The function of chromogranin A (CGA) is reviewed, and the radioimmunometric determination of plasma CGA was evaluated as a marker of pheochromocytoma using a comparison of pheochromocytoma patients immediately before surgery (group P, n=25, 635±451 ng/ml) with other groups of patients, i.e. pheochromocytoma patients approximately 1 year after removal of tumor (group PP, n=13, 69±33 ng/ml), medullary thyroid carcinoma patients (group M, n=22, 106±59 ng/ml), congenital adrenal hyperplasy patients (n=33, 65±40 ng/ml), and controls (n=31, 66±29 ng/ml). A CGA level above cut off value 130 ng/ml was found in 24 of 25 patients in group P, 1 (relapse) of 13 patients in group PP, and 4 of 22 patients in group M. In the group P we found a significant association between the size of the tumors removed and plasma CGA concentrations (p=0.0016), and also a significant (p=0.0016) relationship between plasma CGA concentrations and PASS score rating the malignity of pheochromocytoma. We can conclude that plasma CGA concentration as determined by radioimmunometric assay (which is simple without the necessity of special laboratory equipment) is an effective marker of pheochromocytoma with association to malignity and tumor mass., R. Bílek, L. Šafařík, V. Ciprová, P. Vlček, L. Lisá., and Obsahuje bibliografii a bibliografické odkazy
The molecular karyotype of Paranosema grylli Sokolova, Seleznev, Dolgikh et Issi, 1994, a monomorphic diplokaryotic microsporidium, comprises numerous bright and faint bands of nonstoichiometric staining intensity. Restriction analysis of chromosomal DNAs by ''karyotype and restriction display'' 2-D PFGE has demonstrated that the complexity of molecular karyotype of P. grylli is related to the pronounced length polymorphism of homologous chromosomes. The background of this phenomenon is discussed in the context of ploidy state, reproductive strategy and population structure in this microsporidium. We propose that the remarkable size variation between homologous chromosomes in P. grylli may be a consequence of ectopic recombination at the chromosome extremities.
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.
Available data on the distribution and karyology of Nannospalax (superspecies leucodon) from the Carpathian Basin are summarized. We argue that four chromosomal forms of the species complex are endemic to the Carpathian Basin and their former and recent distribution based on museum specimens, literature overview and our own observations is mapped. Based on current distribution data, a preliminary extinction risk-assessment is presented for each of these forms. In spite of the current IUCN category applied for the whole superspecies (i.e. “Least Concern”), one of the chromosomal forms is regarded hereby as Vulnerable, one as Endangered, and two as Data Deficient.
A cytogenetic investigation was performed in eight species of the spittlebug genus Philaenus using silver-NOR (AgNOR)-banding and fluorescence in situ hybridization (FISH) with 18S rDNA and (TTAGG)n telomeric probes. This is the first application of FISH technique in the Auchenorrhyncha, a suborder of the Hemiptera. FISH along with the rDNA probe revealed differences between species in the number and chromosomal location of major ribosomal RNA gene sites, the so-called nucleolar organizer regions (NORs). However, we found a lack of perfect correlation between the results of AgNOR-staining and rDNA-FISH in the detection of NORs. FISH with the telomeric probe confirmed that the chromosome ends of the Philaenus species are composed of the (TTAGG)n nucleotide sequence, which is a common motif of insect telomeres., Anna Maryanska-Nadachowska, Valetnina G. Kuznetsova, Tatyana V. Karamysheva., and Obsahuje seznam literatury
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.
In this study, we examined for the first time the distribution of the 28S ribosomal genes in beetles of the subfamily Cassidinae. More than 55% of the species in this subfamily have a similar karyotype, 2n = 16 + Xyp. For this work, we selected species belonging to the tribes Cassidini and Mesomphaliini, which have, respectively, the most conserved and diversified karyotype characteristics within the Cassidinae. An analysis of 11 species revealed that rDNA sites on one pair of autosomes is the most frequent pattern, occurring in 10 species. This condition occurs in the seven genera examined and in species of both of the tribes, Cassidini and Mesomphaliini. Nevertheless, the differences in the locations of 28S rDNA were more pronounced in the tribe Cassidini and among species with similar karyotype characteristics. On the other hand, in Mesomphaliini, the increase in the diploid number was not accompanied by an increase in the number of ribosomal sites. Moreover, the comparison of the number and localization of major rDNA sites with the distribution of constitutive heterochromatin indicates that there is no direct correlation between the dispersion of constitutive heterochromatin and 28S rDNA genes in Cassidinae.
Chromosome number, karyotype formula, C-banding pattern, genome size and DNA base composition were studied in three species of Hyalidae and seven species of Talitridae. A karyotype of 25 chromosome pairs, with median centromeres (FN = 100), was found in all the species of Talitridae analysed and Apohyale prevostii. Genome size (C-value) varies among Talitrida from 0.94 pg in Apohyale crassipes to 2.81 pg in Orchestia gammarellus, and the percentage of AT-DNA in the whole genome ranges from 56.12% in A. crassipes to 68.17% in Sardorchestia pelecaniformis. In comparison with Hyalidae, Talitridae show more uniformity in chromosome number and karyotype formula, and have larger genomes. There is a direct correlation between total DNA content and the amount of C-heterochromatic DNA. The cytogenetical data on Talitrida were compared from a phylogenetic and an evolutional point of view. The increase in genome size during the evolution of the Talitrida possibly had a role in their adaptation to supralittoral life and extreme subaerial conditions.