Three new deep-sea species of Sphaerodoridae (Annelida,Polychaeta) from the eastern tropical South Pacific*

Three sphaerodorid species new to science are described from a manganese nodule area in abyssal depths of around 4150 m in the Peru Basin in the eastern South Pacific. Sphaerodoridium campanulata sp. n. is isolated within the genus, having, apart from spherical macrotubercles, additional dorsal stalked bell-shaped papillae, not previously described. Sphaerodoropsis discolis sp. n. is a species with four rows of dorsal macrotubercles and two pairs of lateral antennae. Sphaerodoropsis translucida sp. n. has six to seven rows of dorsal macrotubercles arrayed in two transverse rows per segment and two pairs of lateral antennae. A brief discussion points to the close relationship between Clavodorum and Sphaerodoridium, and to the present state of Sphaerodoropsis, being inhomogeneous in the characters of the arrangement of the dorsal macrotubercles and the numbers of the lateral antennae. An overview on the latter genus, with an attempt to subdivide it, is given.     

Postnatal development of the respiratory system of the opossum. II. Electron microscopy of the epithelium and pleura.

At birth, the opossum lung is remarkably primitive and consists of a system of branching airways that end in a number of terminal air chambers. From the newborn through the 10 cm stage of development the conducting portion of the lung predominates. The air chambers, which represent portions of the conducting system modified for respiration, are in a constant state of evolution since they are destined to become part of the expanding bronchial system. The airways are devoid of cilia and goblet cells at birth, and are lined by columnar epithelial cells which contain two types of cytoplasmic granules: an electron-dense form and a heterogeneous form. The latter exhibits an electron-dense core surrounded initially by a large halo of flocculent material. This type of granule is not seen beyond the 8 cm stage. The terminal air chambers of the newborn and later stages are lined type I and type II alveolocytes that appear identical to the alveolocytes lining alveoli in the adult. By the 2.5 cm stage, scattered cilia are present in the trachea and bronchi and bands of smooth muscle have differentiated in relation to bronchial epithelium and to proximal areas of the terminal chambers. Citiated cells are separated by ridges composed of light and dark cells which are without cilia and which contain scattered electron-dence granules. Throughout the postnatal period numerous alveolar macrophages and mast cells are noted in relation to the conducting system and pleura. Differentiation of the pleura also occurs during the postnatal period. In the newborn the pleura is simple squamous mesothelium. Later stages develop a thick connective tissue lamina between the pleural mesothelium and lung parenchyma. A large band of elastin is interposed between the mesothelium and underlying bundles of collagen.     

Pleuromeia from the lower triassic of the far east of the U.S.S.R.

Pleuromeia obrutschewii Elias from Russian Island (Russkiy Ostrov, near Vladivostok) is hardly distinguishable from the European P. sternbergii (Muenster) Corda. The sporangia are adaxial, filling spoon-like depressions of the megasporophylls which have sterile tips. P. olenekensis sp. nov. from the Olenek River (northeastern Siberia) has larger sporangia and much larger megaspores with three-layered walls. The outer layer (ectexosporium) is reticulate. It is assumed that in other species this layer is lacking due to imperfect preservation. Mature megasporophylls, when shed, have a buoy-like shape and are often deposited together with cephalopod shells. This suggests a special mechanism of propagation by means of megasporophylls dispersed by water currents. The cosmopolitan distribution of Pleuromeia points to weakened climatic zonation in the Early Triassic.     

II. Contributions to the Ornithology of the East African Islands.

The sea-bird breeding stations in East African waters are enumerated. Between the Lamu archipelago, where many species nest, and the Rovuma the most important station is Latham Island with its Booby colony ( S. dactylatra melanops ), which existed at least 115 years ago. Less than half a dozen terneries (mainly S. dougallii and S. fuscata) are known, and no gullery. Reef-Herons, the only sea-birds to breed on bush-covered islets or in mangroves, are more widespread than the other species. The Terns lay about July, the Reef-Herons a month earlier, and the Gannets about four months later in most years.
Early records of birds in Zanzibar and Pemba are discussed specifically. The recent extinction of Francolins in Zanzibar is taken as proved.
The land-birds of Mafia and the neighbouring islets are listed and discussed, mainly on the basis of a recent collection. The avifauna is purely East African, devoid of endemics, and, considering the size of Mafia and its proximity to the mainland, astonishingly depauperate in some respects. Thirteen families (including Psittacidæ, Coliidæ, Picidæ, Alaudidæ, Timaliidæ, and Zosteropidæ) and several other coastal species are not represented. The phenology is discussed.     

