) with an 18S rDNA probe only confirmed the location of ribosomal cistrons in the sm pair 8, and heteromorphism of these regions between the homologous chromosomes. C-banding revealed the occurrence of weak C-positive heterochromatin in the pericentromeric regions of several chromosomes, in addition to more evident bands interstitially located on some chromosome pairs and in the terminal region of the short arms in pair 8. C-banding plus CMA3 revealed light fluorescent signals in different chromosomes of the karyotype, with a strong terminal site in pair 8, indicating the occurrence of several GC-rich heterochromatic regions in this species. Our results provide the first description of the Astyanax jacuhiensis karyotype, showing karyotype similarities when compared to various populations of A. altiparanae and A. bimaculatus, indicating that chromosomal features are very similar for these three species.


2021 ◽  
pp. 1-8
Author(s):  
Alex M.V. Ferreira ◽  
Patrik F. Viana ◽  
Jansen Zuanon ◽  
Tariq Ezaz ◽  
Marcelo B. Cioffi ◽  
...  

Despite conservation of the diploid number, a huge diversity in karyotype formulae is found in the Ancistrini tribe (Loricariidae, Hypostominae). However, the lack of cytogenetic data for many groups impairs a comprehensive understanding of the chromosomal relationships and the impact of chromosomal changes on their evolutionary history. Here, we present for the first time the karyotype of Panaqolus tankei Cramer & Sousa, 2016. We focused on the chromosomal characterization, using conventional and molecular cytogenetic techniques to unravel the evolutionary trends of this tribe. P. tankei, as most species of its sister group Pterygoplichthini, also possessess a conserved diploid number of 52 chromosomes. We observed heterochromatin regions in the centromeres of many chromosomes; pairs 5 and 6 presented interstitial heterochromatin regions, whereas pairs 23 and 24 showed extensive heterochromatin regions in their q arms. In situ localization of 18S rDNA showed hybridization signals correlating with the nucleolus organizer regions, which are located in the q arms of pair 5. However, the 5S rDNA was detected in the centromeric and terminal regions of the q arms of pair 8. (TTAGGG)n hybridized only in the terminal regions of all chromosomes. Microsatellite in situ localization showed divergent patterns, (GA)15 repeated sequences were restricted to the terminal regions of some chromosomes, whereas (AC)15 and (GT)15 showed a scattered hybridization pattern throughout the genome. Intraspecific comparative genomic hybridization was performed on the chromosomes of P. tankei to verify the existence of sex-specific regions. The results revealed only a limited number of overlapping hybridization signals, coinciding with the heterochromatin in centromeric regions without any sex-specific signals in both males and females. Our study provides a karyotype description of P. tankei, highlighting extensive differences in the karyotype formula, the heterochromatin regions, and sites of 5S and 18S rDNA, as compared with data available for the genus.


2020 ◽  
Vol 194 (4) ◽  
pp. 480-497
Author(s):  
Maoyin Sheng ◽  
Mengdi Gao ◽  
Linjiao Wang

Abstract Heterochromatin banding patterns and the physical locations of 45S and 5S rDNA loci in mitotic metaphase chromosomes in 22 Epimedium spp. and two Vancouveria spp. species were studied using orcein staining and double-colour fluorescent in situ hybridization, respectively. Four types of chromosomal heterochromatin bands (satellite, centromeric, intercalary and terminal) were detected in all species, and there was clear variation in the number of bands and total length. In all species examined, at least one pair each of 45S and 5S rDNA signals was detected. The position of 5S rDNA is more conserved than that of 45S rDNA. The chromosomal distribution of 45S rDNA loci detected in Epimedium can be divided into three types. The chromosomal distributions of heterochromatin bands and 45S and 5S rDNA loci were closely related to the geographical distribution and may provide important evidence concerning the classification and systematics of Epimedium. Finally, based on results of the present study and pervious research, the centre of origin and formation of modern geographical distribution of Epimedium are discussed.


