The meadow spittlebug genus Philaenus (Auchenorrhyncha: Aphrophoridae) is known to display marked colour polymorphism. This study presents the results of a karyotype analysis of P. arslani from Lebanon using conventional chromosome staining, C-banding, fluorescent banding using base-specific fluorochromes (CMA3 and DAPI) and AgNOR-staining. This species has 2n = 18 + neo-XY, and differs from P. spumarius both in the number of chromosomes and sex chromosome system. During meiosis, the neo-XY bivalent is clearly heteromorphic being the largest in the complement. Furthermore, sex chromosomes show marked differences in C-banding pattern. The NOR-bearing chromosomes are the first and one of the middle-sized pairs of autosomes. NORs are G-C rich. Furthermore, some blocks of constitutive heterochromatin on the sex chromosomes are also G-C rich. All other C-bands are DAPI or DAPI/ CMA3 positive, thus containing A-T rich DNA. The significant difference in the karyotype of P. arslani and P. spumarius indicates chromosomal transformations during the evolution of the genus Philaenus.
Chromosomes of the males of five species of Odontura, belonging to the subgenera Odontura and Odonturella, were analyzed. Intensive evolution of the karyotype was recorded, both in terms of changes in the numbers of chromosomes (from 2n = 31 to 27) and the sex chromosome system (from X0 to neo-XY and X0 to neo-X1X2Y). Karyotype evolution was accompanied by tandem autosome fusions and interspecific autosomal and sex chromosome differentiation involving changes in the locations of nucleolar organizer regions, NORs, which were revealed by silver impregnation and confirmed by FISH using an 18S rDNA probe. O. (Odonturella) aspericauda is a polytypic species with X0 and neo-X1X2Y sex determination. The latter system is not common in tettigoniids. It possibly originated by a translocation of a distal segment of the original X chromosome onto a medium sized autosome, resulting in a shortened neo-X1 and a metacentric neo-Y. The remaining autosome homologue became the neo-X2 chromosome. This shift from X0 to neo-X1X2Y is supported by the length of the X chromosome and location of the NOR/rDNA. and Elżbieta Warchałowska-Śliwa, Anna Maryańska-Nadachowska, Beata Grzywacz, Tatjana Karamysheva, Arne W. Lehmann, Gerlind U.C. Lehmann, Klaus-Gerhard Heller.
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.
Fluorescence in situ hybridization (FISH) is a technique used to determine the chromosomal position of DNA and RNA probes. The present study contributes to knowledge on jumping plant-lice genomes by using FISH with 18S rDNA and telomeric (TTAGG)n probes on meiotic chromosomes of Psylla alni (2n = 24 + X), Cacopsylla mali (2n = 22 + neo-XY and 20 + neo-X1X2Y), C. sorbi (2n = 20 + neo-XY), Baeopelma foersteri (2n = 14 + X), and Rhinocola aceris (2n = 10 + X). This is the first study that has used FISH on the hemipteran superfamily Psylloidea. We found that the chromosomes of all studied species contain the insect-type telomere motif, (TTAGG)n. In C. mali and C. sorbi, the neo-sex chromosomes originating from autosome-sex chromosome fusions showed no interstitially located clusters of TTAGG repeats, suggesting their loss or inactivation. Similarly, no interstitial (TTAGG)n clusters were detected in an extremely large autosome pair of B. foersteri that most likely originated from a fusion of at least five ancestral chromosome pairs. Clusters of 18S rDNA were detected on the fused and second largest autosome pairs of B. foersteri and on one of the large autosome pairs of the remaining species. In C. mali and B. foersteri, the rDNA clusters were shown to coincide with the NORs as detected by the AgNOR method. Finally, we speculate, based on the obtained FISH markers, on the mechanisms of karyotype evolution of psylloid species differing in chromosome numbers and sex chromosome systems., Anna Maryańska-Nadachowska, Valentina G. Kuznetsova, Natalia V. Golub, Boris A. Anokhin., and Obsahuje bibliografii
The distribution patterns of the X0/XX and neo-XY/neo-XX chromosome races, subraces, and "hybrids" between subraces of the grasshopper P. sapporensis were analyzed. The origin of the observed variation is Robertsonian translocations between a sex chromosome and an autosome, and chromosome rearrangements. The fixation levels of inversions varied depending on geographic regions. No hybrid population is known implying that a strong reproductive isolation system exists in hybrids between the different chromosomal races. The probable reasons for the purity of X0 and neo-XY chromosome races and high chromosome polymorphism in contact zones between chromosomal subraces are discussed. The presence of isolating barriers between chromosome races indicates a review of the taxonomic structure of P. sapporensis is required. It is proposed to divide P. sapporensis into two sibling species, which differ in the chromosome mechanisms of the sex determination system.The analysis of the distribution of chromosomal races and subraces of P. sapporensis allows a reconstruction of the history of this species in the Okhotsk sea region.
Karyotypes and testis structure of 14 species representing 9 genera (Latissus, Bubastia, Falcidius, Kervillea, Mulsantereum, Mycterodus, Scorlupaster, Scorlupella and Zopherisca) of the planthopper tribe Issini (Issidae) are presented. All the karyotypes are illustrated by meiotic and occasionally mitotic figures. The male karyotypes of most of the species analyzed are 2n = 26 + X, the exception being Falcidius limbatus, which has a karyotype of 2n = 24 + neo-XY. The latter is the first report of the neo-XY system in the family Issidae. The species studied are found to be similar in having NORs on the largest pair of autosomes, but differ significantly in the amount and distribution of C-heterochromatin along the chromosomes. In contrast to the conserved chromosome numbers, the highly variable follicle number in the testes suggests rapid evolution of the tribe Issini. On the basis of its specific follicle number, it is proposed that Zopherisca tendinosa skaloula Gnezdilov & Drosopoulos, 2006 be upgrade to a species: Z. skaloula stat. n. The cytological and taxonomic significance of results presented are discussed.
The aim of this study was to obtain information on the karyotypes, testes and ovaries of three fulgoroid families, mainly in the Issidae but also in the Caliscelidae and Acanaloniidae. For the Issidae, the data is for 19 species belonging to 11 genera of the subtribes Issina (2 species, 1 genus), Hysteropterina (14 species, 9 genera) and Agalmatiina (3 species, 2 genera) of the tribe Issini. The male karyotypes are shown to be quite uniform across the tribe, with 2n = 26 + X in all species studied except Latilica maculipes (Melichar, 1906) with 2n = 24 + X. The modal karyotype, 2n = 26 + X, matches the most probable ancestral state in the Fulgoroidea. In the majority of cases the number of seminal follicles in males and ovarioles in females are stable within but fairly variable among the species, the modal value of the follicle number is 10 per testis. Contrary to what might be expected from other fulgoroid families, such as the Dictyopharidae and Delphacidae, the variability in these characters revealed neither regular trends nor evident correspondence with the taxonomy of Issidae. In the Caliscelidae, all species studied had testes consisting of 6 follicles each and karyotypes of 2n = 24 + X and 26 + XY, respectively, in 3 and 1 species. The only representative studied of the Acanaloniidae, Acanalonia bivittata (Say, 1825), had 2n = 24 + X and 13 follicles in its testis. The variability in all the characters investigated is discussed and compared to other fulgoroid families, primarily to the most extensively studied families, Delphacidae and Dictyopharidae.