2-Chlorobenzoic acid and 2,5-dichlorobenzoic acid metabolism by crude extracts of Pseudomonas sp. CPE2 strain

F. FAVA, F. BALDONI AND L. MARCHETTI. 1996. Crude extracts of Pseudomonas sp. CPE2 strain, which is capable of growing on 2-chlorobenzoic acid (2–CBA) and 2,5–dichlorobenzoic acid (2,5–dCBA) in the absence of other carbon sources, were found to be capable of bioconverting 2–CBA and 2,5–dCBA to catechol and 4–chlorocatechol, respectively, by a reaction requiring molecular oxygen and exogenous NADH. Extracts obtained from 2–CBA-grown cells in the presence of 2–CBA and from 2,5–dCBA-grown cells in the presence of 2,5–dCBA were found to have activities similarly influenced by the assay parameters pH, temperature, and by concentration of oxygen, protein, Fe²⁺, FAD and NADH in the assay medium. In addition, the activity of the two crude extracts in the presence of 2–CBA or 2,5–dCBA was described by very similar Michaelis-Menten kinetic parameters. These observations led to the speculation that a unique broad-spectrum chlorobenzoate 1,2–dioxygenase catalyses the 2–CBA and 2,5–dCBA metabolism both in 2–CBA-and 2,5–dCBA-grown CPE2 cells.     

Record of a larval Parataeniophorus brevis from Hawaii

A 7.2 mm notochordal-length larva of Parataeniophorus brevis is described and illustrated from the fifth and the smallest specimen, collected near Hawaii. This larva is compared to all other described species of the family Mirapinnatidae, and is unique in having the unpaired fin rays developing in the finfold. The three species of Parataeniophorus can be distinguished on the basis of the number of dorsal-fin and anal-fin rays: bertelseni , 18–20 and 16–18; brevis , 13–16 and 13–15; gulosus 28–33 and 23–29, respectively.     

An ER membrane protein,Sop4, facilitates ER export of the yeast plasma membrane [H+]ATPase,Pma1

We have analyzed the mechanism by which Sop4, a novel ER membrane protein, regulates quality control and intracellular transport of Pma1–7, a mutant plasma membrane ATPase. At the restrictive temperature, newly synthesized Pma1–7 is targeted for vacuolar degradation instead of being correctly delivered to the cell surface. Loss of Sop4 at least partially corrects vacuolar mislocalization, allowing Pma1–7 routing to the plasma membrane. Ste2–3 is a mutant pheromone receptor which, like Pma1–7, is defective in targeting to the cell surface, resulting in a mating defect. sop4Δ suppresses the mating defect of ste2–3 cells as well as the growth defect of pma1–7 . Visualization of newly synthesized Pma1–7 in sop4Δ cells by indirect immunofluorescence reveals delayed export from the ER. Similarly, ER export of wild-type Pma1 is delayed in the absence of Sop4 although intracellular transport of Gas1 and CPY is unaffected. These observations suggest a model in which a selective increase in ER residence time for Pma1–7 may allow it to achieve a more favorable conformation for subsequent delivery to the plasma membrane. In support of this model, newly synthesized Pma1–7 is also routed to the plasma membrane upon release from a general block of ER-to-Golgi transport in sec13–1 cells.     

A new genus and species of deep demersal fish (Teleostei: Stephanoberycidae) from the tropical eastern North Atlantic

A novel stephanoberycid genus and species, Abyssoberyx levisquamosus Merrett & Moore is reported from bottom‐trawl abyssal captures in 4490–4640 m depth. It has cycloid scales, differing from Stephanoberyx , Acanthochaenus and Hispidoberyx with spinoid scales; has 1–2 dorsal fin spines, differing from Acanthochaenus and Malacosarcus with 0, Gibberichthys with 5–6 and Hispidoberyx with 3–5 spines; has 5–7 + 14–15 gill rakers, differing from Stephanoberyx with 12–15 + 25–27 and Acanthochaenus and Malacosarcus with 8 + 17–20 gill rakers. Selected aspects of the osteology of A. levisquamosus are described, to confirm that it shares several features in common with other stephanoberycid genera and allied stephanoberycoids. Aspects of its biology and ecology are discussed.     