On the nature of P.P.L.O.

Summary In a number of strains of the three species of P.P.L.O. of human origin coccoid elements have been observed, which are Gram positive or Gram variable and of very small size (<0.5 μ). They are able to grow in pure culture on the surface of nutrient agar in very small colonies. Although they have bacterial characteristics, they could not be identified as known bacteria. Agglutination tests are in favour of a serological relationship between the coccoid elements and P.P.L.O. The suggestion that these elements might be an outside contamination is made unlikely by several observations. The supposition that P.P.L.O.s are L forms of these coccoid elements should be considered further.     

The phylogenetic odyssey of the erythrocyte. III. Fish, the lower vertebrate experience.

The piscine erythrocyte can be considered the prototype of the red cells that are distributed among inframmalian vertebrates. It is a permanently nucleated, hemoglobin-ladened, oval, flattened, biconvex disc. Ultrastructurally it demonstrates a cytoskeleton comprised of a marginal band and a membrane skeleton which are responsible for the erythrocyte's conversion to an ellipsoid during morphogenesis and endow it with resilience to physical trauma. Erythropoiesis initiates in the yolk sac, followed in many fishes, by the intermediate cell mass. These sites are the sources of the transitory, primitive generation red cells which apparently make their first phylogenetic appearance in fishes and which are subsequently represented in all classes of vertebrates including mammals. Production of definitive generation erythrocytes is centered in evolutionary "pre-splenic" tissue of the gastrointestinal tract or in the spleen in cyclostomes, dipnoi, and chondrichthyes while in teleosts it is typically located in the kidneys with or without splenic participation. The blood is a major site of erythrocyte maturation in the lower fishes and exhibits significant numbers of immature erythroid cells plus occasional mitotic figures. Some teleosts also circulate developing erythroid cells. Certain fishes have occasional circulating erythroplastids, conceptually a portent of phylogenetic changes in higher vertebrates. Remarkably, some bristlemouths have denucleated erythrocytes exclusively in the circulation. The largest piscine erythrocytes are found in the dipnoi, myxines, and chondrichthyes. Primitive fish with the exception of the endothermic sharks tend to have lower hemoglobin concentrations than the modern teleosteans. The very highest hemoglobin concentrations are attained by the endothermic scombrids. Erythrocyte-based data have a broad extent and are variably affected by age, sex, season and environment. This report includes a substantial selection of illustrations (fish species and rbc micrographs).     

Cyanobacterial phycobilisomes. Characterization of the phycobilisomes of Synechococcus sp. 6301.

A procedure is described for the preparation of stable phycobilisomes from the unicellular cyanobacterium Synechococcus sp. 6301 (also known as Anacystis nidulans). Excitation of the phycocyanin in these particles at 580 nm leads to maximum fluorescence emission, from allophycocyanin and allophycocyanin B, at 673 nm. Electron microscopy shows that the phycobilisomes are clusters of rods. The rods are made up of stacks of discs which exhibit the dimensions of short stacks made up primarily of phycocyanin (Eiserling, F. A., and Glazer, A. N. (1974) J. Ultrastruct. Res. 47, 16-25). Loss of the clusters, by dissociation into rods under suitable conditions, is associated with loss of energy transfer as shown by a shift in fluorescence emission maximum to 652 nm. Synechococcus sp. 6301 phycobilisomes were shown to contain five nonpigmented polypeptides in addition to the colored subunits (which carry the covalently bound tetrapyrrole prosthetic groups) of the phycobiliproteins. Evidence is presented to demonstrate that these colorless polypeptides are genuine components of the phycobilisome. The nonpigmented polypeptides represent approximately 12% of the protein of the phycobilisomes; phycocyanin, approximately 75%, and allophycocyanin, approximately 12%. Spectroscopic studies that phycocyanin is in the hexamer form, (alpha beta)6, in intact phycobilisomes, and that the circular dichroism and absorbance of this aggregate are little affected by incorporation into the phycobilisome structure.     

