Cytogenetic and Genome Research最新文献

{"title":"A Familial Case of 1q31.2q32.2 Deletion with No Phenotypic Presentation.","authors":"Rebecca Littlefield, Jennifer Weiss, Anna Zakas","doi":"10.1159/000543937","DOIUrl":"10.1159/000543937","url":null,"abstract":"<p><strong>Introduction: </strong>Deletions of the interstitial region of chromosome 1q are rare and associated with clinical features including growth restriction, developmental delays, and dysmorphic features. Here, we describe an asymptomatic family with an interstitial 1q31 deletion found incidentally.</p><p><strong>Case presentation: </strong>A 42-year-old male presented with concerns for colonic polyps and underwent multigene panel analysis for hereditary tumor predisposition syndromes which identified a full-gene deletion of CDC73.</p><p><strong>Conclusion: </strong>Microarray analysis of peripheral blood DNA showed a 6.9-Mb heterozygous deletion of 1q31.2q32.2 encompassing 33 genes in both proband and daughter. The absence of symptoms, including any autosomal dominant conditions associated with variants in this region, has been identified in only 1 case report while most other cases of 1q31 deletions report a range of clinical presentations. Further description of 1q31 deletions is essential to the development of genotype-phenotype interpretation and to decrease the uncertainty of care recommendations for patients and their families.</p>","PeriodicalId":11206,"journal":{"name":"Cytogenetic and Genome Research","volume":" ","pages":"23-30"},"PeriodicalIF":1.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143514405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Meiosis in Hybrids: Looking for the Order in Disorder.","authors":"Irina Bakloushinskaya, Sergey Matveevsky","doi":"10.1159/000546658","DOIUrl":"10.1159/000546658","url":null,"abstract":"<p><strong>Background: </strong>The study of gametogenesis in hybrids between intraspecific chromosomal forms or distinct species is mainly aimed at identifying the successful outcome of the process to produce balanced, viable gametes. At the same time, deviations from typical meiotic progression patterns may provide a pivotal mechanism for speciation.</p><p><strong>Summary: </strong>The long history of studying the process of gametogenesis and the development of methodological approaches have helped clarify the cytological and molecular processes that occur during meiosis. Since the early 1980s, Prof. Oxana Kolomiets has been studying meiosis in various species, including mole voles Ellobius, with a focus on chromosome synapsis and other key events during prophase I. Research on hybrids from different chromosomal forms of mole voles has uncovered notable differences in how meiosis progresses and its impact on fertility. In cases where Robertsonian translocations exhibit incomplete homology, various chromosomal multivalents form during prophase I. These configurations are often so complex that the chance of producing balanced gametes appears minimal. Moreover, there were also variations in the formation of trivalents. These discrepancies are thought to arise due to the involvement of distinct chromosomes in Robertsonian translocations, which lead to alterations in the spatial structure of the nucleus. Autosomes and sex chromosomes can exhibit disparities in trajectories of movement, synapsis, and recombination in meiosis. These disparities manifest most distinctly in hybrids, where atypical interchromosomal interactions, including those between sex chromosomes and autosomes, occur. Such interactions are absent in normal meiocytes, highlighting the altered meiotic processes in hybrids.</p><p><strong>Key messages: </strong>Chromosomal rearrangements, such as Robertsonian translocations, neocentromeres, and dicentric chromosomes, alter nuclear architecture, leading to meiotic irregularities that disrupt the progression of meiosis and gametogenesis. Meiotic irregularities cause variation in hybrid fertility. The analysis of meiosis I prophase turns out to be highly efficient for understanding the mechanisms of speciation.</p>","PeriodicalId":11206,"journal":{"name":"Cytogenetic and Genome Research","volume":" ","pages":"255-271"},"PeriodicalIF":1.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144198462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detection and Genetic Analysis of Small Supernumerary Marker Chromosomes in Prenatal Diagnosis.","authors":"Jiangfeng Qin, Yanfei Zeng, Yinghua Luo, Biyu Lu, Jiaolian Ya, Pengfei Cai, Ling Zhang, Yan Mei, Dejian Yuan, Xiaoni Wei, Yuchan Xu","doi":"10.1159/000546051","DOIUrl":"10.1159/000546051","url":null,"abstract":"<p><strong>Introduction: </strong>Small supernumerary marker chromosomes (sSMCs) are small structurally abnormal chromosomes whose origin and structure are difficult to determine by conventional cytogenetic banding techniques. The aims of the study were to analyze sSMCs discovered in prenatal diagnosis, explore the origin and clinical significance of fetal sSMCs, and inform genetic counseling and reproductive health care.