Type Of Translocation Research Articles

Effects of a carrier’s sex and age on the segregation patterns of the trivalent of Robertsonian translocations

To investigate the effects of a carrier's sex and age on the segregation patterns of the trivalent of Robertsonian translocations. This retrospective study was designed to analyze the segregation patterns of the trivalent and euploidy rates of blastocysts. Data were collected from 154 couples with Robertsonian translocation (77 with a female carrier and 77 with a male carrier). Embryos were diagnosed via array comparative genomic hybridization between January 2013 and July 2017. The segregation patterns of the trivalent of 604 blastocysts were analyzed according to the carrier's sex and age. The proportion of alternate segregation was significantly higher (82.9% vs. 55.2%) in the male carriers than in the female carriers of Robertsonian translocation, and the proportion of adjacent segregation was significantly lower (16.8% vs. 42.6%), with no difference in 3:0 segregation. The segregation patterns were similar in same-sex carriers when analyzed according to the type of translocation. The carrier's age had no influence on the segregation patterns of the trivalent. The proportions of the trivalent's meiotic segregation pattern differ significantly according to the carrier's sex in Robertsonian translocations and are independent of the carrier's age. A significantly higher proportion of alternate segregation for normal or balanced chromosome contents was observed in the blastocysts of the male carriers than in those of the female carriers.

The application of PGT-A for carriers of balanced structural chromosomal rearrangements

The aim of this study was to analyze differences in chromosomal aberrations and euploidy in embryos of each translocation type and gender of carrier in the case series of 10 couples with balanced translocations who underwent IVF with embryos trophectoderm (TE) biopsy and PGT-A to detect chromosomal aberrations. This is a Case Series (Retrospective study). In each case, controlled ovarian hyperstimulation, oocyte insemination with intracytoplasmic sperm injection (ICSI) and cultivation gave multiple blastocysts, that underwent trophectoderm (TE) biopsy with PGT-A analysis using aCGH and NGS. Number of total unbalanced translocations compared to the number of sporadic aneuploid embryos was 39.6% to 39.6% (50% to 50% of all 37 aneuploid embryos). The highest euploidy rate was in male carrier group – 26.7% and the lowest in the Robertsonian translocation carrier group – 18.2%. Sporadic aneuploidy – 68.2% was highest in Robertsonian translocation carrier group and lowest in female group – 11.1%. Chromosomal aberrations related to translocation were highest in female carrier group – 77.8% and lowest in Robertsonian translocation carrier group – 13.6%. Our study showed that expectancy of total embryo aneuploidy rates will be higher in carriers, than in people with normal karyotype. The prevalence of chromosomal aberrations related to translocation was 4.5 times higher in Reciprocal carrier group than in Robertsonian translocation carrier group. Among maternal and paternal carrier groups, the embryos from female carriers had the lowest euploidy rate, unbalanced translocation rate 4.7 times higher than in the male carrier group and higher total aneuploidy rates.

Direct quantification of the translocation activities of Saccharomyces cerevisiae Pif1 helicase

Saccharomyces cerevisiae Pif1 (ScPif1) is known as an ATP-dependent DNA helicase that plays critical roles in a number of important biological processes such as DNA replication, telomere maintenance and genome stability maintenance. Besides its DNA helicase activity, ScPif1 is also known as a single-stranded DNA (ssDNA) translocase, while how ScPif1 translocates on ssDNA is unclear. Here, by measuring the translocation activity of individual ScPif1 molecules on ssDNA extended by mechanical force, we identified two distinct types of ssDNA translocation. In one type, ScPif1 moves along the ssDNA track with a rate of ∼140 nt/s in 100 μM ATP, whereas in the other type, ScPif1 is immobilized to a fixed location of ssDNA and generates ssDNA loops against force. Between the two, the mobile translocation is the major form at nanomolar ScPif1 concentrations although patrolling becomes more frequent at micromolar concentrations. Together, our results suggest that ScPif1 translocates on extended ssDNA in two distinct modes, primarily in a ‘mobile’ manner.

