Spontaneous comedones on the skin of hairless descendants of Mexican hairless dogs

In the first experiment, the skin sebum and humidity, perspiration ability of sweat glands, and histology of spontaneous comedones were examined in hairless descendants of Mexican hairless dogs. The skin of females showed lower humidity than that of males. Some animals with a large number of comedones exhibited remarkably high skin sebum scores. The comedones were distributed throughout the dorsal skin, and a cluster of lesions was found mainly in the limbs and prepuces. The sweat glands showed no perspiration in the sudorific test. Histologically, both infant and adult animals had lesions of micro- and/or "blackhead" comedones. Plugged follicles containing abundant keratic substances associated well-developed sebaceous glands. Spontaneous comedones in the skin of hairless dogs were grossly and histologically similar to the acne vulgaris observed in human beings. The skin of some adult animals showed a large number of protrusive comedones which were solid cystic structures containing organized substances. In the second experiment, three kinds of antiacne agents (sulfur and camphor, sulfur and resorcinol, and ibuprofen piconol) were applied daily to the test sites for one month. These antiacne agents caused prominent extrusion of keratin plugs from follicular sites. The results suggest that the hairless dogs are a predictive model for evaluating the efficacy of antiacne agents proposed for acne treatment.

N3-phenacyluridine, a novel hypnotic compound, interacts with the benzodiazepine receptor

N3-Phenacyluridine (3-phenacyl-1-beta-D-ribofuranosyluracil) has potent sedative and hypnotic activities following intracerebroventricular injection in mice. To study the mechanism of action of N3-phenacyluridine, the interaction of this compound with the benzodiazepine receptor has been investigated. Results obtained showed that this compound inhibited specific binding of [3H]flunitrazepam to synaptic membranes of bovine cortex in a concentration-dependent fashion (IC50 = 129 microM). Scatchard analysis of [3H]flunitrazepam binding revealed that N3-phenacyluridine interacted with the ligand at the benzodiazepine receptor binding site in a competitive manner. Ro15-1788 (8-fluoro-3-carboethoxy-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5a ]1, 4-benzodiazepine), a benzodiazepine receptor antagonist, also inhibited the specific binding of [3H]flunitrazepam in the presence of the compound. The results suggest that the pharmacological activity of N3-phenacyluridine may be partially mediated through the benzodiazepine receptor.

Separable cis-regulatory elements that contribute to tissue- and site-specific alpha 2(XI) collagen gene expression in the embryonic mouse cartilage

Type XI collagen is a structural component of the cartilage extracellular matrix and plays an important role in skeletal morphogenesis. As a step toward defining the molecular mechanisms responsible for the regulation of type XI collagen expression, we characterized the promoter region of the mouse alpha 2(XI) collagen gene (Coll1a2). We also generated transgenic mice harboring various fragments of the promoter and the first intron of Coll1a2 linked to the Escherichia coli beta-galactosidase gene to identify the cis-acting elements responsible for tissue- and site-specific expression during development. Cloning and sequence analysis of the 5' flanking region of Coll1a2 showed that the putative 3' end of the retinoid X receptor beta gene was located 742 bp upstream of the Coll1a2 start site. This suggested that the promoter region of Coll1a2 was localized within this 742-bp sequence, which contained multiple consensus regulatory elements. Examination of the transgenic mice revealed that the longest DNA construct (containing the entire promoter and first intron sequences) directed lacZ expression in the notochord as well as in the primordial cartilage throughout the body, with the pattern of expression mimicking that of endogenous Coll1a2 transcripts. On the other hand, deletion of the upstream approximately 290 bp resulted in the elimination of lacZ expression in the primordial cartilage of the carpals, tarsals, and vertebral bodies, whereas lacZ expression in the notochord and in the other primordial cartilage elsewhere was not affected. Deletion of the first intron sequence also resulted in the loss of lacZ expression in the primordial cartilage of the carpals, tarsals, and vertebral bodies, as well as in the notochord. These results demonstrate that the upstream 742-bp and first intron segments of the mouse Coll1a2 gene contain the necessary information to confer high level tissue-specific expression in mouse embryos. In addition, our observations suggest the presence of site-specific cis-acting elements that control Coll11a2 gene expression in different cartilaginous components of the skeleton.

