Karyotyping and identifying all of the chromosomes of allopolyploid Brassica juncea using multicolor FISH

Chromosome identification and karyotype using fluorescence in situ hybridization(FISH)provides a technical platform for genome and cytogenetic studies. Brassica juncea(brown mustard, 2n = 4× = 36; genome AABB) is an allopolyploid species that originated from a spontaneous hybridization of Brassica rapa and Brassica nigra and contains many valuable traits. In this study, a multicolor FISH procedure allowing the identification of all 18 chromosomal pairs was developed by two-step hybridizations with probes on the same metaphase chromosomes. The distribution patterns and chromosomal localizations of six repeat sequences(satellite repeat p Br STR, 5S r DNA, 45 S r DNA, B genome-specific repeat p BNBH35, and centromeric satellite repeats Cent Br1 and Cent Br2) on B. juncea chromosomes were characterized.Comparative karyotype analyses showed that the genome is relatively stable in comparison with its diploid progenitor species and revealed intraspecific karyotypic diversity among three accessions of B. juncea. This study provides valuable information about the genome evolution of B. juncea and a toolkit that will be helpful for chromosome identification.

Completely Distinguishing Individual A-genome Chromosomes and Their Karyotyping Analysis by Multiple BAC-FISH

Multiple BAC-FISH is a powerful tool for modern cytogenetic researching in both animals and plants.But in cotton,this technique is unavailable due to the high percentage of repetitive sequences.

Comprehensive Genetic Analysis by Integration of Conventional Karyotyping and Interphase FISH Helps Refinement of Biological Subclasses with Clinical Impact in Chronic Lymphocytic Leukemia

Background: Various genetic technologies have been employed in the identification of genomic complexity and refinement of prognostic classification of clinically heterogeneous disease of chronic lymphocytic leukemia (CLL). Objective: The present study of interphase cytogenetics and conventional karyotyping was undertaken to perform comprehensive analysis of CLL genetics with an approach to refine early prognostication of disease. Material & Methods: Retrospective analysis by fluorescence in situ hybridization (FISH) was carried out on total 671 patients of CLL at diagnosis between 2008 and 2015. Conventional cytogenetics studies were performed in 50 of 671 patients using CPG Oligonucleotide + IL-2 and TPA (12-O-Tetradecanyl Phorbol 13-acetate) for stimulation of lymphocytes cultures. Results: Interphase cytogenetics could detect recurrent abnormalities such as del(13q14), +12, del(17p13), del(11q22), del(6q23) in 71% of cases. The incidence of del(13q) was higher in Rai stage 0, I, II (p = 0.0005);whereas patients with ≥2 aberrations were more common in advance stage III, IV (p = 0.001). Frequency of IgH translocation was 7%. Morphology and immunophenotypic analysis revealed atypical CLL with higher frequency of t(14;19) than t(14;18). Conventional karyotype could detect abnormal karyotype in 97% of cases which displayed targeted FISH abnormalities along with additional non-targeted chromosomal abnormalities. Patients with negative FISH markers showed clonal non-recurrent numerical and structural changes. The complex karyotype was identified in 24% cases which included targeted FISH aberrations as well as non-targeted numerical and structural abnormalities like deletions, and unbalanced translocations. A significant association was observed between complex karyotype and coexistence of ≥2 FISH markers (p = 0.009) and del(11q22) &/or del(17p) (p = 0.03). Conclusion: Our data of interphase FISH with integration of conventional karyotyping revealed genomic complexity that helped identification of biological subclasses with clinical impact at diagnosis. Further, these cytogenetic subclasses along with molecular markers are likely to evolve more refined prognostic groups, which will help design risk-adapted therapies in B-CLL.