2018 ◽  
Vol 12 (4) ◽  
pp. 515-528 ◽  
Author(s):  
Natalia V. Golub ◽  
Viktor B. Golub ◽  
Valentina G. Kuznetsova

The karyotypes of 10 species from 9 genera of the family Tingidae (Hemiptera, Heteroptera, Cimicomorpha) are described and illustrated for the first time. These species are: Agrammaatricapillum (Spinola, 1837), Catoplatuscarthusianus (Goeze, 1778), Dictylaplatyoma (Fieber, 1861), Lasiacanthahermani Vásárhelyi, 1977, Oncochilasimplex (Herrich-Schaeffer, 1830), Tingis (Neolasiotropis) pilosa Hummel, 1825, and T. (Tropidocheila) reticulata Herrich-Schaeffer, 1835, all with 2n = 12A + XY, as well as Acalyptamarginata (Wolff, 1804), Derephysia (Paraderephysia) longispina Golub, 1974, and Dictyonotastrichnocera Fieber, 1844, all with 2n = 12A + X(0). Moreover, genera Catoplatus Spinola, 1837, Derephysia Spinola, 1837, and Oncochila (Herrich-Schaeffer, 1830) were explored cytogenetically for the first time. Much as all other hitherto studied lace bugs, the species studied here have 12 autosomes but differ in their sex chromosome systems. The ribosomal clusters were localized on male meiotic cells of all ten species already mentioned and, additionally, in Acalyptacarinata Panzer, 1806 known to have 2n = 12A + X (Grozeva and Nokkala 2001) by fluorescence in situ hybridization (FISH) using a PCR amplified 18S rDNA fragment as a probe. In all cases, rDNA loci were located interstitially on a pair of autosomes. Furthermore, two species possessed some additional rDNA clusters. Thus, Acalyptamarginata showed clearly defined interstitial clusters on one more pair of autosomes, whereas Derephysialongispina had a terminal cluster on the X-chromosome. FISH performed with the telomeric (TTAGG)n probe did not reveal labelling in chromosomes of any species studied. Hence, the results obtained provide additional evidence for the karyotype conservatism, at least regarding the number of autosomes, for variation in chromosomal distribution of rDNA loci between species and for the lack of the ancestral insect telomeric sequence TTAGG in lace bugs. Preliminary taxonomic comments are made basing on some cytogenetic evidence.


2020 ◽  
Vol 14 (3) ◽  
pp. 417-435 ◽  
Author(s):  
Elżbieta Warchałowska-Śliwa ◽  
Beata Grzywacz ◽  
Anna Maryańska-Nadachowska ◽  
Klaus-Gerhard Heller ◽  
Claudia Hemp

Gonatoxia helleri Hemp, 2016 is one of the most widespread bush-crickets of the genus Gonatoxia Karsch, 1889 in East Africa. This species with seven large chromosomes (2n♂ = 7) differs from other representatives of the genus Gonatoxia drastically by its reduced chromosome number, the asymmetrical karyotype including karyomorphs rarely found in tettigoniids, as well as in irregularities in the course of meiosis. To better understand the origin of such an exceptional karyotype, chromosomes of 29 specimens from four populations/localities were studied using classical techniques, such as C-banding, silver impregnation, fluorochrome double staining and fluorescence in situ hybridization (FISH) technique with 18S rDNA and (TTAGG)n telomeric probes. FISH showed many 18S rDNA loci as well as interstitial telomeric sequences, where chromosome morphology varied in these components in terms of quantity and distribution. The 18S rDNA loci coincided with active NORs and C-banding patterns. We suggest that a combination of Robertsonian rearrangements and/or multiple common tandem fusions involving the same chromosomes contributed to the formation of this karyotype/karyomorphs. The results are the first step towards a better understanding of chromosomal reorganization and evolution within the genus Gonatoxia. Low chromosome number, together with the incidence of chromosomal polymorphism that is higher in G. helleri than previously reported in bush-crickets, implies that this species can be a valuable new model for cytogenetic and speciation studies. Our findings suggest that chromosomal translocations lead to diversification and speciation in this species and could be the driving force of adaptive radiation.


Genome ◽  
2014 ◽  
Vol 57 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Naiara Pereira Araújo ◽  
Ana Carolina Loss ◽  
Dirceu A. Cordeiro-Junior ◽  
Kátia Regina da Silva ◽  
Yuri L.R. Leite ◽  
...  

Phyllomys (Echimyidae, Rodentia) is a genus of Neotropical rodents with available cytogenetic data restricted to six out of 13 species, mainly based on simple staining methods, without detailed analyses. In this work, we present new karyotypes for Phyllomys lamarum (diploid number 2n = 56, fundamental number or number of autosomal arms FN = 102) and Phyllomys sp. (2n = 74, FN = 140) from the state of Minas Gerais, southeastern Brazil. We provide the first GTG- and CBG-banding patterns, silver-staining of the nucleolar organizer regions (Ag-NORs), and fluorescence in situ hybridization (FISH) with telomeric and 45S rDNA probes of Phyllomys. In addition to examining their chromosomes and phenotypic characters, we sequenced mitochondrial DNA from the specimens analyzed to confirm their taxonomic identification. The comparison of the distinctive chromosome complements of our specimens with those of other species of Phyllomys already published allowed us to conclude that chromosome data may be very useful for the taxonomy of the genus, as no two species analyzed presented the same diploid and fundamental numbers (2n and FN).


