Performance evaluation and user experience of BT-50 transportation unit with automated and scheduled quality control measurements.

OBJECTIVES: Even in the current era of hematology analyzer automation and peripheral equipment, quality control sample measurement remains a manual task, leading to variability in quality control data and increased workload. In this study, we evaluated the performance of quality control measurement using the BT-50 Transportation Unit (BT-50, Sysmex, Kobe, Japan), equipped with a scheduled automatic quality control function, to ensure measurement accuracy and streamline the workflow of hematology testing. METHODS: We evaluated the automatic measurement performance of quality control samples using the BT-50 for six representative blood test parameters: WBC (white blood cell), RBC (red blood cell), HGB (hemoglobin), HCT (hematocrit), PLT (platelet), and RET% (reticulocyte percent). We evaluated the equivalence and compared measurement accuracy between the BT-50 and the manual method. We then compared the variability to other laboratories and confirmed the stability of quality control samples. We also evaluated changes in workflow and staff resources before and after the introduction of the BT-50. RESULTS: The quality control measurement results for the BT-50 and the manual method were found to be equivalent for all six parameters. The variability measured by the BT-50 was lower for some parameters compared to the manual method. Furthermore, the workflow was streamlined by reducing manual processes, resulting in increased efficiency. CONCLUSIONS: We confirmed the performance of quality control measurements using the schedule function of the BT-50. Introducing the BT-50 reduced the operator's workload, improved operational efficiency, and promoted the standardization of quality control measurements.

Hemichordate genomes and deuterostome origins.

Acorn worms, also known as enteropneust (literally, 'gut-breathing') hemichordates, are marine invertebrates that share features with echinoderms and chordates. Together, these three phyla comprise the deuterostomes. Here we report the draft genome sequences of two acorn worms, Saccoglossus kowalevskii and Ptychodera flava. By comparing them with diverse bilaterian genomes, we identify shared traits that were probably inherited from the last common deuterostome ancestor, and then explore evolutionary trajectories leading from this ancestor to hemichordates, echinoderms and chordates. The hemichordate genomes exhibit extensive conserved synteny with amphioxus and other bilaterians, and deeply conserved non-coding sequences that are candidates for conserved gene-regulatory elements. Notably, hemichordates possess a deuterostome-specific genomic cluster of four ordered transcription factor genes, the expression of which is associated with the development of pharyngeal 'gill' slits, the foremost morphological innovation of early deuterostomes, and is probably central to their filter-feeding lifestyle. Comparative analysis reveals numerous deuterostome-specific gene novelties, including genes found in deuterostomes and marine microbes, but not other animals. The putative functions of these genes can be linked to physiological, metabolic and developmental specializations of the filter-feeding ancestor.

Integrated omics unveil the secondary metabolic landscape of a basal dinoflagellate.

BACKGROUND: Some dinoflagellates cause harmful algal blooms, releasing toxic secondary metabolites, to the detriment of marine ecosystems and human health. Our understanding of dinoflagellate toxin biosynthesis has been hampered by their unusually large genomes. To overcome this challenge, for the first time, we sequenced the genome, microRNAs, and mRNA isoforms of a basal dinoflagellate, Amphidinium gibbosum, and employed an integrated omics approach to understand its secondary metabolite biosynthesis. RESULTS: We assembled the ~ 6.4-Gb A. gibbosum genome, and by probing decoded dinoflagellate genomes and transcriptomes, we identified the non-ribosomal peptide synthetase adenylation domain as essential for generation of specialized metabolites. Upon starving the cells of phosphate and nitrogen, we observed pronounced shifts in metabolite biosynthesis, suggestive of post-transcriptional regulation by microRNAs. Using Iso-Seq and RNA-seq data, we found that alternative splicing and polycistronic expression generate different transcripts for secondary metabolism. CONCLUSIONS: Our genomic findings suggest intricate integration of various metabolic enzymes that function iteratively to synthesize metabolites, providing mechanistic insights into how dinoflagellates synthesize secondary metabolites, depending upon nutrient availability. This study provides insights into toxin production associated with dinoflagellate blooms. The genome of this basal dinoflagellate provides important clues about dinoflagellate evolution and overcomes the large genome size, which has been a challenge previously.

Evidence for at least six Hox clusters in the Japanese lamprey (Lethenteron japonicum).