Repetitive sequence analysis and karyotyping reveal different genome evolution and speciation of diploid and tetraploid Tripsacum dactyloides

In the subtribe Maydeae, Tripsacum and Zea are closely related genera. Tripsacum is a horticultural crop widely used as pasture forage. Previous studies suggested that Tripsacum might play an important role in maize origin and evolution. However, our understanding of the genomics and the evolution of Tripsacum remains limited. In this study, two diploids,T. dactyloides var. meridionale(2n = 36, MR) and T. dactyloides(2n = 36, DD), and one tetraploid,T. dactyloides(2n = 72, DL) were sequenced by low-coverage genome sequencing followed by graph-based cluster analysis. The results showed that 63.23%, 59.20%, and 61.57% of the respective genome of MR, DD, and DL were repetitive DNA sequence. The proportions of different repetitive sequences varied greatly among the three species. Fluorescence in situ hybridization(FISH) analysis of mitotic metaphase chromosomes with satellite repeats as the probes showed that the FISH signal patterns of DL were more similar to that of DD than to that of MR. Comparative analysis of the repeats also showed that DL shared more common repeat families with DD than with MR. Phylogenetic analysis of internal transcribed spacer region sequences further supported the evolutionary relationship among the three species. Repetitive sequences comparison showed that Tripsacum shared more repeat families with Zea than with Coix and Sorghum. Our study sheds new light on the genomics of Tripsacum and differential speciation in the Poaceae family.

Karyotyping of Brassica napus L. Based on C0t-1 DNA Banding by Fluorescence In Situ Hybridization

In order to precisely recognize and karyotype Brassica napus L. chromosomes, C0t-1 DNA was extracted from its genomic DNA, labeled with biotin-1 1-dUTP and in situ hybridized. The hybridized locations were detected by Cy3-conjugated streptavidin. Specific fluorescence in situ hybridization （FISH） signal bands were detected on all individual chromosome pairs. Each chromosome pair showed specific banding patterns. The B. napus karyotype has been constructed, for the first time, on the basis of both Cot-1 DNA FISH banding patterns and chromosome morphology.

A likely paleo-autotetraploidization event shaped the high conservation of Nyssaceae genome

Scientific knowledge about the ancestral genome of core eudicot plant kingdom can potentially have profound impacts on both basic and applied research,including evolution,genetics,genomics,ecology,agriculture,forestry,and global climate.To investigate which plant conserves best the core eudicots common ancestor genome,we compared Arcto-Tertiary relict Nyssaceae and 30 other eudicot plant families.The genomes of Davidia involucrata(a known living fossil),Camptotheca acuminata and Nyssa sinensis,one per existent genus of Nyssaceae,were performed comparative genomic analysis.We found that Nyssaceae originated from a single Nyssaceae common tetraploidization event(NCT)-autotetraploidization 28-31 Mya after the core eudicot common hexaploidization(ECH).We identified Nyssaceae orthologous and paralogous genes,determined its chromosomal evolutionary trajectory,and reconstructed the Nyssaceae most recent ancestor genome.D.involucrata genome contained the entire seven paleochromosomes and 17 ECH-generated eudicot common ancestor chromosomes and was the slowest in mutation among the analyzed 42 species of 31 plant families.Combing both its high retention of paleochromosomes and its low mutation rate,D.involucrata provides the best case in conservation of the core eudicot paleogenome.

Repeated pregnancy losses with multiple aneuploidies and major genomic imbalance:A case report

Rationale:If one of the partners is having balanced autosomal translocation,it is usually observed that the offspring inherit either normal chromosomes,balanced translocation identical to one of the parent or unbalanced chromosomal rearrangements of the same parental chromosome having translocation.Concern:A unique case presented with history of 8 miscarriages for genetic counseling.The last abortus material evaluation showed monosomy of chromosome X(Turner syndrome)in all the analyzed cells.There was a history of infertility and also repeated second trimester abortions on the paternal side.On the maternal side,there was a history of intellectual disability.Diagnose:History of repeated abnormal pregnancy outcomes.Wife’s karyotype is normal;however,husband shows translocation between chromosome 4 and 22.Intervention:Peripheral blood sample around 3 mL was collected for karyotype.Embryo biopsy was done and DNA was extracted and processed for whole exome sequencing.Outcomes:Wife’s karyotype is normal and husband has translocation between chromosome 4 and 22.Surprisingly,the entire pregnancy outcome including embryo screening has different,complete or partial aneuploidies of chromosomes other than chromosome 4 and 22.Main lesson:Though the translocation in one of the parent is balanced,we have to think beyond traditional ways for evaluating a couple with repeated pregnancy loss as we cannot predict the errors at cell division.Option of in vitro fertilization and preimplantation genetic diagnosis in couples having balanced translocations should be discussed so that early intervention can prevent the agony of pregnancy loss.

