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Here, a comprehensive cytogenetic analysis of three species of tenebrionid beetles: Alphitobius diaperinus, Tenebrio molitor and Zophobas morio, is presented. This paper also contains a review of the cytogenetic information for each species and adds new data. The male karyotype of both T. molitor and Z. morio is 2n = 18 + Xyp, with large heterochromatic blocks in the pericentromeric regions of all chromosomes. The male A. diaperinus karyotype is 2n = 18 + X0, also with heterochromatic pericentromeric regions in all chromosomes. The location of the nucleolar organizer regions (NORs) differs in each species: in A. diaperinus, it is located on the smallest pair of autosomes, while in T. molitor, it is on two pairs of autosomes and both sex chromosomes. In contrast, it is exclusively located on the X chromosome in Z. morio. Telomere analysis revealed that all species have TCAGG repeats in their telomeres, but lack the canonical TTAGG insect telomeric motif. In addition, a study of the distribution of satellite DNA and composition revealed that each species has a main satellite DNA family forming the pericentromeric heterochromatin. Fluorescence in situ hybridization of each of these satellites did not produce hybridization signal in the other two species, indicating a divergence in repetitive DNA composition among them. This study adds to the understanding of chromosomal organization, heterochromatin distribution and repetitive DNA dynamics in tenebrionid beetles and sheds light on their cytogenetic diversity and evolutionary significance. [ABSTRACT FROM AUTHOR]

Cytogenetic studies in Sturisoma are rare; this genus had 11 valid species distributed in basins in South America. In this article, we aimed to expand on the cytogenetic data available for Sturisoma, contributing to the record of the karyotype and other chromosomal characteristics of both minor and major ribosomal DNA of S. barbatum from the upper Paraguay River basin. This population had diploid chromosome number 66, a karyotype composed of 20 metacentric, 14 submetacentric, 14 subtelocentric, and 18 acrocentric chromosomes, and a fundamental number of 114 for both sexes. Heterochromatic regions were observed in the short arms of the nucleolus organizer regions (NOR)-bearing chromosome pair. Fluorescence in situ hybridization revealed a single 18S site and multiple 5S ribosomal DNA sites. Data from NORs confirmed the tendency of this family to present simple NORs sites, as well as multiple sites of 5S ribosomal DNA. Pericentric inversions (or other types of centromeric shift) and/or deletions appear essential in the karyotype evolution and differentiation among S. barbatum. The present data are valuable to help in understanding karyotypic evolution in Loricariidae. [ABSTRACT FROM AUTHOR]

Two endemic Anatolian nemacheilids were studied cytogenetically for the first time. Diploid chromosome numbers, chromosome morphologies in the karyotypes and also C-band and Ag-NOR banding properties were recorded for the two species of Oxynoemacheilus. The diploid chromosome number is 50 and karyotypes contained 34 biarmed and 16 monoarmed chromosomes in Oxynoemacheilus axylos Yoğurtçuoğlu et al. 2022. In O. nasreddini Yoğurtçuoğlu et al. 2021, there are 30 biarmed and 20 monoarmed chromosomes. No heteromorphic sex chromosomes were determined. C-band patterns and the number of Ag-NORs were different between the two studied species. [ABSTRACT FROM AUTHOR]

This contribution provides the first karyotype description of Hemidactylus mercatorius and discusses the interspecific chromosome diversification in the genus. Chromosomal analysis was performed on samples from different Malagasy populations using standard karyotyping, Ag-NOR staining, and banding methods (sequential C-banding + Giemsa, + Chromomycin A3, +4′,6-diamidino-2-phenylindole). Irrespective of sex or sampling locality, H. mercatorius shows a karyotype of 2n = 42 with metacentric (1, 18–21), submetacentric (4), subtelocentric (5, 11), and acrocentric pairs (all the remaining pairs). There was no heteromorphic chromosome pair and no clear distinction between macro- and microchromosomes. NORs were localised close to the centromeres of a medium acrocentric pair (14). Heterochromatic blocks were identified on the telomeric and centromeric regions of most chromosome pairs. A comparison with the karyotype of H. mabouia highlights that the different morphology of several chromosome pairs clearly distinguishes the two species, contrasting the previously proposed synonymy. The differences between the karyotypes of H. mercatorius and H. mabouia concern the number of biarmed and acrocentric elements, suggesting the occurrence of several chromosome inversions. Considering all the available karyotype data on Hemidactylus and its sister genus Cyrtodactylus, it is possible to advance an evolutionary hypothesis on their chromosomal evolution, starting from a common ancestor with 2n = 48 and all acrocentric elements. From this ancestral condition, the karyotype diversification in the two genera has been prevalently characterised by a progressive accumulation of fusions and inversions which have reduced the total chromosome count and increased the number of biarmed chromosomes. [ABSTRACT FROM AUTHOR]

Abstract Hypostomus is distributed by Central and South America basins, with diverse species with taxonomic conflicts. This way, the integration of auxiliary techniques contributes to understanding the systematics and phylogeny of the group. Thus, this study aimed to investigate the Hypostomus cochliodon and H. boulengeri from the Onça stream (Paraguai River basin) by allozyme and cytogenetic techniques. Hypostomus boulengeri showed a diploid number of 68 chromosomes (14m+14sm+18st+22a), multiple NOR revealed by Ag-NOR and 18S rDNA FISH, a polymorphism of heterochromatin in acrocentrics and the presence of B microchromosome. Hypostomus cochliodon showed a diploid number of 64 chromosomes (16m+26sm+14st+8a); despite the single NOR, some individuals showed NOR in both telomeres detected by Ag-NOR and 18S rDNA FISH. Isozyme identified two diagnostic loci (Idh-A and Gdh-A) between the two species and multiple loci with unique alleles in H. boulengeri. The genetic variability indicated by the mean heterozygosity (He) was 0.2461 and 0.0309 in H. boulengeri and H. cochliodon,respectively.Thus, this study reports the first cytogenetic data for H. boulengeri and the first isozymatic data for H. boulengeri and H. cochliodon. The two species presented evident cytogenetic and isoenzymatic differences with the obtaining of exclusive genetic markers providing support for future evolutionary studies in the group.

Abstract Cytogenetic techniques have been improving over the last decades, providing useful information for the systematics and evolution of several groups, such as social insects. On the other hand, karyotypic data are still incipient for most wasp genera. For instance, only 21 out of the 242 species of Polistes were karyotyped, generally with data restricted to number and morphology. Therefore, this study aimed to revisit the karyotype structure of Polistes canadensis, providing unpublished information based on traditional cytogenetic methods (karyotyping, C-banding and base-specific fluorochrome staining). Males and females of P. canadensis were characterized by haploid and diploid numbers of n=28 and 2n=56, respectively. The karyotype formula was established in 2K=18M+22SM+16A with a predominance of pericentromeric heterochromatin and terminal GC+ sites in 16 chromosome pairs. These data suggest that fissions and inversions may be involved in the group karyoevolution. It should be pointed out that our results differ significantly from the first cytogenetic report in this species, which may be related to the outdated method of obtaining mitotic chromosomes or misidentification. As a matter of fact, the improved cytogenetic methods from the present study provided reliable information about the karyotype of P. canadensis that can be used in further comparative cytotaxonomic and evolutionary analyses of social wasps.

