Long-term recovery from mine drainage disturbance of a macroinvertebrate community in the Ichi-kawa River,Japan

The effects of mine drainage on a benthic macroinvertebrate community and its recovery have been investigated for 25 years in the Ichi-kawa River in western Japan, focusing especially on change in community structure. Concentrations of arsenic, copper and zinc in the water were distinctly higher at sites just below the drainage than an upstream reference site before mine closure in 1973. Benthic communities there were severely damaged, as evidenced by reductions in the number of families and biomass. Chironomidae and a mayfly, Epeorus latifolium, predominated at the impacted sites, whereas stenopsychid caddisflies were dominant at the reference site. After mine closure, zinc concentrations significantly decreased downstream, although they remained higher than at the reference site. Following this, family richness and biomass of benthic communities clearly increased. In addition, the percentage of Trichoptera increased and, finally, Stenopsychidae became the dominant family in 1996 at all sites except just below the drainage. Therefore, the dominance of Stenopsychidae at the impacted sites is expected to be an indicator of complete recovery of the benthic community from the effect of mine drainage.     

A new species,Gazza rhombea, from the Indo-West Pacific, with a redescription ofG. achlamys Jordan & Starks, 1917 (Perciformes: Leiognathidae)

Gazza rhombea sp.nov. is described from 61 type and 81 non-type specimens, 19–176 mm in standard length, collected from the Indo-West Pacific. The species is similar to other congeners in general body appearance, differing from them in having the dorsolateral surface of the body scaled anterior to the dorsal fin origin, but not reaching to a vertical through the tip of the posterior branch of the supratemporal canal (vs. dorsolateral surface of body naked anterior to base of sixth or seventh dorsal fin spine base inG. achlamys; dorsolateral surface of body with scales extending anteriorly beyond tip of posterior branch of supratemporal canal inG. minuta), and having a long narrow anterodorsal extension from the subocular silvery region, in contact with the orbit only proximally (vs. broad anterodorsal extension, with proximal and distal contact with orbit inG. dentex).Gazza rhombea is also distinguishable fromG. achlamys andG. minuta by the morphology of the first dorsal fin pterygiophore, and the neural and hemal spines of the fifth preural centrum. The new species has usually been misidentified asG. achlamys, which is redescribed here, owing to its similarly deep-bodied appearance.     

Molecular phylogeny and radiation time of Erysiphales inferred from the nuclear ribosomal DNA sequences

Phylogenetic relationships of Erysiphales within Ascomycota were inferred from the newly determined sequences of the 18S rDNA and partial sequences of the 28S rDNA including the D1 and D2 regions of 10 Erysiphales taxa. Phylogenetic analyses revealed that the Erysiphales form a distinct clade among ascomycetous fungi suggesting that the Erysiphales diverged from a single ancestral taxon. The Myxotrichaceae of the Onygenales was distantly related to the other onygenalean families and was the sister group to the Erysiphales calde, with which it combined to form a clade. The Erysiphales/Myxotrichaceae clade was also closely related to some discomycetous fungi (Leotiales, Cyttariales and Thelebolaceae) including taxa that form cleistothecial ascomata. The present molecular analyses as well as previously reported morphological observations suggest the possible existence of a novel evolutionary pathway from cleistothecial discomycetous fungi to Erysiphales and Myxotrichaceae. However, since most of these fungi, except for the Erysiphales, are saprophytic on dung and/or plant materials, the questions of how and why an obligate biotroph like the Erysiphales radiated from the saprophytic fungi remain to be addressed. We also estimated the radiation time of the Erysiphales using the 18S rDNA sequences and the two molecular clockes that have been previously reported. The calculation showed that the Erysiphales split from the Myxotrichaceae 190–127 myr ago. Since the radiation time of the Erysiphales does not exceed 230 myr ago, even when allowance is made for the uncertainty of the molecular clocks, it is possible to consider that the Erysiphales evolved after the radiation of angiosperms. The results of our calculation also showed that the first radiation within the Erysiphales (138–92 myr ago) coincided with the date of a major diversification of angiosperms (130–90 myr ago). These results may support our early assumption that the radiation of the Erysiphales coincided with the evolution of angiosperm plants. Contribution No. 152 from the Laboratory of Plant Pathology, Mie University     

Redescription ofpolydactylus macrochir (günther, 1867), a senior synonym ofP. sheridani (macleay, 1884) (perciformes: Polynemidae)

Polydactylus macrochir (Günther, 1867), for many years identified asP. sheridani (Macleay, 1884), is redescribed as valid and a senior synonym of the latter species, following examination of the holotype of the former and comparative material.Polydactylus macrochir is characterized by 14 or 15 pectoral-fin rays (usually 14), five pectoral filaments, 70–76 pored lateral-line scales, 32–35 gill rakers, occipital profile concave in adults, posterior margin of maxilla extending considerably beyond posterior margin of adipose eyelid, depth of posterior portion of maxilla greater than dermal eye opening in adults, second spine of first dorsal fin very strong and long pectoral-fin rays (22–27% of standard length).Polydactylus macrochir is currently known only from northern Australian and southern Papua New Guinea, being endemic to those areas.     

