{"title":"Assessing the Genetic Integrity of Embryos Carrying X/Y-Autosome Balanced Translocations through SNP-Based PGT-SR.","authors":"Yueyun Lan, Jinhui Shu, Sheng He, Jingsi Luo, Jiasun Su, Wei Li, Chaofan Zhou, Xianglian Tang, Yuan Wei, Minpan Huang, Caizhu Wang, Xin Zhao, Zhan Li, Qingming Qiu, Hong Zhou, Peng Huang","doi":"10.1159/000548936","DOIUrl":"https://doi.org/10.1159/000548936","url":null,"abstract":"<p><strong>Introduction: </strong>The influence of X/Y-autosomal translocations on reproductive competence is determined by both the cytogenetic positioning of translocation breakpoints and the potential disruption of critical genomic regions essential for reproductive physiology, particularly gene-dense Y-chromosomal segments or X-chromosome loci associated with ovarian folliculogenesis. This investigation examined four cases of cytogenetically balanced X/Y-autosomal translocations through the Single Nucleotide Polymorphism (SNP) and Preimplantation genetic testing for structural rearrangements (PGT-SR)(SNP-based PGT-SR), enabling concurrent assessment of embryonic chromosomal integrity and precise differentiation between euploid embryos and balanced translocation carriers.</p><p><strong>Cases: </strong>Cases 1-2 exhibited Y-autosomal translocations with breakpoints localized to the azoospermia factor (AZF) critical region, while cases 3-4 demonstrated X-autosomal translocations where breakpoints mapped outside ovarian functional domains (Xq13-q28). Embryo selection utilizing SNP-based PGT-SR achieved clinical transfer of euploid embryos lacking the parental translocation in cases 2 and 4. Case 3, following multidisciplinary counseling, opted for transfer of a balanced translocation carrier euploid embryo with conserved genomic architecture. Prenatal diagnostic evaluations demonstrated complete concordance with PGT-SR outcomes. Conclusions:The impact of chromosomal translocation on reproduction is contingent upon whether the breakpoint location influences critical functional regions. SNP-based PGT-SR can accurately determine the genetic status of embryos exhibiting balanced X/Y-autosomal translocations by systematically evaluating the integrity of the embryo's genetic material. This approach enhances detection accuracy and mitigates the risk of transmitting the translocation to subsequent generations.</p>","PeriodicalId":11206,"journal":{"name":"Cytogenetic and Genome Research","volume":" ","pages":"1-18"},"PeriodicalIF":1.3,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145291620","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":"High Amplification of CLA-SAT-149 Satellite DNA in Bighead Catfish: Insights into Satellite DNA Evolution in Clariid Lineages.","authors":"Worapong Singchat, Wattanawan Jaito, Trifan Budi, Thitipong Panthum, Narongrit Muangmai, Chaiwut Grudpan, Jarungjit Grudpan, Suphada Kiriratnikom, Kyudong Han, Darren K Griffin, Prateep Duengkae, Yoichi Matsuda, Kornsorn Srikulnath","doi":"10.1159/000548841","DOIUrl":"10.1159/000548841","url":null,"abstract":"<p><strong>Introduction: </strong>Satellite DNA (satDNA) is an important component of eukaryotic genomes that influences chromosomal organization and evolution. This study investigates the sequence diversity, chromosomal distribution, and copy number variation of the CLA-SAT-149 satDNA family (149 bp) in four clariid catfish species, Clarias macrocephalus, C. gariepinus, C. batrachus, and C. nieuhofii, as well as in F1 hybrids and backcross (BC) progeny.</p><p><strong>Methods: </strong>Fluorescence in situ hybridization (FISH) was used to map CLA-SAT-149 on metaphase chromosomes. Quantitative PCR (qPCR) quantified copy number variation. Amplicon sequencing was applied to characterize sequence variants, and Bayesian clustering analysis was used to assess genetic relationships among subfamilies.</p><p><strong>Results: </strong>Chromosome mapping showed species-specific signals present in C. macrocephalus and F1 hybrids but absent in C. gariepinus and C. nieuhofii. qPCR revealed significantly higher copy numbers in C. macrocephalus. Two sequence variants were identified: the canonical 149-bp (subfamily A) and an 85-bp derivative (subfamily B). Bayesian analysis indicated multiple genetically distinct subgroups among species. F1 hybrids and BC progeny exhibited unique sequence profiles and copy number patterns, while C. nieuhofii lacked CLA-SAT-149 entirely.</p><p><strong>Conclusion: </strong>The results support lineage-specific expansion, amplification, and loss of CLA-SAT-149 in clariid catfish, consistent with the satDNA library model. These patterns provide insights into satDNA evolution and have potential applications in aquaculture genetics, hybrid identification, and species differentiation.</p>","PeriodicalId":11206,"journal":{"name":"Cytogenetic and Genome Research","volume":" ","pages":"1-30"},"PeriodicalIF":1.3,"publicationDate":"2025-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145243450","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}