2011 ◽  
Vol 39 (No. 3) ◽  
pp. 73-83 ◽  
Author(s):  
O. Horňáková ◽  
M. Závodná ◽  
M. Žáková ◽  
J. Kraic ◽  
F. Debre

The study of diversity in common bean was based on morphological and agronomical characteristics, differentiation of collected accessions by morphological and molecular markers, detection of genetic variation, and duplicates detection in bean landraces. The analysed 82 accessions of common bean (Phaseolus vulgaris L.) were collected in the Western andEastern Carpatien as landrace mixtures. Their seeds were segregated and pooled according to their characteristics; they were further multiplicated, and introduced into the collection. An extensive variation in plant and seed traits was discovered in thirty-three morphological and agronomical characteristics. Nevertheless, some of the accessions were identical in these characteristics. Cluster analysis grouped genotypes into two main branches, reflecting the growth type, seed size parameters, and thousand-seed weight. Molecular differentiation studies were performed by multilocus polymorphism detection in microsatellite and minisatellite DNA regions. Cluster analysis based on molecular data also grouped genotypes but no linkage to morphological traits was revealed. Bean accessions with very similar or identical morphological characters were clearly distinguished by DNA banding patterns. The presence of duplicates was excluded.  


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Beata Grzywacz ◽  
Elżbieta Warchałowska-Śliwa ◽  
Maciej Kociński ◽  
Klaus-Gerhard Heller ◽  
Claudia Hemp

AbstractEast African mountains constitute a network of isolated habitat islands among dry savannah and are thus ideal for studying species diversification processes. This study elucidated the phylogenetic and phylogeographic relationships of all bushcricket species comprising the genus Aerotegmina. Our analysis indicated that large-scale climatic and topographic processes in Africa are likely to have driven speciation in this group, and revealed the cytogenetic traits of the species. Molecular phylogeny supported the monophyly of Aerotegmina and showed that the genus probably originated in the old Eastern Arc Mountains of Tanzania and Kenya. Two lineages were distinguished: small- and large-sized species with geographically distinct habitats. The underlying processes are thought to be eight dispersals, ten vicariance events, and one extinction event linked to repeated fragmentation of the African rainforest. Those processes, in conjunction with habitat change, probably also led to the spatial separation of the species into a northern clade with a diploid number of chromosomes 2n = 32 + X0 or 2n = 30 + neo-XY and a southern clade with a reduced number of chromosomes (2n = 28 + X0 or 24 + neo-X1X2Y). Karyotype analysis suggests that Aerotegmina is currently in the process of speciation.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Melquizedec Luiz Silva Pinheiro ◽  
Cleusa Yoshiko Nagamachi ◽  
Talita Fernanda Augusto Ribas ◽  
Cristovam Guerreiro Diniz ◽  
Patricia Caroline Mary O´Brien ◽  
...  

Abstract Background The Scolopacidae family (Suborder Scolopaci, Charadriiformes) is composed of sandpipers and snipes; these birds are long-distance migrants that show great diversity in their behavior and habitat use. Cytogenetic studies in the Scolopacidae family show the highest diploid numbers for order Charadriiformes. This work analyzes for the first time the karyotype of Actitis macularius by classic cytogenetics and chromosome painting. Results The species has a diploid number of 92, composed mostly of telocentric pairs. This high 2n is greater than the proposed 80 for the avian ancestral putative karyotype (a common feature among Scolopaci), suggesting that fission rearrangements have formed smaller macrochromosomes and microchromosomes. Fluorescence in situ hybridization using Burhinus oedicnemus whole chromosome probes confirmed the fissions in pairs 1, 2, 3, 4 and 6 of macrochromosomes. Conclusion Comparative analysis with other species of Charadriiformes studied by chromosome painting together with the molecular phylogenies for the order allowed us to raise hypotheses about the chromosomal evolution in suborder Scolopaci. From this, we can establish a clear idea of how chromosomal evolution occurred in this suborder.


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