The karyotypes of pseudoscorpions of three families, Geogarypidae, Garypinidae and Olpiidae (Arachnida: Pseudoscorpiones), were studied for the first time. Three species of the genus Geogarypus from the family Geogarypidae and 10 species belonging to 8 genera from the family Olpiidae were studied. In the genus Geogarypus the diploid chromosome numbers of males range from 15 to 23. In the family Olpiidae the male chromosome numbers vary greatly, from 7 to 23. The male karyotype of single studied member of the family Garypinidae, Garypinus dimidiatus, is composed of 33 chromosomes. It is proposed that the karyotype evolution of the families Geogarypidae and Olpiidae was characterised by a substantial decrease of chromosome numbers. The diploid numbers of some olpiids are the lowest known 2n within pseudoscorpions and even one of the lowest within the class Arachnida. In spite of a considerable reduction of diploid numbers, all species studied possess a X0 sex chromosome system that is widespread and probably ancestral in pseudoscorpions. Moreover, X chromosomes retain conservative metacentric morphology in the majority of species. During the first meiotic division of males, a high number of chiasmata were observed in some species, up to five per bivalent in Indolpium sp. The transient stage between pachytene and diplotene is typically characterised by extensive decondensation of chromatin in males of geogarypids and in Calocheiridius libanoticus, and we interpret this as a diffuse stage. This is recorded in pseudoscorpions for the first time. The relationships between some species belonging to the family Olpiidae are discussed based on the data obtained.
Cephalcia masuttii sp. n. is described from the SE Alps of Europe, based on morphological, biological, and genetic studies. The larvae feed gregariously on Picea abies. The species has been recorded also from Central Siberia and NE China, where the larvae feed on Picea obovata and Picea koraiensis, respectively. Indications exist that it may be more widely distributed in Europe and northern Asia. The strict gregariousness of larvae of this species is peculiar among spruce feeders of Cephalcia. Morphologically the adults are most similar to Cephalcia alashanica, with which they are compared. An allozyme analysis showed that the populations from Europe and China are quite similar and clearly different from the other species living on spruce. The karyotype of C. masuttii (n = 25) is also described.
We report the karyotype characteristics including chromosome numbers of Saga campbelli campbelli, S. c. gracilis, and S. rammei using the following classical cytogenetic methods: C-banding, silver staining, and fluorochrome staining DAPI and CMA3. We also present FISH data showing the distribution of telomeric repeats and 18S rDNA on the chromosomes of these species and the results of similar studies cited in the literature on S. hellenica, S. natoliae, and S. rhodiensis. The five European Saga species exhibit a high rate of karyotype evolution. In addition to changes in chromosome number and morphology (by chromosomal inversion and/or chromosome fusion), interspecific autosomal differentiation involved changes in the distribution and quantity of constitutive heterochromatin and GC-rich regions, as well as the number and location of NORs. In the present study we focused on testing a hypothetical model of karyotype evolution in Saga, with particular reference to the cytogenetic mapping of rDNA and telomeric sequences. Variation in the distribution of rDNA and location of Ag-NORs are novel phylogenetic markers for the genus Saga.
We karyotyped six species of Microtus voles collected along the southern edge of their range in northern and western Iran. Diploid and fundamental numbers were as follows: M. socialis and M. paradoxus 2n = 62, FNa = 60,
M. qazvinensis 2n = 54, FNa = 54, M. transcaspicus 2n = 52, FNa = 52, and
M. mystacinus (= M. rossiaemeridionalis) 2n = 54, FNa = 54. Two cytotypes were retrieved in M. irani from its type locality: 2n = 48, FNa = 46 and 2n = 64, FNa = 62. While our results confirmed an early report of 2n = 64 for this vole, the 2n = 48 cytotype remains unexplained. Karyological variability is relatively low in social voles and chromosomal data contribute little to individual species recognition. We argue that Arvicola mystacinus
De Filippi, 1865, described from Lar Valley (north-east of Tehran) is the oldest available name for 2n = 54 voles with the following synonyms:
M. subarvalis Meyer, Orlov & Skholl, 1969, M. epiroticus Ondrias, 1966, and
M. rossiaemeridionalis Ognev, 1924.
The results of a karyological study on the dormice Myoxus glis (2n=62) and Dryomys nitedula (2n=48), the ground squirrel Spermophilus citellus/i> (2n=40) and the red bank vole Myodes glareolus (2n=56) from Greece are presented. A part from the clarification of their diploid chromosome number, a more elaborate study of their karyotype was conducted and the G- and C- banding patterns are provided for the first time in Greek populations of these species. In particular, heterochromatin distribution in D. nitedula seems to be more extensive than previously thought, contrasting M. glis, in which heterochromatin seems to be absent. On the other hand, the Y chromosome of M. glareolus was found to be a fully heterochromatic submetacentric. In overall, the comparison of our karyological results, with those of other Eurasian populations reinforce the belief that the karyotypes of the studied species are conservative, displaying small degrees of variation, usually restricted to the size and morphology of the sex chromosomes.