Diversified Chromosome Rearrangements Detected in a Wheat‒Dasypyrum breviaristatum Substitution Line Induced by Gamma-Ray Irradiation.

To determine the composition of chromosome aberrations in a wheat‒Dasypyrum breviaristatum substitution line with seeds treated by a dose of gamma-rays (200 Gy), sequential non-denaturing fluorescence in situ hybridization (ND-FISH) with multiple oligonucleotide probes was used to screen individual plants of the mutagenized progenies. We identified 122 types of chromosome rearrangements, including centromeric, telomeric, and intercalary chromosome translocations from a total of 772 M1 and 872 M2 plants. The frequency of reciprocal translocations between B- and D-chromosomes was higher than that between A- and D-chromosomes. Eight translocations between D. breviaristatum and wheat chromosomes were also detected. The 13 stable plants with multiple chromosome translocations displayed novel agronomic traits. The newly developed materials will enhance wheat breeding programs through wheat‒Dasypyrum introgression and also facilitate future studies on the genetic and epigenetic effects of translocations in wheat genomics.

Analysis of Chromosomal Damage Caused by Acetamiprid

Abstract Different chemicals can have genotoxic effects on the body, as confirmed by chromosome damage detection. Using conventional cytogenetic analysis and fluorescence in situ hybridization, we tested the extent of chromosome damage caused by the acetamiprid-based insecticide Mospilan 20SP on bovine peripheral blood lymphocytes at concentrations of, 2.5, 5, 25 and 50 µg.ml−1 after a 24 h incubation period. During the experiment, the presence of unstable aberrations—chromosomal and chromatid breaks and gaps—were detected by conventional cyto-genetic analysis. With increasing insecticide concentrations, we observed a statistically significant increase in chromosome damage frequency after 24 hours of exposure. Fluorescence in situ hybridization was used to detect stable structural aberrations; whole-chromosome painting probes for bovine chromosomes 1 and 7 (BTA 1 and BTA 7) were used for this purpose. As a result of exposure to the insecticide, neither BTA 1/BTA 7 translocations nor other types of translocations were observed.

Persistence of rye (Secale cereale L.) chromosome arm 1RS in wheat (Triticum aestivum L.) breeding programs of the Great Plains of North America

Rye (Secale cereale L.) chromosome arm 1RS has been used world-wide by wheat (Triticum aestivum L.) breeding programs as a source of pest- and pathogen-resistance genes, and to improve grain yield and stress tolerance. The most common vehicles used to access 1RS are various 1AL.1RS and 1BL.1RS wheat-rye chromosomal translocations. Over the past 25 years, advanced North American wheat breeding lines were evaluated, first by assay of secalin storage proteins, and later by use of DNA marker TSM0120, for the presence of these two translocations. Both methods provide accurate and efficient means of identifying and differentiating 1BL.1RS and 1A.1RS. Both 1Al.1RS and 1BL.1RS wheats were found in all tested years. 1AL.1RS lines were more common in southern Great Plains breeding programs. 1AL.1RS lines were released as cultivars at a frequency identical to that of wild-type breeding lines. In contrast, 1BL.1RS breeding lines were developed by breeding programs throughout the Great Plains, but fewer were released as cultivars. Both 1RS translocation types persist in Great Plains breeding programs. The lower rate of release of 1BL.1RS cultivars no doubt is a consequence of the more drastic effects on breadmaking quality relative to those observed with 1AL.1RS.

Analysis of chromosomes of embryos derived from translocation carriers during preimplantation genetic diagnosis cycles

To explore the effect of chromosomal translocations on the composition of embryonic chromosomes and its mechanism. For 52 couples with one partner carrying a chromosomal translocation, results of next generation sequencing of all embryos derived from 61 cycles were divided into different groups based on the type of translocations, gender of the carrier, and maternal age. Effect of parental chromosomal translocations on the composition of embryonic chromosomes of each group was analyzed. A significant difference was found between carriers of reciprocal and Robertsonian translocations in terms of proportion of abnormal embryos and structurally normal chromosomes (63.3% vs. 27.5%, and 1.1% vs. 0.3%, respectively). Compared with male carriers, there was an increase in the rate of abnormalities for female carriers (67.2% vs. 58.3% for reciprocal translocations, and 45.5% vs. 13.8% for Robertsonian translocations). The risk for chromosomal abnormality also increased with the maternal age. No significant difference was found in the proportion of abnormal embryos between carriers divided by involvement of acrocentric chromosomes or terminal chromosomal breakpoints. The types of parental translocation, gender of carrier, maternal age, and interchromosomal effect have certain effect on the composition of embryonic chromosomes.