Wild and domesticated emmer (ВВАА, 2n = 28) are of significant interest for expanding the genetic diversity of common wheat as sources of a high protein and microelement grain content, resistance to many biotic and abiotic factors. Particular interest in these species is also determined by their close relationship with Triticum aestivum L., which facilitates interspecific hybridization. The objective of this work was to analyze the nature of alien introgressions in hybrid lines from crossing common wheat varieties with T. dicoccoides and T. dicoccum, and to assess the effect of their genome fragments on the cytological stability of introgression lines. A C-banding technique and genotyping with SNP and SSR markers were used to determine localization and length of introgression fragments. Assessment of cytological stability was carried out on the basis of chromosome behavior in microsporogenesis. A molecular cytogenetic analysis of introgression wheat lines indicated that the inclusion of the genetic material of wild and domesticated emmer was carried out mainly in the form of whole arms or large fragments in the chromosomes of the B genome and less extended inserts in the A genome. At the same time, the highest frequency of introgressions of the emmer genome was observed in chromosomes 1A, 1B, 2B, and 3B. The analysis of the final stage of meiosis showed a high level of cytological stability in the vast majority of introgression wheat lines (meiotic index was 83.0–99.0 %), which ensures the formation of functional gametes in an amount sufficient for successful reproduction. These lines are of interest for the selection of promising material with agronomically valuable traits and their subsequent inclusion in the breeding process.

The water-hyacinth grasshopper, Cornops aquaticum (Orthoptera: Acrididae), shows a clinal variation for 3 Robertsonian translocation (centric fusion) polymorphisms in the southern extreme of its wide geographical distribution. It is a Neotropical semiaquatic grasshopper that lives, feeds, and lays eggs exclusively on floating plants of the family Pontederiaceae, or water-hyacinths, between 23° N (Southern Mexico) and 35° S (Central Argentina and Uruguay). Given the invasive-species status of Pontederia (formerly Eichhornia) crassipes and the voraciousness of these grasshoppers, they were considered as a potential biological control agent in addition to other natural enemies. We already described the association of the rearrangements with geographical and climatic variables, phenotypic variation, trivalent orientation, effects on recombination, and relationship with microsatellite variability. Here we analyze the distribution of constitutive heterochromatin in 2 populations of C. aquaticum in order to (i) provide consistent markers for a better distinction between all chromosomes, those which are involved in the centric fusions, and those which are not, and (ii) describe possible polymorphisms for C-positive supernumerary segments, given that, on conventional staining analysis, it was frequent to find heteromorphic autosomal bivalents. The cytogenetic analysis allowed us to get a detailed characterization of the constitutive heterochromatin distribution, providing unmistakable chromosome markers of the large, fusion-bearing chromosomes as well as the C-positive, polymorphic supernumerary segments. [ABSTRACT FROM AUTHOR]

Copyright of Ege Journal of Fisheries & Aquatic Sciences (EgeJFAS) / Su Ürünleri Dergisi is the property of Ege Journal of Fisheries & Aquatic Sciences (EgeJFAS) / Su Urunleri Dergisi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this investigation, the mitotic chromosomes of Centaurea nicaeensis All. are characterized. Using various cytogenetic techniques, fundamental information on the genomic organization of the species was obtained. The aceto-orcein staining allowed for the determination of the ploidy level. The karyotype is then characterized by the presence of three chromosomal types: five metacentric pairs, four submetacentric pairs, of which three carry satellites, and one subtelocentric pair; the karyotype is 1A according to Stebbins category. Differential Giemsa staining revealed the presence of two distinct forms of constitutive heterochromatin. The first type is associated with centromeric regions, while the second type detects the presence of two B chromosomes and is associated with satellites and telomeres. Chromomycin A3 staining revealed the presence of GC-rich heterochromatin on all chromosomes, predominantly at the telomere ends. [ABSTRACT FROM AUTHOR]

Dragonflies of the family Gomphidae (order Odanata) possess characterstic club-like structure in the last segment of abdomen. Male germ cell chromosomes of Lamelligomphus biforceps, Nepogomphus walli and Onychogomphus grammicus of family Gomphidae were investigated, using carbolfuchsin staining, C-banding, silver nitrate staining and sequence specific staining. All the three possess chromosome complement 2n = 23, which is the type number of the family Gomphidae with XO/XX sex determining mechanism. Terminal C-bands are present on the autosomal bivalents, while bivalents show variation in distribution of NORs (Nuclear Organiser Regions). X chromosome is C- positive and NOR rich in all the species. All the autosomes show CMA3 (Chromomycin A3) bright signals in Lamelligomphus biforceps, whereas bright DAPI (4′,6-diamidino-2-phenylindole) signals in Onychogomphus grammicus, and both DAPI and CMA3 bright signals in Nepogomphus walli. The X chromosome of L. biforceps possesses DAPI bright signals, while it reveals both DAPI and CMA3 bright signals in N. walli and O. grammicus. Cytogenetic analyses of all the species have been done for the first time. [ABSTRACT FROM AUTHOR]

This contribution provides the first karyotype description of Hemidactylus mercatorius and discusses the interspecific chromosome diversification in the genus. Chromosomal analysis was performed on samples from different Malagasy populations using standard karyotyping, Ag-NOR staining, and banding methods (sequential C-banding + Giemsa, + Chromomycin A3, +4′,6-diamidino-2-phenylindole). Irrespective of sex or sampling locality, H. mercatorius shows a karyotype of 2n = 42 with metacentric (1, 18–21), submetacentric (4), subtelocentric (5, 11), and acrocentric pairs (all the remaining pairs). There was no heteromorphic chromosome pair and no clear distinction between macro- and microchromosomes. NORs were localised close to the centromeres of a medium acrocentric pair (14). Heterochromatic blocks were identified on the telomeric and centromeric regions of most chromosome pairs. A comparison with the karyotype of H. mabouia highlights that the different morphology of several chromosome pairs clearly distinguishes the two species, contrasting the previously proposed synonymy. The differences between the karyotypes of H. mercatorius and H. mabouia concern the number of biarmed and acrocentric elements, suggesting the occurrence of several chromosome inversions. Considering all the available karyotype data on Hemidactylus and its sister genus Cyrtodactylus, it is possible to advance an evolutionary hypothesis on their chromosomal evolution, starting from a common ancestor with 2n = 48 and all acrocentric elements. From this ancestral condition, the karyotype diversification in the two genera has been prevalently characterised by a progressive accumulation of fusions and inversions which have reduced the total chromosome count and increased the number of biarmed chromosomes.

