Description of four new species in the hard coral genus Acropora Oken, 1815 (Scleractinia: Astrocoeniina: Acroporidae) from south-east Africa

Four new species in the hermatypic scleractinian coral genus Acropora art described from southeast Africa. Two species, A. natalensis sp. nov. and A. mossambica sp. nov. , occur in both South Africa and Mozambique. Two species, A. sordiensis sp. nov. , and A. branchi sp. nov. , are only known from northern Natal in South Africa. A. branchi sp. nov. and A. mossambica sp. nov. are intertidal species and were collected from permanent tidal pools. A. sordiensis sp. nov. and A. natalensis sp. nov. are strictly subtidal species.     

Momordica sahyadrica sp. nov. (Cucurbitaceae), an endemic species of Western Ghats of India

Momordica sahyadrica is a new species occurring in a very narrow habitat range in Western Ghats of India. Formerly, material of it was placed under Momordica dioica , but it appeared distinct from that species in various morphological and ecological features. It is described and illustrated with a note on its distribution and ecology.     

A Review of Some Species of Myxidium Bütschli, 1882 (Myxozosporea) From Eels (Anguilla Spp.)

SYNOPSIS. Myxidium spores from various eel hosts ( Anguilla spp.) are compared. Myxidium anguillae, M. enchelypterygii, M. illinoisense, M. serum , and M. zealandicum are synonymized with M. giardi , a ubiquitous species reported from A. anguilla, A. rostrata, A. mossambica, A. japonica, A. reinhardtii, A. bicolor pacifica, A. australis , and A. dieffenbachii. Myxidium uchiyamae, M. lentiforme, M. matsuii and M. acinum are retained, and 2 new species described. Species other than M. giardi appear to be restricted to the Indo-Pacific region.     

Uromyces umiamensis, a new rust species on Momordica cochinchinensis in India

Uromyces umiamensis is described as a new rust fungus (Basidiomycota, Uredinales) of Momordica cochinchinensis (Cucurbitaceae) from Meghalaya, in northeastern India. The species differs from the known Uromyces species on members of Cucurbitaceae in terms of the character of the teliospores and aeciospores and its apparently demicyclic life cycle. Besides U. yakushimensis and the present species, all Uromyces species known from cucurbits occur in the New World. A key to known Uromyces species on Cucurbitaceae is provided.     

The 1H nuclear-magnetic-resonance spectra of Neurotoxin I and cardiotoxin Vii4 from Naja mossambica mossambica.

Two toxins from the venom of Naja mossambica mossambica, neurotoxin I and cardiotoxin VII4, were investigated in aqueous solution by high-resolution 1H nuclear magnetic resonance (NMR) techniques at 360 MHz. The spectral characterization of the proteins included determination of the number of slowly exchanging amide protons which can be observed in 2H2O solution, measurement of the amide proton chemical shifts and exchange rates, characterization of the aromatic spin systems and the internal mobilities of aromatic rings, and studies of the pH dependence of the NMR spectra. For numerous resonances of labile and non-labile protons quite outstanding pH titration shifts were observed. It is suggested that these NMR parameters provide a useful basis for comparative structural studies of different proteins in the large group of homologous snake toxins. As a first application the NMR data presently available in the literature on neurotoxin II from Naja naja oxiana, toxin alpha from Naja nigricollis and erabutoxin a and b from Laticauda semifasciata have been used to compare these three proteins with neurotoxin I from Naja mossambica mossambica. This preliminary comparative study provides evidence that the same type of spatial structure prevails for these four homologous neurotoxins and that the folding of the backbone corresponds quite closely to that observed in the crystal structure of erabutoxin b. A second application is the comparison of cardiotoxin VII4 from Naja mossambica mossambica with the neurotoxins. The experimental data indicate that the folding of the polypeptide backbone is closely similar, but that the cardiotoxin molecule is markedly more flexible than the neurotoxins.     

Isolation and characterization of 10 SSR markers of Momordica charantia (Cucurbitaceae)

? Premise of the study: Microsatellite markers were isolated and characterized from the genome of Momordica charantia (bitter melon) to be applied in studies of genetic diversity and population structure. ? Methods and Results: Twenty-five microsatellite loci were isolated from the genome of bitter melon using the Fast Isolation by AFLP of Sequences COntaining Repeats (FIASCO) method. Ten loci were polymorphic, and the number of alleles per locus ranged from three to seven, with the observed heterozygosity ranging from 0.46 to 0.65. The markers also amplified successfully in the related species M. cochinchinensis and Cucurbita pepo. ? Conclusions: These markers will have potential utility for applications in genetic diversity evaluation, molecular fingerprinting, identification, comparative genomics analysis, and genetic mapping in Momordica species, as well as in C. pepo.     

