Variation in the Conventional and Banded Karyotypes among Populations of Arvicola amphibius (L., 1758) (Mammalia: Rodentia) from Turkey

Chromosomal characteristics of water voles (Arvicola amphibius) were studied in ten populations including 33 samples from Anatolia, Turkey. The C-banding pattern and NORs distribution were analysed in four samples from Eastern Anatolia. The conventionally stained karyotypes showed the standard complement of the species (2n = 36, NFa = 60-62, NF = 64-66). Variation in the number of autosomal arms originated from the alternative presence of a subtelocentric or an acrocentric autosomal pair. C-banding provided further support for differentiation of the amount and distribution of C-heterochromatin between populations from Central Europe and Asia Minor. Chromosomal variation among Turkish populations was manifested by the number of autosomal arms, positive C-bands and NOR-carrying autosomes

Highly divergent 16S rRNA sequences in ribosomal operons of Scytonema hyalinum (Cyanobacteria)

A highly divergent 16S rRNA gene was found in one of the five ribosomal operons present in a species complex currently circumscribed as Scytonema hyalinum (Nostocales, Cyanobacteria) using clone libraries. If 16S rRNA sequence macroheterogeneity among ribosomal operons due to insertions, deletions or truncation is excluded, the sequence heterogeneity observed in S. hyalinum was the highest observed in any prokaryotic species thus far (7.3± 9.0%). The secondary structure of the 16S rRNA molecules encoded by the two divergent operons was nearly identical, indicating possible functionality. The 23S rRNA gene was examined for a few strains in this complex, and it was also found to be highly divergent from the gene in Type 2 operons (8.7%), and likewise had nearly identical secondary structure between the Type 1 and Type 2 operons. Furthermore, the 16S-23S ITS showed marked differences consistent between operons among numerous strains. Both operons have promoter sequences that satisfy consensus requirements for functional prokaryotic transcription initiation. Horizontal gene transfer from another unknown heterocytous cyanobacterium is considered the most likely explanation for the origin of this molecule, but does not explain the ultimate origin of this sequence, which is very divergent from all 16S rRNA sequences found thus far in cyanobacteria. The divergent sequence is highly conserved among numerous strains of S. hyalinum, suggesting adaptive advantage and selective constraint of the divergent sequence

Highly divergent 16S rRNA sequences in ribosomal operons of Scytonema hyalinum (Cyanobacteria)

A highly divergent 16S rRNA gene was found in one of the five ribosomal operons present in a species complex currently circumscribed as Scytonema hyalinum (Nostocales, Cyanobacteria) using clone libraries. If 16S rRNA sequence macroheterogeneity among ribosomal operons due to insertions, deletions or truncation is excluded, the sequence heterogeneity observed in S. hyalinum was the highest observed in any prokaryotic species thus far (7.3± 9.0%). The secondary structure of the 16S rRNA molecules encoded by the two divergent operons was nearly identical, indicating possible functionality. The 23S rRNA gene was examined for a few strains in this complex, and it was also found to be highly divergent from the gene in Type 2 operons (8.7%), and likewise had nearly identical secondary structure between the Type 1 and Type 2 operons. Furthermore, the 16S-23S ITS showed marked differences consistent between operons among numerous strains. Both operons have promoter sequences that satisfy consensus requirements for functional prokaryotic transcription initiation. Horizontal gene transfer from another unknown heterocytous cyanobacterium is considered the most likely explanation for the origin of this molecule, but does not explain the ultimate origin of this sequence, which is very divergent from all 16S rRNA sequences found thus far in cyanobacteria. The divergent sequence is highly conserved among numerous strains of S. hyalinum, suggesting adaptive advantage and selective constraint of the divergent sequence

Comparison of the Chromosome Banding Pattern in the 2

We present the karyotype characteristics of five cytotypes of mole rats (Nannospalax) with 56 chromosomes revealed by the C-banding and AgNOR staining analyses. We attempt to investigate if the specific distinction between the populations from Thrace (N. leucodon) and Anatolia (N. xanthodon) is reflected also in their karyotypic differentiation. The specimens from each of the five populations studied revealed a distinct karyotype which was different from those found in other populations. The fundamental number of autosomal arms varied from 68 to 72. The amount of C-heterochromatin was larger in the Thrace sample of N. leucodon compared to the Anatolian population of N. xanthodon. The active NOR sites were recorded on five autosomal pairs in N. leucodon, whereas only three or four pairs bearing NOR were observed in N. xanthodon. Differences between the studied populations were quantified in the analysis of the distribution pattern of the C-positive bands and the AgNOR sites in individual chromosomes which indicated a basal position of the Thrace sample of N. leucodon and its divergence from other studied populations. The karyotypes of the 56-chromosome populations of N. leucodon and N. xanthodon are thus distinctly different

