Cytogenetic and Genome Research最新文献

{"title":"Transposable Elements and Sex Chromosome Evolution in <italic>Eulimnadia texana</italic>.","authors":"Chathumadavi Ediriweera, Stephen C Weeks","doi":"10.1159/000548721","DOIUrl":"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":"30-45"},"PeriodicalIF":1.3,"publicationDate":"2026-01-01","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}

{"title":"Erratum.","authors":"","doi":"10.1159/000549238","DOIUrl":"10.1159/000549238","url":null,"abstract":"&lt;p&gt;&lt;p&gt;In ISCN 2024: An International System for Human Cytogenomic Nomenclature [Cytogenet Genome Res 2024;164(suppl 1); https://doi.org/10.1159/000538512 and https://doi.org/10.1159/isbn.978-3-318-07331-7] by Hastings RJ, Moore S, Chia N (editors), the following corrections to the ISCN should be noted. Please contact the ISCN Standing Committee via the forum if you identify any additional errata.In Chapter 4, Section 4.2.1 Chromosome Abnormality Description Rules, Rule f, the lineNeoplasia: 46,XX,t(9;22)(q34;q11.2)[10]/47,XX,t(9;22),+der(22)[10]Should correctly read:Neoplasia: 46,XX,t(9;22)(q34;q11.2)[10]/47,XX,t(9;22),+der(22)t(9;22)[10]In Chapter 4, Section 4.5.3k Nomenclature for Clones, Mosaics and Chimeras, the linesRelated neoplastic clones: 46,XX,del(7)(q22),+8[10]/46,XX,i(7)(q10),+8[12]Should correctly read:Related neoplastic clones: 47,XX,del(7)(q22),+8[10]/47,XX,i(7)(q10),+8[12]Related neoplastic clones: 46,XY,del(5)(q13q31),-7[3]/46,XY,del(5)(q13),-7[17]Should correctly read:Related neoplastic clones: 45,XY,del(5)(q13q31),-7[3]/45,XY,del(5)(q13),-7[17]In Chapter 5, Section 5.5.3 Derivative Chromosomes, Rule c, example iv, the lineThe additional derivative chromosome 4 is listed before the translocation following the chromosome order rule (see Section 4.3)Should correctly read:The additional derivative chromosome 4 is listed before the translocation following the alphabetical order rule (see Section 4.3)In Chapter 5, Section 5.4.1 Specification of Chromosomes and Breakpoints, Rule eAlternatively, uncertainty of breakpoints may be indicated by a question mark (?), e.g., 1p1? (see Section 4.2.1) or by a tilde (∼), e.g., 1p34∼p35 (see Section 4.2.1)Should correctly read:Alternatively, uncertainty of breakpoints may be indicated by a question mark (?), e.g., 1p1? (see Section 4.2.1) or by a tilde (∼), e.g., 1p35∼p34 (see Section 4.2.1)In Chapter 5, Section 5.4.1 Specification of Chromosomes and Breakpoints, Rule hIf the rearrangement involves a single chromosome the breakpoints are not separated by a semicolon (;), e.g., inv(2)(p23q11.2), del(4)(p15.3p16.1), r(18)(p11.2q23)Should correctly read:If the rearrangement involves a single chromosome the breakpoints are not separated by a semicolon (;), e.g., inv(2)(p23q11.2), del(4)(p16.1p15.3), r(18)(p11.2q23)In Chapter 5, Section 5.4.2 Karyotype format for Designing Structural Chromosome Abnormalities, Rule b, example i, the textThe abnormal chromosome 11 has resulted from a complex translocation involving chromosomes 5, 8 and 11, t(5;8;11;5)(q23;q24.1;q12;q11.2)Should correctly read:The abnormal chromosome 11 has resulted from a complex translocation involving chromosomes 5, 8 and 11, der(11)t(5;11)(q11.2;q12)t(5;8)(q23;q24.1)In Chapter 5, Section 5.5.9.2 Insertion between Two Chromosomes, Rule a, the linea. Interchromosomal insertions (ins) are three-break rearrangements in which part of one chromosome is inserted at a point of breakage in the same or another chromosomeShould correctly read:a","PeriodicalId":11206,"journal":{"name":"Cytogenetic and Genome Research","volume":" ","pages":"64-66"},"PeriodicalIF":1.3,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145741493","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":"Characterization of <italic>DMRT1</italic> Variants for Testis Determination and Differentiation in Emu.","authors":"Yuki Kimura, Miki Okuno, Luisa Matiz-Ceron, Shusei Mizushima, Shoichiro Mitsukawa, Yutaka Suzuki, Takehiko Itoh, Asato Kuroiwa","doi":"10.1159/000548251","DOIUrl":"10.1159/000548251","url":null,"abstract":"<p><strong>Introduction: </strong>DMRT1 on the Z chromosome is a conserved male sex-determining gene in birds. In chickens, a representative model species of Neognathae, the function of DMRT1 has been well characterized. In contrast, Palaeognathae species such as the emu possess less differentiated sex chromosomes and thus provide a valuable system for investigating avian sex determination, yet molecular studies remain limited. We investigated the timing of sex determination and the expression of key genes involved in gonadal differentiation in emu and further characterized DMRT1 variants.