Three New Ranidae Mitogenomes and the Evolution of Mitochondrial Gene Rearrangements among Ranidae Species

Various types of gene rearrangements have been discovered in the mitogenoes of the frog family Ranidae. In this study, we determined the complete mitogenome sequence of three Rana frogs. By combining the available mitogenomic data sets from GenBank, we evaluated the phylogenetic relationships of Ranidae at the mitogenome level and analyzed mitogenome rearrangement cases within Ranidae. The three frogs shared an identical mitogenome organization that was extremely similar to the typical Neobatrachian-type arrangement. Except for the genus Babina, the monophyly of each genus was well supported. The genus Amnirana occupied the most basal position among the Ranidae. The [Lithobates ＋ Rana] was the closest sister group of Odorrana. The diversity of mitochondrial gene arrangements in ranid species was unexpectedly high, with 47 mitogenomes from 40 ranids being classified into 10 different gene rearrangement types. Some taxa owned their unique gene rearrangement characteristics, which had significant implication for their phylogeny analysis. All rearrangement events discovered in the Ranidae mitogenomes can be explained by the duplication and random loss model.

Bcl-2 GENE REARRANGEMENT DETERMINED BY PCR AS AMEAN TO DETECT MINIMAL RESIDUAL DISEASE INMALIGNANT LYMPHOMAS

Objective: To develop a sensitive method to detect minimal residual disease and to elucidate the significance of bcl-2 gene rearrangement in diagnosis and treatment of malignant lymphoma. Methods: Using polymerase chain reaction (PCR) to detect bcl-2 gene rearrangement and using serial dilution method to define the sensitivity of PCR. Results: In 9 different malignant lymphoma cell lines, Su-DHL-4 and Su-DHL-6 were shown bcl-2(MBR)/JH rearrangement, the sensitivity of PCR was 1:105. In 16 patients with follicular lymphoma, the peripheral blood and bone marrow were PCR positive in 4 cases both at initial diagnosis and after complete remission. Conclusion: Detection of bcl-2 gene rearrangement by PCR provides a sensitive and specific assay of minimal residual disease. It is helpful to improve staging of disease, prognosis and evaluation of the treatment results.

Clonal immunoglobulin heavy chain and T-cell receptor γ gene rearrangements in primary gastric lymphoma

AIM:To study the diagnostic value of immunoglobulin heavy chain(IgH)and T-cell receptorγ (TCR-γ)gene monoclonal rearrangements in primary gastric lymphoma(PGL).METHODS:A total of 48 patients with suspected PGL at our hospital were prospectively enrolled in this study from January 2009 to December 2011.The patients were divided into three groups(a PGL group,a gastric linitis plastica group,and a benign gastric ulcer group)based on the pathological results(gastric mucosal specimens obtained by endoscopy or surgery)and follow-up.Endoscopic ultrasonography(EUS)and EUSguided biopsy were performed in all the patients.The tissue specimens were used for histopathological examination and for IgH and TCR-γ gene rearrangement polymerase chain reaction analyses.RESULTS:EUS and EUS-guided biopsy were successfully performed in all 48 patients.In the PGL group(n=21),monoclonal IgH gene rearrangements were detected in 14(66.7%)patients.A positive result for each set of primers was found in 12(57.1%),8(38.1%),and 4(19.0%)cases using FR1/JH,FR2/JH,and FR3/JH primers,respectively.Overall,12(75%)patients with mucosal-associated lymphoid tissue lymphoma(n=16)and 2(40%)patients with diffuse large B-cell lymphoma(n=5)were positive for monoclonal IgH gene rearrangements.No patients in the gastric linitis plastica group(n=17)and only one(10%)patient in the benign gastric ulcer group(n=10)were positive for a monoclonal IgH gene rearrangement.No TCRgene monoclonal rearrangements were detected.The sensitivity of monoclonal IgH gene rearrangements was 66.7%for a PGL diagnosis,and the specificity was96.4%.In the PGL group,8(100%)patients with stage IIE PGL(n=8)and 6(46.1%)patients with stage IE PGL(n=13)were positive for monoclonal IgH gene rearrangements.CONCLUSION:IgH gene rearrangements may be associated with PGL staging and may be useful for the diagnosis of PGL and for differentiating between PGL and gastric linitis plastica.