Cyclostomes, comprising jawless vertebrates such as lampreys and hagfishes, are the sister group of living jawed vertebrates (gnathostomes) and hence an important group for understanding the origin and diversity of vertebrates. In vertebrates and other metazoans, Hox genes determine cell fate along the anteroposterior axis of embryos and are implicated in driving morphological diversity. Invertebrates contain a single Hox cluster (either intact or fragmented), whereas elephant shark, coelacanth, and tetrapods contain four Hox clusters owing to two rounds of whole-genome duplication ("1R" and "2R") during early vertebrate evolution. By contrast, most teleost fishes contain up to eight Hox clusters because of an additional "teleost-specific" genome duplication event. By sequencing bacterial artificial chromosome (BAC) clones and the whole genome, here we provide evidence for at least six Hox clusters in the Japanese lamprey (Lethenteron japonicum). This suggests that the lamprey lineage has experienced an additional genome duplication after 1R and 2R. The relative age of lamprey and human paralogs supports this hypothesis. Compared with gnathostome Hox clusters, lamprey Hox clusters are unusually large. Several conserved noncoding elements (CNEs) were predicted in the Hox clusters of lamprey, elephant shark, and human. Transgenic zebrafish assay indicated the potential of CNEs to function as enhancers. Interestingly, CNEs in individual lamprey Hox clusters are frequently conserved in multiple Hox clusters in elephant shark and human, implying a many-to-many orthology relationship between lamprey and gnathostome Hox clusters. Such a relationship suggests that the first two rounds of genome duplication may have occurred independently in the lamprey and gnathostome lineages.

Distribution coefficients (K(d)) of stable iodine in estuarine and coastal regions, Japan, and their relationship to salinity and organic carbon in sediments.

The sediment-water distribution coefficient, (K(d)), is one of the most important parameters in radionuclide assessment models. In this study, we determined K ds of stable iodine (I) in estuarine and coastal regions. We studied 16 estuarine and coastal regions of Japan and obtained I data on water and sediments. Data on salinity, pH, dissolved organic carbon and dissolved oxygen in water, and organic carbon (OC) in sediments were also obtained as estuarine variables. Determined (K(d))S of I in the Sagami River estuary decreased along the salinity gradient (salinity range, 0.1-33.8), indicating that salinity is one of the important factors controlling the (K(d)) values; however, when the (K(d)) values were compared among all the estuaries, the difference between minimum and maximum (K(d)) values varied by about two orders of magnitude in a narrow salinity range of 30.0-34.4. A significant correlation between (K(d)) value and OC content in sediments was observed in all the stations with a salinity of ≥ 30 except for stations in the Ishikari and Onga River estuaries. The exceptions are probably due to different sources of the sediments, which are explained by the results of relatively low I/OC ratios in sediments in those two estuaries, compared to the other estuaries. Thus, OC in sediments as well as salinity may be responsible for the variation of (K(d))S of I in the estuarine and coastal regions.

[Two elderly patients with advanced breast cancer successfully treated by tri-weekly docetaxel].

Case 1: An 86-year-old woman had an invasive breast cancer with dermal infiltration. Bone metastases were found in the femur and lumbar vertebrae. She was treated with 2 courses of 70 mg docetaxel (DOC) chemotherapy every 3 weeks, after which the tumor dramatically decreased in size. Following this treatment, she underwent a radical mastectomy. Case 2: An 80-year-old woman had a 10 cm tumor in the right breast. Lung and bone metastases were also found. Two 80 mg courses of DOC reduced the lung and bone metastases, and the size of the breast tumor. She underwent a local excision. Hormonal therapy is a standard treatment for hormone-sensitive breast cancer in elderly patients. It is suitable for patients who have a declining quality of life (QOL), although chemotherapy shows a higher response rate and takes less time than hormonal therapy. However, it is difficult to continue chemotherapy until pCR is achieved, even for chemotherapy-effective patients because the side effects of chemotherapy are severe. Therefore, local excision after chemotherapy is necessary for breast cancer patients to improve their QOL, even if there are distant metastatic lesions.

Surgical training in video-assisted neck surgery-based thyroidectomy using fresh frozen human cadavers.

