scholarly journals Comparative FISH mapping of ribosomal DNA clusters and TTAGG telomeric sequences to holokinetic chromosomes of eight species of the insect order Psocoptera

2019 ◽  
Vol 13 (4) ◽  
pp. 403-410 ◽  
Author(s):  
Natalia Golub ◽  
Boris Anokhin ◽  
Valentina Kuznetsova

Repetitive DNAs are the main components of eukaryotic genome. We mapped the 18S rDNA and TTAGG telomeric probe sequences by FISH to meiotic chromosomes of eight species of the order Psocoptera considered a basal taxon of Paraneoptera: Valenzuela burmeisteri (Brauer, 1876), Stenopsocus lachlani Kolbe, 1960, Graphopsocus cruciatus (Linnaeus, 1768), Peripsocus phaeopterus (Stephens, 1836), Philotarsus picicornis (Fabricius, 1793), Amphigerontia bifasciata (Latreille, 1799), Psococerastis gibbosa (Sulzer, 1766), and Metylophorus nebulosus (Stephens, 1836). These species belong to five distantly related families of the largest psocid suborder Psocomorpha: Caeciliusidae, Stenopsocidae, Peripsocidae, Philotarsidae, and Psocidae. We show that all the examined species share a similar location of 18S rDNA on a medium-sized pair of autosomes. This is the first study of rDNA clusters in the order Psocoptera using FISH. We also demonstrate that these species have the classical insect (TTAGG)n telomere organization. Our results provide a foundation for further cytogenetic characterization and chromosome evolution studies in Psocoptera.

2017 ◽  
Vol 153 (3) ◽  
pp. 147-157 ◽  
Author(s):  
Valentina G. Kuznetsova ◽  
Anna Maryańska-Nadachowska ◽  
Nazar A. Shapoval ◽  
Boris A. Anokhin ◽  
Anatoly P. Shapoval

We studied the karyotypes of 8 dragonfly species originating from the Curonian Spit (the Baltic Sea, Russia) using C-banding and FISH with 18S rDNA and “insect” telomeric (TTAGG)n probes. Our results show that Leucorrhinia rubicunda, Libellula depressa, L. quadrimaculata, Orthetrum cancellatum, Sympetrum danae, and S. vulgatum from the family Libellulidae, as well as Cordulia aenea and Epitheca bimaculata from the family Corduliidae share 2n = 25 (24 + X) in males, with a minute pair of m-chromosomes being present in every karyotype except for that of C. aenea. Major rDNA clusters are located on one of the large pairs of autosomes in all the species. No hybridization signals were obtained by FISH with the (TTAGG)n probe in the examined species with the only exception of S. vulgatum. In this species, clear signals were detected at the ends of almost all chromosomes. This finding raises the possibility that in Odonata the canonical “insect” (TTAGG)n telomeric repeat is in fact present but in very low copy number and is consequently difficult to detect by in situ hybridization. We conclude that more work needs to be done to answer questions about the organization of telomeres in this very ancient and thus phylogenetically important insect order.


2017 ◽  
Vol 153 (4) ◽  
pp. 213-222 ◽  
Author(s):  
Melanie McClure ◽  
Bernard Dutrillaux ◽  
Anne-Marie Dutrillaux ◽  
Vladimir Lukhtanov ◽  
Marianne Elias

Mitotic and meiotic chromosomes from 2 taxa of the genus Melinaea, M. satevis cydon and M. “satevis” tarapotensis (Lepidoptera: Nymphalidae), and from hybrids produced in captivity were obtained using an improved spreading technique and were subsequently analyzed. In one of the taxa, the presence of trivalents and tetravalents at diakinesis/metaphase I is indicative of heterozygosity for multiple chromosome fusions or fissions, which might explain the highly variable number of chromosomes previously reported in this genus. Two large and complex multivalents were observed in the meiotic cells of the hybrid males (32 chromosomes) obtained from a cross between M. “s.” tarapotensis (28 chromosomes) and M. s. cydon (40-43 chromosomes). The contribution of the 2 different haploid karyotypes to these complex figures during meiosis is discussed, and a taxonomic revision is proposed. We conclude that chromosome evolution is active and ongoing, that the karyotype of the common ancestor consisted of at least 48 chromosomes, and that evolution by chromosome fusion rather than fission is responsible for this pattern. Complex chromosome evolution in this genus may drive reproductive isolation and speciation, and highlights the difficulties inherent to the systematics of this group. We also show that Melinaea chromosomes, classically considered as holocentric, are attached to unique, rather than multiple, spindle fibers.


1992 ◽  
Vol 117 (5) ◽  
pp. 935-948 ◽  
Author(s):  
F Klein ◽  
T Laroche ◽  
ME Cardenas ◽  
JF Hofmann ◽  
D Schweizer ◽  
...  

Topoisomerase II (topoII) and RAP1 (Repressor Activator Protein 1) are two abundant nuclear proteins with proposed structural roles in the higher-order organization of chromosomes. Both proteins co-fractionate as components of nuclear scaffolds from vegetatively growing yeast cells, and both proteins are present as components of pachytene chromosome, co-fractionating with an insoluble subfraction of meiotic nuclei. Immunolocalization using antibodies specific for topoII shows staining of an axial core of the yeast meiotic chromosome, extending the length of the synaptonemal complex. RAP1, on the other hand, is located at the ends of the paired bivalent chromosomes, consistent with its ability to bind telomeric sequences in vitro. In interphase nuclei, again in contrast to anti-topoII, anti-RAP1 gives a distinctly punctate staining that is located primarily at the nuclear periphery. Approximately 16 brightly staining foci can be identified in a diploid nucleus stained with anti-RAP1 antibodies, suggesting that telomeres are grouped together, perhaps through interaction with the nuclear envelope.