Outcome of Infants Younger Than 1 Year with Acute Lymphoblastic Leukemia Treated with the Interfant-06 Protocol; Results from an International Randomised Study

INTRODUCTIONInfant acute lymphoblastic leukemia is a high-risk subtype characterized by a very high incidence of KMT2A (MLL) gene rearrangements. In 1999, a large international consortium (Interfant) commenced; the first Interfant-99 protocol (Pieters et al, Lancet 2007) was used as baseline for the current Interfant-06 study, which run in 18 groups worldwide.AIMSTo determine:In a randomised study whether two AML-type courses ADE (araC, daunorubicin, etoposide) and MAE (mitoxantrone, araC, etoposide) after induction improved outcome compared to the consolidation IB course in KMT2A-rearranged cases (MR and HR risk group). With a target of 320 randomised cases, the study had 80% power to detect a DFS difference of 16% at 3 years (41% DFS in the control arm, α=0.05).The prognostic relevance of clinical and biological parameters.The outcome of Interfant-06 versus Interfant-99.The role of SCT in HR patients and in MR patients with MRD ≥ 10e-4 at the start of OCTADAD.As Interfant-99 showed outcome differences between the West-European/North-American groups who started Interfant (original countries) versus other countries that joined later, analyses were also performed separately in these groups.RISK GROUPS AND TREATMENTThree risk groups were defined: low risk (LR) - KMT2A germline; high risk (HR) - KMT2A rearrangement plus age < 6 months plus white blood cell count (WBC) >300 x 10e9/L or a poor prednisone response; medium risk (MR) - comprised all other KMT2A-rearranged cases.Treatment consisted of induction (prednisone prephase, dexamethasone, VCR, asparaginase, DNR), consolidation phase, either IB (araC, 6-MP, cyclofosfamide) or ADE/MAE in the experimental arm, MARMA (HD-araC, HD-MTX, 6-MP, asparaginase), OCTADAD (VCR, dexamethasone, asparaginase, DNR, 6-TG, araC, cyclofosfamide) and maintenance (6-MP, MTX) with intrathecal therapy in all courses. All HR patients were allocated to receive allogeneic stem cell transplantation (SCT). After June 2009, SCT was also undertaken in MR cases with MRD ≥ 10 e-4 at start of OCTADAD as the Interfant-99 update showed a very poor outcome for these patients.RESULTS651 infants were included (167 LR, 320 MR, 164 HR). In the original countries, 6-yr EFS (SE) and survival rates were 49.4 (2.5) and 62.1 (2.4) respectively, which were each 6% (not significantly) higher than in Interfant-99 study. In the other countries, the 6-yr EFS and survival rates were 39.0 (3.6) and 49.7 (3.7). The outcome of patients treated in the original countries was significantly better than in other countries due to lower rates of toxic death and resistant disease. The 6-year EFS and survival of all 651 cases were 46.1 (2.1) and 58.2 (2.0) respectively.330/407 eligible cases (81%) were randomised. The 6-yr cumulative incidence (CI) of relapse with ADE/MAE was 47.5 (4.0) which was not significantly (p = 0.11) lower than the 54.9 (4.1) with IB. The 6-yr CI of death in remission was 10.2 (2.4) with ADE/MAE versus 8.3 (2.2) with IB (p = 0.51). This resulted in no significant differences in 6-yr DFS rates of 39.3 (4.0) and 36.8 (3.9) respectively (the 3-yr DFS were 45.3 [3.9] versus 38.6 [3.9]).The 6-yr EFS rate of 164 HR patients was 20.9 (3.4) with the intention to use SCT in all HR patients; 76 of them received SCT as many HR patients had very early events. Out of 23 MR patients with MRD ≥ 10e-4 before OCTADAD, 16 received SCT; 4/23 are in CCR. In total, 14.4% of MR/HR patients receiving SCT died of transplant-related mortality.T(4;11) and t(11;19) translocated cases had a significantly lower EFS than other KMT2A-rearranged cases (p = 0.005). Multivariate analyses identified KMT2A rearrangement, age < 6 months, WBC ≥ 300 x 10e9/L, and poor prednisone response but not CD10, type of MLL translocation and sex as significant predictors of adverse DFS.CONCLUSIONSThe Interfant-06 study is by far the largest study performed in infant ALL. The 6-yr survival in West-European/North-American countries is 62%, which is 12% higher than in other participating countries. Two postinduction AML-type chemotherapy courses versus course IB did not lead to a significant better DFS. 6-yr survival rates are 6% higher than on Interfant-99, which is not a statistically significant improvement. Pilot studies by COG and Interfant are currently exploring the feasibility of adding azacytidine and blinatumomab to the Interfant backbone, which may lead to a worldwide randomised trial with these drugs in infant ALL. DisclosuresLocatelli:Miltenyi: Honoraria; Bellicum: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; bluebird bio: Consultancy; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees. Vora:Jazz: Other: Advisory board; Medac: Other: Advisory board; Pfizer: Other: Advisory board; Amgen: Other: Advisory board; Novartis: Other: Advisory board.

