Satellite DNAs (satDNAs) are abundant components of eukaryotic genomes, playing pivotal roles in chromosomal organization, genome stability, and evolution. Here, we combined cytogenetic and genomic methods to characterize the satDNAs in the genomes of Leptidea butterflies. Leptidea is characterized by the presence of a high heterochromatin content, large genomes, and extensive chromosomal reshuffling as well as the occurrence of cryptic species. We show that, in contrast to other Lepidoptera, satDNAs constitute a considerable proportion of Leptidea genomes, ranging between 4.11% and 11.05%. This amplification of satDNAs, together with the hyperactivity of transposable elements, contributes to the substantial genome expansion in Leptidea. Using chromosomal mapping, we show that, particularly LepSat01-100 and LepSat03-167 satDNAs, are preferentially localized in heterochromatin exhibiting variable distribution that may have contributed to the highly diverse karyotypes within the genus. The satDNAs also exhibit W-chromosome accumulation, suggesting their involvement in sex chromosome evolution. Our results provide insights into the dynamics of satDNAs in Lepidoptera genomes and highlight their role in genome expansion and chromosomal organization, which could influence the speciation process. The high proportion of repetitive DNAs in the genomes of Leptidea underscores the complex evolutionary dynamics revealing the interplay between repetitive DNAs and genomic architecture in the genus.

• MeSH
• Phylogeny MeSH
• Genome, Insect * MeSH
• Heterochromatin genetics   MeSH
• Karyotype * MeSH
• Chromosome Mapping MeSH
• Evolution, Molecular * MeSH
• Butterflies * genetics   MeSH
• DNA, Satellite * genetics   MeSH
• DNA Transposable Elements MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH

Syndrom Noonanové je časté dědičné onemocnění s heterogenním genetickým podkladem a velkou variabilitou v klinických projevech. Postižení pacienti mají kromě různých vrozených vad a abnormalit i zvýšené riziko rozvoje maligního onemocnění v dětském věku. V následujících kazuistikách prezentujeme dvě typické hematoonkologické diagnózy, pojící se se syndromem Noonanové - tranzientní myeloproliferativní poruchu a akutní lymfoblastickou leukemii. Odlišnosti v anamnéze, cestě k diagnóze i průběhu léčby hematoonkologického onemocnění nás navedly k hledání genetického podkladu potíží s následným potvrzením syndromu Noonanové.

Noonan syndrome is a common hereditary condition with a heterogeneous genetic background and great variability in clinical manifestations. In addition to various birth defects and abnormalities, the affected patients have also an increased risk of developing a malignant disease in childhood. In the following case reports, we present two typical hemato-oncological diagnoses associated with Noonan syndrome - transient myeloproliferative disorder and acute lymphoblastic leukemia. Differences in the case history, diagnostic process and the course of treatment led us to search for the genetic basis of the difficulties with the subsequent confirmation of Noonan's syndrome.

• MeSH
• Precursor Cell Lymphoblastic Leukemia-Lymphoma diagnosis   genetics   therapy   MeSH
• Genetic Testing MeSH
• Hematologic Neoplasms * etiology   genetics   pathology   MeSH
• Leukemia, Myelomonocytic, Juvenile pathology   therapy   MeSH
• Infant MeSH
• Leukocytosis etiology   therapy   MeSH
• Humans MeSH
• Myeloproliferative Disorders diagnosis   genetics   pathology   therapy   MeSH
• Neoplasms diagnosis   classification   pathology   MeSH
• Noonan Syndrome * diagnosis   complications   pathology   MeSH
• Child, Preschool MeSH
• Risk MeSH
• Check Tag
• Infant MeSH
• Humans MeSH
• Male MeSH
• Child, Preschool MeSH
• Female MeSH
• Publication type
• Case Reports MeSH

The remarkable fish biodiversity encompasses also great sex chromosome variability. Harttia catfish belong to Neotropical models for karyotype and sex chromosome research. Some species possess one of the three male-heterogametic sex chromosome systems, XY, X1X2Y or XY1Y2, while other members of the genus have yet uncharacterized modes of sex determination. Particularly the XY1Y2 multiple sex chromosome system shows a relatively low incidence among vertebrates, and it has not been yet thoroughly investigated. Previous research suggested two independent X-autosome fusions in Harttia which led to the emergence of XY1Y2 sex chromosome system in three of its species. In this study, we investigated evolutionary trajectories of synteny blocks involved in this XY1Y2 system by probing six Harttia species with whole chromosome painting (WCP) probes derived from the X (HCA-X) and the chromosome 9 (HCA-9) of H. carvalhoi. We found that both painting probes hybridize to two distinct chromosome pairs in Amazonian species, whereas the HCA-9 probe paints three chromosome pairs in H. guianensis, endemic to Guyanese drainages. These findings demonstrate distinct evolutionary fates of mapped synteny blocks and thereby elevated karyotype dynamics in Harttia among the three evolutionary clades.