</p><p><strong>Methods: </strong>Karyotyping was performed on pregnant women who underwent prenatal diagnosis in a Chinese hospital between April 2018 and April 2024. The sSMC cases encountered were further analyzed using copy number variation sequencing (CNV-seq) to determine the origin of the sSMCs and assess their clinical significance. Uniparental disomy (UPD) was excluded in the families with de novo sSMC cases using multiplex fluorescence PCR and capillary electrophoresis.</p><p><strong>Results: </strong>Out of 30,114 prenatal samples, 30 cases of sSMCs were identified, yielding a detection rate of 0.10%. Family analysis was performed on 23 of these cases, revealing 4 cases inherited and 19 cases of  de novo aberrations. CNV-seq was conducted on 27 cases, with 14 showing no abnormalities and 13 exhibiting CNVs. Among the 10 cases where the origin of the sSMC was clearly identified, the duplications involved chromosomes 4, 10, 12, 15, 18, X, and Y, with pathogenic CNVs accounting for 70.0% (7/10) and variants of uncertain clinical significance accounting for 30.0% (3/10). Out of the 30 women with sSMCs detected, 13 chose to terminate the pregnancy, representing 43.3% (13/30). A follow-up was conducted on 13 de novo sSMC cases that were negative for CNV-seq. Among the live-born fetuses, all except one, who presented with speech delay, showed normal clinical features. UPD testing was successfully performed on 3 families (including the 3-year-old girl with speech delay), and all results were negative.</p><p><strong>Conclusion: </strong>Utilizing both karyotyping and molecular genetic testing is advantageous for effectively screening and identifying sSMCs. CNV-seq is recommended as an important supplementary method for sSMC identification, thereby providing more detailed genetic counseling for prenatal diagnosis.</p>","PeriodicalId":11206,"journal":{"name":"Cytogenetic and Genome Research","volume":" ","pages":"70-84"},"PeriodicalIF":1.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143987128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamics of RTEL1 Helicase in Meiotic Cells: Spatiotemporal Distribution during Prophase I in the Rat <italic>Rattus norvegicus</italic>.","authors":"Sergey N Matveevsky, Sergey N Matveevsky, Yuri F Bogdanov","doi":"10.1159/000545191","DOIUrl":"10.1159/000545191","url":null,"abstract":"<p><strong>Introduction: </strong>DNA helicases are vital for preserving genome integrity and ensuring the correct process of meiosis. Despite their recognized significance, the precise roles and spatial dynamics of these enzymes during meiotic prophase I remain largely unexplored.</p><p><strong>Methods: </strong>The key methodology of this study consisted of immunocytochemical staining and statistical evaluation.</p><p><strong>Results: </strong>Our results demonstrate that RTEL1 (Regulator of Telomere Elongation 1) helicase is present in regions that have just initiated synapsis, emphasizing that chromosome synapsis is essential for this helicase. Since RTEL1 and replication protein A (RPA) were previously shown to colocalize in somatic cells, we sought to assess this relationship in meiosis. During early pachytene, when RTEL1 and RPA levels are at their peak, several immuno-foci of these proteins exhibited complete or partial overlap, suggesting colocalization in some chromosomal regions, though some remained distinct. The earlier appearance of RPA in meiotic nuclei supports the notion that it may facilitate RTEL1 recruitment for DNA repair. As meiosis progresses from early pachytene to diplotene, the significant decrease in RTEL1 and RPA signals underscores their predominant involvement in early prophase I.</p><p><strong>Conclusion: </strong>This study identifies RTEL1 as the third helicase, following BLM and FANCJ, to be detected in prophase I, suggesting that additional helicases may be added to this list in the future. Its unique synapsis-dependent behavior distinguishes it from the other two helicases, which do not exhibit such a pattern. Furthermore, our findings suggest that RTEL1 can demonstrate antirecombinase activity within synaptonemal complexes and functions as part of the meiotic helicase complex, which regulates critical aspects of meiotic processes.</p>","PeriodicalId":11206,"journal":{"name":"Cytogenetic and Genome Research","volume":" ","pages":"118-127"},"PeriodicalIF":1.