</p><p><strong>Methods: </strong>Sex determination stage was identified by anatomical comparison of male and female embryonic gonads. Expression of seven genes (DMRT1, AMH, SOX9, NR5A1, FOXL2, CYP19A1, and RSPO1) was examined by mRNA-seq and RT-PCR. DMRT1 splicing variants were predicted by in silico analysis and 3' RACE was used to identify alternative polyadenylation (APA) variants.</p><p><strong>Results: </strong>The gonadal differentiation occurred at HH25-28 based on gonadal morphology. Gene expression analysis revealed emu-specific patterns not observed in chickens. Notably, RSPO1 was highly expressed in females at HH24-25, preceding DMRT1 expression in males at HH28-29, suggesting ovarian differentiation begins earlier. We identified three splicing variants and four APA variants of DMRT1, with variant 1 predominant during gonadal development.</p><p><strong>Conclusion: </strong>These findings suggest that while molecular sex differentiation mechanisms are largely conserved between Palaeognathae and Neognathae, they differ in parts. In particular, early RSPO1 expression may initiate ovarian differentiation prior to testis determination by DMRT1. The presence of emu-specific DMRT1 variants further indicates possible species-specific mechanisms in testis development.</p>","PeriodicalId":11206,"journal":{"name":"Cytogenetic and Genome Research","volume":" ","pages":"6-19"},"PeriodicalIF":1.3,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144946244","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":"Robertsonian Translocation Rob(13;19) Identified in Guinea Pig (<italic>Cavia porcellus</italic>, Rodentia).","authors":"Halina Cernohorska, Svatava Kubickova, Petra Musilova, Miluse Vozdova","doi":"10.1159/000548825","DOIUrl":"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 analyze 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 the guinea pig, 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":"1-5"},"PeriodicalIF":1.3,"publicationDate":"2026-01-01","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":"Chromosomal Instability in Mouse-Induced Pluripotent Stem Cells: Insights into X and Y Aneuploidies.","authors":"Marianna Paulis, Paola Rebuzzini, Lucia Susani, Paolo Vezzoni, Lorenzo Fassina, Maurizio Zuccotti, Silvia Garagna","doi":"10.1159/000549096","DOIUrl":"10.1159/000549096","url":null,"abstract":"<p><strong>Introduction: </strong>Induced pluripotent stem (iPS) cells share key features with embryonic stem (ES) cells, including similar limitations such as the accumulation of (epi)genetic and genomic alterations. However, sex chromosome instability in mouse iPS cells remains poorly understood. This retrospective study aimed to investigate this phenomenon by analyzing mouse iPS cell clones. Specifically, we examined whether factors such as passage number, cell sex, founder cell type, or reprogramming method influence the presence or absence of sex chromosome abnormalities.</p><p><strong>Methods: </strong>Sex chromosome stability was evaluated in 26 independent male and female mouse iPS cell clones using standard karyotyping techniques. Additionally, we analyzed an artificially generated XXY iPS cell model, in which an extra X chromosome was introduced into a normal XY cell line. Statistical analyses were conducted on the karyotyping results and correlated with both continuous variables (e.g., passage number) and categorical variables (e.g., cell sex, founder cell type, and reprogramming method).</p><p><strong>Results: </strong>Female iPS cell clones displayed significantly higher levels of sex chromosome instability compared to their male counterparts, regardless of the founder cell type or reprogramming strategy. A similar pattern of X chromosome instability was also observed in the XXY iPS cell model.</p><p><strong>Conclusion: </strong>Our findings demonstrate that sex chromosome instability occurs in mouse iPS cells, as previously reported in mouse ES cells, suggesting a conserved phenomenon across pluripotent stem cell types. Importantly, the presence of multiple X chromosomes in the pluripotent state appears to contribute to this instability. Further studies are required to elucidate the underlying molecular mechanisms.