Gene Rearrangement Analysis of Orbital Lymphoid Infiltrating Disorders

Purpose:To determine whether the use of polymerase chain reaction for B-cell gene rearrangement in patients with orbital lymphoid infiltrate disorders could be useful in the diagnosis of lymphoma,especially,in differentiating benign lesion from malignant one.Methods:In addition to clinical,pathological,and immunohistochemical evaluations,48 cases of orbital lymphoid infiltrate disorders were examined for immunoglobulin heavy(IgH)gene rearrangement by means of PCRto amplify the FR3region with formalin-fixed and paraffin-embedded tissues.Results:Gene rearrangement in the third frame-work of the IgH region was detected in specimens obtained from15cases of malignant lymphoma,4of reactive lymphoid hyperplasia and3of orbital pseudotumor.All of these patients showed a discrete band(100bp)which reflected monoclonal proliferation of B lymphocytes.5cases of malignant lymphoma,6ofreactive lymphoid hyperplasia and 15of orbital pseudotumor did not show a discrete band on PCR.Conclusions:The FR3 region gene rearrangement of Ig heavy in patients with orbital lymphoid infiltrate disorders may be an additional diagnostic tool in differentiating benign from malignant lymphoid diseases and in offering a useful adjunct for diagnosis in difficult or unclear cases.It is a reliable and practical method of gene diagnosis in orbital lymphoid infiltrate disorders and helps to identify the molecular mechanism of malignant lymhoma.Eye Science2000;16:15-21.

Detection of IgH and T-cell receptor gene rearrangement in leukemia by PCR amplification and its clinical application

PCR amplification was used to detect immunoglobulin heavy chain (IgH), T-cell receptor (TCR)Vγ1-Jγ, Vδ2-Dδ 3 rearranged genes in 45 cases of acute lymphoblastic leukemia (ALL) and IgH gene rearrangement in 41 cases acute nonlymphoblastic leukemia (ANLL). The positive percentage of the IgH, TCR Vγ1-Jγ and Vδ 2-Dδ3 gene rearrangement was found to be 66. 7%, 62.2%, and 35. 6%, respectively in 45 ALL patients. Multiple rearranged IgH gene bands were found in 8 (26. 7% ) out of 30 ALL patients with IgH gene rearrangement. IgH gene rearrangemens were found in 7 (17. 1% ) out of 41 ANLL patients. ALL patients with positive IgH rearranged gene were with B cell and those with positive TCR Vγ1-Jγ gene rearrangements and with negative IgH rearranged gene were with T-ALL,those with positive both IgH and TCR Vδ2-Dδ3 rearranged genes mostly were with preB-ALL. The complete remission (CR) rate was low in ALL patients with multiple rearranged heavy chains and ANLL patients with IgH gene rearrangement, who were more likely to have a clinical relapse, which may be due to clonal evolution. In complete remission (CR) patients, the cytologic relapse fell behind postive PCR results for an average periods of 7. 2 weeks (range 2 to 23 weeks). Using PCR to detect rearranged genes could be helpful in determining the efficacy of chemotherapy, predicting clinical relapse, assisting gene typing and predicting prognosis.