Halina Cernohorska, Svatava Kubickova, Petra Musilova, Miluse Vozdova
{"title":"Robertsonian translocation rob(13;19) identified in guinea pig (Cavia porcellus, Rodentia).","authors":"Halina Cernohorska, Svatava Kubickova, Petra Musilova, Miluse Vozdova","doi":"10.1159/000548825","DOIUrl":"https://doi.org/10.1159/000548825","url":null,"abstract":"<p><strong>Introduction: </strong>The domestic guinea pig (Cavia porcellus, Caviidae) is an important laboratory species, model for human medical research, worldwide spread pet and a source of food in specific parts of South America. Data on chromosomal abnormalities in guinea pigs are really limited, probably due to the complexity of their karyotype (2n = 64).</p><p><strong>Methods: </strong>G-and C-banding and fluorescence in situ hybridization (FISH) using human chromosome-specific painting probes were used to analyse the karyotype and identify chromosomes involved in a newly discovered Robertsonian translocation.</p><p><strong>Results: </strong>Karyotype 63,XY,rob(13;19) was revealed in a phenotypically normal, fertile domestic guinea pig male. The chromosomes involved in the fusion were verified using FISH with human whole chromosome probes and known guinea pig - human chromosome synteny.</p><p><strong>Conclusion: </strong>This finding adds to the limited cytogenetic data available on guinea pigs, and provides a basis for further investigation of their chromosomal variation and its biological significance. Our results indicate the need for chromosome studies in this cytogenetically mostly neglected species, especially in breeding populations used for biomedical research.</p>","PeriodicalId":11206,"journal":{"name":"Cytogenetic and Genome Research","volume":" ","pages":"1-11"},"PeriodicalIF":1.3,"publicationDate":"2025-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145228461","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":"Transposable elements and sex chromosome evolution in Eulimnadia texana.","authors":"Chathumadavi Ediriweera, Stephen C Weeks","doi":"10.1159/000548721","DOIUrl":"https://doi.org/10.1159/000548721","url":null,"abstract":"<p><strong>Introduction: </strong>Sex chromosomes often evolve through suppressed recombination and accumulation of transposable elements (TEs) on the sex-limited chromosome, leading to divergence and eventual degeneration. The clam shrimp Eulimnadia texana possesses proto-sex chromosomes (Z and W) at an early evolutionary stage, providing a unique opportunity to examine the initial genomic changes underlying sex chromosome differentiation. Additionally, both sex chromosomes are expressed in homogametic ZZ and WW shrimp, allowing a regular expression of both sex chromosomes in homozygotes.</p><p><strong>Methods: </strong>We analyzed newly assembled ZZ (male) and previously published WW (hermaphrodite) genomes of E. texana. Sex-linked markers were mapped to identify the Z chromosome. TEs were annotated using a species-specific repeat library and RepeatMasker. The Z and W chromosomes were divided into bins and randomization tests compared TE accumulation between the sex chromosomes as well as between corresponding regions within these two chromosomes; the latter was focused on the putative sex-determining regions of both the Z and W. Kimura distance-based analyses were used to estimate TE age divergence.</p><p><strong>Results: </strong>The Z chromosome showed no significant TE enrichment relative to autosomes but was enriched for DNA transposons. The W chromosome exhibited significantly higher retrotransposon (LTR and LINE) accumulation. Only the sex-determining region of the W showed significantly elevated retrotransposon content compared to the Z. TE age landscapes indicated recent bursts of retrotransposon activity on the W.</p><p><strong>Conclusion: </strong>These findings support theoretical predictions that retrotransposons accumulate in non-recombining regions, while DNA transposons are associated with recombining chromosomes. The W chromosome of E. texana shows early signs of differentiation, with localized retrotransposon buildup, while the Z remains autosome-like. This study highlights E. texana as a valuable model for understanding the genomic mechanisms of early sex chromosome evolution.</p>","PeriodicalId":11206,"journal":{"name":"Cytogenetic and Genome Research","volume":" ","pages":"1-24"},"PeriodicalIF":1.3,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145191317","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}