Clinical manifestations and the prenatal diagnosis of trisomy 7 mosaicism:Two case reports

BACKGROUND The clinical manifestations of trisomy 7 mosaicism are diverse and nonspecific,so prenatal diagnosis is very difficult.CASE SUMMARY Two pregnant women with abnormal prenatal screening results were included.One was a 22-year-old woman(G1P0).At 31st week of gestation,ultrasound revealed that the posterior horn of the left lateral ventricle was 10 mm and the right renal pelvis had a separation of 7 mm.The other pregnant woman was 33 years old(G2P1L1A0),and her fetus was found to have a cardiac malformation at the 24th week of gestation.Copy number variation sequencing,whole-exome sequencing and karyotype analysis were carried out after amniocentesis,and both fetuses were diagnosed with trisomy 7 mosaicism.After parental counseling,one woman continued the pregnancy,and the other woman terminated the pregnancy.CONCLUSION In trisomy 7 mosaicism,the low proportion of trisomy does not lead to abortion,but can result in abnormal fetal development,which can be detected via ultrasound.Therefore,clinicians need to pay more attention to various aspects of fetal growth and development,combining with imaging,cellular,molecular genetics and other methods to perform comprehensive evaluations of fetuses to provide more reliable genetic counseling for pregnant women.

Digital Karyotyping with Whole Genomic Sequencing for Complex Congenital Disorder

Complex congenital disorders may be caused by multiple genetic alterations and/or environmental hazards. Diagnosis and management of these diseases are usually difficult. Robust next-generation sequencing （NGS） technologies provide unprecedented opportunities to maximize mutation detection and improve genetic counseling and clinical management. Targeted or whole exome sequencing （WES） mainly detects protein-coding DNA sequence aberrations and is the major DNA sequencing technology that is entering clinical practice （Liu et al., 2014）.

Karyotyping of Brassica oleracea L.based on rDNA and Cot-1 DNA fluorescence in situ hybridization

To explore an effective and reliable karyotyping method in Brassica crop plants,Cot-1 DNA was isolated from Brassica oleracea genome,labeled as probe with Biotin-Nick Translation Mix kit,in situ hybridized to mitotic spreads,and where specific fluorescent bands showed on each chromosome pair.25S and 5S rDNA were labeled as probes with DIG-Nick Translation Mix kit and Biotin-Nick Translation Mix kit,respectively,in situ hybridized to mitotic preparations,where 25S rDNA could be detected on two chromosome pairs and 5S rDNA on only one.Cot-1 DNA contains rDNA and chromosome sites identity between Cot-1 DNA and 25S rDNA was determined by dual-colour fluores-cence in situ hybridization.All these showed that the karyo-typing technique based on a combination of rDNA and Cot-1 DNA chromosome landmarks is superior to all but one.A more exact karyotype of B.oleracea has been analyzed based on a combination of rDNA sites,Cot-1 DNA fluorescent bands,chromosome lengths and arm ratios.

Chromosomal microarray analysis vs.karyotyping for fetal ventriculomegaly:a meta-analysis

Background:Chromosomal abnormalities are important causes of ventriculomegaly(VM).In mild and isolated cases of fetal VM,obstetricians rarely give clear indications for pregnancy termination.We aimed to calculate the incidence of chromosomal abnormalities and incremental yield of chromosomal microarray analysis(CMA)in VM,providing more information on genetic counseling and prognostic evaluation for fetuses with VM.Methods:The Chinese language databases Wanfang Data,China National Knowledge Infrastructure,and China Biomedical Literature Database(from January 1,1991 to April 29,2020)and English language databases PubMed,Embase,and Cochrane Library(from January 1,1945 to April 29,2020)were systematically searched for articles on fetal VM.Diagnostic criteria were based on ultrasonographic or magnetic resonance imaging(MRI)assessment of lateral ventricular atrium width:≥10 to<15 mm for mild VM,and≥15 mm for severe VM.Isolated VM was defined by the absence of structural abnormalities other than VM detected by ultrasonography or MRI.R software was used for the meta-analysis to determine the incidence of chromosomal abnormalities and incremental yield of CMA in VM,and the combined rate and 95%confidence interval(CI)were calculated.Results:Twenty-three articles involving 1635 patients were included.The incidence of chromosomal abnormalities in VM was 9%(95%CI:5%-12%)and incremental yield of CMA in VM was 11%(95%CI:7%-16%).The incidences of chromosomal abnormalities in mild,severe,isolated,and non-isolated VM were 9%(95%CI:4%-16%),5%(95%CI:1%-11%),3%(95%CI:1%-6%),and 13%(95%CI:4%-25%),respectively.Conclusions:Applying CMA in VM improved the detection rate of abnormalities.When VM is confirmed by ultrasound or MRI,obstetricians should recommend fetal karyotype analysis to exclude chromosomal abnormalities.Moreover,CMA should be recommended preferentially in pregnant women with fetal VM who are undergoing invasive prenatal diagnosis.CMA cannot completely replace chromosome karyotype analysis.