Progress in clinical diagnosis and treatment of colorectal cancer with rare genetic variants

Targeted therapy is crucial for advanced colorectal cancer(CRC) positive for genetic drivers. With advances in deep sequencing technology and new targeted drugs, existing standard molecular pathological detection systems and therapeutic strategies can no longer meet the requirements for careful management of patients with advanced CRC. Thus, rare genetic variations require diagnosis and targeted therapy in clinical practice. Rare gene mutations, amplifications, and rearrangements are usually associated with poor prognosis and poor response to conventional therapy. This review summarizes the clinical diagnosis and treatment of rare genetic variations, in genes including erb-b2 receptor tyrosine kinase 2(ERBB2), B-Raf proto-oncogene, serine/threonine kinase(BRAF), ALK receptor tyrosine kinase/ROS proto-oncogene 1, receptor tyrosine kinase(ALK/ROS1), neurotrophic receptor tyrosine kinases(NTRKs), ret proto-oncogene(RET), fibroblast growth factor receptor 2(FGFR2), and epidermal growth factor receptor(EGFR), to enhance understanding and identify more accurate personalized treatments for patients with rare genetic variations.

Epidemiological Surveillance: Genetic Diversity of Rotavirus Group A in the Pearl River Delta, Guangdong, China in 2019

Objective This study aimed to understand the epidemic status and phylogenetic relationships of rotavirus group A(RVA)in the Pearl River Delta region of Guangdong Province,China.Methods This study included individuals aged 28 days–85 years.A total of 706 stool samples from patients with acute gastroenteritis collected between January 2019 and January 2020 were analyzed for 17 causative pathogens,including RVA,using a Gastrointestinal Pathogen Panel,followed by genotyping,virus isolation,and complete sequencing to assess the genetic diversity of RVA.Results The overall RVA infection rate was 14.59%(103/706),with an irregular epidemiological pattern.The proportion of co-infection with RVA and other pathogens was 39.81%(41/103).Acute gastroenteritis is highly prevalent in young children aged 0–1 year,and RVA is the key pathogen circulating in patients 6–10 months of age with diarrhea.G9P[8](58.25%,60/103)was found to be the predominant genotype in the RVA strains,and the 41 RVA-positive strains that were successfully sequenced belonged to three different RVA genotypes in the phylogenetic analysis.Recombination analysis showed that gene reassortment events,selection pressure,codon usage bias,gene polymorphism,and post-translational modifications(PTMs)occurred in the G9P[8]and G3P[8]strains.Conclusion This study provides molecular evidence of RVA prevalence in the Pearl River Delta region of China,further enriching the existing information on its genetics and evolutionary characteristics and suggesting the emergence of genetic diversity.Strengthening the surveillance of genotypic changes and gene reassortment in RVA strains is essential for further research and a better understanding of strain variations for further vaccine development.

Mitochondrial gene rearrangement within genus Gasteruption(Hymenoptera: Evanioidea: Gasteruptiidae)

The complete mitochondrial genome of the Gasteruption parvicollarium Enderlein （GenBank accession number： KR270643） was sequenced in the study. Totally 17 009 bp sequence was determined with an A＋T content of 83.81%, including full set of typical animal mitochondrial genes. Two protein-coding and 10 tRNA genes as well as the A＋T-rich region were rearranged compared with the putative ancestral arrangement of insects. Most of the rearranged genes were located in the ancestral region of trnl-trnQ-trnM-nad2-trn W-trnC-trn Y- coxl-trnL2. The other rearranged genes are trnN and trnS1 located in the tRNA cluster trnA- trnR-trnN-trnSl-trnE-trnF and trnS2 located between cob and nadl. Remote inversion is dominant rearrangement event in G. parvicollarium mitochondrial genome, involving two protein-coding and 8 tRNA genes. Compared with the other mitochondrial genome reported in the same genus of Gasteruption, the inverted trnN was translocated to the tRNA cluster between cox1 and nad2 in G. parvicollarium. This is the first report of mitochondrial gene rearrangement occurred within genus of Hymenoptera. Our study points to a recently occurred gene rearrangement event in the Gasteruption species.

