Life under the snow: A year-round transcriptome analysis of Antarctic mosses in natural habitats provides insight into the molecular adaptation of plants under extreme environment.

Mosses are vital components of ecosystems, exhibiting remarkable adaptability across diverse habitats from deserts to polar ice caps. Sanionia uncinata (Hedw.) Loeske, a dominant Antarctic moss survives extreme environmental condition through perennial lifecycles involving growth and dormancy alternation. This study explores genetic controls and molecular mechanisms enabling S. uncinata to cope with seasonality of the Antarctic environment. We analysed the seasonal transcriptome dynamics of S. uncinata collected monthly from February 2015 to January 2016 in King George Island, Antarctica. Findings indicate that genes involved in plant growth were predominantly upregulated in Antarctic summer, while those associated with protein synthesis and cell cycle showed marked expression during the winter-to-summer transition. Genes implicated in cellular stress and abscisic acid signalling were highly expressed in winter. Further, validation included a comparison of the Antarctic field transcriptome data with controlled environment simulation of Antarctic summer and winter temperatures, which revealed consistent gene expression patterns in both datasets. This proposes a seasonal gene regulatory model of S. uncinate to understand moss adaptation to extreme environments. Additionally, this data set is a valuable resource for predicting genetic responses to climatic fluctuations, enhancing our knowledge of Antarctic flora's resilience to global climate change.

Salicylic acid-induced transcriptional reprogramming by the HAC-NPR1-TGA histone acetyltransferase complex in Arabidopsis.

Plant immunity depends on massive expression of pathogenesis-related genes (PRs) whose transcription is de-repressed by pathogen-induced signals. Salicylic acid (SA) acts as a major signaling molecule in plant immunity and systemic acquired resistance triggered by bacterial or viral pathogens. SA signal results in the activation of the master immune regulator, Nonexpressor of pathogenesis-related genes 1 (NPR1), which is thought to be recruited by transcription factors such as TGAs to numerous downstream PRs. Despite its key role in SA-triggered immunity, the biochemical nature of the transcriptional coactivator function of NPR1 and the massive transcriptional reprogramming induced by it remain obscure. Here we demonstrate that the CBP/p300-family histone acetyltransferases, HACs and NPR1 are both essential to develop SA-triggered immunity and PR induction. Indeed HACs and NPR1 form a coactivator complex and are recruited to PR chromatin through TGAs upon SA signal, and finally the HAC-NPR1-TGA complex activates PR transcription by histone acetylation-mediated epigenetic reprogramming. Thus, our study reveals a molecular mechanism of NPR1-mediated transcriptional reprogramming and a key epigenetic aspect of the central immune system in plants.

Repression of flowering under a noninductive photoperiod by the HDA9-AGL19-FT module in Arabidopsis.

Posttranslational acetylation of histones is reversibly regulated by histone deacetylases (HDACs). Despite the evident significance of HDACs in Arabidopsis development, the biological roles and underlying molecular mechanisms of many HDACs are yet to be elucidated. By a reverse-genetic approach, we isolated an hda9 mutant and performed phenotypic analyses on it. In order to address the role of HDA9 in flowering, genetic, molecular, and biochemical approaches were employed. hda9 flowered early under noninductive short-day (SD) conditions and had increased expression of the floral integrator FLOWERING LOCUS T (FT) and the floral activator AGAMOUS-LIKE 19 (AGL19) compared with the wild-type. The hda9 mutation increased histone acetylation and RNA polymerase II occupancy at AGL19 but not at FT during active transcription, and the HDA9 protein directly targeted AGL19. AGL19 expression was higher under SD than under inductive long-day (LD) conditions, and an AGL19 overexpression caused a strong up-regulation of FT. A genetic analysis showed that an agl19 mutation is epistatic to the hda9 mutation, masking both the early flowering and the increased FT expression of hda9. Taken together, our data indicate that HDA9 prevents precocious flowering under SD conditions by curbing the hyperactivation of AGL19, an upstream activator of FT, through resetting the local chromatin environment.

[The Effect of Improved Culturing Method on the Detection Rate of Chromosome Karyotyping in Multiple Myeloma].