The Use of the A.P.I. Lactobacillus System for the Characterization of Pediococci

A commercially produced system for the identification of Lactobacillus , by which the reactions of concentrated cell suspensions towards 50 substrates may be determined, is useful for the characterization of strains of Pediococcus . Suitable conditions for inoculum preparation vary for slow and fast growing strains; the influence of cell concentration on the results is described. The reactions are classified in terms of their value for species characterization and the results are shown to agree well with those in other studies where classical procedures have been used.     

Taxonomic studies on the Chlorarachniophyta. II. Generic delimitation of the chlorarachniophytes and description of Gymnochlora stellata gen. et sp. nov. and Lotharella gen. nov.

A new chlorarachniophytan alga, Gymnochlora stellata Ishida et Y. Hara gen. et sp. nov., has been isolated from Anae Island in Guam. It is a green, star-shaped, unicellular, amoeboid organism with several filopodia that do not form a reticulopodial network. Neither zoospores nor walled coccoid cells have been observed throughout the life cycle. The chloroplast ultrastructure is similar to those of described species; however, the pyrenoid matrix, which is invaded by many tubular structures originating from the inner membrane of the chloroplast envelope, is unique. A classification system is proposed for the Chlorarachniophyta. In this system, the ultrastructural features of the pyrenoid and the location of the nucleomorph in the periplastidial compartment are used as generic criteria, while the morphological features of the vegetative cells and life cycle patterns are used for species criteria. The described species, except for Cryptochlora perforans Calderon-Saenz et Schnetter, are also reassessed under the new system, and consequent nomenclatural requirements for the genus Chlorarachnion are dealt with in this paper. The taxonomic rank of a previously described species, Chlorarachnion globosum Ishida et Y. Hara, is elevated and Lotharella globosa (Ishida et Y. Hara) Ishida et Y. Hara gen. nov. et comb. nov. is proposed.     

Studies on the product of antigenic recognition. III. Nature of PAR.

The product of antigenic recognition (PAR) is an antigen-antibody complex with granulotactic activity. The following results support his conclusion. PAR generated by cell-bound or shed T-cell RS or the recognizing structure of T alloantisera and alloantigen can be destroyed by heating at 56 degrees C for 30 min, because of inactivation of a heat-labile component supplied by alloantigen. Recognizing partners of these complexes are heat-stable. They form PAR anew when alloantigen is added or upon confrontation with anti-RS serum. They are also capable of inducing anti-RS sera. PAR preparations composed of these recognizing structures and antibodies to them are heat-inactivated at much higher temperatures, because both partners of the complex are relatively heat-stable. Heat-labile PAR complexes (recognizing structures and alloantigen) pass anti-mouse immunoglobulin immunosorbent, but are retained specifically by alloantiserum (via alloantigen of the complex) or by anti-RS serum (via RS of the complex) bound to the column.     

The fine structure of the cysticercoid of Hymenolepis diminuta. III. The scolex.

Transmission electron microscopy of the scolex of the 8-day-old Hymenolepis diminuta cysticercoid demonstrates its resemblance to the scolex of the adult. A syncytial tegument composed of external and internal layers is connected by cytoplasmic extensions. Fully developed microtriches are present. Furthermore, a basement membrane, muscle layers, and medullary region containing flame cells, nerve tissue, and other cell bodies are observed. Of particular interest is the presence of discrete sensory endings whose function is discussed.     

Immunodiffusion systematics of the primates. Part V. The Platyrrhini.

Evolutionary relationships between New World monkeys and marmoset genera and the place of the Ceboidea within the primates are considered in terms of the immunological specificity of ceboid proteins. Antigenic distances between the New World primates are measured using antisera produced in rabbits to nine ceboid genera: Alouatta, Aotes, Ateles, Callicebus, Cebus, Chiropotes, Lagothrix, Saimiri and Saguinus. A cladogram constructed on the basis of increasing degrees of antigenic distance between branches depicts Ceboidea as a monophyletic assemblage within which Alouatta is grouped with the Atelinae genera, Lagothrix and Ateles, Chiropotes joins Cacajao and Cebus joins Saimiri. The joining of the cebid genera Aotes and Callicebus with callithricid genera Callimico and Saguinus into a single complex lineage suggests that Cebidae is a paraphyletic or polyphyletic taxon. A phylogenetic taxonomy for Platyrrhini is proposed.     

Simulations of the erythrocyte cytoskeleton at large deformation. II. Micropipette aspiration.