THE RELATIONSHIP BETWEEN NON-HODGKIN'S LYMPHOMA AND THE GENE REARRANGEMENT

Objective: To investigate the pattern of clonal rearrangement of immunoglobulin heavy chain gene (IGH) and T cell receptor γ gene (TCRγ) of Non Hodgkin's lymphoma (NHL) Methods: Bone marrow smears of 211 patients of NHL were detected by PCR, the rearranged IGH and TCRγ gene was amplified using oligonucleotide primers Results: The clonal rearrangement of IGH gene was detectable in 51 2% (108/211); the clonal rearrangement of TCRγ gene was detectable in 21 3% (45/211); both IGH and TCRγ was detectable in 5 7% (12/211); no clonal rearrangement in 21 8% (46/211) And compared clonal gene rearrangement with pathological type and primary site of tumor Ten patients of NHL were investigated serially 5/10 patients still had clonal gene rearrangement at clinical complete remission Conclusion: It demonstrated that this assay may be useful in monitoring the minimal residual disease (MRD) and in evaluating effectiveness of therapy

T-CELL RECEPTOR GENE REARRANGEMENT ANALYSIS IN THE PRIMARY CUTANEOUS T-CELL LYMPHOMA

Object: The present paper is to evaluate the significance of T cell receptor (TCR) gene rearrange ments in primary cutaneous T cell lymphomas (PCTCL) as detected by analysis of Southern Blot (SBA) and polymerase chain reaction (PCR). Patients and Methods: Skin specimens and peripheral blood samples were taken from 44 patients with PCTCL, including 30 patients with mycosis fungoides (MF), 2 patients with Sezary's syndrome (SS), and 12 patients with PCTCL other than MF and SS (PNCTCL). 11 patients with a presumptive diagnosis of MF, 23 patients with lymphoproliferative dermatoses including lymphomatoid papulosis (LyP) and 8 patients with benign cutaneous lymphoid infiltrates were simultaneously studied by the amplification of junctional V (variable) J (joining) sequences of the rearranged TCRγ genes by PCR(TCRγPCR) and the analysis of TCRb chain genes by SBA(TCRβSBA) for detection of clonal gene rearrangements (GR). One lymph node specimen of a case with MF IIA was also detected by TCRγ PCR and TCRβSBA. Results: In MF, GR were detected by TCRγPCR and TCRβSBAb in 83.3 85.7% and 66.7% 71.4% of skin specimens of cases IIA IIB and in 57.1% 70.0% and 14.3% 10.0% of those of cases IA IB, respectively. GR were seen in 66.7% 71.4% and 33.3% 43.0.% of blood samples of cases IIA IIB, and 42.9% 40.0% and 0 10.0% of those of cases IA IB, respectively. GR was confirmed by TCRγ PCR and TCRβSBA in one lymph node showing dermato pathic lymphadenopathy of a case with MF IIA. In 11 patients of clinically suspected MF, GR were present in skin specimens of 5 cases (45.4%) and in blood samples of 3 cases ( 27.3% ) by TCRγ PCR. In PNCTCL, GR were found in 9 skin specimens (90.0%) from 10 patients detected by TCRγ PCR and in 6 skin specimens (75.0%) from 8 patients detected by TCRβSBA. GR were also seen in 6 blood samples (72.8%) from 11 patients detected by TCRγ PCR, and in 7 blood samples (70.0%) from 10 patients by TCRβSBA. In SS and LyP, GR were detected by TCRγ PCR and TCRβSBA in each of the two skin specimens of two cases with LyP and in each of the two blood samples of two cases with SS. GR were seen in one skin specimen of one case with SS and one blood sample of one case with LyP detected by TCRγPCR. Conclusions: This study demonstrated that TCRγ PCR is a rapid, more sensitive tool than TCRβSBA, can be used in the analysis of T cell clonality in skin, lymph node and blood samples of patients with PCTCL and indicated that this method forms a useful supplement to other methods for diagnosis of early and suspected MF, confirmation of PNCTCL and determination of extracutaneous involvement of lymph node and blood.