</p>","PeriodicalId":11206,"journal":{"name":"Cytogenetic and Genome Research","volume":" ","pages":"67-78"},"PeriodicalIF":1.3,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145367811","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":"Coexistence of Mosaic Marker Chromosome and Isodisomy 1 in Reproductive Failure: A Cytogenomic Case Report and Review of the Literature.","authors":"Sadiye Ekinci, Ekin Aydın, Şule Altıner","doi":"10.1159/000549338","DOIUrl":"10.1159/000549338","url":null,"abstract":"<p><strong>Introduction: </strong>Reproductive failure has been associated with various chromosomal abnormalities, including small supernumerary marker chromosomes (sSMCs). In rare cases, uniparental disomy (UPD) may also contribute to reproductive problems, particularly when involving imprinted regions or in cases of isodisomy where autosomal recessive disorders may manifest. UPD involving chromosome 1 (UPD1) is rare and has not been linked to a consistent phenotype.</p><p><strong>Case presentation: </strong>We present a 27-year-old woman with a 5-year history of reproductive difficulty, including one biochemical pregnancy loss and one clinically recognized miscarriage at 8 weeks of gestation. Cytogenetic analysis revealed mosaicism for a small sSMC derived from chromosome 1. SNP microarray identified complete UPD1 without copy number changes. Fluorescence in situ hybridization (FISH) confirmed centromeric material of chromosome 1 in the marker chromosome.</p><p><strong>Conclusion: </strong>To the best of our knowledge, this is the first reported case combining mosaic sSMC(1) and complete UPD1 in a phenotypically healthy woman with reproductive failure. The coexistence of these abnormalities likely reflects a postzygotic chromosomal rescue mechanism. These findings underscore the diagnostic value of integrated cytogenomic analyses in unexplained reproductive failure and subfertility.</p>","PeriodicalId":11206,"journal":{"name":"Cytogenetic and Genome Research","volume":" ","pages":"125-132"},"PeriodicalIF":1.3,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145421335","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":"Molecular Characterization of <italic>MECOM</italic> Rearrangements in Two Cases with Myelodysplastic Syndrome and t(2;3)(p23;q26.2).","authors":"Zhongxia Qi, Sonam Prakash, Jingwei Yu","doi":"10.1159/000550151","DOIUrl":"10.1159/000550151","url":null,"abstract":"<p><strong>Introduction: </strong>MECOM rearrangements are frequently observed in myeloid neoplasms and associated with poor prognosis. Among the genomic alterations leading to MECOM rearrangements, t(2;3)(p13∼p25;q26.2) accounts for approximately 13% of reported cases. However, the precise DNA breakpoints of this translocation have not been previously reported, nor has the mechanism by which it alters MECOM expression been fully elucidated. In this report, we describe two cases with myelodysplastic syndromes (MDS) and t(2;3)(p23;q26.2). Our genomic characterization of these two t(2;3) translocations provided insights into the molecular mechanism of MECOM activation.</p><p><strong>Case presentation: </strong>Case 1 is a 44-year-old female who presented with new anemia and thrombocytopenia. She was treated with azacitidine. After two allogeneic stem cell transplants, her disease relapsed with rapid progression to acute myeloid leukemia (AML). The patient passed away 1 year after progression to AML and 8 years after initial diagnosis. Case 2 is a 75-year-old female who was incidentally found to have macrocytic anemia with rare circulating blasts. She remained asymptomatic from anemia and did not require transfusions or treatment. Her disease progressed to MDS with excess blasts 3 years later. Patient was treated with azacitidine. Fifteen months later, her disease further progressed to AML. She passed away 5 months later and four and a half years after initial diagnosis. DNA sequencing analysis of these two cases revealed that the t(2;3)(p23;q26.2) breakpoints were within the regulatory regions of ZFP36L2 and THADA on chromosome 2 and the proximity of MECOM on chromosome 3, creating a novel regulatory configuration for MECOM. Notably, the translocation breakpoints differed by 270 kb on chromosome 2 and 93 kb on chromosome 3, resulting in distinct translocated regulatory elements with varying sizes and proximities to MECOM. These structural differences may influence the level of MECOM upregulation and contribute to variation in disease severity and progression.