The frequencies of two hereditary coat colour types were determined in a sample of weasels, Mustela nivalis (n=1280) from the Czech and Slovak Republics. White pelage was found in four (0.49%) individuals collected in the period between October and April (n=824). All the other individuals studied had type II vulgaris coloration, characterised by an irregular border between the upper brown part of the body and the white underbelly. Distal white coloration on the feet and upper lip appeared to be unreliable in distinguishing between the two basic types of weasel summer coat. The karyotypes of five weasels from different parts of the Czech Republic contained large heterochromatic arms in six pairs of autosomes. The absence of a large heterochromatic arm in autosomal pair No. 7 differentiates the chromosomal complement of the central European weasels from those occurring in the northern parts of their range. The same karyotype found in Czech weasels was also found in an individual from European Turkey. Comparison of the available data on coat colour and chromosomal variation confirmes the existence of three major phylogenetic lineages of weasels in Europe.
In the present work, we have characterized the chromosomes of 13 Cassidinae beetles, belonging to four tribes, the broad aim being to increase the cytogenetic data and establish the mechanisms involved in chromosome evolution of this subfamily, which appear to be conserved karyotypically, i.e. 2n = 16 + Xyp. The analysis of mitotic and meiotic cells revealed a high diversity of diploid numbers (2n = 18, 2n = 22, 2n = 26, 2n = 32, 2n = 36, 2n = 40, 2n = 42), and the presence of sex chromosome system of the Xyp type in most species, with the exception of two representatives that exhibited Xyr and XY systems. C-banding showed constitutive heterochromatin predominantly localized in the pericentromeric region of the chromosomes, but differences regarding the number of chromosomes with positive C-bands, intensity of the blocks, and presence of additional bands in autosomes and/or sex chromosomes were observed among the species investigated. Our data revealed that the karyotype 2n = 16 + Xyp does not occur in all 13 tribes of the Cassidinae characterized cytogenetically, seeming to be only a shared feature among the species of the Cassidini. Variations in the C-band pattern, mainly in closely related species, suggest that the interspecific karyotype diversification occurred as a result of changes in the quantity and distribution of constitutive heterochromatin. The occurrence of the Xyp sex chromosome system in the tribe Mesomphaliini, which showed the highest diversity of simple and multiple systems among the coleopteran as a whole, reinforces the view that derived systems originated by chromosome rearrangements involving the Xyp ancestral system., Amália T. Lopes, Flávia R. Fernandes, Marielle C. Schneider., and Obsahuje bibliografii
The chromosome set of N. anomalus from Bulgaria was studied by means of C-, and NOR-banding. The diploid chromosome number of this species is known to be 2n=52 (NF = 98, NFa = 94). In all the studied individuals, the X chromosome appeared to be the second longest submetacentric chromosome, whereas the Y chromosome was a medium-sized submetacentric chromosome, consisting of heterochromatin. Such morphology of the Y chromosome was not described previously. The extent and localization of C-bands in the pericentromeric regions varied between the pairs of chromosomes. The nucleolar organizer regions (NOR’s) were observed in four pairs of autosomes.
Diachasmimorpha longicaudata (Hymenoptera: Braconidae) is a parasitoid wasp widely used in the biological control of fruit flies. In this paper, we present a detailed analysis of the karyotype of this species based on the results of classical and molecular cytogenetic techniques. The cytogenetic analysis confirmed the male and female chromosome numbers previously reported (n = 20, 2n = 40). The entire short arm of most chromosomes is made up of a large constitutive heterochromatic segment. The high heterochromatin content differentiates D. longicaudata from other braconid species. Fluorescence in situ hybridization (FISH) using autologous 18S rDNA probes revealed six clusters of rDNA, i.e. six nucleolar organizer regions (NORs), in the heterochromatic short arms of different chromosomes in the haploid male karyotype. This number is exceptionally high for Hymenoptera, which usually have two NORs in the diploid complement. It is noteworthy that these rDNA-FISH experiments represent the first use of this technique on a braconid species using autologous probes. Since Ag-NOR-bands were coincident with C-positive bands on metaphase chromosomes, it was not possible to identify active nucleoli. The physical characteristics of the D. longicaudata karyotype, especially the content and distribution of heterochromatin and the number and location of rDNA clusters, contribute to a better understanding of the structure and organization of braconid chromosomes and provide a basis for genomic and evolutionary studies., Leonela Carabajal Paladino ... [et al.]., and Obsahuje seznam literatury
Differences in the karyology of two species, Centricnemus leucogrammus and Peritelus familiaris (Coleoptera: Curculionidae), were investigated in order to elucidate their taxonomic position of the taxa. Previously both species were placed in one genus whereas the latest taxonomic revision puts them in separate genera. Cytogenetic analysis of P. familiaris and C. leucogrammus showed significant differences in karyotype structure and confirmed their present taxonomic status. The diploid set of C. leucogrammus consists of 22 chromosomes with a fundamental number of arms (FN) of 45 and little variation in morphology and length. Peritelus familiaris has 24 chromosomes with FN of 47 and a more diverse karyotype. The karyotype evolution might have occured by centric fissions of autosomes. At pachytene and diplotene in spermatocytes, each chromosome bivalent showed a small band of pericentric heterochromatin. The bands were hardly visible or undetectable in other stages of spermatogenesis, namely mitotic metaphase, diakinesis, metaphase I and II. The nucleolar organizer regions (NORs) were active at premeiotic stages and early meiosis, but invisible at meiotic metaphase I, metaphase II, and mitotic metaphase. These results indicate the usefulness of cytogenetic methods in taxonomic evaluations.