Confusing finding of quantitative fluorescent polymerase chain reaction analysis in invasive prenatal genetic diagnosis:A case report

BACKGROUND Quantitative fluorescent polymerase chain reaction(QF-PCR)is a rapid prenatal diagnostic method for abnormalities on chromosomes 21,18,and 13 and sex chromosomal aneuploidy.However,the value of QF-PCR in diagnosing chromosomal structural abnormalities is limited.In this article,we report a confusing QF-PCR finding in a pregnant woman who underwent amniocentesis.CASE SUMMARY The short tandem repeat marker AMXY(Xp22.2/Yp11.2)located on the sex chromosome exhibited a trisomic biallelic pattern,indicating that the karyotype of the fetus might be 47,XYY.Chromosome analysis performed on cultured amniocytes showed a normal male karyotype of the fetus.Copy number variation sequencing confirmed a 500 kb duplication at Yp11.2-Yp11.2(chrY:6610001_7110000)and a 250 kb duplication at Yp11.2-Yp11.2(chrY:7110001_7360000).CONCLUSION In conclusion,the comprehensive application of different methods could achieve a higher detection rate and accuracy for the prenatal diagnosis of chromosomal disorders through chromosomal testing.

A likely autotetraploidization event shaped the Chinese mahogany(Toona sinensis)genome

Chinese mahogany(Toona sinensis) is of considerable medical and economic importance, and its genome has been deciphered. However, the process underlying its polyploidy is unclear, and the chromosomal evolutionary trajectory is poorly understood. Here, by reanalysing the T.sinensis genome, we found evidence of a tetraploidization event(T. sinensis special tetraploidization, TST) that occurred approximately 15-17 million years ago(MYA) after the core eudicot-common hexaploidization(ECH or gamma) event. We characterized the synonymous nucleotide substitution rates(Ks values) of collinear genes and found that T. sinensis genes affected by the TST evolve at a slower rate than Acer yangbiense genes. Furthermore, we identified homologous genes related to polyploidization and speciation and constructed multiple alignments with different reference genomes. Notably, the significant balance of gene retention and loss characterized in the two TST-derived subgenomes suggests an autopolyploid nature of the TST. Moreover, we deduced the chromosomal karyotypes of the two subgenomes and identified 7chromosomal fusions that have shaped the T. sinensis genome;more information is available on a newly constructed karyotype platform(http://www.cgrpoee.top/Toona_sinensis/index.html). The T. sinensis genome preserves the ancestral chromosome structure of dicotyledons well and could serve as a good reference for understanding genomic changes in other Meliaceae and Sapindales plants. In addition, we verified that tandem duplication and the ECH have promoted the expansion of terpene synthase(TPS) genes;conversely, the TST seems to have inhibited expansion of these genes. This present effort has clarified the polyploidy events of the T. sinensis genome, filled gaps in the history of karyotype evolution, and laid a solid foundation for further genomic studies in the Meliaceae research community and beyond.