A recurrent 1992delCT mutation of the type X collagen gene in a Japanese patient with Schmid metaphyseal chondrodysplasia

We report here a recurrent frameshift mutation within the carboxyl-terminal noncollagenous domain coding region of the type X collagen gene (COL10A1) in a Japanese patient with Schmid metaphyseal chondrodysplasia. The mutation involves deletion of a CT dinucleotide from position 1992 (1992delCT), and produces a frameshift which creates a premature termination codon close to the site of the deletion. The predicted length of the mutant polypeptide is 664 amino acids, which is shorter than the wild type polypeptide (680 amino acids). A 1992delCT mutation of COL10A1 has been previously reported in one family. The independent occurrence of de novo mutation of this specific dinucleotide repeat suggests that this region is a possible mutational hot spot on COL10A1.

Intraabdominal contamination after gallbladder perforation during laparoscopic cholecystectomy and its complications

BACKGROUND

Gallbladder perforation often occurs during laparoscopic cholecystectomy.

METHODS

The frequency and causes of gallbladder perforation as well as the relevant clinical background factors were investigated in 110 patients undergoing laparoscopic cholecystectomy. We also evaluated intraperitoneal contamination by bacteria and gallstones at the time of gallbladder perforation and investigated whether perforation caused early or late postoperative complications.

RESULTS

Intraoperative gallbladder perforation occurred in 29 of the 110 patients (26.3%). It was caused by injury with an electric knife during dissection of the gallbladder bed, injury during gallbladder retraction with grasping forceps, injury during gallbladder extraction from the abdomen, and slippage of cystic duct clips (potentially causing bile and stone spillage). Perforation was more frequent in patients with positive bile cultures and in those with pigment stones (p < 0.02), but not in patients with cholecystitis or cystic duct obstruction. The peritoneal cavity was contaminated by bacteria in 11/29 patients (37.9%) and by spilled stones in 3/29 patients (10.3%). There was no difference in the incidence of postoperative complications between the patients with and without perforation either in the early postoperative period or during follow-up for 24-42 months. Only one patient developed abdominal pain and fever in the early postoperative period, and they were probably related to perforation.

CONCLUSIONS

Although gallbladder perforation is sometimes unavoidable during laparoscopic cholecystectomy, the risk of severe complications appears to be minimized by early closure of perforation, retrieval of as many of the spilled stones as possible, and intraperitoneal lavage.

[A case of severe hypertension caused by stellate ganglion block in a patient with facial palsy]

We report a case of severe hypertension following stellate ganglion block. A 61-year old woman received the left stellate ganglion block with 5 ml of 1% mepivacaine for her left facial palsy. Before the stellate ganglion block, blood pressure was 120/68 mmHg and heart rate was 62 b.p.m. Seven minutes after the left stellate ganglion block, blood pressure increased to 230/140 mmHg, but heart rate was unchanged. Systolic blood pressure remained above 190 mmHg for 60 minutes following the stellate ganglion block. We suggest that the extreme increase in blood pressure was due to the vagal nerve block associated with the left stellate ganglion block.

Determination of bioconcentration potential of tetrachloroethylene in marine algae by 13C

The use of stable isotope of organic-carbon, organic-13C, as a tracer for the determination of the concentration of tetrachloroethylene (PCE), CA, in Heterosigma akashiwo and Skeletonema costatum was examined. CA determined by the 13C and GC methods showed good agreement with each other. This suggests that it is reasonable and reliable to determine the bioconcentration potential of PCE in marine algae. Fitting values of bioconcentration potential parameters, including uptake rate constant k1, elimination rate constant k2 and bioconcentration factor on the basis of dry weight BCFD, were done not only to the time course for PCE uptake by the algae with the bioconcentration model, but also to experimental data for "percent inhibition(%) approximately exposure concentration of PCE approximately time" with the combined bioconcentration and probability model. The values obtained from the bioconcentration model were consistent with those from the combined bioconcentration and probability model. With the parameters (such as k1, k2, growth rate constant kG, critical concentration of HOCs in the organism resulting in growth inhibition CA* and spread factor S) the variability in toxicity (such as EC10, EC50, EC70) can be estimated from the combined bioconcentration and probability model, which fits well with the experimental observations.

