Re-description and taxonomy ofpentanchus profundicolus smith & radcliffe, based on a second specimen from the philippines (chondrichthyes, carcharhiniformes, scyliorhinidae)

Pentanchus profundicolus is an enigmatic shark, characterized by a single dorsal fin. The holotype, which was collected in 1909 from the Philippines, had remained the only known example of the species for 90 years. A second specimen, collected from the same waters, is re-described. The presence of a single dorsal fin remains equivocal in so far as it represents the normal condition for the species. Aspects of the species' relationship with the species ofApristurus are discussed.     

Skill-Specific Changes in Somatosensory Nogo Potentials in Baseball Players

Athletic training is known to induce neuroplastic alterations in specific somatosensory circuits, which are reflected by changes in somatosensory evoked potentials and event-related potentials. The aim of this study was to clarify whether specific athletic training also affects somatosensory Nogo potentials related to the inhibition of movements. The Nogo potentials were recorded at nine cortical electrode positions (Fz, Cz, Pz, F3, F4, C3, C4, P3 and P4) in 12 baseball players (baseball group) and in 12 athletes in sports, such as track and field events and swimming, that do not require response inhibition, such as batting for training or performance (sports group). The Nogo potentials and Go/Nogo reaction times (Go/Nogo RTs) were measured under a somatosensory Go/Nogo paradigm in which subjects were instructed to rapidly push a button in response to stimulus presentation. The Nogo potentials were obtained by subtracting the Go trial from the Nogo trial. The peak Nogo-N2 was significantly shorter in the baseball group than that in the sports group. In addition, the amplitude of Nogo-N2 in the frontal area was significantly larger in the baseball group than that in the sports group. There was a significant positive correlation between the latency of Nogo-N2 and Go/Nogo RT. Moreover, there were significant correlations between the Go/Nogo RT and both the amplitude of Nogo-N2 and Nogo-P3 (i.e., amplitude of the Nogo-potentials increases with shorter RT). Specific athletic training regimens may induce neuroplastic alterations in sensorimotor inhibitory processes.     

Coevolution and Hierarchical Interactions of Tomato mosaic virus and the Resistance Gene Tm-1

During antagonistic coevolution between viruses and their hosts, viruses have a major advantage by evolving more rapidly. Nevertheless, viruses and their hosts coexist and have coevolved, although the processes remain largely unknown. We previously identified Tm-1 that confers resistance to Tomato mosaic virus (ToMV), and revealed that it encodes a protein that binds ToMV replication proteins and inhibits RNA replication. Tm-1 was introgressed from a wild tomato species Solanum habrochaites into the cultivated tomato species Solanum lycopersicum. In this study, we analyzed Tm-1 alleles in S. habrochaites. Although most part of this gene was under purifying selection, a cluster of nonsynonymous substitutions in a small region important for inhibitory activity was identified, suggesting that the region is under positive selection. We then examined the resistance of S. habrochaites plants to ToMV. Approximately 60% of 149 individuals from 24 accessions were resistant to ToMV, while the others accumulated detectable levels of coat protein after inoculation. Unexpectedly, many S. habrochaites plants were observed in which even multiplication of the Tm-1-resistance-breaking ToMV mutant LT1 was inhibited. An amino acid change in the positively selected region of the Tm-1 protein was responsible for the inhibition of LT1 multiplication. This amino acid change allowed Tm-1 to bind LT1 replication proteins without losing the ability to bind replication proteins of wild-type ToMV. The antiviral spectra and biochemical properties suggest that Tm-1 has evolved by changing the strengths of its inhibitory activity rather than diversifying the recognition spectra. In the LT1-resistant S. habrochaites plants inoculated with LT1, mutant viruses emerged whose multiplication was not inhibited by the Tm-1 allele that confers resistance to LT1. However, the resistance-breaking mutants were less competitive than the parental strains in the absence of Tm-1. Based on these results, we discuss possible coevolutionary processes of ToMV and Tm-1.     

The molecular basis of mutations at the Waxy locus from Amaranthus caudatus L.: evolution of the waxy phenotype in three species of grain amaranth

Polymorphisms at the Waxy locus of Amaranthus caudatus L. collected from a wide range of regions were used to investigate genetic diversity and mutation sites. A comparison of the Waxy locus revealed a very high level of sequence conservation. This result clearly showed low environmental and evolutionary variability in the Waxy gene. We also performed screening to confirm the mutation sites in the coding sequences of all accessions. The results indicate that one insertion in the coding region of Waxy genes was responsible for the change in perisperm starch leading to the waxy phenotype in all accessions of this species, and thus that a single mutation event altered the regulation of the Waxy gene during the domestication of this crop. In addition, phylogenetic analysis showed that waxy phenotypes within each of three species, A. caudatus, A. cruentus and A. hypochondriacus, originated separately or differentiated from nonwaxy phenotypes of each species through a single mutational event (i.e., a frame shift or base substitution). We also compared obvious structural features of the coding sequence of waxy and nonwaxy phenotypes with those of low-amylose phenotypes in A. caudatus. The Waxy coding sequences of low-amylose phenotypes do not show polymorphisms and are identical with those of waxy phenotypes. This could mean that there is another gene that encodes a key enzyme responsible for amylose synthesis as the elementary quantity in tissues other than perisperm in A. caudatus.     