Unique Roberts syndrome with bilateral congenital glaucoma: A case report

BACKGROUND Congenital glaucoma associated with Roberts syndrome(RS)is an unusual and unique condition.No previous report describes this association.A multidisciplinary approach including molecular studies were conducted to reach the final diagnosis.CASE SUMMARY We present a rare case of a 1-wk-old male with RS associated with bilateral congenital glaucoma,left ectopic kidney,and left-hand rudimentary digits.A comprehensive approach was applied by which bilateral non-penetrating glaucoma surgery was performed with good control of intraocular pressure for more than 6 mo.Cytogenetic and molecular testing were conducted and revealed normal measurements.CONCLUSION This report described a case of a male baby with clinical features of RS but with a negative molecular analysis,presenting with left-hand rudimentary digits,bilateral congenital glaucoma,and left ectopic kidney.To the best of our knowledge,this is the first case reported with phocomelia,bilateral congenital glaucoma,and unilateral ectopic kidney.

Correlation between Reasons for Prescription and Karyotype Results in Patients Referred for Suspected Chromosomal Abnormalities

Karyotype prescription is based on clinical signs (or reasons for karyotype prescription) which are phenotypic manifestations associated with chromosomal abnormalities. The aim of this study was to establish a correspondence between karyotype indications and their results in patients. This was a retrospective study that was carried out in the Histology-Embryology-Cytogenetics laboratory of the University Hospital of Cocody-Abidjan from 2014 to 2019. 58 patient files were identified and included the indication or reason for prescribing a constitutional karyotype and the biological result obtained. An individual data sheet was used to collect the data. 17 reasons for prescription were identified and divided into 2 groups. Sexual ambiguity was the most frequent reason (29.3%). The first group (G1) represented the 10 reasons for which the karyotype results were normal. The second group (G2) corresponded of the 7 motives with normal or abnormal karyotype results. Several anomalies were listed according to these reasons: inversions, mosaics (anomalies of number and structure) and trisomy 21. The last was the most frequent chromosomal anomaly (69.24%). It was found in several reasons for karyotype prescription: malformations, neurological disorders, suspected trisomy and cardiac pathology. Several factors could explain these results, among which are the limits of the karyotype and the non-genetic causes that can induce these abnormal phenotypes. Complementary examinations to the karyotype are molecular cytogenetic techniques, notably fluorescence in situ hybridization (FISH) and array comparative genomic hybridization (Array-CGH).

烟台绵枣儿的核型研究(英文)

[Objective] The aim of this study was to investigate the chromosome number and the karyotype of Scilla scilloides in Yantai.[Method]Root tips of Scilla scilloides were pretreated by 8-hydroxyquinoline,then fixed,dissociated and stained for slice production.The chromosome number was analyzed by microscopic examination,and then cells with good chromosomal morphology and dispersal chromosome were studied by microscopic photos.[Result]The somatic chromosome number of Scilla scilloides in Yantai was 2n=16+1Bs,while the karyotype formula was K(2n)=2x=16+1Bs=6m+4sm(2SAT)+4st+2t+1Bs and the karyotype classification was "3B" type.[Conclusion]Karyotype comparison,division of cell type and evolution of Scilla scilloides in Yantai are discussed,which provides basis for cytogenetics,evolutionary genetics,modern taxonomy and genetic breeding.

Combination of Cytogenetic Analysis and Molecular Screening in Patients with de novo Acute Myeloid Leukemia

Nowadays the role of genetic findings in determining the diagnosis,therapy and prognosis of acute myeloid leukemia(AML) has become more valuable.To improve and validate the detection of clonal chromosomal aberrations in leukemia,we designed a combined application of karyotyping with multiplex reverse transcription-polymerase chain reaction(RT-PCR) and fluorescence in situ hybridization(FISH),and addressed the expression and distribution of fusion genes among the subtypes of Chinese adult patients with de novo AML.Multiplex RT-PCR assays were performed on 477 samples from newly diagnosed AML patients,and cytogenetic data were obtained from 373 of them by R or G banding techniques and those in some cases were confirmed by FISH.The PCR products in some suspected cases were tested by two-directional sequencing.The results showed that except unqualified samples,fusion genes were detected by multiplex RT-PCR in 211 of 474 patients(44.51%),including AML1-ETO,CBFβ-MYH11,PML-RARα,PLZF-RARα,NPM-RARα,MLL rearrangements,BCR-ABL,DEK-CAN,SET-CAN,TEL-PDGFR,TLS-ERG,AML1-MDS1(EVI-1).In 373 patients,who took both multiplex RT-PCR and karyotype analysis,the detection rate of chromosomal aberrations by using multiplex RT-PCR and karyotyping was 160/373(42.89%) and 179/373(47.98%) respectively,and the combination could optimize the detection rate of clonal genetic abnormalities to 216/373(57.90%).The PCR results from 11 cases 'normal' in karyotyping but abnormal in RT-PCR for MLL rearrangements were confirmed by two-directional sequencing.It is concluded that karyotype studies remain the cornerstone for genetic testing;conventional cytogenetics and molecular-based methods are complementary tests for the detection of clonal genetic aberrations in AML,especially for the cryptic or submicroscopic aberrations.Once a genetic marker has been identified by combined analysis,it could be used to monitor residual disease during/after chemotherapy,by quantitative RT-PCR and/or FISH.