Development and characterization of polymorphic microsatellite markers in Momordica charantia (Cucurbitaceae)

? Premise of the study: Polymorphic microsatellite markers were developed for Momordica charantia L. to investigate the genetic diversity and population structure within and between M. charantia and its four related species (Cucurbita pepo L., Luffa cylindrical L., Lagenaria siceraria L., and Cucumis sativus L.). ? Methods and Results: Using the Fast Isolation by AFLP of Sequence COntaining Repeats (FIASCO) method, 16 polymorphic microsatellite loci were identified in 36 individuals of M. charantia. Across all the M. charantia samples, the number of alleles per locus ranged from three to eight. Seven primers successfully amplified in the four related species. ? Conclusions: These markers will be useful to study population ecology and population differentiation among M. charantia species and its related species.     

Cucurbitane glucosides from Momordica charantia leaves as oviposition deterrents to the leafminer, Liriomyza trifolii

The American serpentine leaf mining fly, Liriomyza trifolii, whose larva feeds on more than 120 plant species is well characterized by its high degree of polyphagy. Observations on the oviposition behavior by L. trifolii demonstrated that among cucurbitaceous plants, Momordica charantia is rarely attacked by L. trifolii. The methanol extract of M. charantia leaves strongly deterred the females from ovipositing on kidney bean leaves treated at a concentration of 1 g leaf equivalent extract/ml. Analysis of the polar fraction of the methanol extract of M. charantia leaves resulted in the isolation of a novel cucurbitane glucoside, 7-O-beta-D-glucopyranosyl-3,23-dihydroxycucurbita-5,24-dien-19-al, named momordicine IV, along with another known compound, momordicine II. Momordicine II and IV deterred oviposition by L. trifolii significantly when bioassays were carried out on kidney bean leaves treated at 75.6 and 20.3 microg/cm2 leaf surface, respectively. There was no synergistic effect on oviposition deterrent when the two compounds were combined in their natural abundance.     

Activation of phospholipase A(2) by long chain fatty acyl groups involves a novel unstable linkage

The acidic isoform of phospholipase A(2) from Naja mossambica mossambica was activated by treatment with a molar equivalent of oleoyl imidazolide. Modification of the protein was accompanied by 50% quenching of tryptophan fluorescence and a significant red shift. The (3)H(9,10) labeled oleoyl residue was co-eluted with the enzyme during gel filtration in the presence of 20% 1-propanol or excess albumin, both of which remove free oleic acid from the enzyme. In contrast, the adduct was labile as to electrophoresis on SDS-PAGE and acid or alkali urea PAGE. The formation of a covalently linked adduct was demonstrated by electrospray mass spectrometry in the presence of 2% formic acid. No such adduct was formed by the phospholipase A(2) isoform from Naja naja atra, which differs in sequence from the N. mossambica mossambica isoform by seven residues including 2 histidine residues and 1 lysine residue. We conclude that oleoyl imidazolide activates the N. mossambica mossambica enzyme by forming an acyl adduct which is unstable as to protein denaturation. The magnitude of tryptophan fluorescence quenching indicates that the site of acylation lies in the sequence WWHF.     

Acanthocephalus reunionensis n sp (Acanthocephala: Echinorhynchidae), a parasite of Anguilla species (Anguillidae) from Reunion Island

In a survey of 118 eels Anguilla bicolor, A. marmorata and A. mossambica, (Anguillidae) indigenous to Reunion Island in the Mascarene island group, western Indian Ocean, a new species of acanthocephalan, Acanthocepholus reunionensis n. sp., was found. With a proboscis hook formula of 19 rows of 4-5 hooks, and elongated cement glands arranged in three pairs, this species differs from all other species in the genus. This is the first record of the genus Acanthocephalus occurring in eels from the African Region.     

赤(瓜包)亚族植物叶片中脉的比较解剖

本文对赤(瓜包)属(Thladiantha Bunge)、白兼果属(Baijiana A.M.Lu et J.Q.Li)和苦瓜属(Momordica L.)共11种植物叶片中脉进行了比较解剖学研究。除苦瓜属一种外,其余10种的叶片中脉解剖学资料均为首次报道。分析结果表明:叶片中脉维管束的数目以及排列方式具有分类学意义,而种间和种内维管束数目的减少,在一定程度上反映出植物迁移和演化的方向。     

Paraquimperia Africana n. sp (Nematoda : Quimperiidae), a new intestinal parasite of the eel Anguilla mossambica Peters, in South Africa

A new seuratoid nematode of the family Quimperiidae, Paraquimperia africana n. sp., is described from the small intestine of the longfin eel, Anguilla mossambica Peters, from the Eastern Cape Province, South Africa. The new species is characterized mainly by the presence of a ventral sucker in mature males, short spicules (147-171 microm), the number and arrangement of caudal papillae, the postesophageal position of the excretory pore, and by the slender female tail. In this new species, a variability in the number (3-5 pairs) of subventral preanal papillae was observed. Paraquimperia africana is the first representative of the genus in Africa. In view of recent reports, Paraquimperia aditum (Mueller, 1934) is considered a junior synonym of Paraquimperia tenerrima (Linstow, 1878). Paraquimperia xenentodonia Gupta and Bakshi, 1984 is considered a species inquirenda.     