Endoscopic surgery has been introduced in various surgical fields. Endoscopic surgery requires different skills from open surgery due to the restricted surgical field and difficulty in identifying anatomical structures from certain viewpoints. Therefore, surgeons need to undergo sufficient surgical training before performing such surgery in the clinical setting. We examined the utility of fresh frozen human cadavers for surgical training aimed at introducing video-assisted neck surgery (VANS) at our department. First, we performed surgical training using fresh human cadavers four times. Next, we performed hemi-thyroidectomy with VANS in 5 clinical patients. After the cadaver training and the actual surgery, the surgeons evaluated each step of the surgical procedure using a 3-point scale. In the cadaver training, the scores for steps : creation of a subcutaneous tunnel and lifting up the skin flap and pre-thyroid muscles were higher than other steps. And a tracheal injury occurred as a complication. However, we were able to recognize anatomical structures under the endoscopic view. And it was also useful for confirming the role of surgical staff and simulating the placement of surgical equipment. Surgical training using fresh frozen human cadavers was effective at introducing a new surgical method. J. Med. Invest. 66 : 293-296, August, 2019.

Alternative mRNA Splicing in Three Venom Families Underlying a Possible Production of Divergent Venom Proteins of the Habu Snake, Protobothrops flavoviridis.

Snake venoms are complex mixtures of toxic proteins encoded by various gene families that function synergistically to incapacitate prey. A huge repertoire of snake venom genes and proteins have been reported, and alternative splicing is suggested to be involved in the production of divergent gene transcripts. However, a genome-wide survey of the transcript repertoire and the extent of alternative splicing still remains to be determined. In this study, the comprehensive analysis of transcriptomes in the venom gland was achieved by using PacBio sequencing. Extensive alternative splicing was observed in three venom protein gene families, metalloproteinase (MP), serine protease (SP), and vascular endothelial growth factors (VEGF). Eleven MP and SP genes and a VEGF gene are expressed as a total of 81, 61, and 8 transcript variants, respectively. In the MP gene family, individual genes are transcribed into different classes of MPs by alternative splicing. We also observed trans-splicing among the clustered SP genes. No other venom genes as well as non-venom counterpart genes exhibited alternative splicing. Our results thus indicate a potential contribution of mRNA alternative and trans-splicing in the production of highly variable transcripts of venom genes in the habu snake.

[A case of occult breast cancer successfully treated by capecitabine in combination with weekly paclitaxel followed by FEC (75)].

A 78-year-old woman was referred to our hospital complaining of a hard nodule on the left side of her neck. Histological examination of this nodule showed metastatic carcinoma from breast cancer. Further examination revealed paraaortic lymph node swelling and no breast tumors. We diagnosed her tumors as occult breast cancer and its metastasis to lymph nodes (cT0N3cM1, Stage IV). We used weekly paclitaxel followed by a FEC75 regimen. The neck nodule size did not change after administration twice. We added capecitabine to the weekly paclitaxel, which had decreased the size of the nodule immediately. After this chemotherapy, PET-CT revealed that the lymph node metastasis had disappeared completely. It was considered that the addition of capecitabine in the early phase of the regimen was useful for this case.

Overexpression of IGF2 and IGF2 receptor in malignant solitary fibrous tumor with hypoglycemia: a case report.

BACKGROUND: Solitary fibrous tumor (SFT) is a prototypical mesenchymal neoplasm that induces non-islet cell tumor hypoglycemia (NICTH) due to overproduction of insulin-like growth factor 2 (IGF2). We here report the case of a malignant SFT associated with a hypoglycemia attack. CASE PRESENTATION: An 81-year-old man with a large subphrenic mass presented with hypoglycemia and loss of consciousness. His serum insulin and IGF1 levels were relatively low, suggesting an excessively high serum IGF2 levels. Preoperative Western blotting of serum confirmed the overproduction of high-molecular-weight IGF2. After total tumor resection, the patient recovered from hypoglycemia without the need for further treatment. Histological examination revealed proliferation of spindle cells and frequent nuclear mitoses with STAT6 and CD34 immunoreactivity, which led to the diagnosis of malignant SFT. IGF2 was strongly upregulated in the tumor upon immunohistochemistry, consistent with the report of NICTH. In addition, the tumor expressed IGF2 receptor (IGF2R) but not IGF1R. CONCLUSIONS: The present results indicate that the tumor co-expressed IGF2 and IGF2R. IGF2R has not previously been recognized as a tyrosine kinase receptor participating in cell signal transduction. Thus, further case series are required to determine whether IGF2R overexpression reflects the action of an unknown autocrine/paracrine system involving IGF2 for cell proliferation or for the scavenging and degradation of IGF2.