N6-Methyladenosine Modification Regulates Cell Metabolism in Acute Myeloid Leukemia

As the most abundant internal RNA modification in eukaryotes, N6-methyladenosine (m6A) modification has been recently linked to various physiological and pathological processes, including tumorigenesis. m6A marks on mRNAs are mainly deposited by the METTL3/METTL14/WTAP methyltransferase (“writer”) complex and could be removed by “eraser” proteins such as FTO or ALKBH5. We have shown recently that METTL14 (Weng H et al., Cell Stem Cell, 2018) and FTO (Li Z et al., Cancer Cell, 2017) both function as oncogenes in acute myeloid leukemia (AML), which together with the finding that METTL3 is also oncogenic in AML suggest that the m6A machinery plays critical roles in AML pathogenesis.Similar to other epigenetic modifications, the effect of m6A modification relies on effector proteins, the so-called m6A “reader” proteins. We recently identified a new class of m6A reader proteins, the IGF2BP protein family, which stabilize m6A-containing mRNAs and promote their translation through their K Homology (KH) domains (Huang H et al., Nature Cell Biology, 2018). Despite the well-studied oncogenic roles of IGF2BPs in solid cancer, little is known on the functions of IGF2BP proteins in leukemia.By analyzing expression of the IGF2BPs in AML using The Cancer Genome Atlas (TCGA) dataset, we found that one of the three IGF2BP genes, IGF2BP2, is highly expressed in AML compared to the vast majority of other types of cancer. Our qPCR assays also showed a significant elevated expression of IGF2BP2 in mononuclear cells from primary AML patients with various types of chromosome translocation (t(11q23), n=17, P<0.0001; t(15;17), n=5, P=0.0021; t(8;21), n=7, P<0.0001; inv(16), n=6, P<0.0001) compared to those from healthy donors (n=15). Knockdown of IGF2BP2 inhibits Mll-AF9-mediated colony forming in vitro (sh#1 vs. shCtrl, P=0.0113; sh#2 vs. shCtrl, P=0.0136), whereas overexpression of wild-type IGF2BP2 (wt vs. vehicle, P=0.0025), but not the inactive KH3-4-mutated form (mut vs. vehicle, P=0.3178), promotes cell immortalization. In addition, IGF2BP2-promoted cell transforming ability of Mll-AF9 was largely abolished in the absence of Mettl14 in bone marrow cells from Mettl14 conditional knockout mice (IGF2BP2/Ctrl in the presence of Mettl14=1.90±0.15, P=0.0030; IGF2BP2/Ctrl in the absence of Mettl14=1.28±0.10, P=0.0323). Such data indicate that the effect of IGF2BP2 on promoting cell immortalization is m6A dependent. Moreover, depletion of Igf2bp2 delays in vivo leukemogenesis mediated by Mll-AF9 and greatly prolonged the survival of recipient mice (shCtrl, medium survival=81 days, n=7; shIgf2bp2, medium survival>200 days, n=7; P=0.0031).To better understand the molecular mechanism underlying the role of IGF2BP2 