Inhibition of Nitrogen Fixation in Soybean Plants Supplied with Nitrate III. Kinetics of the Formation of Nitrosylleghemoglobin and of the Inhibition of Formation of Oxyleghemoglobin

In order to elucidate the mechanism of inhibition, by nitrite,of the formation of oxyleghemoglobin (LbO₂ and the mechanismof generation of nitrosylleghemoglobin (LbNO), kinetic analysesof results of measurements of oxygen uptake and spectrophotometricassays of leghemoglobin were performed. The decrease, by nitrite, in the oxygen-binding capacity ofleghemoglobin was caused by the increase in levels of LbNO formedfrom ferrous leghemoglobin. In this case, the oxygen-bindingsite of leghemoglobin was competitively occupied by nitric oxideproduced from nitrite. The kinetic constants for the generation of LbNO from leghemoglobinand nitrite were 5.7 ? 10 for the association rate constant,4.4 ? 10^–5 for the dissociation rate constant, and 1.3? 10⁶ for the equilibrium constant. From calculations basedon the equilibrium constant, it appears that LbO₂ is presentin small amounts in nodules of plants supplied with nitrate.Furthermore, the dissociation rate constant for LbNO was muchsmaller than that for LbO₂ or carboxyleghemoglobin (LbCO). Thisdifference indicates that, once formed, LbNO is harder to dissociatethan LbO₂ or LbCO. Thus, the accumulation of LbNO in the nodule cytosol, as a resultof the supply of nitrate, would inhibit nitrogenase activitythrough a decrease in the diffusion of oxygen that results froma lack of LbO₂. (Received December 18, 1989; Accepted April 13, 1990)     

A novel core protein as well as polymorphic epithelial mucin carry peanut agglutinin binding sites in human gastric carcinoma cells: sequence analysis and examination of gene expression.

The peanut agglutinin (PNA)-binding site is protein-bound Gal beta 1-->3GalNAc, and is a tumor-associated carbohydrate marker expressed in many human carcinomas. PNA-binding glycoproteins isolated from KATO-III human gastric carcinoma cells were deglycosylated by trifluoromethanesulfonic acid, and rabbit antibodies against the core proteins were used to screen a lambda gt11 expression library constructed from these cells. Two different core proteins were identified by this approach. One was polymorphic epithelial mucin (PEM), initially found in breast carcinomas. PEM mRNA was expressed in normal tissues of the stomach, colon, and lung, but not in the small intestine, thyroid, and spleen. High levels of PEM mRNA were detected in some nude mouse-transplanted carcinomas, i.e. colorectal, pancreatic, stomach, and lung carcinomas. The other core protein was a novel one called MGC-24, which has a molecular mass of 24 kDa, is rich in hydroxyl amino acids and cysteine, and lacks repeating motifs. The mature MGC-24 glycoprotein behaved as a high-molecular-mass one upon SDS-polyacrylamide gel electrophoresis even after neuraminidase treatment. Treatment with endo-alpha-N-acetylgalactosaminidase in the absence of neuraminidase significantly changed the staining pattern by anti-MGC-24, confirming that MGC-24 carried PNA-binding sites. MGC-24 mRNA was intensely expressed in normal tissues of the colon, small intestine and thyroid, and in some nude mouse-transplanted colorectal and pancreatic adenocarcinomas.     

Temporal increase of two proteins in PC-12 pheochromocytoma cells induced by nerve growth factor

Two-dimensional gel electrophoresis revealed two protein spots, a (molecular weight 70,000, pI 4.6) and b (molecular weight 69,000, pI 4.4) in PC-12 cells (rat pheochromocytoma cells). When the cells were induced to differentiate with nerve growth factor, the amount of protein in spot a, and later spot b increased with time, then the amount in both spots gradually decrease to undetectable level. These spots were not detected in adult rat brain nor in other cell lines of rat and mouse. Thus, these proteins can be used as markers to follow the differentiation of PC-12 cells.