</p><p><strong>Conclusion: </strong>Our findings highlighted that, despite cytogenetic similarity, different t(2;3) translocations may exert distinct regulatory effects depending on the precise breakpoint locations. Thus, molecular characterization of MECOM rearrangements is critical for understanding disease pathogenesis and prognosis in myeloid neoplasms and may lead to the development of novel treatment.</p>","PeriodicalId":11206,"journal":{"name":"Cytogenetic and Genome Research","volume":" ","pages":"1-6"},"PeriodicalIF":1.3,"publicationDate":"2025-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145793450","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":"A 30-Year Cytogenetic Follow-Up Study on a Thyroid Cancer Patient after Internal Radioiodine Therapy.","authors":"Adayabalam S Balajee, Terri L Ryan, Maria B Escalona, Alvis E Foster","doi":"10.1159/000550010","DOIUrl":"10.1159/000550010","url":null,"abstract":"<p><strong>Introduction: </strong>Radioiodine (131I) is commonly used for the treatment of hyperthyroidism and for differentiated thyroid cancer as an ablative therapy. Radioiodine (131I) constitutes almost 90% of the therapies that are currently performed in the nuclear medicine field. In this study, retrospective cytogenetic follow-up analysis was performed after 29 years (2023) and 30 years (2024) in a papillary thyroid cancer patient who received the second round of 131I treatment in 1994.</p><p><strong>Methods: </strong>Metaphase chromosomes prepared from the in vitro culture of peripheral blood lymphocytes of the patient were utilized for the analysis of unstable (dicentrics and fragments) and stable chromosome aberrations (simple, complex, and clonal). For dicentric chromosome detection, fluorescence in situ hybridization (FISH) was performed using human centromere- and telomere-specific peptide nucleic acid probes. Chromosome translocations were detected by a cocktail of DNA probes for individual chromosomes (1, 2, and 4) and multicolor FISH (mFISH) probe for the entire human genome. Micronuclei were analyzed by cytokinesis block micronucleus assay (CBMN). Absorbed radiation dose was estimated at 95% confidence intervals from the frequencies of chromosome aberrations (dicentric chromosomes and translocations) using correlation coefficients of the γ-rays dose-response curve using the DoseEstimate_v5.1 algorithm.</p><p><strong>Results: </strong>The percentage of cells with stable and unstable chromosome aberrations remained the same (∼8%) in the patient during the entire retrospective study albeit variations in the frequencies of reciprocal and nonreciprocal translocations. The frequency of color junctions (chromosome exchange events) detected by the mFISH technique showed a sharp increase in this study (0.33/cell) compared to our earlier study (0.19/cell). The persistence of clonal translocation involving chromosomes 14;15 was observed in 1-1.6% of the total cells analyzed. In the 29-year follow-up study, one complex translocation involving chromosomes 1, 9, and 14 was detected by mFISH in a total of 200 cells.</p><p><strong>Discussion: </strong>Our findings indicate that the past internal therapeutic exposure of radioiodine results in long-lasting chromosomal damage and the retrospective study of this nature will be useful for monitoring the progression of any oncogenic events driven by chromosomal instability in the hematopoietic system of 131I therapy patients.</p>","PeriodicalId":11206,"journal":{"name":"Cytogenetic and Genome Research","volume":" ","pages":"1-12"},"PeriodicalIF":1.3,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145741529","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":"A Unique Case of Mosaicism for Two Robertsonian Translocations, rob(17;27) and rob(17;29), in a Subfertile Mare (<italic>Equus caballus</italic>).","authors":"Mayra N Mendoza Cerna, Hailey Anderson, Giora Avni, Gila Kahila Bar-Gal, Rytis Juras, Terje Raudsepp","doi":"10.1159/000549928","DOIUrl":"10.1159/000549928","url":null,"abstract":"<p><strong>Introduction: </strong>Robertsonian translocations (ROBs) or centric fusions of acrocentric chromosomes are the most common structural chromosomal rearrangements in mammals. ROBs are of medical and veterinary concern because of associated subfertility and congenital disorders but are also of interest as a mechanism of chromosome and karyotype evolution. While ROBs are well documented in humans, mice, and cattle/bovids, they are extremely rare in horses, despite the 18 acrocentric chromosomes in the horse karyotype.