OBJECTIVE: To investigate an improved culturing method for karyotyping analysis, and increase the detection rate of cytogenetic abnormalities in patients with multiple myeloma (MM), so as to provide more powerful information for the clinical diagnosis, prognosis stratification, and individualized treatment of MM patients. METHODS: Eighty newly-diagnosed MM patients were enrolled and divided into two groups. In observation group, IL-6 (10 ng/ml) and GM-CSF (30 ng/ml) were supplemented in the culture medium, while no stimulating factor was added in control group. The samples from both groups were cultured for 72 hours under the same conditions, and their karyotypes were analyzed by G-banding. The detection rate of the cytogenetic abnormalities, as well as the corresponding characteristics were compared between the two groups. RESULTS: The detection rate of the chromosome aberrations was greatly increased in the observation group compared with the control group, the overall detection rate was 72.5% and 22.5%, respectively, as well as 80.0% and 19.2% in the subgroup of ≤60 years old, 68.0% and 28.6% in the subgroup of > 60 years old, which showed significant statistical differences (P<0.05). CONCLUSION: The modification of the culturing method with the addition of IL-6 (10 ng/ml) and GM-CSF (30 ng/ml) dual stimulating factors followed by incubation for 72 hours can effectively increase the detection rate of abnormal karyotypes in MM patients.

Double minute chromosomes in acute myeloid leukemia and myelodysplastic syndromes are associated with complex karyotype, monosomal karyotype, TP53 deletion, and TP53 mutations.

Double minute chromosomes (DMs) are rare in hematologic malignancies. We presented the cytogenetic characteristics and clinical features of the largest single-center cohort of acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) patients with DMs. A total of 2576 AML patients and 1642 MDS patients were investigated, and 30 patients (AML = 19; MDS = 11) who had DMs were followed up. DMs were more common in primary AML (94.7%) and MDS (90.9%). Monosomal karyotypes (MK) were also the main cytogenetic characteristics, like complex karyotypes (CK). AML with myelodysplasia-related changes (AML-MRC) and MDS-refractory anemia with excess blasts (MDS-RAEB) was common in this cohort. We conclude that DMs-positive AML and DMs-positive MDS are associated with older age, complex karyotypes, monosomal karyotypes, TP53 deletion and TP53 mutations. DMs are a type of chromothripsis, which can be observed by the karyotype analysis. MYC and KMT2A were the most commonly amplified genes in DMs. Most patients with DMs presented an extremely poor prognosis.

Bilineal Extramedullary Blast Crisis as an Initial Presentation of Chronic Myeloid Leukemia: A Case Report and Literature Review.

BACKGROUND Chronic myeloid leukemia (CML) is a clonal myeloproliferative disorder characterized by the Philadelphia chromosome generated by the reciprocal translocation t(9: 22)(q34;q11). CML is usually diagnosed in the chronic phase. Blast crisis represents an advanced phase of CML. Extramedullary blast crisis as the initial presentation of CML with bone marrow remaining in chronic phase is an unusual event. Further, extramedullary blast crisis with T lymphoid/myeloid bilineal phenotype as an initial presentation for CML is extremely unusual. CASE REPORT Here, we report the case of a 49-year-old male with rapidly enlarged submandibular lymph nodes. Biopsy specimen from the nodes revealed a characteristic appearance with morphologically and immunohistochemically distinct myeloblasts and T lymphoblasts co-localized in 2 adjacent regions, accompanied by chronic phase of the disease in bone marrow. The presence of the BCR/ABL1 fusion gene within both cellular populations in this case confirmed the extramedullary disease represented a localized T lymphoid/myeloid bilineal blastic transformation of CML. After 3 courses of combined chemotherapy plus tyrosine kinase inhibitor treatment, the mass was completely regressed with a 3-log decrease in BCR/ABL1 transcript from baseline. Five months after the diagnosis, the patient showed diminished vision, hand tremors, and weakness of lower extremities. Flow cytometric immunophenotyping of cerebrospinal fluid revealed the presence of myeloid blasts. An isolated central nervous system relapse of leukemia was identified. Following high-dose systemic and intrathecal chemotherapy, the patient continued to do well. CONCLUSIONS The possibility of extramedullary blast crisis as an initial presentation in patients with CML should be considered. Further, an isolated central nervous system blast crisis should be considered if neurological symptoms evolve in patients who have shown a good response to therapy.

[HLA antigen compatibility between patients with hematologic diseases and their parents].

This study was aimed to investigate and analyze the HLA antigen compatibility between patients with hematologic diseases and their parents so as to provide basis for selecting the suitable donors in haploidentical hematopoietic stem cell transplantation. The HLA low resolution for 174 families was typed and analyzed by using PCR-SSP. The results showed that 52.30% of patients with hematologic diseases possessed father and/or mother with HLA matching over haploidentity, 10.92% patients were over 8/10 matched with their father and/or mother. 11.49% were over semi-matched with both their father and mother. The rate of 6/10 matched pairs (28.16%), 7/10 matched pairs (16.1%) and 8/10 matched pairs (8.62%) were all beyond 5%; 9/10 (2.3%) and 10/10 matched pairs (1.15%) were all below 5%. It is concluded that with the matching degree increasing between two generations, HLA matching rate is decreasing. Over 50% and 10% patients were over HLA semi-matched and 8/10 matched with their father and/or mother, respectively. This high matching rate offered a big chance for success of haploidentical HSCT. Patients are more likely over semi-matched with their father and/or mother when they have high frequency and strong linkage HLA disequilibrium. High frequency and strong linkage disequilibrium in populations are main reason, and population concentrating and isolated living may be another reason for this phenomenon.