in AML, we performed RNA-seq in IGF2BP2 knockdown AML cells or control cells. Integrated analysis of the RNA-seq data with our previously published cross-linking immunoprecipitation (CLIP) data (GSE90639 and GSE21918) reveals that targets of IGF2BP2 are enriched in biosynthesis of amino acids (P=0.0079) and metabolic pathways (P=0.0160). Expression changes of selected target genes, such as MYC, PHGDH, and ASNS, were confirmed by qPCR and immunoblotting in IGF2BP2 knockdown cells, with similar pattern being observed in METTL3 or METTL14 depleted cells. PHGDH encodes the key metabolic enzyme that catalyzes the rate-limiting step of the serine (Ser) biosynthesis pathway, whereas ASNS encodes an enzyme that converts aspartate (Asp) and glutamine (Gln) to asparagine (ASN) and glutamate (Glu). Metabolic profiling reveals that the synthesis of selected amino acids, including Ser, Asn, and Glu, was decreased in IGF2BP2-depleted cells (P=0.0415 for Ser, P=0.0109 for Asn, P=0.0018 for Glu), similar to that in METTL3 (P=0.0433 for Ser, P=0.0155 for Asn, P=0.0005 for Glu) or METTL14 (P=0.0478 for Ser, P=0.0057 for Asn, P=0.0043 for Glu) depleted cells. As expected, shRNA-mediated knockdown of IGF2BP2 in AML cells resulted in a significant inhibition on the glycolytic rate (P=0.0029 for sh#1, P=0.0024 for sh#2) and cell growth (P<0.0001 for both shRNAs from Day 1 to Day 4). Collectively, our data demonstrate a critical role of IGF2BP2 in AML pathogenesis as an m6A reader and provide novel evidence on the involvement of the m6A machinery on regulation of cell metabolism, which may have therapeutic implications for AML. DisclosuresNo relevant conflicts of interest to declare.

The inner mitochondrial membrane protein ANT1 modulates IL-6 expression via the JNK pathway in macrophages.

Mitochondria are increasingly associated with inflammation. Here, we focus on the relationship between inflammation and adenine nucleotide translocator type 1 (ANT1), which is localized in the mitochondrial inner membrane. ANT1 plays an important role in oxidative phosphorylation, and mutations in the ANT1 gene are responsible for mitochondrial diseases. Ample studies have demonstrated that ANT1 has a critical role in cardiomyocytes and neurons, but little has been reported on its functions in immune cells. We knocked down ANT1 expression in macrophages and examined inflammatory cytokine expression after lipopolysaccharide stimulation. ANT1 knockdown reduces the expression of IL-6. JNK, upstream of IL-6, is downregulated, but other MAP kinases and the NF-κB signaling remain unchanged. These results suggest that ANT1 modulates IL-6 expression through JNK in macrophages.

Is sperm FISH analysis still useful for Robertsonian translocations? Meiotic analysis for 23 patients and review of the literature