Geckos (Gekkota), the species-rich clade of reptiles with more than 2200 currently recognized species, demonstrate a remarkable variability in diploid chromosome numbers (2n = 16–48) and mode of sex determination. However, only a small fraction of gekkotan species have been studied with cytogenetic methods. Here, we applied both conventional (karyotype reconstruction and C-banding) and molecular (fluorescence in situ hybridization with probes for rDNA loci and telomeric repeats) cytogenetic analyses in seven species of geckos, namely Blaesodactylus boivini, Chondrodactylus laevigatus, Gekko badenii, Gekko cf. lionotum, Hemidactylus sahgali, Homopholis wahlbergii (Gekkonidae) and Ptyodactylus togoensis (Phyllodactylidae), in order to provide further insights into the evolution of karyotypes in geckos. Our analysis revealed the presence of interstitial telomeric repeats in four species, but we were not able to conclude if they are remnants of previous chromosome rearrangements or were formed by an accumulation of telomeric-like satellite motifs. Even though sex chromosomes were previously identified in several species from the genera Hemidactylus and Gekko by cytogenetic and/or genomic methods, they were not detected by us in any examined species. Our examined species either have poorly differentiated sex chromosomes or, possibly, environmental sex determination. Future studies should explore the effect of temperature and conduct genome-wide analyses in order to identify the mode of sex determination in these species. [ABSTRACT FROM AUTHOR]

Scincoidea, the reptilian clade that includes girdled lizards, night lizards, plated lizards and skinks, are considered as a lineage with diversity in sex-determining systems. Recently, the hypothesis on the variability in sex determination in skinks and even more the absence of sex chromosomes in some of them has been rivalling. Homologous, evolutionary stable XX/XY sex chromosomes were documented to be widespread across skinks. However, sex determination in the other scincoidean families is highly understudied. ZZ/ZW sex chromosomes have been identified only in night lizards and a single species of plated lizards. It seems that although there are different sex chromosome systems among scincoidean lineages, they share one common trait: they are mostly poorly differentiated and often undetectable by cytogenetic methods. Here, we report one of the exceptions, demonstrating for the first time ZZ/ZW sex chromosomes in the plated lizard Zonosaurus madagascariensis. Its sex chromosomes are morphologically similar, but the W is clearly detectable by comparative genomic hybridization (CGH), suggesting that the Z and W chromosomes highly differ in sequence content. Our findings confirm the presence of female heterogamety in plated lizards and provides novel insights to expand our understanding of sex chromosome evolution in scincoidean lizards. [ABSTRACT FROM AUTHOR]

Copyright of Ege Journal of Fisheries & Aquatic Sciences (EgeJFAS) / Su Ürünleri Dergisi is the property of Ege Journal of Fisheries & Aquatic Sciences (EgeJFAS) / Su Urunleri Dergisi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Tandemly arranged and dispersed repetitive DNA sequences are important structural and functional elements that make up a significant portion of vertebrate genomes. Using high throughput, low coverage whole genome sequencing followed by bioinformatics analysis, we have identified seven major tandem repetitive DNAs and two fragments of LTR retrotransposons in the genome of the Nile crocodile (Crocodylus niloticus, 2n = 32). The repeats showed great variability in structure, genomic organization, and chromosomal distribution as revealed by fluorescence in situ hybridization (FISH). We found that centromeric and pericentromeric heterochromatin of C. niloticus is composed of previously described in Crocodylus siamensis CSI-HindIII and CSI-DraI repetitive sequence families, a satellite revealed in Crocodylus porosus, and additionally contains at least three previously unannotated tandem repeats. Both LTR sequences identified here belong to the ERV1 family of endogenous retroviruses. Each pericentromeric region was characterized by a diverse set of repeats, with the exception of chromosome pair 4, in which we found only one type of satellite. Only a few repeats showed non-centromeric signals in addition to their centromeric localization. Mapping of 18S–28S ribosomal RNA genes and telomeric sequences (TTAGGG)n did not demonstrate any co-localization of these sequences with revealed centromeric and pericentromeric heterochromatic blocks. [ABSTRACT FROM AUTHOR]

The use of the gene pool of wild relatives, which have a significant reserve of genetic diversity, is of immediate interest for breeding common wheat. The creation and use of synthetic forms as “bridges” is an effective method of transferring valuable genetic material from wild relatives to cultivated wheat. For this purpose, genome addition, genome substitution and recombinant “secondary” synthetic forms have been created in the P.P. Lukyanenko National Center of Grain. The synthetic recombination form RS5 (BBAASDt ), in which the third genome consists of chromosomes of Aegilops speltoides (S) and Aegilops tauschii (Dt ), was obtained from crossing the synthetic forms Avrodes (BBAASS) and M.it./Ae. tauschii (BBAADt Dt ), in which the D genome from Ae. tauschii was added to the BBAA genomes of the durum wheat cultivar Mutico italicum. Introgression lines resistant to leaf rust, yellow rust and powdery mildew have been obtained from backcrosses with the susceptible common wheat cultivars Krasnodarskaya 99, Rostislav and Zhirovka. Twelve resistant lines that additionally have high technological characteristics of grain and flour have been selected. The cytological study (С-banding) has revealed chromosomal modifications in 6 of 8 lines under study. The rearrangements mainly affected the chromosomes of the D genome, 1D, 3D, 4D, 6D and 7D. It was found that in most cases the genetic material from the synthetic form RS5 in the studied lines was represented by substituted chromosomes from Ae. tauschii. In line 5791p17, the substitution of chromosomes 6D from Ae. tauschii and 7D from Ae. speltoides was revealed. Substitutions 4D(4Dt ), 6D(6Dt ) from Ae. tauschii and 7D(7S) from Ae. speltoides were obtained for the first time. Molecular analysis of 12 lines did not reveal effective leaf rust resistance genes, presumably present in synthetic forms of M.it./Ae. tauschii and Avrodes. It is assumed that the lines may carry previously unidentified genes for fungal disease resistance, in particular for resistance to leaf rust, from Ae. tauschii and Ae. speltoides.

