The present study focused on the evolution of the karyotype in 21 taxa of the genus Isophya, which was done by mapping the location on the chromosomes of ribosomal RNA (rRNA) coding genes using fluorescence in situ hybridization (FISH) with an 18S rDNA probe and using silver staining (AgNO3) to evaluate the activity of major rDNA clusters. Since the chromosome number and sex determination do not vary in this genus, the above markers were used in a detailed comparison of the cytogenetic features of species of Isophya. The species analyzed were placed into three groups based on the location of rDNA on their chromosomes: (1) rDNA-FISH signals only on the two long pairs of autosomes, (2) rDNA-FISH signals on one long and one short pair of autosomes, and (3) rDNA-FISH signals on three to five different sized pairs of autosomes. These groupings partly correspond to the morphological groupings proposed in earlier studies. One long pair of autosomes frequently carried rDNA in all the Isophya species and probably is a plesiomorphic character for these taxa. The cytogenetic mapping revealed great variability among Isophya species in the chromosomal location of major rDNA clusters. Our results suggest that the observed variation in the number of rDNA clusters can be an important species-group specific phylogenetic marker. Analysis of 18S rDNA hybridization signals showed that the evolutionary dynamics of rDNA in this genus is remarkably high and accompanied by changes in the structure of chromosomes bearing rDNA at an inter- and intra-specific level. The telomeric sequence (TTAGG)n hybridized with the termini of most of chromosomes, however, some chromosome ends lacked signals probably due to a low copy number of telomeric repeats. and Beata Grzywacz, Anna Maryańska-Nadachowska, Dragan P. Chobanov, Tatjana Karamysheva, Elżbieta Warchałowska-Śliwa.
1_Chromosomes of six European species (one with two subspecies) of Orthoptera belonging to the tribes Ephippigerini and Bradyporini were analyzed using C-banding, Ag-NOR, DAPI (AT-rich)/CMA3 (GC-rich) staining and fluorescence in situ hybridization (FISH) using the 18S rDNA and (TTAGG)n telomeric probes with the aim to better understand chromosomal organization and evolutionary relationships between genera and subgenera within and across both tribes. The evolution of karyotypes was studied in terms of changes in chromosome number (2n) and morphology (FN, the fundamental number – i.e. the number of chromosome arms including the X chromosome). The ancestral 2n = 31 was reduced to 2n = 29 (FN = 31) and 27 (FN = 31) by one or two Robertsonian fusions in the Ephippigerini. Whereas in the Bradyporini 2n = 27 (FN = 32) as a result of two Robertsonian translocations and a pericentric inversion in the X chromosome. The quantity of heterochromatin in GC-rich regions distinguished the karyotypes of Ephippigerini (only a single CG-rich band on one autosome pair) from those of Bradyporini (CG-rich bands on all chromosomes). FISH using the 18S rDNA probe localized 1–3 rDNA clusters to autosomes and/or to the X chromosome in all species examined. The rDNA loci coincided with active NORs as determined by Ag-NOR staining. A comparison of the location of the single NOR/rDNA in two species of the genus Steropleurus (Ephippigerini) suggests that the reduced chromosome number in S. pseudolus results from a Robertsonian fusion between two pairs of autosomes, one of them carrying the NOR/rDNA as in S. stalii (and also in E. ephippiger)., 2_Whereas the karyotypes of three species of the genus Bradyporus, though showing the same chromosome number and morphology, differed in the number and distribution of NORs/rDNA sites [one autosomal in B. (B.) dasypus versus three in B. macrogaster and B. (C.) oniscus, two of them X-linked]. Trends in karyotype diversification of the taxa based on the present data and previous research are discussed. In some individuals belonging to the species Bradyporus (B.) dasypus and B. (C.) m. macrogaster B chromosomes (Bs) were detected: acrocentric (the smallest elements in the complement) and submetacentric (similar to medium-sized autosomes), respectively., Elzbieta Warchalowska-Sliwa ... [et al.]., and Obsahuje seznam literatury
The Poecilimon ornatus group has an exclusively European distribution and includes the largest species in the genus. A revision of the taxa belonging to this group in Bulgaria and Macedonia (Central and Eastern Balkan Peninsula) is presented. Nine taxa described from Bulgaria are synonymised with 3 previously known species, as follows: Poecilimon ornatus (= P. mistshenkoi marzani, syn. n., P. mistshenkoi tinkae, syn. n., P. mistshenkoi vlachinensis, syn. n.), P. affinis s. str. (= P. mistshenkoi mistshenkoi, syn. n., P. affinis ruenensis, syn. n., P. affinis rilensis, syn. n., P. affinis medimontanus, syn. n., P. harzi, syn. n.) and P. hoelzeli (= P. kisi, syn. n.). The synonymy of P. poecilus with P. affinis and the subspecific status of P. affinis komareki are confirmed. One species, Poecilimon jablanicensis, sp. n., is described as new to science. A tabulated key, lists and maps of all known localities and oscillograms of the songs of all the species in this group are presented. The phylogenetic relationships and evolutionary trends in the Poecilimon ornatus group are discussed.