• Publication type
• Journal Article MeSH

A colorectal adenoma, an aberrantly growing tissue, arises from the intestinal epithelium and is considered as precursor of colorectal cancer (CRC). In this study, we investigated structural and numerical chromosomal aberrations in adenomas, hypothesizing that chromosomal instability (CIN) occurs early in adenomas. We applied array comparative genomic hybridization (aCGH) to fresh frozen colorectal adenomas and their adjacent mucosa from 16 patients who underwent colonoscopy examination. In our study, histologically similar colorectal adenomas showed wide variability in chromosomal instability. Based on the obtained results, we further stratified patients into four distinct groups. The first group showed the gain of MALAT1 and TALAM1, long non-coding RNAs (lncRNAs). The second group involved patients with numerous microdeletions. The third group consisted of patients with a disrupted karyotype. The fourth group of patients did not show any CIN in adenomas. Overall, we identified frequent losses in genes, such as TSC2, COL1A1, NOTCH1, MIR4673, and GNAS, and gene gain containing MALAT1 and TALAM1. Since long non-coding RNA MALAT1 is associated with cancer cell metastasis and migration, its gene amplification represents an important event for adenoma development.

• MeSH
• Adenoma * genetics   pathology   MeSH
• Chromosomal Instability MeSH
• Colorectal Neoplasms * genetics   pathology   MeSH
• Humans MeSH
• Precancerous Conditions * genetics   pathology   MeSH
• RNA, Long Noncoding * genetics   MeSH
• Comparative Genomic Hybridization MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH

Vysokoškolská učebnice, která se zaměřuje na lékařskou genetiku.; Kniha je určena studentům medicíny. Využijí ji však i studenti přírodovědeckých fakult a také žáci středních škol, kteří se připravují k přijímacím zkouškám na vysoké školy.

• MeSH
• Genetics, Medical MeSH

• Conspectus
• Obecná genetika. Obecná cytogenetika. Evoluce
• Učební osnovy. Vyučovací předměty. Učebnice
• NML Fields
• genetika, lékařská genetika
• NML Publication type
• učebnice vysokých škol

We report on a major update to the animal rDNA loci database, which now contains cytogenetic information for 45S and 5S rDNA loci in more than 2600 and 1000 species, respectively.The data analyses show the following: (i) A high variability in 5S and 45S loci numbers, with both showing 50-fold or higher variability. However, karyotypes with an extremely high number of loci were rare, and medians generally converged to two 5S sites and two 45S rDNA sites per diploid genome. No relationship was observed between the number of 5S and 45S loci. (ii) The position of 45S rDNA on sex chromosomes was relatively frequent in some groups, particularly in arthropods (14% of karyotypes). Furthermore, 45S rDNA was almost exclusively located in microchromosomes when these were present (in birds and reptiles). (iii) The proportion of active NORs (positively stained with silver staining methods) progressively decreased with an increasing number of 45S rDNA loci, and karyotypes with more than 12 loci showed, on average, less than 40% of active loci. In conclusion, the updated version of the database provides some new insights into the organization of rRNA genes in chromosomes. We expect that its updated content will be useful for taxonomists, comparative cytogeneticists, and evolutionary biologists. .

• MeSH
• Databases, Genetic MeSH
• Species Specificity MeSH
• Karyotype MeSH
• Karyotyping MeSH
• Evolution, Molecular MeSH
• DNA, Ribosomal genetics   MeSH
• RNA, Ribosomal, 5S genetics   MeSH
• RNA, Ribosomal genetics   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH

V novém vydání učebnice studenti najdou vysvětlení obecných principů genetiky a podrobnější informace o speciálních podoblastech, jako je např. cytogenetika, molekulární genetika nebo imunogenetika a genetika ontogeneze.Jednotlivé kapitoly jsou doplněny o velmi dobře vybrané názorné ilustrace a celou škálu příkladů a kontrolních otázek, a to včetně výsledků, které jsou přiloženy v poslední kapitole.Učební text je napsán zejména pro studenty bakalářskýchnelékařských studijních oborů, ale také pro studující některých oblastí chemie.; V novém vydání učebnice studenti najdou vysvětlení obecných principů genetiky a podrobnější informace o speciálních podoblastech, jako je např. cytogenetika, molekulární genetika nebo imunogenetika a genetika ontogeneze.Jednotlivé kapitoly jsou doplněny o velmi dobře vybrané názorné ilustrace a celou škálu příkladů a kontrolních otázek, a to včetně výsledků, které jsou přiloženy v poslední kapitole. Učební text je napsán zejména pro studenty bakalářských nelékařských studijních oborů, ale také pro studující některých oblastí chemie.