Influence of the type of furnace on behavior of radioactive cesium in municipal solid waste thermal treatment.

Municipal solid waste (MSW) contaminated by radioactive cesium (r-Cs) has been incinerated since the Fukushima Daiichi Nuclear Power Plant accident. Eight thermal treatment plants with four different types of furnaces were comprehensively investigated to provide fundamental data to improve our understanding of the behavior of r-Cs in various types of MSW thermal treatment facilities. R-Cs tended to distribute to the fly ash (FA) more than to the residue from the bottom of the furnace (bottom ash, incombustibles or slag). The r-Cs concentrations in the FA depended on the type of furnace and followed the order; fluidized-bed incinerator < stoker type incinerator < gasification melting furnaces. Shaft-type gasification melting furnace separated r-Cs selectively into FA and simultaneously discharged decontaminated slag. The leaching rate of r-Cs from FA was high, 30-100%, and independent of the type of furnace, whereas r-Cs in the residue from the bottom of the furnace scarcely dissolved in water. Heat recovery ash e.g. gas cooler ash was characterized by intermediate r-Cs concentrations and leachabilities compared with bottom residue and FA in stoker type and fluidized-bed incinerator. In the case of shaft-type gasification melting furnace, however, heat recovery ash showed similar property to FA due to a cyclone followed by heat recovery process. We evaluated whether baghouses (air- pollution control equipment) successfully removed r-Cs from flue gas. In all cases, r-Cs in flue gas was below the limit of detection after baghouse. We concluded that different types of furnaces affected r-Cs distributions, but flue gases from baghouse systems of all types of furnaces were safe.

JunB regulates homeostasis and suppressive functions of effector regulatory T cells.

Foxp3-expressing CD4+ regulatory T (Treg) cells need to differentiate into effector Treg (eTreg) cells to maintain immune homeostasis. T-cell receptor (TCR)-dependent induction of the transcription factor IRF4 is essential for eTreg differentiation, but how IRF4 activity is regulated in Treg cells is still unclear. Here we show that the AP-1 transcription factor, JunB, is expressed in eTreg cells and promotes an IRF4-dependent transcription program. Mice lacking JunB in Treg cells develop multi-organ autoimmunity, concomitant with aberrant activation of T helper cells. JunB promotes expression of Treg effector molecules, such as ICOS and CTLA4, in BATF-dependent and BATF-independent manners, and is also required for homeostasis and suppressive functions of eTreg. Mechanistically, JunB facilitates the accumulation of IRF4 at a subset of IRF4 target sites, including those located near Icos and Ctla4. Thus, JunB is a critical regulator of IRF4-dependent Treg effector programs, highlighting important functions for AP-1 in Treg-mediated immune homeostasis.

The habu genome reveals accelerated evolution of venom protein genes.

Evolution of novel traits is a challenging subject in biological research. Several snake lineages developed elaborate venom systems to deliver complex protein mixtures for prey capture. To understand mechanisms involved in snake venom evolution, we decoded here the ~1.4-Gb genome of a habu, Protobothrops flavoviridis. We identified 60 snake venom protein genes (SV) and 224 non-venom paralogs (NV), belonging to 18 gene families. Molecular phylogeny reveals early divergence of SV and NV genes, suggesting that one of the four copies generated through two rounds of whole-genome duplication was modified for use as a toxin. Among them, both SV and NV genes in four major components were extensively duplicated after their diversification, but accelerated evolution is evident exclusively in the SV genes. Both venom-related SV and NV genes are significantly enriched in microchromosomes. The present study thus provides a genetic background for evolution of snake venom composition.

Bivalve-specific gene expansion in the pearl oyster genome: implications of adaptation to a sessile lifestyle.