Marsílio S P Rocha, Gideão W W F Costa, Marcelo B Cioffi, Luiz A C Bertollo, Vanessa C S Oliveira, Karlla D J Amorim, Wagner F Molina
{"title":"Karyoevolutionary Processes in Atlantic Damselfishes of the Genus <italic>Stegastes</italic> (Pomacentridae).","authors":"Marsílio S P Rocha, Gideão W W F Costa, Marcelo B Cioffi, Luiz A C Bertollo, Vanessa C S Oliveira, Karlla D J Amorim, Wagner F Molina","doi":"10.1159/000548331","DOIUrl":"10.1159/000548331","url":null,"abstract":"<p><strong>Background: </strong>The damselfishes, an extremely diverse group of herbivorous fish, stands out as an important and ubiquitous ecological component of coral reefs. In the Western South Atlantic, the genus Stegastes is the most representative, whose evolutionary paths and taxonomic status of insular endemic species have been better evaluated. To clarify the karyotypic evolution involved in the diversification of this group, cytogenetic analyses were performed in four nominal species (Stegastes variabilis and Stegastes fuscus, distributed in Brazilian coastal regions; Stegastes rocasensis and Stegastes sanctipauli, from Rocas Atoll and São Paulo and São Pedro Archipelago) and one subspecies (S. fuscus trindadensis, from Trindade and Martim Vaz Archipelago).</p><p><strong>Results: </strong>Classical cytogenetic protocols and fluorescence in situ hybridization (FISH) with 18S and 5S rDNA probes were used for comparative analyses. All species had 2n = 48 chromosomes, with high FN values ranging from 88 to 92. Stegastes rocasensis and S. sanctipauli shared identical cytogenetic patterns, while S. f. trindadensis revealed a syntenic arrangement of 18S and 5S rDNA sites not found in S. fuscus from the Brazilian coast.</p><p><strong>Conclusion: </strong>The karyotypic evolution of Stegastes was predominantly driven by multiple pericentric inversions (and/or centromere shifts), resulting in changes in the internal organization of chromosomes. S. rocasensis and S. sanctipauli have similar cytogenetical patterns, as well as S. fuscus and S. f. trindadensis indicating incipient evolutionary differentiation in insular species. Mapping other repetitive DNA sequences provided an exceptional opportunity to clarify chromosomal changes and their association with the evolutionary diversification of Stegastes species.</p>","PeriodicalId":11206,"journal":{"name":"Cytogenetic and Genome Research","volume":" ","pages":"1-10"},"PeriodicalIF":1.3,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145005926","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}
Subin Myong, Jenna K Cosby, Brianna N Padilla, David M Opozda, Jacob D Kahn, Naima Akter, Eileen T O Apos Toole, Natalie J Nannas
{"title":"<italic>Zea mays</italic> Meiotic Spindle Ultrastructure Reveals Kinetochore-Microtubule Interface and Embedded Membrane Components.","authors":"Subin Myong, Jenna K Cosby, Brianna N Padilla, David M Opozda, Jacob D Kahn, Naima Akter, Eileen T O Apos Toole, Natalie J Nannas","doi":"10.1159/000547002","DOIUrl":"10.1159/000547002","url":null,"abstract":"<p><strong>Introduction: </strong>Spindles are microtubules-based machines whose primary function is to accurately segregate chromosomes in both mitotic and meiotic cell division. The structure of spindles is critical for their function; errors in morphology or attachment to chromosomes lead to aneuploidy, potentially resulting in disease, infertility, and lethality. Electron microscopy studies have yielded fine-detail spindle ultrastructures in many plant and animal species, but no studies have investigated the spindle of Zea mays, a critical crop, and cytogenetic model system.</p><p><strong>Methods: </strong>Here we use electron tomography (ET), reconstruction, and modeling to obtain three-dimensional, nanometer-resolution of the Z. mays meiotic spindle. Structures such as microtubules, kinetochores, vesicles, membrane channels, and nuclear envelope were modeled through a partial spindle reconstruction, and confirmed using immunostaining and live fluorescence microscopy.