Karyotype and genome size variation in white-flowered Eranthis sect. Shibateranthis (Ranunculaceae)

Comparative karyomorphological analyses of six out of the eight white-flowered species of Eranthis sect. Shibateranthis have been carried out. All studied specimens of E. byunsanensis, E. lobulata, E. pinnatifida, and E. stellata had a somatic chromosome number 2n = 16 with basic chromosome number x = 8. On the contrary, E. tanhoensis and E. sibirica had a basic chromosome number x = 7. The specimens of E. tanhoensis were diploid with 2n = 14, while the specimens of E. sibirica were polyploid with 2n = 42. Monoploid chromosome sets of the investigated diploid species had 4–5 metacentric chromosomes and 2–4 submetacentric/subtelocentric/acrocentric chromosomes. The highest level of interchromosomal asymmetry, estimated via CVCL, was found in E. byunsanensis and E. pinnatifida. The highest levels of intrachromosomal asymmetry (MCA) and heterogeneity in centromere position (CVCI) were found in E. lobulata and E. byunsanensis, while E. sibirica had the most symmetric karyotype. A multivariate PCoA analysis of basic karyotype parameters (2n, x, THL, CVCL, MCA, and CVCI) highlighted no overlap among species accessions, which was also confirmed by LDA. The average absolute monoploid DNA content (1Cx) of the 23 investigated samples of six Eranthis species varied from 9.26 ± 0.25 pg in E. sibirica to 15.93 ± 0.32 pg in E. stellata. Overall karyological affinity was highlighted between E. lobulata and E. stellata, on one side, and between E. byunsanensis and E. pinnatifida, on the other side. Interestingly, there was no significant correlation between total haploid (monoploid) chromosome length (THL) and 1Cx values in these species.

Neopedies taimensis n. sp. of Brazilian Dichroplini (Orthoptera: Acrididae, Melanoplinae) from Rio Grande do Sul, Brazil

Neopedies taimensis n. sp. is described as a new species of grasshopper from the genus Neopedies Hebard, 1931 collected in Taim Ecological Station, State of Rio Grande do Sul, Brazil. This description is supported with photographs that detail the male and female external and internal morphological characteristics. The new species differs from the other species known by furculae developed and sclerotized, epiproct with two protuberances, cerci quadrangular indented and sclerotized, ancorae developed and lophi with posterior projections divergent. In addition, we present habitat notes, geographic distribution, key to the species of genus and chromosome complement. Chromosome analyses were performed using standard staining procedures, showing diploid number of 2n = 23, X0♂/24, XX♀ and the karyotype made up of exclusively acrocentric chromosomes.

CHROMOSOMAL POLYMORPHISM IN BULGARIAN PATIENTS WITH REPRODUCTIVE PROBLEMS – ONE GENETIC CENTRE EXPERIENCE

Chromosomal polymorphism is described as normal variants at chromosomal regions with no impact on the phenotype but a possible correlation to infertility and recurrent spontaneous abortions. The aim of this study was to evaluate the effect of the chromosomal polymorphisms involved in families with reproductive failures in the Bulgarian population. Material and methods: A total of 1733 patients with unexplained reproductive failures who visited the Laboratory of Medical Genetics – Varna, Bulgaria, (2004 - 2019) were investigated by conventional cytogenetic analysis GTG and CBG differential banding techniques and analyzed at the resolution 400-550 GTG bands. Results: Chromosomal polymorphisms were found in 173 infertile patients (9,98%). The sex distribution was 6,52% males and 3,46% females. The most frequent finding was inv(9)(qh) (23,7%). The other chromosomal variants, which were found, consisted: 9qh+/- variants (15,1%); polymorphisms on the short arms of the acrocentric chromosomes (21,4%); 16qh+ (12,7%) and 1qh+ (6,9%). Y chromosome polymorphism was found in 27,4% of the males with polymorphisms. Two rare cases of polymorphism involving the centromere regions - 19qcenh+ and 20pcenh+ were also found. Conclusion: There is growing evidence that polymorphisms may have a clinical impact on fertility and could take part in the etiology of RF. In this study, we found a significantly high percentage of polymorphisms (9,98%) among the tested patients, and they were more common among males. The statistical significance of increased incidence of chromosome variations found in our study emphasizes the need for routine evaluation of their role in families with RF in our country.