Nonlinear partial least squares modeling of phenyl alkylamines with the monoamine oxidase inhibitory activities

The nonlinear partial least squares (PLS) method is a nonlinear version of PLS. In this approach, a quadratic inner relation is used instead of the linear inner relation in PLS. Since the quadratic inner relation can be extended to a general form, it is said that the nonlinear PLS method has a high potential for nonlinear modelling. However, few applications of the method have been appeared in quantitative structure--activity relationships (QSAR) studies, because the mathematical descriptions underlying the algorithm were not so clear. In this paper, we have carried out the QSAR analysis of four monoamine oxidase (MAO) inhibitory activities using the nonlinear PLS method. The in vitro and in vivo MAO inhibitory activities were analyzed separately. From the PLS loadings, the structural requirements could be estimated and the utility of the nonlinear PLS method was demonstrated.

[Gynecological management of climacteric syndrome with psychiatric disorders]

PURPOSE

To discriminate patients with severe mental disorders from those complaining of menopausal symptoms, psychological tests were performed on patients who visited the menopausal clinic. The effectiveness of hormone replacement therapy (HRT) in patients with slight mental disorders was also evaluated.

SUBJECTS AND METHODS

Patients with menopausal symptoms (n = 150, 41-59 yr. old) were interviewed by a psychiatrist (according to DSM-III-R) and classified as the climacteric syndrome group (C) and the mental disorder group (P). The patients were also evaluated by the Menopausal index (MI), Maudsley Personality Inventory (MPI) and Self-rating depression Scale (SDS). The patients with severe mental disorders were eliminated and the remaining patients with menopausal symptoms were treated with conjugated equine estrogen (0.625 mg/day) and medroxyprogesterone acetate (2.5mg/day) for 24 weeks.

RESULTS

1) Thirty six patients were diagnosed as P (24%) and seven of them were diagnosed as having major depression (4.7% of the all patients). 2) MPI-N (neurosis scale) in C was 16.2 +/- 10, and in P was 30.5 +/- 9.0, and SDS in C and P were 39.0 +/- 8.0, and 51.4 +/- 8.9, respectively. In both psychological test, P shows a significantly higher value than C (p < 0.01). 3) Ninety point six % of the patients responded. HRT was not effective in 63.2% of P, but when psychotropic drugs were combined, significant improvement (p < 0.05) was observed.

CONCLUSION

One fourth of the patients were suspected of having mental disorders in the menopausal clinic, and 5% of the patients needed the care of the psychiatrist. And the application of MPI and SDS was useful in helping the gynecologist to differentiate and classify the mental disorders to some extent. The applicability and effectiveness of HRT for patients with mild mental disorders were suggested.

An experimental model of bone metastasis by human lung cancer cells: the role of parathyroid hormone-related protein in bone metastasis

In the formation of bone metastasis, osteoclastic bone resorption is necessary before the expansion of tumor cells from bone marrow to bone, and several cytokines, which possess osteoclast-stimulating activity, could be involved in this step. In this paper, we describe a bone metastasis model in nude mice using human lung squamous cell carcinoma-derived cells (HARA), in which the parathyroid hormone-related protein (PTHrP) gene, one of the most potent osteoclast-activating factors, is strongly expressed. The injection of HARA cells (1 x 10(5)) into the left cardiac ventricle resulted in tumor colonies exclusively in the skeletal system at 4 and/or 8 weeks after inoculation. An anti-PTHrP antibody injected via a tail vein reduced the incidence of bone metastases, number of tumor colonies, and tumor volume after the inoculation of HARA cells. The injection of another line of human lung squamous cell carcinoma-derived cells (QG-56), in which the PTHrP gene is not expressed, resulted in no bone metastasis. These findings suggest that PTHrP plays an important role in the formation of bone metastasis.

Transmembrane glutamic acid residues play essential roles in the metal-tetracycline/H+ antiporter of Staphylococcus aureus

Three transmembrane aspartyl residues play essential roles in the transposon Tn10-encoded metal-tetracycline/H+ antiporter (Tet(B)) [Yamaguchi, A. et al. (1992) J. Biol. Chem. 267, 7490-7498]. The tetK gene-encoding tetracycline resistance protein (Tet(K)) of Staphylococcus aureus mediates metal-tetracycline/H+ antiport similarly to Tet(B); however, it has no transmembrane aspartyl residue. On the other hand, Tet(K) has three glutamyl residues, Glu-30, Glu-152 and Glu-397, in the putative transmembrane regions. In the present work, tet(K) gene was expressed in Escherichia coli and the transport activity was measured in everted membrane vesicles. When these glutamyl residues were replaced with Gln, the tetracycline transport activity was almost completely lost, indicating the important roles of these residues in Tet(K). In the case of Glu-397, even the charge-conserved mutation to Asp caused complete loss of the activity. On the other hand, the mutation of Glu-30 and Glu-152 to Asp resulted in significant retention of transport activity. These results are similar to those on the mutation of the three transmembrane aspartyl residues in Tet(B), indicating that the transmembrane glutamyl residues in Tet(K) play roles similar to those of the transmembrane aspartyl residues in Tet(B).