The karyotypes of two Anatolian endemic leuciscid species, Pseudophoxinus alii Küçük, 2007 and P. elizavetae Bogutskaya, Küçük & Atalay, 2007, were studied using conventional cytogenetic methods. The diploid chromosome numbers were invariably 2n = 50. The chromosome morphology in the karyotypes was as follows: 18 metacentric, 24 submetacentric and eight subtelo-acrocentric chromosomes in P. alii and eight metacentric, 34 submetacentric and eight subtelo-acrocentric chromosomes in P. elizavetae. Heteromorphic sex chromosomes were not observed in the two species. The largest chromosome pair in the karyotypes of P. alii and P. elizavetae was a subtelo-acrocentric. C-bands were determined on the pericentromeric regions of the most of the chromosomes in P. alii and on the pericentromeric regions of some chromosomes in P. elizavetae. Multiple nucleolus organizer regions (NORs) were observed in the two species. A review of the data on the karyotypes of 13 species of the genus Pseudophoxinus occurring in Turkey is presented. [ABSTRACT FROM AUTHOR]

Taxonomy in Bufonidae witnessed notable transformations. Bufotes viridis and Epidalea calamita, previously included in genus Bufo, were relocated in other genera, while the genus Bufo was restricted to members of the earlier Bufo bufo group. On the other hand, Bufo bufo sensu lato now includes four species: Bufo bufo, Bufo spinosus, Bufo verrucosissimus and Bufo eichwaldi. In this study, we examined three species of three Bufonidae genera (B. spinosus, B. viridis and E. calamita) by conventional (C-banding and Ag-NOR staining) and molecular (in situ hybridization with probes for telomeric repeats and rDNA loci, and genomic in situ hybridization (GISH)) cytogenetic methods. C-banding patterns are reported for the first time for B. spinosus and E. calamita populations from Iberian Peninsula and for B. viridis from Greece, and reveal several differences with the reported C-banded karyotypes described for other European populations of these species. Silver staining shows size heteromorphisms of the signals at the Nucleolar Organizing Region (NOR). By contrast, FISH with ribosomal probes only reveal size heteromorphism of rDNA sequences in E. calamita, suggesting that the differences observed after silver staining in B. spinosus and B. viridis should be attributed to differences in chromosomal condensation and/or gene activity rather than to differences in the copy number for ribosomal genes. Regarding telomeric repeats, E. calamita is the only species with interstitial telomeric sequences (ITS) located on centromeric regions, probably originated by accumulation of telomeric sequences in the centromeric heterochromatin. Finally, we analyzed the composition and distribution of repetitive sequences by genome in situ hybridization. These experiments reveal the accumulation of repetitive sequences in centromeric regions of the three species, although these sequences are not conserved when species from different genera are compared. [ABSTRACT FROM AUTHOR]

The recent discovery of two independently evolved XX/XY sex determination systems in the snake genera Python and Boa sparked a new drive to study the evolution of sex chromosomes in poorly studied lineages of snakes, where female heterogamety was previously assumed. Therefore, we examined seven species from the genera Eryx, Cylindrophis, Python, and Tropidophis by conventional and molecular cytogenetic methods. Despite the fact that these species have similar karyotypes in terms of chromosome number and morphology, we detected variability in the distribution of heterochromatin, telomeric repeats, and rDNA loci. Heterochromatic blocks were mainly detected in the centromeric regions in all species, although accumulations were detected in pericentromeric and telomeric regions in a few macrochromosomes in several of the studied species. All species show the expected topology of telomeric repeats at the edge of all chromosomes, with the exception of Eryx muelleri, where additional accumulations were detected in the centromeres of three pairs of macrochromosomes. The rDNA loci accumulate in one pair of microchromosomes in all Eryx species and in Cylindrophis ruffus, in one macrochromosome pair in Tropidophis melanurus and in two pairs of microchromosomes in Python regius. Sex-specific differences were not detected, suggesting that these species likely have homomorphic, poorly differentiated sex chromosomes. [ABSTRACT FROM AUTHOR]

Key words: garlic; chromosome - c-banding; FISH; Allicin- gene mapping EN garlic chromosome - c-banding FISH Allicin- gene mapping Garlic (Allium sativum) is a diploidspecies belonging to the genusAllium of the Liliaceae family, order Asparaguses'is well known that Garlic originatedfrom the main center of Allium diversitythat stretches from the Mediterraneanbasin to central Asia (Ipek and Simon,2001). In the present work, three allicinsignals were localized on the chromatin ofboth interphase and metaphase of the nonboltercultivar (AZO 3), whereas foursigns were scattered on chromosomes ofthe bolter cultivar (Egaseed 2).A relationshipmay be found between the number ofallicin gene signals and bolt differentiationin Garlic. SUMMARY In order to study c-banding patternsand the allocation of the allicin gene onGarlic chromosomes, some cytologicalexaminations on two Garlic cultivars(Egaseed 2 and AZO 3) were done. Garlic, chromosome, c-banding, FISH, chromosome - c-banding, Allicin- gene mapping. [Extracted from the article]

Many chromosome assays rely on the quantification of chromosome abnormalities in cells, and one important abnormality is the existence of more than one centromere for each chromosome. The quantification of such abnormalities has been studied before. However, this process is labor-intensive and time consuming. Thus, this assay is challenging for ex-laboratory applications, where speed is required. We present a visualization method that uses a cheap stain—DAPI, long (e.g., high-resolution) chromosomes and our modified C-banding method for labeling chromosomes. The labeled chromosomes can then be easily seen with a conventional and readily available fluorescence microscopy system. This method achieves an acceleration of the detection of the presence of constitutive heterochromatin in chromosomal centromeres by more than 10 times, to ~2 h, in Human lymphocyte cells and in cells of the human Jurkat line. This new procedure will ultimately provide an easier and cheaper alternative to FISH/PNA probes, or the classic Giemsa staining method. Simplification and reduction in time of the overall procedure will enable the utilization of centromere-counting assays in laboratory and ex-laboratory applications, including in emergency response. [ABSTRACT FROM AUTHOR]

A new race was determined in a population of mole rats Nannospalax xanthodon from Karaman. In addition, a hybrid with 2n = 59 chromosomes was detected between the populations of the Ugurlu race. The karyotype of the new race contained 58 chromosomes, including 11 biarmed pairs and 17 acrocentric pairs in the autosomal complement (NFa=78). The X chromosome was submetacentric (NF=82). The karyotype of a hybrid form contained 59 chromosomes, including two heteromorphic pairs in the autosomal complement (NFa=75). The X chromosome was submetacentric (NF=79). The dark centromeric C-bands were observed in some biarmed and acrocentric autosomes in both new race and hybrid form. C-heterochromatic short arms were found in some autosomal pairs in the only new race. The X chromosome possessed centromeric C-positive band in both new race and hybrid form. NORs were detected on the short arms of three pairs of autosomes in the Ugurlu race and two in the hybrid form. The karyotype characteristics observed in the new race are obviously different among hitherto studied 2n= 58 populations of blind mole rats; therefore, it can be evaluated as a new chromosome race of N. xanthodon. In this study, finding a new hybrid with interracial hybridisation is important for future studies in terms of the chromosomal evolution of blind mole rats. [ABSTRACT FROM AUTHOR]