Coccidian Parasites (Apicomplexa: Eimeriidae) of Nerodia spp. (Serpentes: Colubridae), with a Description of a New Species of Eimeria

Eimeria conanli n. sp. (Apicomplexa: Eimeriidae) is described from intestinal contents and feces of Nerodia erythrogaster transversa and N harteri harteri from northcentral Texas. Oocysts of the new species are ellipsoid in shape. 17.9 × 13.0(15–21 × 12–15) μm, with a smooth, thin, single-layered wall; shape index 1.4 (1.2–1.5). One to several (usually 2) polar granule(s) and an oocyst residuum are present, but a micropyie is absent. Sporocysts are elongate, 12.9 × 5.2 (13–15 × 5–6) -m, apparently without a true Stieda body structure. Each sporoeyst contains an ellipsoid residuum, 3.9 × 3.2 (3–6 × 2–4) μm, and elongate sporozoites, 11.4 × 2.5 (10–14 × 2–3) μm in situ, each with a spherical or subspherical anterior refractile body and spherical to ellipsoid posterior refractile body. In addition to the new species, oocysts of 4 previously described eimerians from colubrid snakes were found in these hosts.     

Production of metabolic and waste products by intensively farmed rainbow trout, Salmo gaivdnevi Richardson

The pollution production rate as measured by the increase in the amounts of ammonia, phosphate, nitrate, urea, and faeces in an intensive fish farm is described and is related to the amount of food fed per day or the biomass weight. Pollution production varied with fish size. Main pollutants produced per kg food fed per day were ammonia 31–37 g; phosphate 5.2–5.9 g; nitrate 9–15 g and suspended solids 40–9O g. Expressed as g kg⁻¹ fish produced per day ammonia ranged from 0.3–0.8 g; phosphate 0.067–0.17 g; nitrate 0.13–0.21 g and suspended solids 0.80–0.94 g. These rates differ from those reported in previous studies and these differences may be attributed to the design of the Shearwater farming system which involves self cleaning, intensively stocked tanks, a system which ultimately gives a more accurate assessment of pollution rates.     

Ultrastructure of Draparnaldia glomerata (Chaetophorales, Chlorophyceae). 1. The flagellar apparatus of the zoospore

The fine structure of the quadriflagellate zoospores of Draparnaldia glomerata (Vauch.) Agardh is described with emphasis on the flagellar root system and compared with the flagellar apparatus of related green algae. It is demonstrated that the flagellar root system in Draparnaldia is similar to that of the zoospore of Uronema belkae. Common features include presence of a cruciate root system (formula 2–5–2–5), prominent striated distal fibre connecting opposite basal bodies, a system I striated root component associated with the 2–stranded root, association of electron dense material with the 5–stranded root, mode of arrangement of the basal bodies in the absolute configuration model, and presence of four striated peripheral fibres interconnecting adjacent basal bodies. Differences exist in the shape of the striated peripheral fibres, the origin of the 2– and 5– stranded roots in the proximal part of the flagellar apparatus, and the architecture and striation pattern of the proximal part of the system I fibre that detaches from the 2–stranded root between adjacent basal bodies. Both the 2– and 5–stranded roots originate near the basal bodies and descend deeply into the zoospore. One of the 5–stranded roots passes near the eyespot of the chloroplast. The implications of these findings for the taxonomic position of the genus Draparnaldia are discussed. In addition, an evaluation is given of the present status of the order Chaetophorales. Suggestions are given to standardize some aspects of the current terminology of the cruciate flagellar root system in green algae.     

Amidation of β-Amyloid Peptide Strongly Reduced the Amyloidogenic Activity Without Alteration of the Neurotoxicity

Abstract: β-Amyloid accumulates in cerebral deposits in Alzheimer's disease, so to test the correlation between the neurotoxic and fibrillogenic capacity of β-amyloid, we synthesized a peptide homologous to fragment 25–35 of β-amyloid (β25–35) and amidated at the C-terminus (β25–35-NH₂). As the amidation strongly reduced the amyloidogenic capacity of β25–35, we compared its neurotoxic activity in the amidated (β25–35-NH₂) and nonamidated forms. The viability of primary cultures from fetal rat hippocampus was reduced in a dose-related manner (10–100 µ M ) similarly by β25–35 and β25–35-NH₂, whereas a scrambled peptide, amidated or nonamidated, did not alter the neuronal viability. The neurotoxic activity of β25–35-NH₂ is mediated by apoptosis as demonstrated by morphological and biochemical investigations. Electron microscopy examination of culture media with β25–35 or β25–35-NH₂ incubated with neuronal cells for 7 days confirmed the high level of fibrillogenic activity of β25–35 and the almost total absence of fibrils in the solution with β25–35-NH₂. Furthermore, staining with thioflavine S was used to identify amyloid fibrils, and only the cultures exposed to β25–35 exhibited intense staining associated with neuronal membranes. These data indicate that the neurotoxic activity of the β-amyloid fragment is independent of the aggregated state of the peptide.     