IOP1 Protein Is an External Component of the Human Cytosolic Iron-Sulfur Cluster Assembly (CIA) Machinery and Functions in the MMS19 Protein-dependent CIA Pathway

The emerging link between iron metabolism and genome integrity is increasingly clear. Recent studies have revealed that MMS19 and cytosolic iron-sulfur cluster assembly (CIA) factors form a complex and have central roles in CIA pathway. However, the composition of the CIA complex, particularly the involvement of the Fe-S protein IOP1, is still unclear. The roles of each component are also largely unknown. Here, we show that MMS19, MIP18, and CIAO1 form a tight “core” complex and that IOP1 is an “external” component of this complex. Although IOP1 and the core complex form a complex both in vivo and in vitro, IOP1 behaves differently in vivo. A deficiency in any core component leads to down-regulation of all of the components. In contrast, IOP1 knockdown does not affect the level of any core component. In MMS19-overproducing cells, other core components are also up-regulated, but the protein level of IOP1 remains unchanged. IOP1 behaves like a target protein in the CIA reaction, like other Fe-S helicases, and the core complex may participate in the maturation process of IOP1. Alternatively, the core complex may catch and hold IOP1 when it becomes mature to prevent its degradation. In any case, IOP1 functions in the MMS19-dependent CIA pathway. We also reveal that MMS19 interacts with target proteins. MIP18 has a role to bridge MMS19 and CIAO1. CIAO1 also binds IOP1. Based on our in vivo and in vitro data, new models of the CIA machinery are proposed.     

Prospectively Isolated Cancer-Associated CD10+ Fibroblasts Have Stronger Interactions with CD133+ Colon Cancer Cells than with CD133? Cancer Cells

Although CD133 has been reported to be a promising colon cancer stem cell marker, the biological functions of CD133⁺ colon cancer cells remain controversial. In the present study, we investigated the biological differences between CD133⁺ and CD133⁻ colon cancer cells, with a particular focus on their interactions with cancer-associated fibroblasts, especially CD10⁺ fibroblasts. We used 19 primary colon cancer tissues, 30 primary cultures of fibroblasts derived from colon cancer tissues and 6 colon cancer cell lines. We isolated CD133⁺ and CD133⁻ subpopulations from the colon cancer tissues and cultured cells. In vitro analyses revealed that the two populations showed similar biological behaviors in their proliferation and chemosensitivity. In vivo analyses revealed that CD133⁺ cells showed significantly greater tumor growth than CD133⁻ cells (P = 0.007). Moreover, in cocultures with primary fibroblasts derived from colon cancer tissues, CD133⁺ cells exhibited significantly more invasive behaviors than CD133⁻ cells (P<0.001), especially in cocultures with CD10⁺ fibroblasts (P<0.0001). Further in vivo analyses revealed that CD10⁺ fibroblasts enhanced the tumor growth of CD133⁺ cells significantly more than CD10⁻ fibroblasts (P<0.05). These data demonstrate that the in vitro invasive properties and in vivo tumor growth of CD133⁺ colon cancer cells are enhanced in the presence of specific cancer-associated fibroblasts, CD10⁺ fibroblasts, suggesting that the interactions between these specific cell populations have important roles in cancer progression. Therefore, these specific interactions may be promising targets for new colon cancer therapies.     

Effect of dibutyryl cAMP on cell cycle progression of rat brain tumor cells in vitro

Summary Autoradiographic and flow microfluorometry analyses have been applied to a study of perturbed cell kinetics in 9L rat brain tumor cells treated with dibutyryl cyclic AMP and theophylline alone and in combination in vitro. At a concentration of 1 mM each, cell growth ceased shortly after the administration of these drugs. The results indicate that cells in S and G₂ phase at the time of drug administration can undergo mitosis even though a considerable prolongation of G₂ phase was apparent. However, cells in G₁ at the time of drug administration were arrested in that phase whereas those cells in S or G₂ were able to complete one mitosis before becoming arrested in the G₁ phase. This blocking effect was reversible, and cells resumed proliferation at a normal rate shortly after the removal of these drugs. This work was supported in part by NIH Cancer Research Center Grant CA-13525 and CA-19992 from NCI, and by the Association for Brain Tumor Research. Presented at the 6th International Cell Cycle Conference, March, 1976, New Orleans, Louisiana. The tumor used in this study was provided by William H. Sweet, Paul T. Kornblith, Janette L. Messer and Beverly O. Whitman of the Massachusetts General Hospital, Boston, Massachusetts.     

Records ofApristurus herklotsi (Lamniformes,Scyliorhinidae) and discussion of its taxonomic relationships

Additional specimens of the rareApristurus herklotsi are reported, and the characteristic features of this species are discussed.A. herklotsi is concluded to be a distinct species, having a very long snout, a narrow distance between the nostrils, a long caudal fin, a short abdomen, numerous teeth on both jaws, and a low number of monospondylous vertebrae.A. herklotsi appears to be mature at about 44 cm in total length.     

Application of high-performance liquid chromatography with a chemiluminescence detection system to determine catecholamines in urine

Chemiluminescence generated with the reaction of bis(2,4,6-trichlorophenyl)oxalate and hydrogen peroxide was applied to a detection system for high-performance liquid chromatography to determine fluorescamine-labeled catecholamines. The sensitivity of the chemiluminescence detection system with 25 fmol of detection limit was approximately 20 times higher than that of a conventional fluorescence detection system. Norepinephrine and dopamine in human urine were determined by the use of the new high-performance liquid chromatography detection system with the coefficient of variation of less than 4.0%. Good correlations (r = 0.998 for norepinephrine and r = 0.999 for dopamine) were obtained between the values by the present method and the conventional method.