Anti-atherosclerotic effect of E5324, an inhibitor of acyl-CoA:cholesterol acyltransferase, in Watanabe heritable hyperlipidemic rabbits

E5324, n-butyl-N'-[2-[3-(5-ethyl-4-phenyl-1H-imidazol-1-yl)propoxy]-6- methylphenyl]urea, a novel and potent inhibitor of acyl-CoA:cholesterol acyltransferase (ACAT), was evaluated for its anti-atherosclerotic and lipid-lowering effects in Watanabe heritable hyperlipidemic (WHHL) rabbits. At 3 months of age, 40 male WHHL rabbits were divided into 4 groups. The rabbits were fed a standard rabbit chow (control group), or standard rabbit chow containing E5324 (0.1% or 0.02%) or 1% probucol for 16 weeks. Even the high dose of E5324 did not lower the plasma total cholesterol levels throughout the experiment. Probucol slightly reduced the plasma cholesterol levels, and showed anti-atherosclerotic activity, i.e., reductions of atherosclerotic plaque formation and cholesterol content in the aorta. Although E5324 did not lower plasma cholesterol, atherosclerotic plaque formation in the aortic arch and thoracic aorta was reduced (by about 34% and 41%, respectively, at the high dose; P < 0.05). Cholesterol content in the aortic arch and thoracic aorta was also reduced (by about 59% and 62% at the high dose, respectively) compared with the control. These results suggest that E5324 acts directly on the arterial wall through ACAT inhibition, and prevents the progression of atherosclerosis in WHHL rabbits.

Hyperbaric oxygenation prevents delayed neuronal death following transient ischaemia in the gerbil hippocampus

The mechanism of the neuroprotective effect of hyperbaric oxygenation remains unclear although its clinical benefits have been well recognized for human ischaemic neuronal disease. The preventive effect of hyperbaric oxygenation against delayed neuronal death was investigated in the gerbil following transient forebrain ischaemia. Delayed neuronal death in the gerbil was produced by clips on both the common carotid arteries (10 min). Morphological examination was carried out after several protocols of hyperbaric oxygenation, modified from the protocols for human ischaemic neuronal disease. Neurons in the hippocampal CA1 were well preserved in the gerbils treated with hyperbaric oxygenation, more so than in the gerbils with no hyperbaric oxygenation. Moreover, more neurons were preserved in the CA1 treated with hyperbaric oxygenation within 6 h of the ischaemia, than when the hyperbaric oxygenation was started 24 h after the ischaemia. The induction of heat shock proteins (HSP72 and HSP27) became weaker in the gerbils with hyperbaric oxygenation than in those without hyperbaric oxygenation, as seen immunohistochemically. We also observed an increase in dense bodies, that were shown to be lysosomes and myelinoid structures in the cytoplasm of the neurons ultrastructurally, in the hippocampus with hyperbaric oxygenation. However, no oxygen toxicity to the neurons was detected, up to at least two atmospheres absolute. This experimental system was useful to investigate the preventive mechanism of hyperbaric oxygenation against delayed neuronal death in the gerbil, and to determine the clinical indications and the most effective protocol for hyperbaric oxygenation for ischaemic neuronal damage in the human brain.

Inherited muscular disorder in mutant Japanese quail (Coturnix coturnix japonica): an immunohistochemical study

Cryostat sections of myofibres from the Musculus pectoralis thoracicus of a newly established mutant strain (LWC) of Japanese quail with a myotonic dystrophy-like myopathy were labelled with antibody against myosin heavy chain (MHC) isoforms and neural cell adhesion molecule (N-CAM). The characteristic lesions found in sections of muscle of LWC quail stained with haematoxylin and eosin were type 2B fibre atrophy, sarcoplasmic masses, and ring fibres. Immunohistochemical examination failed to distinguish type 2A and 2B fibres in the LWC quail. Antibody to adult fast MHC, which reacted only with type 2A fibres in normal quail, reacted in LWC quail with type 2B fibres, and to a limited degree with type 2A fibres. Sarcoplasmic masses reacted with both fast and slow MHC antibodies. Some masses also reacted with NCAM antibody, but apparently independently of similar reactions in fibres. These findings suggest that the changes observed in the myofibres of the LWC quail were not neurogenic but represented defects in both the plasma membrane and intermediate filaments.