BackgroundRobertsonian translocations (RobT) are common structural chromosome rearrangements where carriers display a majority of chromosomally balanced spermatozoa from alternate segregation mode. According to some monotony observed in the rates of balanced segregation, is sperm FISH analysis obsolete for RobT carriers?MethodsRetrospective cohort research study on 23 patients analyzed in our center from 2003 to 2017 and compared to the data of 187 patients in literature from 1983 to 2017.Robertsonian translocation carriers were divided in six groups according to the chromosomes involved in the translocation: 9 patients from our center and 107 from literature carrying 45,XY,der(13;14) karyotype, 3 and 35 patients respectively with 45,XY,der(14;21), 5 and 11 patients respectively with 45,XY,der(13;15), 4 and 7 patients respectively with 45,XY,der(14;15), 1 and 4 patients respectively with 45,XY,der(13;22),and 1 and 10 patients respectively with 45,XY,der(14;22).ResultsAlternate segregation mode is predominant in our group of Robertsonian translocation carriers with 73.45% ±8.05 of balanced spermatozoa (min 50.92%; max 89.99%). These results are compliant with the data from literature for all translocations types (p > 0.05) and are consistent among the different types of Robertsonian translocations (p > 0.05) except for der(13;15) that exhibit lower balanced spermatozoa rates (p < 0.05 versus der(13;14), der(14;21), (13;21) and der(15;22)). Normozoospermic patients also display a significantly (p < 0.01) higher rate of balanced sperm cells than patients with abnormal seminograms whatever the defect implied.ConclusionsAccording to the discrepancies observed between der(13;15) and all the other Rob T carriers, the differences observed among patients presenting normal and abnormal sperm parameters and the input in genetical counselling, sperm FISH does not seem obsolete for these patients. Moreover, it seems important to collect more data for rare RobT.

Are different developmental embryo potential and clinical outcome depending on the type of translocation?

Are different developmental embryo potential and clinical outcome depending on the type of translocation?

Examination of Rates and Spectrums of Robertsonian Translocations in the General Population and in Patients with Reproductive Disorders

Robertsonian translocations (rob) are essential in the etiology of congenital malformations and reproductive disorders. However, to date, there has been no systematic comparative analysis of both the frequency and spectrum of rob in different carrier populations. Also, due attention was not paid to the phenomenon of the exceptional rarity of some types of rob. In this paper, the spectrum of rob was determined in the reference group (newborn carriers from the general population and carriers diagnosed prenatally for indications other than family rearrangement) in comparison with groups of carriers with reproductive disorders (infertility and pregnancy loss). The overall rates of rob in the studied groups were calculated as 1.05, 3.3, and 5‰, respectively. It was suggested that homologous translocations do not cause disturbances in spermatogenesis. A rarity of some certain types of translocation could be explained by selection.

Molecular Cytogenetic Characterization of New Wheat-Dasypyrum breviaristatum Introgression Lines for Improving Grain Quality of Wheat.

As an important relative of wheat (Triticum aestivum L), Dasypyrum breviaristatum contains novel high molecular weight glutenin subunits (HMW-GSs) encoded by Glu-1Vb genes. We identified new wheat—D. breviaristatum chromosome introgression lines including chromosomes 1Vb and 1VbL.5VbL by fluorescence in situ hybridization (FISH) combined with molecular markers. We found that chromosome changes occurred in the wheat—D. breviaristatum introgression lines and particularly induced the deletion of 5BS terminal repeats and formation of a new type of 5B-7B reciprocal translocation. The results imply that the D. breviaristatum chromosome 1Vb may contain genes which induce chromosomal recombination in wheat background. Ten putative high molecular weight glutenin subunit (HMW-GS) genes from D. breviaristatum and wheat—D. breviaristatum introgression lines were isolated. The lengths of the HMW-GS genes in Dasypyrum were significantly shorter than typical HMW-GS of common wheat. A new y-type HMW-GS gene, named Glu-Vb1y, was characterized in wheat—D. breviaristatum 1Vb introgression lines. The new wheat—D. breviaristatum germplasm displayed reduced plant height, increased tillers and superior grain protein and gluten contents, improved gluten performance index. The results showed considerable potential for utilization of D. breviaristatum chromosome 1Vb segments in future wheat improvement.

Patterns of care and impact of prognostic factors in the outcome of NUT midline carcinoma: a systematic review and individual patient data analysis of 119 cases.