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143604271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Localization of Ribosomal DNA-Associated Retrotransposons Refines the Heterochromatin Map of the X Chromosome in <italic>Drosophila melanogaster</italic>.","authors":"Tatyana D Kolesnikova, Olga V Veselova, Galina V Pokholkova, Veit Schubert, Mikhail S Klenov","doi":"10.1159/000546918","DOIUrl":"10.1159/000546918","url":null,"abstract":"<p><strong>Introduction: </strong>R1 and R2 retrotransposons specifically integrate into 28S rRNA genes, thereby disrupting many rDNA units within the nucleolar organizer region (NOR) of Drosophila. However, they also appear to play mutualistic roles, contributing to the maintenance of rDNA copy number and the regulation of nucleolar dominance. In addition to their presence in nucleolar rDNA, R1 elements are strongly enriched in the pericentromeric heterochromatin of the X chromosome, located distal to the NOR. This enrichment coincides with several enigmatic genetic phenomena - such as the ABO and cr phenotypes - whose molecular basis remains poorly understood. Notably, this region is one of the least characterized domains of the Drosophila melanogaster genome, lying outside the reference assembly and unresolved in metaphase chromosome preparations.</p><p><strong>Methods: </strong>We performed cytological mapping of R1 and R2 retrotransposons in D. melanogaster heterochromatin using polytene chromosomes from Rif11 mutant, which suppresses under-replication of all types of heterochromatic sequences. These were combined with classical eu-heterochromatic inversions of the X chromosome.</p><p><strong>Results and conclusion: </strong>We identified distinct clusters of both R1 and R2 elements within the X chromosome heterochromatin outside the NOR. R1 elements are highly enriched in the region between the heterochromatic Stellate (hSte) gene cluster and the NOR. This zone exhibits a unique response to Su(var)3-9 mutations, characterized by pronounced decondensation and the formation of a pseudo-puff. Proximal to the R1-enriched domain and adjacent to hSte cluster, we observed a region enriched in R2 elements. The edges of the NOR also show R2 enrichment, likely corresponding to intra-nucleolar domains that accumulate transcriptionally inactive rDNA units. In contrast, nucleolar R1 elements - which also mark inactive rDNA units - are more evenly distributed across the entire NOR. Based on these findings, we propose a refined cytological map of X chromosome heterochromatin in D. melanogaster.</p>","PeriodicalId":11206,"journal":{"name":"Cytogenetic and Genome Research","volume":" ","pages":"175-191"},"PeriodicalIF":1.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144282833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Establishment of Cell Cultures from the Cavefish <italic>Astyanax mexicanus</italic>: A Resource for in vitro Studies of Supernumerary B Chromosome Biology.","authors":"João Pedro Silva Climaco, Cesar Martins, Adauto Lima Cardoso","doi":"10.1159/000546231","DOIUrl":"10.1159/000546231","url":null,"abstract":"<p><strong>Introduction: </strong>Supernumerary B chromosomes have been extensively investigated using diverse in vivo approaches, revealing insights into their origin, nature, evolutionary dynamics, maintenance mechanisms, and effects on their carriers. Despite its broad applicability across various biological research fields, in vitro cell culture remains underexplored as a tool for studying B chromosome biology, with studies limited to using cell cultures only as a source of chromosome preparations.</p><p><strong>Methods: </strong>In the present study, cell cultures of the fish Astyanax mexicanus were established, with (AMEcfB) and without (AMEcf) the B chromosome, using caudal fin tissue collected through nonlethal procedures. These cultures were compared in terms of cell proliferation and in response to environmental stress (pH and temperature) using the MTT and RT-qPCR assay.</p><p><strong>Results: </strong>The AMEcf and AMEcfB cell lines exhibited karyotypic stability and high proliferative potential, demonstrating their suitability for diverse scientific applications. The B chromosome, found exclusively in a subpopulation of AMEcfB cells, influenced cell physiology by affecting cell division dynamics. Experiments under extreme pH and temperature conditions revealed differences in cell viability and gene expression between the two lines, highlighting the role of the B chromosome in modulating environmental responses.</p><p><strong>Conclusion: </strong>These findings align with previous reports on the effects of B chromosomes in living organisms. Thus, the A. mexicanus cell cultures established here represent a promising resource for investigations into B chromosome biology, offering significant ethical, economic, and methodological advantages.</p>","PeriodicalId":11206,"journal":{"name":"Cytogenetic and Genome Research","volume":" ","pages":"327-337"},"PeriodicalIF":1.