Abstract Background Triticum kiharae (AtAtGGDD, 2n = 42) is of interest for the improvement of bread wheat as a source of high grain protein and gluten content, as well as resistance to many diseases. The use of T. kiharae for the improvement of T. aestivum L. is complicated by the fact that the homology degree of their genomes is low and this leads to an unbalanced set of chromosomes in the gametes of its first generations and the elimination of some genotypes. The aim of this study was to analyze the nature of alien introgressions and their effect on the cytological stability of hybrids obtained from crossing of bread wheat varieties with T. kiharae. Results Using C-banding, the presence of entire chromosomes of T. kiharae in the karyotypes of hybrid lines (intergenomic substitution 2G/2B), chromosome arms (centric translocation Т2AtS:2AL) and large inserts in the form of terminal translocations involving chromosomes of 1st, 3rd and 5th homoeologous groups of B- and G-genomes were found. Molecular markers revealed short introgression of T. kiharae into the genome of common wheat varieties. The highest introgression frequency was shown for 1A, 1B, 2A, 5B, and 6A chromosomes, while no foreign chromatin was detected in 4A and 4B chromosomes. A high level of cytological stability (a meiotic index of 88.18–93.0%) was noted for the majority of introgression lines. An exception was found for the lines containing the structural reorganization of chromosome 5B, affecting the main genes of chromosome synapsis in terms of their functioning. Conclusions During the stabilization of hybrid karyotypes, the introgression of genetic material from T. kiharae into the genome of T. aestivum occurs in the form of short fragments detectable only by molecular markers and in the form of whole chromosomes (intergenomic substitution) and their large fragments (centric and terminal translocations). The level of cytological stability achieved in F10 by the majority of introgression lines ensures the formation of functional gametes sufficient for the successful reproduction of the obtained hybrids.

The karyotype of the plant species Krameria cistoidea Hook. & Arn. was studied by assessing chromosome characters such as morphology, size, and C-banding pattern. The karyotype of K. cistoidea was composed only by metacentric chromosomes in the two populations studied. The haploid set length was 51.9±2.3 µm and the mean chromosome size was 8.68±0.78 µm. Some similarities in chromosome morphology and size can be observed among K. cistoidea and K. triandra, in addition to the chromosome number 2n=12 which is conserved within the genus. K. cistoidea exhibited a symmetric banding pattern with large C-bands in the telomeres of the short and long arms of all chromosomes, except the short arm of pair 1. The relative length of the C-bands was 23.5% of the total haploid set length. These cytological results on K. cistoidea are the first data on quantitative karyotype morphology and C-banding patterns in the genus Krameria.

Synthetic recombination form RS7 (BBAAUS), in which the first two genomes, A and B, originate from common wheat, and the third recombinant genome consists of Aegilops speltoides (S) and Ae. umbellulata (U) chromosomes, was obtained from crossing synthetic forms Avrodes (BBAASS) and Avrolata (BBAAUU). Resistant to leaf rust, yellow rust and powdery mildew, introgression lines have been obtained from backcrosses with the susceptible varieties of common wheat Krasnodarskaya 99, Fisht and Rostislav. PCR analysis showed the presence of amplification fragments with marker SCS421 specific for the Lr28 gene in the line 4991n17. The cytological study (С-banding and FISH) of 14 lines has revealed chromosomal modifications in 12 of them. In most cases, the lines carry translocations from Ae. speltoides, which were identified in chromosomes 1D, 2D, 3D, 2B, 4B, 5B and 7B. Also, lines with the substituted chromosomes 1S (1B), 4D (4S), 5D (5S) and 7D (7S) were identified. Lines that have genetic material from Ae. speltoides and Ae umbellulata at once were revealed. In the line 3379n14, translocations in the short arm of chromosome 7D from Ae. umbellulata and chromosomes 5BL, 1DL, 2DL from Ae. speltoides were revealed. The line 4626p16 presumably has a translocation on the long arm of chromosome 2D from Ae. umbellulata and the T7SS.7SL-7DL translocation from Ae. speltoides. The T1DS.1DL-1SL and T3DS.3DL-3SL translocations from Ae. speltoides, and T2DS.2DL-2UL and T7DL.7DS-7US from Ae. umbellulata have been obtained for the first time. These lines may carry previously unidentified disease resistance genes and, in particular, leaf rust resistance genes from Ae. speltoides and Ae. umbellulata.

The development of bread wheat introgressions with alien genetic material from cultural and wild Triticeae species is an effective method for expanding the wheat gene pool necessary for breeding. To date, numerous collections of introgressions as substitutions and chromosome modifications have been obtained; however, the creation and study of wheat with new valuable traits still remain an important line of research. Rye Secale cereale L., whose chromosomes carry genes that control valuable economic and biological characteristics and properties, is widely used to produce new wheat forms. In this study, a wheat-rye translocation obtained by backcrossing the wheat-rye disomic-substitution line 2R(2D)1 with the variety Novosibirskaya 67 was characterized. The chromosomal composition of karyotypes was studied using fluorescent in situ hybridization and C-banding. Two centric translocations, derived from two long arms of chromosomes 2D and 2R, T2DL.2RL, were identified, the remaining 40 wheat chromosomes did not undergo modifications. Meiosis in the lines was stable. Chromosomes T2DL.2RL formed bivalents in all meiocytes, which confirmed their homology. The morphological characteristics of the spike in the T2DL.2RL line and Novosibirskaya 67 did not differ. A comparative analysis of productivity between the T2DL.2RL translocation line and the parental forms, Novosibirskaya 67 and the 2R(2D)1 line, was carried out. The T2DL.2RL line is inferior to Novosibirskaya 67 in all characters with different confidence levels. The productivity characters of the 2R(2D)1 line exceeded or did not differ from those of T2DL.2RL, however, the mass of 1000 grains was significantly lower. The results showed the effect of the T2DL.2RL translocation on the trait “plant height”. This character was significantly lower than that of Novosibirskaya 67 in two vegetation periods. Consequently, the T2DL.2RL translocation reduces plant height and productivity.