Plant community distribution and variation along the Awash river corridor in the main Ethiopian rift

The vegetation along the Awash River (1200-km long) in the main Ethiopian Rift, and its relationship with environmental factors was studied. Seven plant communities were described from the study area: (1) Acacia nilotica subsp . leiocarpa. – Carissa edulis type; (2) Acacia robusta subsp . usambarensis – Acokanthera schimperi type; (3) Celtis africana – Mimusops laurifolia type; (4) Acacia senegal – Acacia mellifera – Dobera glabra type; (5) Acacia nilotica subsp. indica – Ficus capreaefolia type; (6) Lannea schimperi – Glycine wightii type; and (7) Tamarix nilotica – Acacia hocki community type. It has been shown that the plant communities along the river follow an altitudinal gradient. The vegetation of the Awash River is mainly the result of the interactions between edaphic factors, the hydrology, altitude, slope and climate.     

Oxygen uptake through gills and skin in relation to body weight of an air-breathing siluroid fish, Saccobranchus (=Heteropneustes) fossilis

Oxygen uptake through gills and skin has been measured in juvenile and adult Saccobranchus fossilis and its relationship represented by the equation Vo₂= aW^b. When air-breathing is allowed the O₂ uptake via the gills and skin together increases by powers of 1 -084, 0–986 and 1–328 in juvenile, adult and juvenile+adult respectively. When air-breathing is prevented the slope (b) for O₂ uptake via the gills appear to be less in juveniles (0–765) than in adults (0–784) and juveniles+adults together (0–814). Under the same experimental condition, the slope for O₂ uptake via the gills+skin is also less in juveniles (0–478) than in adults (0–799) and juveniles+adults (0–755). Further decrease in the exponent value is found for the oxygen uptake of skin in relation to body weight under surfacing-prevented conditions ( b = 0–542). Different exponent values for juvenile and adult fishes may be due to their different growth pattern and physiology.     

Two new ciliates from Hong Kong coastal water: Orthodonella sinica n. sp. and Apokeronopsis wrighti n. sp. (Protozoa: Ciliophora)

ABSTRACT. The morphology and infraciliature of Orthodonella sinica n. sp. and Apokeronopsis wrighti n. sp., isolated from the coastal water off Hong Kong, were investigated in living and stained specimens. Orthodonella sinica n. sp. is diagnosed as: a marine Orthodonella 150–310 × 40–80 μm in vivo; with a dominant beak-like projection at the anterior end; about 70 somatic kineties; 84–126 dikinetids in the synhymenium; one contractile vacuole in the posterior one-fourth of cell, near the left margin; one conspicuous dorsal suture. Apokeronopsis wrighti n. sp. is diagnosed as: an Apokeronopsis about 150–230 × 35–55 μm in vivo; dark-reddish blood-cell-shaped cortical granules grouped in three rows on the ventral side and two rows on the dorsal side; 23–35 cirri in the right mid-ventral rows (MVR) and 23–32 cirri in the left MVR; six to eight buccal, two frontoterminal, 30–42 left marginal, and 32–43 right marginal cirri; 21–30 transverse cirri extending anteriorly beyond the level of mid-body; consistently three dorsal kineties. The separation of A. wrighti n. sp. and its highly similar congeners Apokeronopsis crassa and Apokeronopsis bergeri was supported by comparison of their SSrRNA gene sequences.     

Morphometries of the respiratory organs of the Indian green snake-headed fish, Channa punctata

Measurements of the dimensions of the different gills and the suprabranchial chambers have been made and the data analysed with respect to body weight using logarithmic transformations (Y = aW^b). The slope (b) for area of the total gill surface is 0–592 and for the supra-branchial chamber 0–696, and their combined respiratory surface: 0–623. The slope values for the surface areas of the 1st, 2nd, 3rd and the 4th gill arches were 0–595,0–578,0–614 and 0–572 respectively.
The slope for secondary lamellae/mm is –0138 and that for the bilateral surface area of an average-sized lamella 0–304.
These results indicate differences in growth patterns for the dimensions of the different gills. The growth-related decrease in the number of secondary lamellae/mm and size of an average secondary lamella together with evidence from "drowning" experiments and diffusing capacity calculation, suggest that this fish is better adapted for aquatic respiration than Anabas or Saccobranchus. The slopes for the total respiratory surface area and gill area seem to be comparatively low in this species.     