INTRODUCTION: Bivalve molluscs have flourished in marine environments, and many species constitute important aquatic resources. Recently, whole genome sequences from two bivalves, the pearl oyster, Pinctada fucata, and the Pacific oyster, Crassostrea gigas, have been decoded, making it possible to compare genomic sequences among molluscs, and to explore general and lineage-specific genetic features and trends in bivalves. In order to improve the quality of sequence data for these purposes, we have updated the entire P. fucata genome assembly. RESULTS: We present a new genome assembly of the pearl oyster, Pinctada fucata (version 2.0). To update the assembly, we conducted additional sequencing, obtaining accumulated sequence data amounting to 193× the P. fucata genome. Sequence redundancy in contigs that was caused by heterozygosity was removed in silico, which significantly improved subsequent scaffolding. Gene model version 2.0 was generated with the aid of manual gene annotations supplied by the P. fucata research community. Comparison of mollusc and other bilaterian genomes shows that gene arrangements of Hox, ParaHox, and Wnt clusters in the P. fucata genome are similar to those of other molluscs. Like the Pacific oyster, P. fucata possesses many genes involved in environmental responses and in immune defense. Phylogenetic analyses of heat shock protein70 and C1q domain-containing protein families indicate that extensive expansion of genes occurred independently in each lineage. Several gene duplication events prior to the split between the pearl oyster and the Pacific oyster are also evident. In addition, a number of tandem duplications of genes that encode shell matrix proteins are also well characterized in the P. fucata genome. CONCLUSIONS: Both the Pinctada and Crassostrea lineages have expanded specific gene families in a lineage-specific manner. Frequent duplication of genes responsible for shell formation in the P. fucata genome explains the diversity of mollusc shell structures. These duplications reveal dynamic genome evolution to forge the complex physiology that enables bivalves to employ a sessile lifestyle in the intertidal zone.

A case of resistance to thyroid hormone diagnosed after total thyroidectomy for thyroid cancer.

This is a case of a woman who was diagnosed with resistance to thyroid hormone after total thyroidectomy for thyroid cancer. Preoperative laboratory examination revealed the syndrome of inappropriate secretion of TSH, however, the patient had no thyrotoxic symptoms and no family history. Based on the results of ultrasonography and fine needle aspiration, she was diagnosed with papillary thyroid carcinoma and underwent total thyroidectomy. After the surgery, she received L-T4 therapy, but her TSH levels remained elevated. MRI was performed on the brain, but no lesions were found in the pituitary gland. Therefore, she was tested for TRß gene, and a previously defined mutation, P453S, was detected. Ultimately, she was diagnosed as RTH and treated with L-T4. In this case, the dose of L-T4 needed to be increased to suppress her TSH levels to the normal range or less, and to prevent stimulating malignant cells. Currently, her dose of L-T4 has been increased, and her TSH levels are still lower than normal, however, she has no thyrotoxic symptoms, recurrence or metastasis of thyroid cancer. The patient is currently under careful observation regarding her circulatory and physiological status. In addition, the results of treatment still need to be monitored and evaluated.

A case of thoracic esophageal cancer undergone esophagectomy after induction chemotherapy in a Jehovah's Witness.

We report the case of a 50-year-old female Jehovah's Witness with advanced esophageal cancer who underwent esophagectomy following induction chemotherapy. She visited our hospital complaining of dysphagia and was diagnosed of advanced esophageal cancer by upper endoscopy. She refused allogeneic transfusion. Induction chemotherapy was performed. Severe anemia occurred as an adverse event. A subtotal esophagectomy was performed after her anemia improved. During the surgery, a large volume of replacement fluid was injected, the blood was diluted, and intraoperative bleeding was relatively reduced. Intraoperative blood salvage was made using Cell Saver. The postoperative course were stable by using autologous blood and albumin infusion. The patient was discharged on postoperative day 27. Jehovah's Witnesses with gastrointestinal malignancies can be treated safely by performing surgical therapy based on blood replacement therapy and autologous blood transfusion.

The Lingula genome provides insights into brachiopod evolution and the origin of phosphate biomineralization.

The evolutionary origins of lingulid brachiopods and their calcium phosphate shells have been obscure. Here we decode the 425-Mb genome of Lingula anatina to gain insights into brachiopod evolution. Comprehensive phylogenomic analyses place Lingula close to molluscs, but distant from annelids. The Lingula gene number has increased to ∼34,000 by extensive expansion of gene families. Although Lingula and vertebrates have superficially similar hard tissue components, our genomic, transcriptomic and proteomic analyses show that Lingula lacks genes involved in bone formation, indicating an independent origin of their phosphate biominerals. Several genes involved in Lingula shell formation are shared by molluscs. However, Lingula has independently undergone domain combinations to produce shell matrix collagens with EGF domains and carries lineage-specific shell matrix proteins. Gene family expansion, domain shuffling and co-option of genes appear to be the genomic background of Lingula's unique biomineralization. This Lingula genome provides resources for further studies of lophotrochozoan evolution.

A matrix metalloproteinase inhibitor, ONO-4817, retards the development of mammary tumor and the progression of uterine adenomyosis in mice.