Karyotypic analysis of intersexuality in Chinese from Taiyuan

Aim: To analyze the kayrotypic patterns of 33 cases of intersexuality in Chinese from Taiyuan, China in order tofurther clarify its mechanism of development and the interrelationship between karyotype and phenotypic sex. Meth-ods: High-resolution GTG-banding chromosome technique was used to analyze the karyotype patterns. Results:In these patients, 57.58% were male pseudohermaphrodites (46, XY), 18.18%, female pseudohermaphrodites (46,XX), 12.12%, true hemaphrodites, and 12.12%, other karyotypes, Although testes can be seen in 88.8% of kary-otypes with Y chromosome, 73.68% of the patients were of female social sex. In 42.82% of patients the social sex isin conformity with their karyotypes. There were 2 cases of male pseudohennaphrodites, where the sex chromosome wasnormal, but abnormalities were found in chromosomes 9, 13, or 14. Conclusion: Sex chromosomes determine thedirection of gonadal and sex differentiation, while the development of the normal gonad and extemal genitalia shouldhave the participation of many autosomal chromosomes as well.

Cellular exposure to muscle relaxants and propofol could lead to genomic instabilityin vitro

Anesthesia is widely used in several medical settings and accepted as safe. However, there is some evidence that anesthetic agents can induce genomic changes leading to neural degeneration or apoptosis. Although chromosomal changes have not been observed in vivo, this is most likely due to DNA repair mechanisms, apoptosis, or cellular senescence. Potential chromosomal alterations after exposure to common anesthetic agents may be relevant in patients with genomic instability syndromes or with aggressive treatment of malignancies. In this study, the P388 murine B cells were cultured in vitro, and spectral karyotyping （SKY） was utilized to uncover genomewide changes. Clinically relevant doses of cisatracurium and propofol increased structural and numerical chromosomal instability. These results may be relevant in patients with underlying chromosomal instability syndromes or concurrently being exposed to chemotherapeutic agents. Future studies may include utilization of stimulated peripheral blood lymphocytes to further confirm the significance of these results.

Chromosomal Alterations in Patients with Alzheimer Disease in Manaus,Amazonas,Brazil

Alzheimer disease(AD)is a complex neurodegenerative pathology that is characterized by a cognitive decline.Its causes and mechanisms are still largely unknown.It has been suggested that both genetic and life exposure factors can contribute to AD development.There are also evidences that chromosomal alterations can be related to this disease.So far,there is not a precise diagnosis for AD,which is given only after the exclusion of other dementia by clinical and neurological examination.The possible association of AD with chromosomal alterations and the easy access of classical cytogenetics analysis are important aspects to consider,given the difficulties in diagnosis.Due to the lack of similar studies in Brazil and the increasing number of AD cases in the state of Amazonas,the aim of this study was to investigate the presence of chromosomal alterations in patients diagnosed with AD in Manaus,Amazonas,Brazil.Peripheral blood lymphocytes of twelve patients and twelve healthy individuals with the same age were analyzed using conventional karyotyping.All AD patients presented cells with autosomal aneuploidy,while no chromosomal alterations were found in the age-matched controls.Also,rare events of double and multiple aneuploidies are being reported in association with AD for the first time.Our results corroborate that the increase in the frequencies of aneuploidies is not related to the aging process itself,but it might be associated to the disease development.However,no chromosomes were preferentially affected in all AD patients,and no consistent karyotype pattern for AD lymphocytes was found.Therefore,our results do not support the use of standard cytogenetics as a tool for AD diagnosis.Future studies are necessary to understand better the association between chromosomal alterations and AD.