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144301348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fork Stalling and Template Switching in a Complex der(6)dn with Duplication of 6q24.3qter and 6p25.3: A Case Report.","authors":"Thania Alejandra Aguayo-Orozco, Ma Guadalupe Domínguez-Quezada, Horacio Rivera, Luis E Figuera, Eduardo Esparza-García, Luis Ángel Núñez-García, Elvira Garza-González, Carlos Córdova-Fletes","doi":"10.1159/000547454","DOIUrl":"10.1159/000547454","url":null,"abstract":"<p><strong>Introduction: </strong>Partial trisomy of the 6q24qter region is a rare chromosomal disorder characterized by variable clinical features and poorly understood mechanistic origins.</p><p><strong>Case presentation: </strong>We describe a de novo complex der(6) chromosome in a patient with features consistent with partial 6q trisomy syndrome, including congenital heart disease, growth restriction, developmental delay, and dysmorphic traits. Molecular Findings: Whole-genome sequencing (WGS) identified duplications of 1.5 Mb on 6p25.3 and 23.3 Mb on 6q24.3-qter. While the 6p duplication appears benign, the phenotype is likely driven by dosage-sensitive 6q genes (ARID1B, TAB2, QKI) and possible additive effects from other duplicated genes. No parental pericentric inversion was detected by classical or molecular cytogenetics, and WGS revealed no inversion-associated breakpoints. Instead, chimeric (q-/q+) and truncated reads at the 6q junction support a replication-based origin, such as reversed template switching. FISH confirmed direct insertion of the 6q segment into 6p25.3, without a del/dup pattern typical of inversion-derived recombinants. Notably, WGS detected no direct 6p-6q junction reads but identified chimeric 6p-15q-6q reads with 2-bp microhomologies, suggesting that chromosome 15 transiently mediated the rearrangement. Interspersed telomeric sequences and flanking Alu elements were also found at both breakpoints.</p><p><strong>Conclusion: </strong>Altogether, these findings support a model in which replication fork stalling and template switching - potentially facilitated by telomere dynamics and repetitive elements - led to the formation of a recombinant-like der(6) chromosome. This case highlights the mechanistic complexity of structural rearrangements and the role of replication-based errors in shaping human genomic variation.</p>","PeriodicalId":11206,"journal":{"name":"Cytogenetic and Genome Research","volume":" ","pages":"361-368"},"PeriodicalIF":1.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144658673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Erratum.","authors":"","doi":"10.1159/000546684","DOIUrl":"10.1159/000546684","url":null,"abstract":"","PeriodicalId":11206,"journal":{"name":"Cytogenetic and Genome Research","volume":" ","pages":"369"},"PeriodicalIF":1.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144539509","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Erratum.","authors":"","doi":"10.1159/000545515","DOIUrl":"10.1159/000545515","url":null,"abstract":"","PeriodicalId":11206,"journal":{"name":"Cytogenetic and Genome Research","volume":" ","pages":"101-102"},"PeriodicalIF":1.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144076737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Jumping Translocation of 3q in a Patient with Mantle Cell Lymphoma: A Case Report and Review of the Literature.","authors":"Elisavet Kouvidi, Georgios Boutsikas, Theofanis Giannikos, Marina Kalomoiraki, Ioanna Haralampous, Dimitra Boulari, Maria Dandoulaki, Maria Roumelioti, Paschalina Pallaki, Ioannis Anagnostopoulos","doi":"10.1159/000546297","DOIUrl":"10.1159/000546297","url":null,"abstract":"<p><strong>Introduction: </strong>Jumping translocations are rare cytogenetic events in hematologic malignancies, involving nonreciprocal translocation of a donor chromosome onto two or more recipient chromosomes.</p><p><strong>Case presentation: </strong>In this paper, we report the first-ever case of a jumping translocation involving the long arm of chromosome 3 in a patient with mantle cell lymphoma. The basic clone had the translocation t(11;14)(q13;q32) and a der(13)t(3;13)(q12;p11), and the three subclones had an additional jumping translocation, involving the translocation of 3q12 onto recipient chromosomes 14p, 15p, and der(14)t(11;14), thus resulting in partial trisomy and tetrasomy 3q.</p><p><strong>Conclusion: </strong>Although the underlying mechanism for the formation of jumping translocations is not well understood, their presence is usually associated with poor prognosis and clonal evolution and additional data are needed for their better clinical management.</p>","PeriodicalId":11206,"journal":{"name":"Cytogenetic and Genome Research","volume":" ","pages":"85-92"},"PeriodicalIF":1.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143995080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}