Surgical treatment of infected thoracic and abdominal aortic aneurysms

Twelve patients with infected aneurysms of the thoracic and abdominal aorta were evaluated. Aneurysmal location, aetiology, bacteriology and treatment modality were analysed to determine the relationship between these factors and outcome. Patients were divided into two groups based on the preoperative states of their infections. Group 1 patients (n = 7) underwent resection after resolution of their active infection. The causative organisms included Staphylococcus epidermidis (two cases). Salmonella spp. (one). Acinetobacter (one), Mycobacterium tuberculosis (one) and unknown organisms (two). Group 2 patients (n = 5) required urgent surgery because of uncontrolled sepsis despite intensive treatment with antibiotics. The causative organisms included Staphylococcus aureus (two cases). Pseudomonas aeruginosa (two) and Salmonella spp. (one). In group 1, three patients underwent closed en bloc excision of the aneurysm with in-situ graft replacement, and four underwent partial resection with in-situ graft replacement. In group 2, three patients underwent resection of the aneurysm with ligation of aorta and extra-anatomic bypass, and two underwent in-situ graft replacement after débridement of infected tissue. Overall, patients in group 1 had a mortality rate of 14% compared with 80% in group 2. These results suggest that the operative approach and method chosen to restore arterial continuity have less of an impact on outcome. The primary determinants of outcome are virulence of the infecting organism and the preoperative state of the infection.

[Respiratory disorders in type-1 hereditary motor and sensory neuropathy]

Type-1 hereditary motor and sensory neuropathy (HMSN I) is a slowly progressive disease resulting in distal muscle weakness with atrophy, and in sensory disturbance. Restrictive lung disease and respiratory muscle failure, common in many advanced neuromuscular disorders, is not a predominant feature of HMSN-I. Recently, there have been several reports of respiratory dysfunction in patients with HMSN I, complicated by diaphragmatic weakness. In five patients with HMSN I (3 men and 2 women, mean age 55.4 yrs), we measured spirometric variables, maximal inspiratory pressure, and maximal expiratory pressure, in both sitting and supine positions. We also studied phrenic nerve conduction by cutaneous stimulation at the posterior border of the sternocleidomastoid muscle. Four of five patients had low maximal inspiratory pressure and abnormally long phrenic nerve latency. Two patients showed evidence of a restrictive lung disorder and daytime alveolar hypoventilation. All-night polysomnography in those two patients revealed periodic decreases in arterial blood oxygen saturation, and episodes of central apnea. We conclude that diaphragmatic dysfunction is not rare in HMSN I, and that maximal inspiratory pressure and phrenic nerve conduction may be useful in the early detection of phrenic nerve involvement.

Erythrocyte deformability in schizophrenic patients

Erythrocyte deformability as a clinical indicator of microcirculatory disturbance was determined in the erythrocyte of 25 schizophrenic patients and of 18 normal controls. Schizophrenic patients had significantly lower erythrocyte deformability than did the normal controls (P < 0.001). This result suggests that microcirculation in schizophrenic patients is disturbed, and that this disturbance might be involved in the pathophysiological genesis of schizophrenia.

Uncleaved env gp160 of human immunodeficiency virus type 1 is degraded within the Golgi apparatus but not lysosomes in COS-1 cells

The fate of newly synthesized human immunodeficiency virus type 1 env gp160 was examined in COS-1 cells. The results of morphological chase experiments involving cycloheximide demonstrated that gp160 was retained in the Golgi apparatus for longer than the half-life of the molecule. The degradation of gp160 was insensitive to both bafilomycin A1 and leupeptin (< 0.2 mM), which block lysosomal proteolysis. However, degradation was effectively suppressed by leupeptin at higher concentrations, maximally at 1.7 mM. Furthermore, undegraded gp160 was accumulated in the Golgi apparatus, but was not detected in lysosomes. These results indicate that in COS-1 cells gp160 is not degraded in lysosomes, but rather that degradation takes place in the Golgi apparatus.