Comparative cytogenetic patterns in Carangidae fishes in association with their distribution range

Carangidae are an important and widespreaded family of pelagic predatory fishes that inhabit reef regions or open ocean areas, some species occupying a vast circumglobal distribution. Cytogenetic comparisons among representatives of its different tribes help to understand the process of karyotype divergence in marine ecosystems due to the variable migratory ability of species. In this sense, conventional cytogenetic investigations (Giemsa staining, Ag-NORs, and C-banding), GC base-specific fluorochrome staining and FISH mapping of ribosomal DNAs were performed. Four species, Elagatis bipinnulata (Quoy et Gaimard, 1825) and Seriola rivoliana (Valenciennes, 1883) (Naucratini), with circumtropical distributions, Gnathanodon speciosus (Forsskål, 1775) (Carangini), widely distributed in the tropical and subtropical waters of the Indian and Pacific oceans, and Trachinotus carolinus (Linnaeus, 1766) (Trachinotini), distributed along the western Atlantic Ocean, were analyzed, thus encompassing representatives of three out its four tribes. All species have diploid chromosome number 2n = 48, with karyotypes composed mainly by acrocentric chromosomes (NF = 50–56). The 18S rDNA/Ag-NORs/GC+ and 5S rDNA loci were located on chromosomes likely homeologs. Karyotypes showed a pattern considered basal for the family or with small variations in their structures, apparently due to pericentric inversions. The migratory capacity of large pelagic swimmers, in large distribution areas, likely restricts the fixation of chromosome changes in Carangidae responsible for a low level of karyotype diversification.

Karyotype, C-band and NOR phenotype of Anatolian endemic fish Squalius anatolicus (Bogutskaya, 1997) (Teleostei, Leuciscidae)

The karyotype and distribution of constitutive heterochromatin and nucleolus organizer regions (NORs) of Anatolian leuciscine endemic to Lake Beysehir, Squalius anatolicus (Bogutskaya, 1997) were analyzed respectively using conventional Giemsa-staining, C-banding and Ag-impregnation. Diploid chromosome number was 2n = 50 and karyotype consisted of 7 pairs of metacentric, 13 pairs of submetacentric, 5 pairs of subtelo- to acrocentric chromosomes, NF value equaled 90. Heteromorphic elements indicating sex chromosomes were not detected. C-banding revealed clear pericentromeric constitutive heterochromatin blocks in several chromosomes. Ag-impregnation revealed the size heteromorphism of NORs that covered almost the entire short arms of the middle-sized submetacentric chromosome pair. The karyotype pattern and simple NOR phenotype of S. anatolicus are nearly identical with that found not only in Squalius species analyzed to date but also in many other representatives of the Eurasian leuciscine cyprinids, which indicates remarkable chromosome stasis in this leuciscid lineage.

A comparative chromosome study on five Minnow fishes (Cyprinidae, Cypriniformes) in Thailand

The cytogenetic comparisons of five Minnow species from Thailand were presented here, i.e., Devario regina, D. laoensis, Rasbora paviana, R. aurotaenia and Esomus metalicus. The mitotic chromosomes were prepared directly from renal cells. Conventional staining and Ag-NOR banding techniques were applied to stain the chromosomes. The results revealed that all Minnow fishes studied possessed the same diploid chromosome number (2n) as 50 chromosomes. The fundamental numbers (NF) of D. laoensis, D. regina, R. paviana, R. aurotaenia and E. metalicus are 100, 100, 98, 98, and 98 respectively. Their karyotypes composing of metacentrics-submetacentrics-acrocentrics-telocentrics were as follows: 6-12-32-0 in D. regina, 6-10-34-0 in D. laoensis, 8-16-24-2 in R. paviana, 8-16-24-2 in R. aurotaenia and 8-10-30-2 in E. metalicus. The Ag-NOR banding technique provides the nucleolar organizer regions (NORs) at subtelomeric region of the short arm chromosome in the a submetacentric or acrocentric chromosomes that are located differently in the different chromosome pairs among species.