Coarse-grained molecular models of the erythrocyte membrane's spectrin cytoskeleton are presented in Monte Carlo simulations of whole cells in micropipette aspiration. The nonlinear chain elasticity and sterics revealed in more microscopic cytoskeleton models (developed in a companion paper; Boey et al., 1998. Biophys. J. 75:1573-1583) are faithfully represented here by two- and three-body effective potentials. The number of degrees of freedom of the system are thereby reduced to a range that is computationally tractable. Three effective models for the triangulated cytoskeleton are developed: two models in which the cytoskeleton is stress-free and does or does not have internal attractive interactions, and a third model in which the cytoskeleton is prestressed in situ. These are employed in direct, finite-temperature simulations of erythrocyte deformation in a micropipette. All three models show reasonable agreement with aspiration measurements made on flaccid human erythrocytes, but the prestressed model alone yields optimal agreement with fluorescence imaging experiments. Ensemble-averaging of nonaxisymmetrical, deformed structures exhibiting anisotropic strain are thus shown to provide an answer to the basic question of how a triangulated mesh such as that of the red cell cytoskeleton deforms in experiment.     

Insertion mutations in the control region of the Gal operon of E. coli. I. Biological characterization of the mutations

Summary Galactose negative mutations are described which reduce the maximum expression of all three gal genes about 100-fold. The residual enzyme synthesis is not or only slightly inducible.These pleiotropic mutations map in the control region of the gal operon. No recombination is observed between these mutations. All mutants revert spontaneously to a Gal⁺ phenotype. In some mutations wildtype-like as well as constitutive revertants are obtained. The frequency of reversion can be increased by nitrosoguanidine (NG) in all mutants. The revertants, induced by this mutagen, are of a constitutive type.     

Electron-microscopic study of the excretory system of hungry females of the tick Hyalomma asiaticum P. Sch. et E. Schl. 2]

In H. asiaticum the cells of the Malpighian tubules and these of the rectal cas have the uniform structure: the apical surface is covered with microvilli, the basal plasmatic membrane forms relatively small invaginations. As to ultrastructural characters, there is no distinct division of the Malpighian tubule into departments. The distal ends of the tubules are not only somewhat enlarged and form the so-called ampulla cells of which are noticeably flattened. The microvilli and basal folds of the plasmatic membrane in this area of the tubule are indistinct. The cells of the ampulla and the neighbouring area of the tubule are characterized by the presence of inclusions with mucopolysaccharide secretion confined by the membrane. The microvilli are most developed on cells of the proximal ends of the Malpighian tubules. Well developed microvilli of the rectal sac form a striated border each containing a microtube inside. The basal invaginations are developed here better than in the cells of the Malpighian tubules.     

Thermodynamic study of the formation of adenine nucleotide-manganese complexes. II. Calorimetric results.

Enthalpic variations in the formation of adenine nucleotide-manganese complexes, as measured by microcalorimetry, are reported. All the results are obtained in the temperature range 6--30 degrees C at I =0.2 and pH values 7.00 or 7.50. All the reactions are endothermic and the deltaH values increase with the length of the phosphate chain and with temperature. The deltaH values are compared with those previously obtained for adenine nucleotide-manganesium complexes. The comparison between calorimetric and potentiometric deltaH values is made. The divergence observed between these results at low temperature leads us to assume the formation of nucleotide aggregates induced by the presence of manganese ions. This hypothesis is confirmed by differential ultraviolet spectra.     

A resolution of the ascertainment sampling problem. III. Pedigrees.

When nuclear families are sampled by an ascertainment procedure whose properties are not known, biased estimates of genetic parameters will arise if an incorrect specification of the ascertainment procedure is made. Elsewhere we have put forward a resolution of this problem by introducing an ascertainment-assumption-free (AAF) method, for nuclear family data, which gives asymptotically unbiased estimators no matter what the true nature of the ascertainment process. In the present paper we extend this method to cover pedigree data. Problems that arise with pedigrees but not with families--for example, the question of which families in a pedigree are "ascertainable"--are also considered. Comparisons of numerical results for pedigrees and nuclear families are also made.     

Genetic structure of the Queckchi Indians. Dental microdifferentiation.

Nine oral morphologic characters were investigated. Their frequencies are compared with those published for other populations. The possibility of using such characters to estimate genetic distance between populations is discussed and the conclusion is reached that, although previous studies have suggested this to be a valid approach, further studies testing this subject are needed.