Sequential changes of tau-site-specific phosphorylation during development of paired helical filaments

It has been reported that many tau sites in neurofibrillary tangles (NFT) are abnormally phosphorylated. We investigated the phosphorylation of tau in the hippocampus of nondemented patients and Alzheimer's disease patients by immunostaining with five site-specific antibodies against phosphorylated tau. In the pretangle stage, tau in neuropil threads was phosphorylated at serines 199, 202 and 409, numbered according to the longest human tau isoform, whereas tau in some neuronal soma was phosphorylated at serines 199, 202, 409 and 422. Tau at the stage of NFT was phosphorylated at serine 396 and threonine 231 in addition to serines 199, 202, 409 and 422. In the advanced stage, tau in ghost tangles was phosphorylated mainly at serine 396. These results suggest that the phosphorylation of each site in tau differs among the maturing stages of neurofibrillary change and that abnormal phosphorylation of tau in the neuronal soma occurs at 199, 202, 409 and 422 earlier than at threonine 231 and serine 396.

p53 and MDM2 expression in oral squamous cell carcinoma

The p53 tumor suppressor gene is the most commonly mutated gene in human cancer and is a frequent abnormality in oral squamous cell carcinoma and its precancerous lesions. MDM2 (murine double minute-2), a new proto-oncogene, may be associated with p53 gene products and may negatively affect the transcriptional activating function of p53. The purpose of this study was to investigate the incidence of MDM2 and its relationship to the expression of p53 in oral squamous cell carcinoma and precancerous lesions. Overexpression of p53 and MDM2 proteins was detected in 52 and 40% of oral squamous cell carcinomas, respectively. p53 gene mutation, absent in normal oral epithelium was observed in 31% of the carcinoma cases. Our finding suggested that MDM2 protein may be an alternative mechanism causing p53 protein dysfunction in oral squamous cell carcinoma.

The construction of novel mobilizable YAC plasmids and their behavior during trans-kingdom conjugation between bacteria and yeasts

Trans-kingdom conjugation is an easy and efficient method for gene transfer from prokaryotes to eukaryotes since it does not require DNA extraction and purification. We constructed novel mobilizable plasmids pAY-YAC-B and pAY-YAC-E. The origin of conjugal transfer (oriT) was inserted at two different positions, pAY-YAC-B contains oriT region in between two telomeres whereas pAY-YAC-E has oriT at the cloning site of pYAC4. By conjugation, both plasmids were successfully transferred from E. coli to S. cerevisiae and S. kluyveri yeasts with the aid of helper plasmid pRH220 which harbors mob and tra genes. The plasmids were transferred more efficiently in S. cerevisiae compared to S. kluyveri. The analyses by restriction enzyme digestion and Southern hybridization indicated that both plasmids maintained their original structure and size in transconjugant yeasts, therefore, reflecting the faithful nicking and subsequent resealing of plasmids during conjugation. The comparison between conjugative transfer and transformation has also been performed and discussed.

Sequence analysis of the genome of the unicellular cyanobacterium Synechocystis sp. strain PCC6803. II. Sequence determination of the entire genome and assignment of potential protein-coding regions

The sequence determination of the entire genome of the Synechocystis sp. strain PCC6803 was completed. The total length of the genome finally confirmed was 3,573,470 bp, including the previously reported sequence of 1,003,450 bp from map position 64% to 92% of the genome. The entire sequence was assembled from the sequences of the physical map-based contigs of cosmid clones and of lambda clones and long PCR products which were used for gap-filling. The accuracy of the sequence was guaranteed by analysis of both strands of DNA through the entire genome. The authenticity of the assembled sequence was supported by restriction analysis of long PCR products, which were directly amplified from the genomic DNA using the assembled sequence data. To predict the potential protein-coding regions, analysis of open reading frames (ORFs), analysis by the GeneMark program and similarity search to databases were performed. As a result, a total of 3,168 potential protein genes were assigned on the genome, in which 145 (4.6%) were identical to reported genes and 1,257 (39.6%) and 340 (10.8%) showed similarity to reported and hypothetical genes, respectively. The remaining 1,426 (45.0%) had no apparent similarity to any genes in databases. Among the potential protein genes assigned, 128 were related to the genes participating in photosynthetic reactions. The sum of the sequences coding for potential protein genes occupies 87% of the genome length. By adding rRNA and tRNA genes, therefore, the genome has a very compact arrangement of protein- and RNA-coding regions. A notable feature on the gene organization of the genome was that 99 ORFs, which showed similarity to transposase genes and could be classified into 6 groups, were found spread all over the genome, and at least 26 of them appeared to remain intact. The result implies that rearrangement of the genome occurred frequently during and after establishment of this species.