Features of the chromosome set of representatives of smoothnosed bats of the North Caucasus

Aim. The aim of this work was to study the chromosome set of some representatives of smooth-nosed bats of the North Caucasus.Material and Methods. Various research methods were used to achieve this goal, including that of dried preparations (the main method for obtaining chromosomal preparations) and that of constructing karyograms.Results. A comparative analysis of the karyological data of 11 species of smooth-nosed bats of the North Caucasus was undertaken and the karyological characteristics of the species accepted in the latest reports on the fauna of Russia and the Caucasus were clarified. The similarity of G -bands in large pairs of meta- and submetacentric chromosomes in Myotis blythi, Myotis mystacinus, Pipistrellus pipistrellus, Pipistrellus kuhli and Vepertilio murinus with bands in small and medium-sized acrocentric chromosomes such as in Eptesicus seotinus may indicate the evolution of the karyotype of the first species by Robertsonian translocation, i.e. compounds of acrocentric chromosomes of Eptesicus serotinus in various combinations. When comparing karyotypes in the family Vespertilionidae, it was found that the karyotype of Eptesicus serotinus is "archaic" (2n=50, NFa=48). With the help of karyological data, the authors composed schemes of phylogenetic relationships of genera in the family Vespertilionidae, which differ to a certain extent from the schemes compiled by taxonomists for representatives of this family.Conclusions. Based on the results obtained, we can conclude that the karyotype of Eptesicus serotinus is the most primitive among the representatives of the order of bats. The primary role in the evolution of this group was played by Robertsonian rearrangements and pericentric inversions (reduction of NFa and 2n from 50 to 38).

A new opilioacarid species (Parasitiformes: Opilioacarida) from Crete (Greece) with notes on its karyotype

A new species of opilioacarid mite, Opilioacarus thaleri n. sp., is described from mid-level elevation close to the seashore in Crete (Greece). It was found on moister sites, under stones or inside stone accumulations in phrygana vegetation. The peak of activity was found to be in early May. The diagnostic morphological characters include 7–8 eugenital setae (female), 5/7 setae on each sclerite at pregenital and genital areas, 11 setae on genital area (male), anterior dorsal shield with two pairs of eyes and 60–70 stout, ribbed setae, 5 (female) or 6 (male) leaf setae plus one pectinate seta on the palp tarsus, and the "simple" type of ovipositor with two pairs of glands, a pair of ducts plus a basal structure. The female karyotype comprises 16 monocentric chromosomes, predominantly with acrocentric morphology. Comparison with data of the ixodids and mesostigmatids indicates that a low number of chromosomes and predomination of acrocentric chromosomes could be plesiomorphies of the parasitiform mites.

Revisiting the Karyotypes of Alligators and Caimans (Crocodylia, Alligatoridae) after a Half-Century Delay: Bridging the Gap in the Chromosomal Evolution of Reptiles

Although crocodilians have attracted enormous attention in other research fields, from the cytogenetic point of view, this group remains understudied. Here, we analyzed the karyotypes of eight species formally described from the Alligatoridae family using differential staining, fluorescence in situ hybridization with rDNA and repetitive motifs as a probe, whole chromosome painting (WCP), and comparative genome hybridization. All Caimaninae species have a diploid chromosome number (2n) 42 and karyotypes dominated by acrocentric chromosomes, in contrast to both species of Alligatorinae, which have 2n = 32 and karyotypes that are predominantly metacentric, suggesting fusion/fission rearrangements. Our WCP results supported this scenario by revealing the homeology of the largest metacentric pair present in both Alligator spp. with two smaller pairs of acrocentrics in Caimaninae species. The clusters of 18S rDNA were found on one chromosome pair in all species, except for Paleosuchus spp., which possessed three chromosome pairs bearing these sites. Similarly, comparative genomic hybridization demonstrated an advanced stage of sequence divergence among the caiman genomes, with Paleosuchus standing out as the most divergent. Thus, although Alligatoridae exhibited rather low species diversity and some level of karyotype stasis, their genomic content indicates that they are not as conserved as previously thought. These new data deepen the discussion of cytotaxonomy in this family.

Unusual chromosomal polymorphism of the common shrew, Sorex araneus L., in southern Belarus

Analysis of the frequency of karyotypes and chromosomal rearrangements in the distributional ranges of four metacentric races of Sorex araneus Linnaeus, 1758 has revealed features that are not typical for polymorphic populations of this species. The frequency of the acrocentric karyotype and heterozygotes for fusion of acrocentric chromosomes turned out to be significantly higher than expected in case of random crossing. As an explanation for the unusual polymorphism, it has been suggested that metacentric races may hybridize with acrocentric populations that remained from the ancient chromosomal form.