2017 ◽  
Vol 152 (4) ◽  
pp. 194-203 ◽  
Author(s):  
José F. de Souza e Sousa ◽  
Patrik F. Viana ◽  
Luiz A.C. Bertollo ◽  
Marcelo B. Cioffi ◽  
Eliana Feldberg

Ctenoluciidae is a Neotropical freshwater fish family whose representatives are known as bicudas. The genus Boulengerella contains 5 species, and 4 of them (B. cuvieri, B. lateristriga, B. lucius, and B. maculata) were cytogenetically analyzed in the present study by conventional and molecular procedures. All 4 species have a very similar karyotype, with 2n = 36 chromosomes (14 metacentrics + 16 submetacentrics + 6 subtelocentrics; FN = 72). However, the heterochromatin distribution pattern is species-specific. In all 4 species, the nucleolus organizer region is located in pair 18, as also confirmed by cytogenetic mapping of 18S rDNA. In turn, 5S rRNA genes are present in 2 chromosome pairs: in pair 1 of all 4 species, and in pair 10 of B. lateristriga, B. maculata, and B. cuvieri, but in pair 4 of B. lucius. The telomeric probe highlighted terminal regions in all chromosomes, as well as an interstitial centromeric sequence in pair 3 of the 3 first-mentioned species. Notably, a conspicuous heteromorphic secondary constriction in chromosomes 18 was found only in the males of the 3 species, rendering one of the homologs much larger than the other one. This feature, associated with a large 18S rDNA block and accumulation of telomeric sequences, suggests the presence of an XX/XY sex chromosome system in the analyzed Boulengerella species.


Genetica ◽  
2011 ◽  
Vol 139 (6) ◽  
pp. 823-831 ◽  
Author(s):  
Joana Carrilho ◽  
Concepción Pérez-García ◽  
Alexandra Leitão ◽  
Isabel Malheiro ◽  
Juan J. Pasantes

2020 ◽  
Vol 14 (3) ◽  
pp. 369-385
Author(s):  
Carini Picardi Moraes de Castro ◽  
Danon Clemes Cardoso ◽  
Ricardo Micolino ◽  
Maykon Passos Cristiano

Telomeric sequences are conserved across species. The most common sequence reported among insects is (TTAGG)n, but its universal occurrence is not a consensus because other canonical motifs have been reported. In the present study, we used fluorescence in situ hybridization (FISH) using telomeric probes with (TTAGG)6 repeats to describe the telomere composition of leafcutter ants. We performed the molecular cytogenetic characterization of six Acromyrmex Mayr, 1865 and one Atta Fabricius, 1804 species (Acromyrmex ambiguus (Emery, 1888), Ac. crassispinus (Forel, 1909), Ac. lundii (Guérin-Mèneville, 1838), Ac. nigrosetosus (Forel, 1908), Ac. rugosus (Smith, 1858), Ac. subterraneus subterraneus (Forel, 1893), and Atta sexdens (Linnaeus, 1758)) and described it using a karyomorphometric approach on their chromosomes. The diploid chromosome number 2n = 38 was found in all Acromyrmex species, and the karyotypic formulas were as follows: Ac. ambiguus 2K = 14M + 12SM + 8ST + 4A, Ac. crassispinus 2K = 12M + 20SM + 4ST + 2A, Ac. lundii 2K = 10M + 14SM + 10ST + 4A, Ac. nigrosetosus 2K = 12M + 14SM + 10ST + 2A, and Ac. subterraneus subterraneus 2K = 14M + 18SM + 4ST + 2A. The exact karyotypic formula was not established for Ac. rugosus. FISH analyses revealed the telomeric regions in all the chromosomes of the species studied in the present work were marked by the (TTAGG)6 sequence. These results reinforce the premise that Formicidae presents high homology between their genera for the presence of the canonical sequence (TTAGG)n.


2002 ◽  
Vol 110 (6) ◽  
pp. 578-586 ◽  
Author(s):  
A. Ruiz-Herrera ◽  
F. García ◽  
C. Azzalin ◽  
E. Giulotto ◽  
J. Egozcue ◽  
...  

Zootaxa ◽  
2007 ◽  
Vol 1668 (1) ◽  
pp. 395-411 ◽  
Author(s):  
LAURENCE A. MOUND ◽  
DAVID C. MORRIS

Two widely different classifications of the insect order Thysanoptera are discussed; an essentially phylogenetic system recognizing nine families in two suborders, and an essentially phenetic system recognizing 40 families in two orders. This paper emphasizes the distinction between “classification” and “systematics”, the former stressing the importance of differences, whereas the latter stresses the importance of derived similarities. A phylogenetic (i.e. systematic) classification incorporates predictions concerning evolutionary relationships that are important throughout biological studies, whether in host and parasite associations, biogeography, comparative physiology or development. The available phenetic classification of Thysanoptera serves no such broader purpose in biology. Recent molecular data derived from the gene 18S rDNA are analysed, but although some groups of taxa are well resolved, the deep relationships within the Thysanoptera remain unclear.


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