ABSTRACT Moenkhausia is a highly specious genus among the Characidae, composed of 96 valid species. Only twelve species have a known karyotype. Thus, here are presented the first cytogenetic data of two allopatric populations of Moenkhausia bonita and one of M. forestii, both belonging to the upper Paraná River basin (PR) with discussion on the evolutionary and cytotaxonomic aspects of the genus. The two species presented 2n = 50 chromosomes but different karyotype formulas and occurrence of 1-2 B chromosomes. These elements are small metacentrics in M. bonita and small acrocentrics in M. forestii. In both species, B chromosomes were euchromatic. Ag-NOR sites were found in pair 3 (metacentric), coinciding with fluorescent in situ hybridization (FISH) by the 18S rDNA probe in both species. However, the species differed in terms of the number and position of 5S rDNA sites. Heterochromatic blocks, mapped in M. bonita showed the least amount of heterochromatin in the terminal and pericentromeric regions, while the M. forestii karyotype revealed a greater amount of interstitial heterochromatic blocks. The karyotype distinctions between the two species, including the morphology of B chromosomes, may contribute as a reference in the taxonomic studies in this group.

The current study analyzed the chromosomal karyotype of Quasipaaspinosa David, 1875 from Hunan Province, China. The karyotype, C-banding, BrdU-banding pattern were characterized using direct preparation of bone-marrow cells and hemocyte cultures. The findings indicated that Q.spinosa was a diploid species (2n = 26) that lacked heteromorphic chromosomes and secondary constrictions. C-banding analysis revealed an abundance of positive signals in the centromere regions, while the BrdU-banding pattern showed three phases in both male and female, occurring consistently and in chronological sequence during S-phase. Notably, there was no asynchronous replication in the late phase. This study enhanced our understanding of the karyotypic structure of Q.spinosa by conventional cytogenetic techniques, thus providing essential scientific insights into the cytogenetics of Q.spinosa ., (Liaoruilin Zhang, Jianguo Xiang, Juan Li, Jie Zhou, Jinliang Hou, Yanfei Huang, Hong Li.)

In fish species, heterochromatinization is one process that could trigger sex chromosome differentiation. The present article describes a nascent XX/XY sex chromosome system evidenced by heterochromatin accumulation and microsatellite (GATA) 8 in Hypostomus albopunctatus from two populations of the Paraná River basin. The specimens of H. albopunctatus from the Campo and Bossi Rivers share the same karyotype. The species exhibits 74 chromosomes (8m+14sm +16st +36a, fundamental number = 112). The C-banding technique suggests male heterogamety in H. albopunctatus , where the Y-chromosome is morphologically like the X-chromosome but differs from it for having long arms that are entirely heterochromatic. Double fluorescence in situ hybridization (FISH) with 18S and 5S rDNA probes confirmed the Ag-nucleolus organizer region sites in a single pair for both populations, and minor rDNA clusters showed interpopulational variation. FISH with the microsatellite (GATA) 8 probe showed a dispersed pattern in the karyotype, accumulating these sequences of sex chromosomes of both populations. FISH with microsatellite (CGC) 10 probe showed interpopulational variation. The absence of differentiated sex chromosomes in H. albopunctatus is described previously, and a new variant is documented herein where XY chromosomes can be seen in an early stage of differentiation.

Moenkhausia is a highly specious genus among the Characidae, composed of 96 valid species. Only twelve species have a known karyotype. Thus, here are presented the first cytogenetic data of two allopatric populations of Moenkhausia bonita and one of M. forestii, both belonging to the upper Paraná River basin (PR) with discussion on the evolutionary and cytotaxonomic aspects of the genus. The two species presented 2n = 50 chromosomes but different karyotype formulas and occurrence of 1-2 B chromosomes. These elements are small metacentrics in M. bonita and small acrocentrics in M. forestii. In both species, B chromosomes were euchromatic. Ag-NOR sites were found in pair 3 (metacentric), coinciding with fluorescent in situ hybridization (FISH) by the 18S rDNA probe in both species. However, the species differed in terms of the number and position of 5S rDNA sites. Heterochromatic blocks, mapped in M. bonita showed the least amount of heterochromatin in the terminal and pericentromeric regions, while the M. forestii karyotype revealed a greater amount of interstitial heterochromatic blocks. The karyotype distinctions between the two species, including the morphology of B chromosomes, may contribute as a reference in the taxonomic studies in this group. [ABSTRACT FROM AUTHOR]

Abstract Taxonomic and cytogenetic aspects of Proceratophrys have not been thoroughly clarified in the literature; thus, the objective of the present study was to provide unprecedent karyotype data regarding P. schirchi, P. laticeps and P. melanopogon. Additionally, the karyotype of P. boiei (2n = 22) and its ZZ / ZW sex chromosome system was analyzed for different populations of southeastern and southern Brazil. All Proceratophrys species have a diploid number of 2n = 22 chromosomes. In P. schirchi, a strong C-band was found in the long arm in one of the homologues of the pair 8 in female metaphasic cells, denoting that this chromosome pair could represent the heteromorphic sex chromosome in a ZZ / ZW sex system. Despite the conserved number of chromosomes, there are considerable chromosomal differences in P. melanopogon and P. boiei (southern Brazil), strongly differentiating them cytogenetically from other species of the genus. Moreover, with the confirmation of chromosomal heteromorphism related to sexual differentiation in P. boiei and the possible description of this system in P. schirchi, the Proceratophrys genus can be regarded as an interesting group for evolutionary studies and sex chromosome differentiation in anurans.

Tandemly arranged and dispersed repetitive DNA sequences are important structural and functional elements that make up a significant portion of vertebrate genomes. Using high throughput, low coverage whole genome sequencing followed by bioinformatics analysis, we have identified seven major tandem repetitive DNAs and two fragments of LTR retrotransposons in the genome of the Nile crocodile (Crocodylus niloticus, 2n = 32). The repeats showed great variability in structure, genomic organization, and chromosomal distribution as revealed by fluorescence in situ hybridization (FISH). We found that centromeric and pericentromeric heterochromatin of C. niloticus is composed of previously described in Crocodylus siamensis CSI-HindIII and CSI-DraI repetitive sequence families, a satellite revealed in Crocodylus porosus, and additionally contains at least three previously unannotated tandem repeats. Both LTR sequences identified here belong to the ERV1 family of endogenous retroviruses. Each pericentromeric region was characterized by a diverse set of repeats, with the exception of chromosome pair 4, in which we found only one type of satellite. Only a few repeats showed non-centromeric signals in addition to their centromeric localization. Mapping of 18S–28S ribosomal RNA genes and telomeric sequences (TTAGGG)n did not demonstrate any co-localization of these sequences with revealed centromeric and pericentromeric heterochromatic blocks.

Abstract Cytogenetic analyses were performed on specimens of Leptodactylus bufonius from different localities in Argentina. Mitotic chromosomes were studied with Giemsa and differential staining techniques (Ag-NOR, C-banding, and CMA3/DAPI) and fluorescence in situ hybridization with the 18S DNAr probe. All specimens showed karyotypes with 2n = 2x = 22 and FN = 44. Secondary constrictions were present in the long arm of chromosome pair 8, coincident with Ag-NOR and hybridization signals of the 18S DNAr probe. The C-banding technique evidenced an important amount of heterochromatin with a sex-linked pericentromeric band in the short arm of chromosome pair 4. This heterochromatic band was heteromorphic in males but present in both homologues of females, and it was CMA3 positive (DAPI negative) at fluorescence staining. The occurrence of heteromorphic XY sex chromosomes in L. bufonius is the second known case in Leptodactylus and the fifth within the speciose family Leptodactylidae.