• Keywords
• Ostatní lékařské obory,
• MeSH
• Human Genetics MeSH
• Human Development MeSH

• NML Fields
• biologie
• genetika, lékařská genetika
• biologie

The widely distributed ray-finned fish genus Carassius is very well known due to its unique biological characteristics such as polyploidy, clonality, and/or interspecies hybridization. These biological characteristics have enabled Carassius species to be successfully widespread over relatively short period of evolutionary time. Therefore, this fish model deserves to be the center of attention in the research field. Some studies have already described the Carassius karyotype, but results are inconsistent in the number of morphological categories for individual chromosomes. We investigated three focal species: Carassius auratus, C. carassius and C. gibelio with the aim to describe their standardized diploid karyotypes, and to study their evolutionary relationships using cytogenetic tools. We measured length (q+plength) of each chromosome and calculated centromeric index (i value). We found: (i) The relationship between q+plength and i value showed higher similarity of C. auratus and C. carassius. (ii) The variability of i value within each chromosome expressed by means of the first quartile (Q1) up to the third quartile (Q3) showed higher similarity of C. carassius and C. gibelio. (iii) The fluorescent in situ hybridization (FISH) analysis revealed higher similarity of C. auratus and C. gibelio. (iv) Standardized karyotype formula described using median value (Q2) showed differentiation among all investigated species: C. auratus had 24 metacentric (m), 40 submetacentric (sm), 2 subtelocentric (st), 2 acrocentric (a) and 32 telocentric (T) chromosomes (24m+40sm+2st+2a+32T); C. carassius: 16m+34sm+8st+42T; and C. gibelio: 16m+22sm+10st+2a+50T. (v) We developed R scripts applicable for the description of standardized karyotype for any other species. The diverse results indicated unprecedented complex genomic and chromosomal architecture in the genus Carassius probably influenced by its unique biological characteristics which make the study of evolutionary relationships more difficult than it has been originally postulated.

• MeSH
• Chromosomes genetics   MeSH
• Diploidy MeSH
• Phylogeny MeSH
• Genetic Variation genetics   MeSH
• Genome genetics   MeSH
• In Situ Hybridization, Fluorescence methods   MeSH
• Carps genetics   MeSH
• Goldfish genetics   MeSH
• Karyotype MeSH
• Karyotyping methods   MeSH
• Chromosome Mapping methods   MeSH
• Polyploidy MeSH
• Fishes genetics   MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

Sex chromatin is a conspicuous body that occurs in polyploid nuclei of most lepidopteran females and consists of numerous copies of the W sex chromosome. It is also a cytogenetic tool used to rapidly assess the W chromosome presence in Lepidoptera. However, certain chromosomal features could disrupt the formation of sex chromatin and lead to the false conclusion that the W chromosome is absent in the respective species. Here we tested the sex chromatin presence in 50 species of Geometridae. In eight selected species with either missing, atypical, or normal sex chromatin patterns, we performed a detailed karyotype analysis by means of comparative genomic hybridization (CGH) and fluorescence in situ hybridization (FISH). The results showed a high diversity of W chromosomes and clarified the reasons for atypical sex chromatin, including the absence or poor differentiation of W, rearrangements leading to the neo-W emergence, possible association with the nucleolus, and the existence of multiple W chromosomes. In two species, we detected intraspecific variability in the sex chromatin status and sex chromosome constitution. We show that the sex chromatin is not a sufficient marker of the W chromosome presence, but it may be an excellent tool to pinpoint species with atypical sex chromosomes.

• MeSH
• Species Specificity MeSH
• In Situ Hybridization, Fluorescence MeSH
• Karyotype MeSH
• Moths genetics   MeSH
• Sex Chromosomes genetics   MeSH
• Sex Chromatin metabolism   MeSH
• Comparative Genomic Hybridization MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Tandem repeats are important parts of eukaryotic genomes being crucial e.g., for centromere and telomere function and chromatin modulation. In Lepidoptera, knowledge of tandem repeats is very limited despite the growing number of sequenced genomes. Here we introduce seven new satellite DNAs (satDNAs), which more than doubles the number of currently known lepidopteran satDNAs. The satDNAs were identified in genomes of three species of Crambidae moths, namely Ostrinia nubilalis, Cydalima perspectalis, and Diatraea postlineella, using graph-based computational pipeline RepeatExplorer. These repeats varied in their abundance and showed high variability within and between species, although some degree of conservation was noted. The satDNAs showed a scattered distribution, often on both autosomes and sex chromosomes, with the exception of both satellites in D. postlineella, in which the satDNAs were located at a single autosomal locus. Three satDNAs were abundant on the W chromosomes of O. nubilalis and C. perspectalis, thus contributing to their differentiation from the Z chromosomes. To provide background for the in situ localization of the satDNAs, we performed a detailed cytogenetic analysis of the karyotypes of all three species. This comparative analysis revealed differences in chromosome number, number and location of rDNA clusters, and molecular differentiation of sex chromosomes.

• Publication type
• Journal Article MeSH