NUT midline carcinoma is a rare tumour occurring in young adults which is frequently misdiagnosed as poorly differentiated squamous cell carcinoma or germ cell tumour. Though considered highly aggressive, there is limited information about the clinical behaviour of such patients. We intended to perform this review of published literature to assess the demographic profile, pattern of care and assess survival outcomes. Two authors independently searched PubMed and Google search for eligible studies from 1950 till July 1 2017 published in English language using MESH terms NUT midline carcinoma; NUT midline carcinoma and radiotherapy and translocation 15:19 tumour. Data of 119 patients were retrieved from 64 publications for statistical analysis. Median age of the entire cohort was 23years (range 0-68years). The analysis revealed equal incidence in males and females (60:58). The present analysis revealed that the most common location is the lung (n = 42) followed by head and neck (n = 40). Median OS for the entire cohort was only 5months with 1 and 5year OS for the entire cohort was 24.99 and 7.09% respectively. Radiotherapy and chemotherapy inclusion in primary treatment had a significant impact on overall survival on univariate analysis while surgery did not affect survival significantly. No impact on overall survival was found based on type of molecular translocation, i.e., NUT-BRD4, NUT-BRD3 or other variants. Inadequate data were available for identify impact of BET inhibitors and HiDAc on PFS and OS. NUT midline carcinoma has dismal prognosis. Radiotherapy and chemotherapy improves survival, but do not provide long term control except in anecdotal cases. Further research is needed to improve outcomes in future.

Inducement and identification of chromosome introgression and translocation of Gossypium australe on Gossypium hirsutum

BackgroundWe previously reported the development of a set of Gossypium hirsutum-G. australe alien chromosome addition lines. Naturally, however, G. hirsutum-G. australe chromosome exchanges were very limited, impeding the stable transference of useful genes from G. australe (G2G2 genome) into the most cultivated cotton, G. hirsutum (AADD).ResultsIn the present report, the pollen from a pentaploid (2n = AADDG2) of G. hirsutum-G. australe was irradiated with seven different doses ranging from 10 to 40 Grays and used to pollinate emasculated flowers of G. hirsutum over three consecutive years. Irradiation greatly increased the genetic recombination rates of the G. hirsutum and G. australe chromosomes and a total of 107 chromosome introgression individuals in 192 GISH-negative (with no GISH signal on chromosome) survived individuals, 11 chromosome translocation individuals (containing 12 chromosome translocation events) and 67 chromosome addition individuals were obtained in 70 GISH-positive (with GISH signal(s) on chromosome(s)) survived individuals, which are invaluable for mining desirable genes from G. australe. Multicolor genomic in situ hybridization results showed that there were three types of translocation, whole arm translocation, large alien segment translocation and small alien segment translocation, and that all translocations occurred between the G2-genome and the A-subgenome chromosomes in G. hirsutum. We also found that higher doses induced much higher rates of chromosome variation but also greatly lowered the seed viability and seedling survivability.ConclusionsIrradiation has been successfully employed to induce chromosome introgressions and chromosome translocations and promote chromosome exchanges between cultivated and wild species. In addition, by balancing the rates of chromosome introgression and translocation to those of seed set, seed germination, and seedling rates in the M1 generation, we conclude that the dosage of 20 Grays is the most suitable. The established methodology may guide the utilization of the tertiary gene pool of Gossypium species such as G. australe in cotton breeding in the future.

Translocation of the upper soil layer in multiple operations of seedbed preparation

Translocation of tracers incorporated into the upper layer of topsoil was evaluated in the course of seedbed preparation for winter wheat. Aluminium cubes with the edge length of 16 mm were used as tracers that were placed into the soil before its tillage into furrows perpendicular to the direction of passes. After the passes of the OPALL-AGRI combined cultivator, the tracers were searched and marked using a metal detector. The translocation of tracers was evaluated during multiple passes on flatland and on the slope. During the seedbed preparation on the slope, downslope and upslope passes in a fall line direction were chosen. Results of the tracers movement measuring that simulate the soil particle translocation indicate a pronounced movement of the upper layer of topsoil during multiple downslope passes of the combined cultivator. A significant translocation was also observed after passes on flatland. A significantly smaller lengthwise translocation of tracers was found out at upslope passes. The type of translocation on flatland and upslope was quite similar, on the other hand, downslope movement was much larger. The upslope passes were found to have a very limited function with regard to the correction of the undesirable downslope movement of soil particles that occurs in the course of tillage.