Molecular mechanism of cardiotoxin action on axonal membranes.

Cardiotoxin isolated from Naja mossambica mossambica selectively deactivates the sodium-potassium activated adenosine triphosphatase of axonal membranes. Tetrodotoxin binding and acetylcholinesterase activities are unaffected by cardiotoxin treatment. The details of association of cardiotoxin with the axonal membrane were studied by following the deactivation of the sodium-potassium activated adenosine triphosphatase and by direct binding measurements with a tritiated derivative of the native cardiotoxin. The maximal binding capacity of the membrane is 42-50 nmol of cardiotoxin/mg of membrane protein. The high amount of binding suggests association of the toxin with the lipid phase of the membrane. It has been shown that cardiotoxin first associates rapidly and reversibly to membrane lipids, then, in a second step, it induces a rearrangement of the membrane structure which produces and irreversible deactivation of the sodium-potassium activated adenosine triphosphatase. Solubilization of the membrane-bound ATPase with Lubrol WX gives an active enzyme species that is resistant to cardiotoxin-induced deactivation. Cardiotoxin binding to the membrane is prevented by high concentrations of Ca 2+ and dibucaine. Although cardiotoxins and neurotoxins of cobra venom have large sequence homologies, their mode of action on membranes is very different. The cardiotoxin seems to bind to the lipid phase of the axonal membrane and inhibits the sodium-potassium activated adenosine triphosphatase, whereas the neurotoxin associates with a protein receptor in the post-synaptic membrane and blocks acetylcholine transmission.     

Aspects of the biology of Tilapia mossambica Peters (Pisces: Cichlidae) in a natural freshwater lake (Lake Sibaya, South Africa)

An account is given of some aspects of the biology of Tilapia mossambica Peters in Lake Sibaya, South Africa. Lake Sibaya is a warm shallow coastal lake with extensive shallow terraces in the littoral which shelve abruptly into underwater valleys. The substrate is predominantly sandy. Aquatic macrophytes are generally restricted to water 1–7 m deep. Adult fishes (over 8 cm standard length) are usually absent from water deeper than 12m and shallower than 0–5 m, whereas juveniles may occur at all depths, and fry only in very shallow water.
T. mossambica inhabits the littoral and sublittoral in the warm and transition periods (August–April) but moves into deep water in the cool season (May–July). Exposed and sheltered areas are utilized for different purposes by adult fishes, the former for nesting, and latter for feeding and mouth–brooding. Habitat selection by males is governed by the availability of suitable nest sites. Nests are most common in sparsely–vegetated sheltered areas. Brooding females preferred sheltered littoral areas but ventured onto the terrace to release the fry. Juveniles and fry inhabited exposed shores with a temperature gradient which reversed diurnally. The breeding, shoaling and feeding behaviour is described. The biology of T. mossambica in Lake Sibaya is compared to data on the same, and similar species, in other systems. The utilization of available resources in the lake by T. mossambica is discussed and reference is made to the importance of the retention of generalized characters for the successful habitation of the cyclically–renewed habitat of the littoral.     

Isolation of a trypsin inhibitor with deletion of N-terminal pentapeptide from the seeds of Momordica cochinchinensis, the Chinese drug mubiezhi.

A trypsin inhibitor, MCCTI-1, with a molecular weight of 3479 Da as determined by mass spectrometry, was isolated from Momordica cochinchinensis seeds with a procedure involving extraction with 5% acetic acid, ammonium sulfate precipitation, ion exchange chromatography on CM-Sepharose and reverse-phase high performance liquid chromatography. The sequence of its first 13 N-terminal amino acid residues was ILKKCRRDSDCPG which was about 85% identical with the sequence of trypsin inhibitor MCTI-1 from Momordica charantia Linn. When compared with the sequences of most other squash family trypsin inhibitors, the sequence of MCCTI-1 was characterized by the deletion of a pentapeptide from the N-terminus. Trypsin inhibitors also existed in seeds of some hitherto uninvestigated Cucurbitaceae species.     

Antioxidative effect of a chymotrypsin inhibitor from Momordica cochinchinensis (Cucurbitaceae) seeds in a primary rat hepatocyte culture.