</p><p><strong>Methods: </strong>We characterize the case using conventional and molecular cytogenetic approaches and DNA analysis.</p><p><strong>Results: </strong>We report the first case of ROB between nonhomologous chromosomes in the horse, whereas the carrier was 50/50 mosaic for two different ROB cell lines - 63,XX,rob(17;27) and 63,XX,rob(17;29) and had no cells with normal karyotype. Both derivative ROB chromosomes had retained two structural centromeres which is also a typical feature of human and bovine ROBs. The clinical phenotype of the mare included small ovaries, irregular estrus, and two pregnancy losses - all consistent with ROB.</p><p><strong>Discussion: </strong>We discuss the role of centromeric satellite sequences in the formation of ROBs but also differences in the prevalence of ROBs in different species, regardless of the number of acrocentric chromosomes. In this context, further molecular studies of the presented case may provide additional clues about the features of centromeric satellite repeats that facilitate or prevent ROBs in general.</p>","PeriodicalId":11206,"journal":{"name":"Cytogenetic and Genome Research","volume":" ","pages":"1-10"},"PeriodicalIF":1.3,"publicationDate":"2025-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145707826","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":"Functional Divergence between the Z and W Alleles of the <italic>UBAP2</italic> Gene Revealed by Differences in Their Expression Patterns in Japanese Quail.","authors":"Daichi Hodota, Shusei Mizushima, Tomoe Kobayashi, Makoto Matsuyama, Asato Kuroiwa","doi":"10.1159/000549458","DOIUrl":"10.1159/000549458","url":null,"abstract":"<p><strong>Introduction: </strong>In birds, males have the homogametic sex chromosomes ZZ, whereas females have the heterogametic ZW. Similar to mammalians, avian Z and W chromosomes are believed to have originated from a pair of autosomes. Over evolutionary time, the W chromosome degenerated, losing many genes. The remaining W-linked genes retain homologs on the Z chromosome. One such gene is UBAP2, which participates in cellular metabolism and signaling through the ubiquitin-proteasome pathway in mammals. However, the functions of its avian homologs, UBAP2Z (Z-linked) and UBAP2W (W-linked), remain poorly understood. To investigate the functional divergence between them in birds, we analyzed their mRNA and protein expression in embryonic gonads of Japanese quail.</p><p><strong>Methods: </strong>Using RNA-seq data of embryonic gonads of Japanese quail, contigs were generated by de novo assembly. The nucleotide sequences were predicted from the contigs by blastn analysis. Expression levels were calculated by bowtie2 and RSEM. Immunohistochemistry and Western blotting employing monoclonal antibodies specific to UBAP2Z and UBAP2W were generated to investigate protein expression and localization. Additionally, far-Western blotting was performed to examine protein-protein interactions.</p><p><strong>Results: </strong>UBAP2Z and UBAP2W nucleotide and amino acid sequences showed high similarity and shared a conserved N-terminal UBA domain. However, UBAP2W expression was consistently lower than that of UBAP2Z and showed a distinct localization pattern from UBAP2Z in embryonic gonads. In males, UBAP2Z was expressed in seminiferous tubules, while in females, it localized to the medulla. By contrast, UBAP2W was exclusively observed in the cortex of female gonads, particularly at developmental stage HH38. Furthermore, UBAP2Z and UBAP2W interacted with different binding partners, indicating divergence in their molecular function.</p><p><strong>Conclusion: </strong>These findings indicate that UBAP2W has a distinct female-specific functional role in avian gonadal differentiation. We propose that UBAP2W contributes to ovarian development and oogenesis through the ubiquitin-proteasome pathway, while UBAP2Z is involved in general cellular regulation across sexes. This study highlights functional divergence between Z- and W-linked paralogs in birds and provides new insights into sex chromosome evolution and gonadal development.</p>","PeriodicalId":11206,"journal":{"name":"Cytogenetic and Genome Research","volume":" ","pages":"1-11"},"PeriodicalIF":1.3,"publicationDate":"2025-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145470791","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}