Abstract Background In prenatal diagnosis, CMA has begun to emerge as a favorable alternative to karyotype analysis, but it could not identify balanced translocations, triploidies, inversion and heteromorphisms. Therefore, conventional cytogenetic and specific staining methods still play an important role in the work-up of chromosome anomaly. This study investigated the application of C-banding and AgNOR-staining techniques in prenatal diagnosis of chromosomal heteromorphisms and some structure abnormalities. Results Among the 2970 samples, the incidence of chromosomal heteromorphisms was 8.79% (261/2970). The most frequent was found to be chromosome Y (2.93%, 87/2970), followed by chromosome 1 (1.65 %, 49/2970), 9 (1.52 %, 45/2970), 22 (0.77 %, 23/2970) and 15 (0.64 %, 19/2970). We compared the incidence of chromosomal heteromorphisms between recurrent spontaneous abortion (RSA) group and control group. The frequency of autosomal hetermorphisms in RSA group was 7.63% higher than that in control group (5.78%), while the frequency of Y chromosomal heteromorphisms was 4.76% lower than that in control group (5.71%). Here we summarized 4 representative cases, inv (1) (p12q24), psu dic (4;17) (p16.3;p13.3), r(X)(p11; q21) and an isodicentric bisatellited chromosome to illustrate the application of C-banding or AgNOR-staining, CMA or NGS was performed to detect CNVs if necessary. Conclusions This study indicated that C-banding and AgNOR-staining were still effective complementary methods to identify chromosomal heteromorphisms and marker chromosomes or some structural rearrangements involving the centromere or acrocentric chromosomes. Our results suggested that there was no evidence for an association between chromosomal heteromorphisms and infertility or recurrent spontaneous abortions. Undoubtedly, sometimes we needed to combine the results of CMA or CNV-seq to comprehensively reflect the structure and aberration of chromosome segments. Thus, accurate karyotype reports and genetic counseling could be provided.

Cytogenetic characterization of five species of genus Coeliccia of family Platycnemididae has been done by conventional staining, C-banding, silver nitrate staining and sequence specific staining. These species were collected from the localities present in Andretta, Bilaspur (Himachal Pradesh) and Nongkhyllem (Meghalaya), India. All the species possess n = 13 as haploid chromosome number, which is the type number of the family with X0–XX sex determining mechanism except Coeliccia bimaculata with n = 12, originated by the fusion of two autosome pairs as complement is characterized by the presence of one large bivalent. m chromosomes are absent in all the species. Mostly, light/dark terminal C-bands and NOR's are seen on the autosomal bivalents, while X chromosome shows variations as large terminal C-band on one side of X chromosome is present in all the species except C. renifera, it is C-positive. Moreover, X chromosome possesses terminal NOR on one side in C. chromothorax, while NOR-positive in C. renifera and NOR-negative in C. bimaculata, C. didyma and C. fraseri. In sequence specific staining, autosomal bivalents are homogeneously stained with both DAPI and CMA3 dyes in C. bimaculata, C. renifera and C. chromothorax, while whole chromosome complement of C. didyma is CMA3 bright and C. fraseri is DAPI bright. [ABSTRACT FROM AUTHOR]

The black-horned capuchin (Sapajus nigritus) is a neotropical primate with wide distribution from southeastern Brazil to northeastern Argentina. Although this species has been described with coat pattern variation, even with intrapopulational differences, and characterized as having the greatest genetic diversity among Sapajus species, there are still few studies on natural populations that contribute to the knowledge of this intraspecific variability. We examined individuals from an as yet unstudied population of Ilha da Marambaia, Rio de Janeiro (RJ) state, Brazil, compared with published data for S. nigritus. We sought to confirm the species through phenotypic and genetic characterization using C-banding and fluorescence in situ hybridization with #11qHe+/21WCP probes for chromosomal constitutive heterochromatin (He+) patterns, and cytochrome c oxidase I and II gene sequences for phylogenetic analysis. The coat presented two color patterns, varying from brown to blackish on the body, yellow to brown on the chest, and white to yellow on the face, besides the presence and shape of the tufts on the head, corresponding to S. nigritus. He+ was identified in pairs 4, 12, 13 and 17, and less consistently in pairs 6, 19 and 21, already described for this species. While most Sapajus species have a large He+ block, here pair 11 was identified without extracentromeric He+, the same as reported for S. nigritus from Argentina. Molecular analysis showed divergence of this population from other S. nigritus sequences, reinforcing a trend already demonstrated when samples from RJ are compared with the rest of the distribution, which may represent an evolutionary deviation. [ABSTRACT FROM AUTHOR]

The data presented in this paper stand as supplementary information of the associated article “Karyological characterization of the common chameleon (Chamaeleo chamaeleon) provides insights on the evolution and diversification of sex chromosomes in Chamaeleonidae” [1]. This work provides (i) raw experimental data on the karyology of the common chameleon Chamaeleo chamaeleon and (ii) the results of bioinformatic analysis on sex-specific and repeated DNA sequences found in the same species. The karyological information here presented includes traditional staining method (Giemsa staining) and sequential C-banding + fluorochromes performed on Tunisian samples of the species. The sequence data include the alignments of the isolated DNA sequences with homologous sequences found in squamate Short Read Archives (SRAs) and the results of searches in public nucleic acid databases.

Cytogenetic analysis of brown trout, Salmo trutta, have been described for different populations and morphs; however, cytogenetic analysis of interspecific brown trout hybrids is unknown. Cultured kidney cells from four brown trout subspecies (Salmo trutta abanticus, S.t. caspius, S.t. fario and S.t. labrax) and their reciprocal hybrids were karyotyped using conventional staining, C-banding and Ag-NOR staining techniques. Chromosome number (2N) and chromosome arm number (NF) ranged from76 to 80 and 98 to 102, respectively. Silver staining revealed the presence of NOR sites on the short arm of the submetacentric chromosome. The size and number of NOR sites showed uniformity. The presence of heterochromatin on different chromosome arms was confirmed by C-banding. The presence and position of constitutive heterochromatin showed variability among individuals. Chromosome structures of purebred brown trout subspecies belonging to the Danubian linage and their hybrids were similar, and no distinctive characteristics were observed in any of the species. The results of this study are applicable to the development of improved conservation and management strategies for brown trout.