The antioxidative activity of a chymotrypsin-specific potato type I inhibitor from Momordica cochinchinensis (MCoCI) (Cucurbitaceae) has been investigated using the primary rat hepatocyte system. tert-Butyl hydroperoxide (t-BHP) was used to induce oxidative stress. Pretreatment of hepatocytes with MCoCI for 24 h significantly reversed t-BHP-induced cell damage, and the associated glutathione depletion and lipid peroxidation. The activities of glutathione-S-transferase and superoxide dismutase were also increased. These results suggested that MCoCI possessed antioxidative activity which may account for some of the pharmacological effects of Momordica cochinchinensis seeds, the traditional Chinese medicine known as Mubiezhi, from which MCoCI was isolated.     

1,2-dotriacontanedioyl-sn-glycero-3-phosphocholine: A cyclic lipid used for phospholipase A2-catalyzed modulation of the liposome surface charge

An aqueous suspension of liposomes, which were made of cyclic 1, 2-dotriacontanedioyl-sn-glycero-3-phosphocholine (dTPC) and 1, 2-diphytanyl-sn-glycero-3-phosphocholine, was incubatedwith phospholipase A2 (Naja mossambica mossambica) in 0.05 M Tris-HCl, pH 7.7-7.8. At 25 degrees C, approximately 30% of the cyclic lipids was digested into 1-(omega-carboxyhentriacontanoyl)-sn-glycero-3-phosphocholine (lyso-dTPC), the original morphology being preserved but with a decrease in the zeta-potential of the membrane from ca. +2 to -1 mv. At 38 degrees C in 30 min, as much as 45% of the cyclic lipids was attacked by the lipase, which resulted in lowering of the potential to -2.5 to -3 mV. The enzymatic surface-charge modulation was discussed in conjunction with a side-selective attack of the phospholipase on the lipid bilayer.     

The structure of the chorion of the egg of the mouthbrooding cichlid fish Tilapia mossambica

In Tilapia mossambica , the zona radiata of the chorion of the egg is greatly reduced and the gelatinous membrane is absent. These modifications can be correlated with the mouth-incubating habit of this species.     

1H nuclear-magnetic-resonance studies of the three-dimensional structure of the cardiotoxin CTXIIb from Naja mossambica mossambica in aqueous solution and comparison with the crystal structures of homologous toxins

Using the previously reported sequence-specific 1H-NMR assignments, structural constraints for the cardiotoxin CTXIIb from Naja mossambica mossambica were collected. These include distance constraints from nuclear Overhauser enhancement measurements both in the laboratory and in the rotating frame, dihedral angle constraints derived from spin-spin coupling constants, and constraints from hydrogen bonds and disulfide bridges. Structure calculations with the distance geometry program DISMAN confirmed the presence of the previously identified antiparallel beta-sheets formed by residues 1-5 and 10-14, and by 20-27, 35-39 and 49-55, and established the nature of the connections between the individual beta-strands. These include a right-handed crossover between the two peripheral strands in the triple-stranded beta-sheet, and a type I tight turn immediately preceding the beta-strand 49-55. The spatial arrangement of the polypeptide backbone in the solution structure of CTXIIb is closely similar to that in the crystal structure of the homologous cardiotoxin VII4 from the same species. In an Appendix the origin of the large pH dependence of two amide proton chemical shifts in CTXIIb is explained.     

Characterization of elapidae snake venom components using optimized reverse-phase high-performance liquid chromatographic conditions and screening assays for alpha-neurotoxin and phospholipase A2 activities

The vast majority of Elapidae snake venoms, genus Naja, includes three classes of toxic polypeptides: alpha-neurotoxins, phospholipases A2, and cardiotoxins. A new experimental approach using reverse-phase high-performance liquid chromatography in particular has been developed, allowing their respective resolution, identification, and quantitation from milligram quantities of venom. First, definition of optimal chromatographic conditions for Naja mossambica mossambica toxins has been ascertained. Different column packing and solvent systems were compared for their efficiency, with particular attention to the ionic strength of the aqueous solvent. A medium-chain alkyl support (octyl) in conjunction with a volatile ammonium formate (0.15 M, pH 2.70)/acetonitrile solvent system was found to be particularly effective. All the components known until now from this venom could be resolved in a single step, and the elution order was alpha-neurotoxins, phospholipases A2, and cardiotoxins with a total recovery of absorbance and toxicity. Then, with these suitable conditions, we describe a new major cardiotoxin molecule in this venom by hydrophobic and not ionic-charge discrimination. Second, specific assays were designed to detect alpha-neurotoxin and phospholipase A2 activities in chromatographic fractions: alpha-neurotoxin activity was determined by competition for the binding of a radiolabeled alpha-neurotoxin to the acetylcholine receptor of the ray electric organ, and phospholipase A2 activity was defined by the enzymatic activity of these toxins with a fluorescent phospholipid as substrate. Finally, the applicability of these new methods to study other Naja snake venoms was demonstrated.