</p><p><strong>Results: </strong>ET revealed that maize spindles contain 8-18 kinetochore microtubules (kMTs) per kinetochore, which are approximately 776 nm in diameter and 316 nm in depth. Small ∼37 nm vesicles were identified, as well as larger (∼5 µm long, 800 nm wide) membrane structures with channels that allow spindle microtubules to pass through. These membrane channels stain positively for the ER-marker protein disulfide isomerase. Imaging of prophase meiotic cells revealed a cross-hatch microtubule arrangement in the perinuclear ring on the external surface of the nuclear envelope, which also contained type II nuclear grooves with transnuclear microtubules passing from the nucleus to the cytoplasm.</p><p><strong>Conclusions: </strong>Z. mays meiotic spindles are similar to animal counterparts with a comparable number of kMTs and pre-spindle transnuclear microtubules but also plant-specific features such as Golgi-derived vesicles to assist cell plate formation, internal ER membrane channels, and a perinuclear microtubule ring that aids spindle assembly. Maize kinetochores have an electron-diffuse ball in cup morphology that is comparable in size to Drosophila kinetochores and larger than mammalian kinetochores.</p>","PeriodicalId":11206,"journal":{"name":"Cytogenetic and Genome Research","volume":" ","pages":"1-17"},"PeriodicalIF":1.3,"publicationDate":"2025-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12503593/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144741617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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
{"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":"1-8"},"PeriodicalIF":1.3,"publicationDate":"2025-07-17","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":"Post-Translational Modifications of the Werner Syndrome Protein WRN.","authors":"Amrita Machwe, David K Orren","doi":"10.1159/000547163","DOIUrl":"10.1159/000547163","url":null,"abstract":"<p><strong>Background: </strong>Werner syndrome has been an excellent model for the study of human aging and how chromosomal instability is related to phenotypes of normal aging including cancer. George Martin devoted his life to the study of Werner syndrome and human aging, and this review is dedicated to his memory.</p><p><strong>Summary: </strong>In this review, we highlight the post-translational modifications of WRN, the protein whose function is lacking in individuals with Werner syndrome. WRN is subject to phosphorylation, acetylation, ubiquitination, and SUMOylation.</p><p><strong>Key messages: </strong>These modifications of WRN control its localization and function in the response to replication fork stress and repair of double-strand breaks that are a consequence of this stress.</p>","PeriodicalId":11206,"journal":{"name":"Cytogenetic and Genome Research","volume":" ","pages":"1-7"},"PeriodicalIF":1.3,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144552594","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":"Clustered Structural Variants Involving PHEX at Xp22 in a Female Patient with X-Linked Hypophosphatemia.","authors":"Erika Uehara, Yasuhiro Naiki, Atsushi Hattori, Maki Fukami, Keiko Matsubara","doi":"10.1159/000547186","DOIUrl":"10.1159/000547186","url":null,"abstract":"<p><strong>Introduction: </strong>X chromosomal structural changes involving PHEX result in X-linked hypophosphatemia (XLH). However, their underlying mechanisms were poorly determined. Moreover, X chromosome inactivation (XCI) statuses in female patients with XLH remain to be studied.</p><p><strong>Case presentation: </strong>We conducted systematic genomic analyses for a woman with XLH and detected a 3.2 Mb tandem duplication at Xp22.33, a 1.9 Mb tandem duplication at Xp22.31, and a 0.8 Mb deletion involving PHEX at Xp22.11 on the paternally derived chromosome. The fusion junctions contained templated insertions and short nucleotide additions indicative of non-homologous end joining (NHEJ) or alternative NHEJ. The patient had random XCI.</p><p><strong>Conclusion: </strong>This study provides evidence that PHEX haploinsufficiency leads to typical XLH in women with random XCI and that a 5.9 Mb rearrangement on Xp22 permits random XCI. Our results, together with previous findings, imply that clustered structural changes due to NHEJ/alternative NHEJ are a unique type of human genomic rearrangements.</p>","PeriodicalId":11206,"journal":{"name":"Cytogenetic and Genome Research","volume":" ","pages":"1-6"},"PeriodicalIF":1.3,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144552593","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}