γANDδCHAIN GENE REARRANGEMENT OF T CELL RECEPTOR IN ACUTE LYMPHOBLASTIC LEUKEMIA

The immunophenotype, rearrangements of T cell receptor(TCR) γ andδchain genes as well as the immunoglobulinheavy chain (IgH)gene were studied in 37 cases ofmorphologically defined acute lymphoblastic leukemia (ALL).According to the expression of differentiation antigens, 8 caseswere classified as T-ALL, 26 B lineage ALL, 2 acute un-differentiated leukemia (AUL) and myeloid phenotype. An or-der of TCR gene rearrangements was observed in T-ALL,with the rearrangement of δgene preceding that of γgene.Both genes were also found frequently rearranged and / or de-leted in high proportions of the ALL of B cell lineage. Howev-er, the patterns of gene rearrangements were somewhat differ-ent between the T and B lineage ALLs. In contrast, the lgHgene rearrangements were observed only in the B lineage ALL.The immunogenotype analysis of ALL proved to be a usefulmarker of the clonality and provided us with important informa-tion on early human lymphoid differentiation. We concludethat the determination of T

Detection of Immunoglobulin Heavy China and T Cell Receptorγ Gene Rearrangement in Lymph Node Aspirates with PCR:Diagnostic Significance for Lymphoproliferative Disorders

Lymph node aspirates of 17 cases with enlarged superficial or isceral lymph nodes were detected for immunoglobulin heavy chain gene rearrangement (IgHRA) and T cell rcceptor γ gene rearrangement (TCRγRA) bypolymerase chain reaction (PCR). Combining with clinical data, pathologic diagnosis and immunophenotapy, we analyse the results as follows: 5 cases with nonlymphoid cancers and 3 cases with reactive lymphadenopathy do not present two kinds of clone gene rearrangements.5 out of 7 cases with NHL show clone gene rearrangements (IgH 3 cases, TCRY 2cases),two kinds of monoclonal band(100-120bp for IgHRA and 170-230bp for TCRγRA) were observed after electrophoresis of amplified DNA products. One case whose clinical sitcaion accorded with features of lymphoma was diagnosed as granulomatous lymphadenitis by pathologist, after gene rearaangement clone TCRγRA was detected,a correct diaguosis as NHL was made then. The significance of detecting the two kinds of gene rearrangement for clinical application and the limitations in diagnosis of lymphoproliferative disorders was discussed.

REARRANGEMENT AND EXPRESSION OF T CELL RECEPTOR β GENE IN HUMAN HEMOPOIETIC CELL LINES AND PRIMARY CELLS FROM ACUTE LYMPHOCYTIC LEUKEMIAS

Using Southern blot, Northern blot and Quick blot methods, we examined the rearrangement and expression of TCR βgene in four early differentiation stage cell lines from human hemopoietic system, namely HL-60, Jurkat, Daudi and Raji cells as well as lymphocytes from 17 acute lymphocytic leukemia （ALL） patients. The results showed. Ⅰ) Rearrangement of TCR βgene was seen in Jurkat cells. A germline pattern was observed in HL-60, Daudi and Raji cells. 2) Eight of 9 patients with T-ALL had cells with rearranged TCR βgene. But two of 3 patients with B-ALL and three of 5 patients with nonT, nonB-ALL also had cells with rearranged TCR βgene. 3) A 1.3 kb full-length transcript and a 1.0 kb truncated transcript were detected in Jurkat cells by probing with 32P-TCR βcDNA. But some leukemic B cells also expressed an incompleted transcript. 4) TCR βmRNA was detected in six of 8 patients with T-ALL, four of 5 patients with nonT, nonB-ALL and one of 3 patients with B-ALL. But the level of expression was quite differ ent. The dual-rearrangement and the abnormal expression may give us a new clue for researching leukemogenesis.