Life Cycle of Eimeria ferrisi Levine & Ivens, 1965 in the Mouse, Mus musculus

SYNOPSIS. The life cycle of Eimeria ferrisi is described from experimentally infected Mus musculus. The prepatent period was 3 days and the patent period was 3–4 days. The endogenous stages were found only in the cecum and colon. Three generations of schizonts were found. Mature 1st-generation schizonts first seen 24 hr postinoculation (PI) measured 10.9 (7–14) × 10.2 (6–13) μm and had 9.6 (7–14) merozoites. Some 2nd-generation schizonts had uninucleate merozoites and others had multinucleate merozoites. The former were first seen in small numbers 36 hr PI and were most abundant 48 hr PI. They measured 9.6 (5–13) × 7.9 (6–12) μm and had 18 (6–25) merozoites. Schizonts with multinucleate merozoites were seen 72 hr PI. Mature 3rd-generation schizonts were seen 72 hr PI. They measured 14.0 (12–18) × 11-0 (9–13) μm and had 12.5 (5–16) merozoites. Macrogamonts were first seen in 72 hr sections. Each young macrogamont had a large nucleus with a prominent nucleolus. Only one type of cytoplasmic granule appeared to be involved in the formation of the oocyst wall. Mature macrogamonts were 11.0 (5–14) × 10.0 (6–13) μm. Crescent-shaped bodies were observed in the parasitophorous vacuole of trophozoites and young macrogamonts. Early microgamonts were first recognized at 96 hr by the presence of darkly stained and irregularly shaped nuclei. Usually, mature microgametes were arranged in long, narrow whorls at the periphery of the microgamont or in whorls at the surface of 2–5 compartments.     

Production of monoclonal antibodies against Clostridium botulinum type E derivative toxin

Abstract Five monoclonal antibodies (MCA; E–8–2, 9–1, 11–2, 12–4, and 13–1) against Clostridium botulinum type E derivative toxin were prepared. Their ELISA titers were higher than or equivalent to that of conventional polyclonal antibody. Three of them (E-8–2, 12–4, and 13–1) possessed the neutralizing activity comparable to that of polyclonal antibody. The results of binding-competition experiments indicated that the monoclonal antibodies bound to different sites on the type E toxin molecule. Immunoblotting analyses demonstrated that E-8–2, 9–1, and 11–2 react to fragment I (heavy chain) of the toxin. By use of these monoclonal antibodies, it may be possible to scrutinize the structure-function relationship of botulinum toxins and cross reactions between type E and F toxins.     

Spinal Cord Dynorphin Precursor Intermediates Decline During Late Gestation

Abstract: This laboratory has previously reported that the maternal opioid analgesia associated with pregnancy and parturition is mediated, at least in part, by a maternal spinal cord dynorphin/κ opioid system. This analgesia is accompanied by an increase in dynorphin peptides (1–17 and 1–8) in the lumbar spinal cord. Levels of trypsin-generated arginine⁶-leucine-enkephalin (Leu-Enk-Arg)-immunoreactive determinants were also determined and used to reflect the content of dynorphin precursor intermediates. In spinal tissue, the amount of dynorphin A (1–17) contained in the form of precursor is, at a minimum, 10-fold higher than the content of mature dynorphin A (1–17) or dynorphin (1–8). During gestational day 22, the content of dynorphin precursor is reduced significantly (∼50%). The decline in the magnitude of dynorphin precursor intermediates in the spinal cord of pregnant rats vastly exceeds the magnitude of increase in the content of dynorphin peptides (1–17 and 1–8). This difference can best be explained by postulating a corresponding increase in the rate of release of spinal cord dynorphin (1–17). It is suggested that enhanced processing of dynorphin precursor intermediates represents the initial biochemical level of adaptation of spinal dynorphin neurons to increased demands of pregnancy.     

Description of a new Lake Tanganyikan cichlid fish of the genus Cyprichromis(Perciformes: Cichlidae) with a note on sexual dimorphism