A northern glacial refugium for bank voles (Clethrionomys glareolus).

peer reviewedThere is controversy and uncertainty on how far north there were glacial refugia for temperate species during the Pleistocene glaciations and in the extent of the contribution of such refugia to present-day populations. We examined these issues using phylogeographic analysis of a European woodland mammal, the bank vole (Clethrionomys glareolus). A Bayesian coalescence analysis indicates that a bank vole population survived the height of the last glaciation (≈25,000–10,000 years B.P.) in the vicinity of the Carpathians, a major central European mountain chain well north of the Mediterranean areas typically regarded as glacial refugia for temperate species. Parameter estimates from the fitted isolation with migration model show that the divergence of the Carpathian population started at least 22,000 years ago, and it was likely followed by only negligible immigration from adjacent regions, suggesting the persistence of bank voles in the Carpathians through the height of the last glaciation. On the contrary, there is clear evidence for gene flow out of the Carpathians, demonstrating the contribution of the Carpathian population to the colonization of Europe after the Pleistocene. These findings are consistent with data from animal and plant fossils recovered in the Carpathians and provide the clearest phylogeographic evidence to date of a northern glacial refugium for temperate species in Europe

A new chromosomal race (2n=44) of Nannospalax xanthodon from Turkey (Mammalia: Rodentia)

This study was supported by Omer Halisdemir University (FEB2011/35, FEB2013/01)A new karyotype for blind mole rats was recorded in Tunceli province in Eastern Turkey. The karyotype contained 44 chromosomes, including 13 biarmed pairs, 7 acrocentric pairs, and one heteromorphic pair with a submetacentric and an acrocentric homologue in the autosomal complement (FNa=69). The X chromosome was submetacentric and the Y chromosome medium-sized subtelocentric (FN=73). Distinct dark centromeric C-bands were observed on most of the biarmed and three pairs of the acrocentric autosomes. The NORs were detected on short arms of three subtelocentric pairs and one acrocentric pair of autosomes. The diploid number of chromosomes and the karyotype characteristics observed are obviously unique among hitherto studied populations of blind mole rats and the complement can be evaluated as a new chromosome race of Nannospalax xanthodon. The distribution ranges of individual chromosome races of the species recorded in Eastern Anatolia are revised and possible interracial hybridization is discussed in respect of the finding of a new race

Gypsum endolithic phototrophs under moderate climate (Southern Sicily): their diversity and pigment composition

In this study, we used microscopic, spectroscopic, and molecular analysis to characterize endolithic colonization in gypsum (selenites and white crystalline gypsum) from several sites in Sicily. Our results showed that the dominant microorganisms in these environments are cyanobacteria, including: Chroococcidiopsis sp., Gloeocapsopsis pleurocapsoides, Gloeocapsa compacta, and Nostoc sp., as well as orange pigmented green microalgae from the Stephanospherinia clade. Single cell and filament sequencing coupled with 16S rRNA amplicon metagenomic profiling provided new insights into the phylogenetic and taxonomic diversity of the endolithic cyanobacteria. These organisms form differently pigmented zones within the gypsum. Our metagenomic profiling also showed differences in the taxonomic composition of endoliths in different gypsum varieties. Raman spectroscopy revealed that carotenoids were the most common pigments present in the samples. Other pigments such as gloeocapsin and scytonemin were also detected in the near-surface areas, suggesting that they play a significant role in the biology of endoliths in this environment. These pigments can be used as biomarkers for basic taxonomic identification, especially in case of cyanobacteria. The findings of this study provide new insights into the diversity and distribution of phototrophic microorganisms and their pigments in gypsum in Southern Sicily. Furthemore, this study highlights the complex nature of endolithic ecosystems and the effects of gypsum varieties on these communities, providing additional information on the general bioreceptivity of these environments.This project was supported by the Czech Science Foundation (Grant/Award No. 17-04270S and 21-03322S), Ministry of Education, Youth and Sports of the Czech Republic, National Programme of Sustainability I (Grant/Award No. LO1416), Charles University (Grant/Award Nos. UNCE/SCI/006 and UNCE 204069), ALGAMIC (Grant/Award No. CZ.1.05/2.1.00/19.0392). JM was supported by the Czech Science Foundation (GAČR) Project No. 22-06374S to accomplish phylogenetic and taxonomic analysis. JW was thankful for the financial support by the PGC2021-124362NB-I00 grant from MCI/AEI (Spain) and FEDER.Peer reviewe