Familial 1p36.3 microduplication resulting from a 1p-9q non-reciprocal translocation

Unlike the 1p36 microdeletion syndrome, which has been extensively described, 1p36 microduplications have rarely been reported. We describe a three years old boy presenting with a severe global developmental delay and a few dysmorphic features. Cytogenetic analyses revealed a maternally inherited 3.35 Mb microduplication of chromosomal band 1p36.3. The maternal grandfather is also carrier of the same chromosomal rearrangement.Interestingly, the duplicated 1p36.3 segment was found to be localized at the telomeric end of the long arms of a chromosome 9, probably deriving from a 1p36.3-9qter non-reciprocal translocation. This particular type of chromosomal translocation has rarely been reported, and its mechanism is unclear. The phenotypical features associated with 1p36.3 microduplication vary due to the non-recurrent breakpoints of the rearrangements in this particular region. However when compiling the few described cases the phenotypical spectrum seems to include mainly developmental delay, mild facial dysmorphism, and neurological, cardiac and skeletal anomalies. The description of new patients carrying a 1p36.3 duplication like ours will lead to further delineation of the phenotypical spectrum and may help to find critical regions and causative genes implicated in the phenotype.

Key steps in unconventional secretion of fibroblast growth factor 2 reconstituted with purified components.

FGF2 is secreted from cells by an unconventional secretory pathway. This process is mediated by direct translocation across the plasma membrane. Here, we define the minimal molecular machinery required for FGF2 membrane translocation in a fully reconstituted inside-out vesicle system. FGF2 membrane translocation is thermodynamically driven by PI(4,5)P2-induced membrane insertion of FGF2 oligomers. The latter serve as dynamic translocation intermediates of FGF2 with a subunit number in the range of 8-12 FGF2 molecules. Vectorial translocation of FGF2 across the membrane is governed by sequential and mutually exclusive interactions with PI(4,5)P2 and heparan sulfates on opposing sides of the membrane. Based on atomistic molecular dynamics simulations, we propose a mechanism that drives PI(4,5)P2 dependent oligomerization of FGF2. Our combined findings establish a novel type of self-sustained protein translocation across membranes revealing the molecular basis of the unconventional secretory pathway of FGF2.

Histology and grading are important prognostic factors in synovial sarcoma

IntroductionThe diagnosis of synovial sarcoma (SS) is currently based on clinical, morphological, immunohistochemical and cytogenetic data. Some of these factors such as grade and histology, specific translocations (SS18-SSX1 vs. SS18-SSX2) and the reduced expression of INI1, were proposed as prognostic variables. The aim of this study was to verify whether histological (grading and histology) and molecular (type of SSX translocation and INI1 expression) characteristics of SS influence the prognosis of the disease. Material and methodsWe retrospectively evaluated 196 patients affected by SS of the extremities treated at our Institution (Istituto Ortopedico Rizzoli, Bologna, Italy). All cases were histologically revised and tumor grade was assessed according to the FNLCC system. Tissue specimens were retrospectively evaluated to check for SS18-SSX fusion type and INI1 expression. ResultsMost SS were monophasic, 28% were biphasic. Eighty tumors (41%) were grade 3. Sixty percent harbored SSX1 translocation, 40% SSX2; 51% maintained the expression of INI1. Sarcoma specific survival (OS) was 56.6% at 5 years and 46.9% at 10 years. Prognosis was worse in those patients monophasic SS (p = 0.011) as in those with a grade 3 tumors (p = 0.083). No correlation was found neither between SSX fusion type nor INI1 expression and survival. LR-free survival was 78.9% at 5 years and 75.9% at 10 years. A higher LR rate was observed in tumors with SSX2 translocation and (p = 0.049) in grade 3 SS (0 = 0.028). DiscussionOur data confirm that not all cases of SS present the same severe outcome. High-risk patients identified on the basis of these parameters may qualify for an aggressive treatment approach.