Diagnostic significance of TCR gene clonal rearrangement analysis in early mycosis fungoides

Mycosis fungoides(MF),the most common type of cutaneous T-cell lymphoma,has various unspecific clinical and histological characteristics.Its early diagnosis is challenging.The application of T-cell receptor(TCR) gene clonal rearrangement to the diagnosis of MF has been widely studied.In this study,we used polymerase chain reaction(PCR) to investigate the diagnostic significance of detecting TCR-γ and-β gene clonal rearrangement in the early diagnosis of mycosis fungoides.PCR for TCR-γ and TCR-β gene rearrangement was performed on 19 patients with suspected early MF,6 with typical MF,and 6 with chronic dermatitis.Of the 19 patients with suspected early MF,13 had TCR-γ gene clonal rearrangement,whereas none had TCR-β gene clonal rearrangement.All patients with typical MF had TCR gene clonal rearrangement,in which 4 showed TCR-γ clonal rearrangement,1 showed TCR-β gene clonal rearrangements,and 1 showed both.No patients with chronic dermatitis had TCR gene clonal rearrangement.These results indicate that TCR gene clonal rearrangement analysis is a useful tool in diagnosing early MF.TCR-γ gene is recommended to the routine analysis,whereas TCR-β gene has potential in combination toward intractable cases.

IMMUNOGLOBULIN GENE REARRANGEMENT IN LYMPHOID TUMORS

Ⅰ. INTRODUCTIONThere are immunoglobulins (Ig) and T cell receptors (TCR) on the surfaces of lymphocytes, which are able to transfer external messages. All the Ig and TCR genes originated in immunoglobulin gene superfamily, and some functive genes have been translated

STUDY ON THE RFLPs AND AMPLICATION AND REARRANGEMENT OF THE TRANSFORMING GENES IN PRIMARY HEPATIC CARCINOMA, GASTRIC CARCINOMA AND BRAIN TUMOR WITH SIX HUMAN ONCOGENE PROBES

By using c-Ha-ras-1, N-ras Wigler (left sequence) and P52C.(right sequence), c-sis, v-erbB, c-myc and v-fos oncogenes as probes, restriction fragment length polymorphisms (RFLPs) of tumor tissue DNAs of 95 patients with gastric carcinoma, primary hepatic carcinoma and brain tumor, and those of 90 normal individuals were studied with the techniques of Southern blot and dot blot. Gene amplification and recombination were also examined in some tumors simultaneously. Some alleles of oncogene are reported in Chinese population for the first time. Moreover, the characteristic frequency of some "rare" alleles and genotypes occurred in some tumor samples is significantly higher than that occured in normal individuals. Pedigree analysis for 2 patients showed that some "rare" alleles are also abandant. Besides, gene amplification and recombination were found in some tumors.

BCL-1 Rearrangement in Acute Lymphocytic Leukemia and Its Clinical Significance

BCL 1 rearrangement (BCL 1/IgH gene rearrangement) in acute lymphocytic leukemia and its clinical significance was investigated. In 38 patients with acute lymphocytic leukemia (ALL), the genomic DNA of mononuclear cells isolated from peripheral blood and bone marrow was amplified by using hemi nested polymerase chain reaction (PCR) technique and the expression of cycline D1 protein of mononuclear cells was detected by using immunohistochemical method. Ten patients with acute granulocytic leukemia, 2 with chronic granulocytic leukemia and 10 with normal bone marrow served as control group. The results showed that BCL 1 rearrangement was detectable in 3 of 38 ALL patients (7.9 %) and cyclin D1 protein positive expression was detected in 4 ALL patients (10 5 %). Three ALL patients with BCL 1 rearrangement were all B cell leukemia (B ALL) and accompanied by cyclin D1 protein expression. No BCL 1/IgH rearrangement or cyclin D1 protein expression was detected in 12 patients with granulocytic leukemia and 10 cases of normal bone marrow. Leukocyte counts in peripheral blood of B ALL patients with BCL 1 rearrangement and(or) cyclin D1 protein expression were significantly increased and the patients had bad reaction to chemotherapy. It was concluded that: 1) BCL 1/IgH gene rearrangement were detected in acute B lymphocytic leukemia; 2) B ALL patients with BCL 1 rearrangement and(or) cyclin D1 protein expression had poor prognosis.