Cyprichromis coloratus , a new cichlid species, is described based on 41 type specimens from the Zambian coast of Lake Tanganyika. It differs from Cyprichromis microlepidotus by having fewer scales in the longitudinal line (41–44 v . 59–70 in C. microlepidotus ) and upper lateral line (31–36 v . 47–59), from Cyprichromis leptosoma by more dorsal‐fin spines (14–15 v . 11–13 in C. leptosoma ) and longitudinal line scales (41–44 v . 38–40), from Cyprichromis pavo by fewer dorsal‐fin spines and soft rays (29–31, usually 30, in total v . 30–32, usually 31, in C. pavo ), and from Cyprichromis zonatus by shallower body depth [24·0–28·5 (26·4 ± 1·1)% of standard length v . 24·5–30·5 (28·4 ± 1·3)% in C. zonatus ] and smaller eye [eye length 25·2–30·9 (27·2 ± 1·1)% of head length v . 27·9–33·3 (30·2 ± 1·2)%]. The new species is also separable from C. microlepidotus , C. pavo and C. zonatus by absence of distinct small spots on the body ( v . pearl grey and yellowish small spots along scale rows on body at least in males of C. microlepidotus and C. pavo ), its distinct dichromatism (particularly on the caudal fin) between males of the same population ( v . dichromatism absent in C. zonatus ) and absence of vertical bands ( v . three or four distinct vertical bands beneath dorsal fin base in live males of C. zonatus ). Cyprichromis coloratus n. sp. also exhibits sexual dimorphism, females having a larger head and males having longer pelvic fin, differences which are discussed in relation to reproductive behaviour. A key to the five species of Cyprichromis is included. A lectotype is designated for Cyprichromis leptosoma .     

A competitive coexistence principle?

Competitive exclusion – n species cannot coexist on fewer than n limiting resources in a constant and isolated environment – has been a central ecological principle for the past century. Since empirical studies cannot universally demonstrate exclusion, this principle has mainly relied on mathematical proofs. Here we investigate the predictions of a new approach to derive functional responses in consumer/resource systems. Models usually describe the temporal dynamics of consumer/resource systems at a macroscopic level – i.e. at the population level. Each model may be pictured as one time-dependent macroscopic trajectory. Each macroscopic trajectory is, however, the product of many individual fates and from combinatorial considerations can be realized in many different ways at the microscopic – or individual – level. Recently it has been shown that, in systems with large enough numbers of consumer individuals and resource items, one macroscopic trajectory can be realized in many more ways than any other at the individual – or microscopic – level. Therefore, if the temporal dynamics of an ecosystem are assumed to be the outcome of only statistical mechanics – that is, chance – a single trajectory is near-certain and can be described by deterministic equations. We argue that these equations can serve as a null to model consumer-resource dynamics, and show that any number of species can coexist on a single resource in a constant, isolated environment. Competition may result in relative rarity, which may entail exclusion in finite samples of discrete individuals, but exclusion is not systematic. Beyond the coexistence/exclusion outcome, our model also predicts that the relative abundance of any two species depends simply on the ratio of their competitive abilities as computed from – and only from – their intrinsic kinetic and stoichiometric parameters.     

Loaches of the genus Lepidocephalichthys, from Manipur, with description of a new species

A new species Lepidocephalichthys manipurensis , is described, confined to the Chandel district of Manipur near the adjoining borderland areas of Manipur, India and Burma (Myanmar). It is distinguished by the following combination of characters: a sharp small black dot just above the upper base of the caudal fin; 8–9 dorsal short dark ashy brown bars from occiput to the base of the caudal fin; absence of scales on the vertex of head; caudal fin fork, pectoral, ventral and anal fins are non-immaculate; least depth of caudal peduncle 50·00–60·24% (mean 54·09) of its length and 7·69–8·11% L , S (mean 8·22); caudal fin with 4–5 W-shaped bands: a single dark black stripe from tip of snout to eye; 8–11 spots on the mid lateral line; and 30–31 vertebrae. A key to the identification of lepidocephalid loaches of Manipur is provided.     

Eimeria sinaitae n. sp. (Apicomplexa: Eimeriidae) from the Rock Agama (Agama sinaita) in Saudi Arabia

Eimeria sinaitae n. sp. is described from the gall bladder of Agama sinaita from Wasie, Saudi Arabia. Sporulated oocysts are elongate-ellipsoid 34.4 times 22.0 (29.0–40.0 times 17.4–24.5) μm. Oocyst wall is smooth, greenish yellow, 1.2 (1.0–1.4) μm thick, and two-layered. Micropyle, polar granule, and oocyst residuum are absent. Sporocysts are ellipsoid 11.4 times 7.6 (9.8–15.0 times 6.7–9.0) μm. Sporocyst residuum is present. The sporocysts lack a Stieda body. Sporozoites are crescent-shaped, blunt at one end and tapered at the other. Eimeria species from Agamidae are compared.     

From Spencer to E-P: Eyewitnessing the Progress of Fieldwork

Strangers Abroad Series: Sir Walter Baldwin Spencer (1860–1929), Fieldwork; Franz Boas (1858–1952), The Shackles of Tradition; William Rivers (1864–1922), Everything Is Relatives; Bron-islaw Malinowski (1884–1942), Off the Verandah; Margaret Mead (1901–1978), Coming of Age; Sir Edward Evans-Pritchard (1902–1973), Strange Beliefs.