[Clinical analysis for 3 cases of HLA-matched between father and son and 1 case of post-hematopoietic stem cell transplant efficacy].

Getting a HLA-matched donor is a key factor for successful hematopoietic stem cell transplantation. People are almost semi-matched with their parents, while a person HLA-matched with his/her father or mother was rarely seen, if so, usually whose father and mother are genetically related. HLA-low resolution for patients and their relatives were performed using PCR-SSP technique and three patients were found HLA-matched with their father in these results. One of them accepted hematopoietic stem cell transplantation using his HLA-matched father as his donor. The results showed that the chimerism was detected as stable complete donor chimerism, fusing gene of MLL-ENL was detected all negatively in the post-transplant period. This case got well hematopoietic reconstruction and GVHD didn't occur, so far he has survived for two years in health conditioning. It is concluded that people HLA-matched with his/her father or mother can be found when there is one identical haplotype of high frequency and strong linkage disequilibrium between father and mother. This case is valuable for hematopoietic stem cell transplantation development.

[A recombination event occurring between HLA-A and -A loci from father's HLA haplotype chromosome].

This study was aimed investigate the recombination event occurring between HLA-A and-A loci discovered from father's HLA haplotype chromosome in a family. Peripheral blood samples were collected from a family. HLA class I (-A, -B, and -Cw) and II (-DRB1 and -DQB1) alleles were amplified and typed by both low and high resolution PCR with sequence-specific primers (PCR-SSP) and sequence-based typing (SBT). The results showed that 2 haplotypes of the patient were A(*)3001-B(*)1302-DRB1(*)0701 and A(*)3001-B(*)5601-DRB1(*)1454 respectively, those of her father were A(*)3001-B(*)1302-DRB1*0701 and A(*)1101-B(*)5601-DRB1(*)1454. Family analysis demonstrated that the patient's A(*)3001-B(*)1302-DRB1(*)0701 came from her mother and A(*)1101-B(*)5601-DRB1(*)1454 came from her father, but the A of patient was A(*)3001 and B, DR were the same to her father. This showed that the chromosome exchange and recombination event of father's 2 haplotypes occurring between HLA-A and -A loci at meiosis. And recombinate haploid chromosome was completely inherited to his daughter 1. HLA typing and Paternity testing demonstrated that father was the natural father, and the recombination event occurring between HLA-A and -A loci of the daughter 1 with father's HLA haplotype chromosome. It is concluded that the HLA-A/A of father's HLA haplotype chromosome recombination event occurring between HLA-A an-A loci has been found in a family in China, which helps further study on the mechanisms of HLA recombination.

[Dynamic detection of chimerism and fusion gene in chronic myeloid leukemia patients relapsed after allogeneic hematopoietic stem cell transplantation].

This study was aimed to investigate the chimerism and fusion gene expression in patients with CML after allo-HSCT, to analyse engraftment and minimal residual disease by using STR-PCR combined with RT-PCR qualitative and quantitative assays, and to evaluate their clinical value for predicting disease relapse. 4 relapsed patients with CML after allo-HSCT were dynamically investigated. Qualitative analysis of donor chimerism was performed by multiplex PCR amplification of STR markers and capillary electrophoresis with fluorescence detection, qualitative detection of bcr/abl transcripts was performed by RT-PCR. The results showed that the 100% donor chimerism appeared in 4 patients on day 28 after transplantation and bcr/abl expression was negative, but the 4 patients were in status of unstable mixed chimerism (DC: 0% - 80.4%) at the different time points during the following up with bcr/abl gene positive. 2 patients of them were continuously mixed chimerism after relapse of CML, the other 2 changed from MC to CC by intervention of clinical treatment. Decreasing values of donor chimerism were detected prior to the occurrence of graft rejection and CML relapse, and bcr/abl gene expression was positive. It is concluded that the results of STR-PCR in the range of its sensitivity fully correspond with bcr/abl tests in patients. The combination of STR-PCR with RT-PCR will provide a highly sensitive and valuable tool for evaluating engraftment, graft rejection, and relapse and predicting GVHD. Furthermore, it can provide a basis for early intervention of clinical treatment, and can identify these high risk patients with molecular or cytogenetic relapse after allo-HSCT.