Two complete mitogenomes of Ocypodoidea(Decapoda: Brachyura), Cleistostoma dilatatum(Camptandriidae) and Euplax sp.(Macrophthalmidae) and its phylogenetic implications

Complete mitochondrial genomes(mitogenomes) can provide useful information for phylogenetic relationships,gene rearrangement, and molecular evolution. In the present study, two newly sequenced mitogenomes of Ocypodoidea(Cleistostoma dilatatum and Euplax sp.) were reported for the first time, which are 15 444 bp and16 129 bp in length, respectively. Cleistostoma dilatatum is the first species in the family Camptandriidae whose complete mitogenome was sequenced. Each mitogenome contains an entire set of 37 genes and a putative control region, but their gene arrangements are largely different. Tandem duplication and random loss model is proposed to account for their gene arrangements. Comparative genomic analyses of 19 mitogenomes clustering in one branch reveal that 18 of them shared the same gene rearrangement, while that of C. dilatatum mitogenome was consistent with the ancestral gene arrangement of Brachyura. The dN/dS ratio analysis shows that all PCGs are evolving under purifying selection. Phylogenetic analyses show that all Macrophalmidae species cluster together as a group, and then form a sister clade with Camptandriidae. Moreover, the polyphyly of three superfamilies(Ocypodoidea, Eriphioidea, and Grapsoidea) is reconfirmed. These findings help to confirm the phylogenetic position of Camptandriidae, as well as provide new insights into the phylogeny of Brachyura.

Comparative mitochondrial genome analysis of Cynoglossidae(Teleost:Pleuronectiformes)and phylogenetic implications

Generally,a teleostean group(e.g.,family or genus)owns one type or a set of similar mitochondrial gene arrangement.It is interesting,however,that four different types of gene arrangement have been found in the mitochondrial genome(mitogenome)of Cynoglossidae species.So far,the possible mechanisms of mitogenomic gene rearrangement and its potential implications have aroused widespread attention and caused lots of controversy.Here,a total of 21 Cynoglossidae mitogenomes and a newly sequenced mitogenome of Cynoglossus puncticpes(Pleuronectiformes:Cynoglossidae)were compared.The length ranges from 16417 bp to 18369 bp,which is mainly caused by the length heteroplasmy of control region(CR).Further analysis reveals that the difference of tandem repeats acts as a determining factor resulting in the length heterogeneity.Like most gene rearrangements of Cynoglossinae mitogenomes,tRNA-Gln gene encoded by the L-strand has translocated to the H-strand(Q inversion),accompanied by the translocation of CR in C.puncticpes mitogenome.The typical IQM order(tRNA-Ile-Gln-Met)changed to QIM order.Tandem duplication/random loss and mitochondrial recombination were accepted as the most possible models to account for the rearrangements in C.puncticpes mitogenome.Phylogenetic trees showed a strong correlation between the gap spacer in the rearranged QIM area and phylogeny,which provides a fresh idea for phylogenetic studies in future.

Detection of BCL2-IGHrearrangement on paraffin-embedded tissue sections obtained from a small submucosal tumor of the rectum in a patient with recurrent follicular lymphoma

A 59-year-old woman was admitted to our hospital because of recurrent follicular lymphorna (FL). Colonoscopic examination revealed a rectal submucosal tumor (SMT) without any erosions and ulcers. In this patient, it was difficult to distinguish non-Hodgkin's lymphoma (NHL) invasion from other disorders of the colon including carcinoid tumor merely based on endoscopic findings. Histopathologic and immunohistochemical studies on biopsy specimens showed an infiltration of atypical lymphocytes that were positive for CD20 and BCL2 but negative for UCHL-1. Fluorescence in situ hybridization on paraffin-embedded tissue sections (T-FISH) identified a translocation of BCL2 with IGHgene.Based on these findings, the tumor was defined as an invasion of FL. T-FISH method is useful for the detection of a monoclonality of atypical lymphocytes in an SMT of the gastrointestinal tract, and particularly for the detection of chromosomal translocations specific to lymphoma subtypes.