Using chromosome C-banding and electrophoresis of grain storage proteins, gliadins, 17 Triticum aestivumAegilops columnaris lines with substitutions of chromosomes of homoeologous groups 1 and 6 were examined. Based on their high polymorphism, gliadins were used to identify alien genetic material. For all of the lines examined, electrophoretic analysis of gliadin spectra confirmed substitution of wheat chromosomes 6A, 6D or 1D for the homoeologous Aegilops chromosomes of genomes Uс or Xс. The substitution manifested in the disappearance of the products of gliadin-coding genes on chromosomes 6A, 6D or 1D with the simultaneous appearance of the products of genes localized on alien chromosomes of genomes Uс or Xс. Thus, Aegilops chromosomes were shown to be functionally active in the alien wheat genome. The absence of alien genes expression in the lines carrying a long arm deletion in chromosome 6Xc suggested that the gliadin-coding locus moved from the short chromosome arm (its characteristic position in all known wheat species) to the long one. This is probably associated with a large species-specific pericentric inversion. In spite of losing a part of its long arm and combination with a non-homologous chromosome of a different genome (4BL), chromosome 1D was fully functioning. For Aegilops, the block type of gliadin components inheritance was shown, indicating similarity in the structural organization of gliadin-coding loci in these genera. Based on determining genetic control of various polypeptides in the electrophoretic aegilops spectrum, markers to identify Ae. columnaris chromosomes 1Xс, 6Xс and 6Uс were constructed.

Background: Triticum kiharae (AtAtGGDD, 2n = 42) is of interest for the improvement of bread wheat as a source of high grain protein and gluten content, as well as resistance to many diseases. The use of T. kiharae for the improvement of T. aestivum L. is complicated by the fact that the homology degree of their genomes is low and this leads to an unbalanced set of chromosomes in the gametes of its first generations and the elimination of some genotypes. The aim of this study was to analyze the nature of alien introgressions and their effect on the cytological stability of hybrids obtained from crossing of bread wheat varieties with T. kiharae. Results: Using C-banding, the presence of entire chromosomes of T. kiharae in the karyotypes of hybrid lines (intergenomic substitution 2G/2B), chromosome arms (centric translocation Т2AtS:2AL) and large inserts in the form of terminal translocations involving chromosomes of 1st, 3rd and 5th homoeologous groups of B- and G-genomes were found. Molecular markers revealed short introgression of T. kiharae into the genome of common wheat varieties. The highest introgression frequency was shown for 1A, 1B, 2A, 5B, and 6A chromosomes, while no foreign chromatin was detected in 4A and 4B chromosomes. A high level of cytological stability (a meiotic index of 88.18–93.0%) was noted for the majority of introgression lines. An exception was found for the lines containing the structural reorganization of chromosome 5B, affecting the main genes of chromosome synapsis in terms of their functioning. Conclusions: During the stabilization of hybrid karyotypes, the introgression of genetic material from T. kiharae into the genome of T. aestivum occurs in the form of short fragments detectable only by molecular markers and in the form of whole chromosomes (intergenomic substitution) and their large fragments (centric and terminal translocations). The level of cytological stability achieved in F10 by the majority of introgression lines ensures the formation of functional gametes sufficient for the successful reproduction of the obtained hybrids. [ABSTRACT FROM AUTHOR]

The genus Atelognathus is composed of five species that occur in the southernmost regions of Argentina and Chile. It belongs to the Batrachylidae, one of the few endemic anuran families from Patagonia. More than 50 yr ago, it was concluded that A. reverberii had a diploid chromosomal complement of 2N = 26, a feature later reported for other congenerics. In this work, we describe the cytogenetics of all known species of Atelognathus (A. nitoi, A. patagonicus, A. praebasalticus, A. reverberii, and A. solitarius) and two additional undetermined populations. Unexpectedly, our analyses showed that all have a diploid chromosomal complement 2N = 24, which contrasts with conclusions of previous studies. We conclude that a karyotype of 2N = 24 is shared in Atelognathus as a derived condition within Batrachylidae. Additionally, we describe and discuss other cytogenetics characters (i.e., nucleolar organizer region location and C-banding patterns) of Atelognathus and related genera of Batrachylidae in an evolutionary framework. [ABSTRACT FROM AUTHOR]

The standard karyotype and C-banding characteristics of six specimens of Anatolian Ground Squirrel Spermophilus xanthoprymnus (Bennett, 1835) collected in Gümüşhane Province and Bitlis Province, Turkey. The karyotype of the individuals from both localities contained 42 chromosomes and all the chromosomes were bi-armed. The arm number of autosomal chromosomes (NFa) was 80 and the fundamental number of chromosomal arms (FN) was 84. The X chromosome was medium-sized and submetacentric. The Y chromosome of Bitlis specimens was smallest and bi-armed, and the Y chromosome of Gümüşhane specimens was medium-sized and subtelocentric. All the autosomes and X chromosome of specimens from both localities possessed distinct centromeric or pericentromeric C-positive bands. An interstitial dark C-band was apparent also on the long arm of the submetacentric autosomal pair 4. However, submetacentric autosomal pair 4 was heteromorphic in the Bitlis specimens due to intrachromosomal translocation. The Y chromosome of Gümüşhane specimens had centromeric C-band and the Y chromosome of Bitlis squirels was entirely euchromatic. [ABSTRACT FROM AUTHOR]

In this work we analyzed the karyotype of Rhinella jimi (Stevaux, 2002) (Anura, Bufonidae) from Picos (Piauí) in Northeastern Brazil. The chromosomes were examined using classical cytogenetic approaches (Giemsa, C-banding, and Ag-NOR staining). This species has 2n = 22 chromosomes, all metacentric or submetacentric. Heterochromatic segments were visualized at the centromeric region and the nucleolus organizer regions (NOR) were restricted to terminal regions of the short arms in pair 7. There was no evidence of heteromorphic sex chromosomes. The chromosomal analysis of R. jimi allowed us to identify a karyotype that is similar to many other species of Rhinella, in which the diploid number remains unchanged and without evidences of structural rearrangements. [ABSTRACT FROM AUTHOR]

The karyotypes of four species of jirds of the genus Meriones Illiger, 1811 from Turkey and Iran (M. tristrami, M. persicus, M. vinogradovi and M. libycus) were studied using C-banding and AgNOR staining. The obtained basic karyotype characteristics of the studied species are in agreement with previously published data. Intra-specific variation in the number of autosomal arms was recorded in M. tristrami. Extensive variations were recorded in the number or localisation of active NOR sites between species and within species. The cytogenetic markers, such as the positive C-bands or NORs, seem to have only limited importance in inter-specific differentiation but they may be applied in studies of the relationships between geographic populations within species. [ABSTRACT FROM AUTHOR]