The inhibitory effects of a novel matrix metalloproteinase inhibitor, ONO-4817, on the development of mammary tumors and the progression of uterine adenomyosis were examined in SHN mice. First, multiparous mice which developed mammary tumors spontaneously were used. The first palpable tumor was removed, and the mice were thereafter fed chow containing ONO-4817. Any second mammary tumor developing in the other mammary fat pad was also removed, and the mice were continuously fed the chow containing ONO-4817. The mice were killed when a third tumor was detected in the other fat pad. The periods between the occurrence of the first and second tumors, and the second and third ones were significantly increased in the mice treated with ONO-4817 compared to the mice not given ONO-4817 treatment. Second, to test ONO-4817 suppression of the progression of the invasion of uterine adenomyotic tissue, mice with experimentally-induced adenomyosis were treated with ONO-4817 for 4 weeks. The degree of pathological progression of adenomyosis was less in the uteri exposed to ONO-4817 than in the uteri not exposed to the inhibitor.

Transfer of 137Cs and stable Cs from paddy soil to polished rice in Aomori, Japan.

Rice is a staple food in Japan and other Asian countries, and the soil-to-plant transfer factor of 137Cs released into the environment is an important parameter for estimating the internal radiation dose from food ingestion. Soil and rice grain samples were collected from 20 paddy fields throughout Aomori Prefecture, Japan in 1996 and 1997, and soil-to-polished rice transfer factors were determined. The concentrations of 137Cs, derived from fallout depositions, stable Cs and K in paddy soils were 2.5-21 Bq kg(-1), 1.2-5.3 and 5000-13000 mg kg(-1), respectively. The ranges of 137Cs, stable Cs and K concentration in polished rice were 2.5-85 mBq kg(-1) dry wt., 0.0005-0.0065 and 580-910 mg kg(-1) dry wt., respectively. The geometric mean of soil-to-polished rice transfer factor of 137Cs was 0.0016, and its 95% confidence interval was 0.00021-0.012. The transfer factor of 137Cs was approximately 3 times higher than that of stable Cs at 0.00056, and they were well correlated. This implied that fallout 137Cs, mostly deposited up to the 1980s, is more mobile and more easily absorbed by plants than stable Cs in the soil, although the soil-to-plant transfer of stable Cs can be used for predicting the long-term transfer of 137Cs. The transfer factors of both 137Cs and stable Cs decreased with increasing K concentration in the soil. This suggests that K in the soil was a competitive factor for the transfers of both 137Cs and stable Cs from soil-to-polished rice. However, the transfer factors of 137Cs and stable Cs were independent of the amount of organic materials in soils.

Draft assembly of the Symbiodinium minutum nuclear genome reveals dinoflagellate gene structure.

BACKGROUND: Dinoflagellates are known for their capacity to form harmful blooms (e.g., "red tides") and as symbiotic, photosynthetic partners for corals. These unicellular eukaryotes have permanently condensed, liquid-crystalline chromosomes and immense nuclear genome sizes, often several times the size of the human genome. Here we describe the first draft assembly of a dinoflagellate nuclear genome, providing insights into its genome organization and gene inventory. RESULTS: Sequencing reads from Symbiodinium minutum were assembled into 616 Mbp gene-rich DNA regions that represented roughly half of the estimated 1,500 Mbp genome of this species. The assembly encoded ∼42,000 protein-coding genes, consistent with previous dinoflagellate gene number estimates using transcriptomic data. The Symbiodinium genome contains duplicated genes for regulator of chromosome condensation proteins, nearly one-third of which have eukaryotic orthologs, whereas the remainder have most likely been acquired through bacterial horizontal gene transfers. Symbiodinium genes are enriched in spliceosomal introns (mean = 18.6 introns/gene). Donor and acceptor splice sites are unique, with 5' sites utilizing not only GT but also GC and GA, whereas at 3' sites, a conserved G is present after AG. All spliceosomal snRNA genes (U1-U6) are clustered in the genome. Surprisingly, the Symbiodinium genome displays unidirectionally aligned genes throughout the genome, forming a cluster-like gene arrangement. CONCLUSIONS: We show here that a dinoflagellate genome exhibits unique and divergent characteristics when compared to those of other eukaryotes. Our data elucidate the organization and gene inventory of dinoflagellates and lay the foundation for future studies of this remarkable group of eukaryotes.