Correction to: The sbGnRH-GTH system in the female short mackerel, Rastrelliger brachysoma (Bleeker, 1851), during breeding season: implications for low gamete production in captive broodstock.

The published online version of this article contained outdated Figs. 4 and 5. The original article has been corrected.

The sbGnRH-GTH system in the female short mackerel, Rastrelliger brachysoma (Bleeker, 1851), during breeding season: implications for low gamete production in captive broodstock.

The short mackerel (Rastrelliger brachysoma) is one of the most economically important fish in Thailand; it is also a prime candidate for mariculture but unfortunately is plagued by reproductive problems that cause low production of gametes in captivity. An understanding of how the brain, pituitary, and gonad axis (BPG) from the neuroendocrine system are involved in the reproductive activity of wild and captive R. brachysoma should help clarify the situation.

Developing human capital for successful implementation of international marine scientific research projects.

The oceans play a crucial role in the global environment and the sustainability of human populations, because of their involvement in climate regulation and provision of living and non-living resources to humans. Maintenance of healthy oceans in an era of increasing human pressure requires a high-level understanding of the processes occurring in the marine environment and the impacts of anthropogenic activities. Effective protection and sustainable resource management must be based, in part, on knowledge derived from successful research.

Evolution of saxitoxin synthesis in cyanobacteria and dinoflagellates.

Dinoflagellates produce a variety of toxic secondary metabolites that have a significant impact on marine ecosystems and fisheries. Saxitoxin (STX), the cause of paralytic shellfish poisoning, is produced by three marine dinoflagellate genera and is also made by some freshwater cyanobacteria. Genes involved in STX synthesis have been identified in cyanobacteria but are yet to be reported in the massive genomes of dinoflagellates.

Origin of saxitoxin biosynthetic genes in cyanobacteria.

Background: Paralytic shellfish poisoning (PSP) is a potentially fatal syndrome associated with the consumption of shellfish that have accumulated saxitoxin (STX). STX is produced by microscopic marine dinoflagellate algae. Little is known about the origin and spread of saxitoxin genes in these under-studied eukaryotes.

Vertical distribution and characterization of aerobic phototrophic bacteria at the Juan de Fuca Ridge in the Pacific Ocean.

The vertical distribution of culturable anoxygenic phototrophic bacteria was investigated at five sites at or near the Juan de Fuca Ridge in the Pacific Ocean. Twelve similar strains of obligately aerobic phototrophic bacteria were isolated in pure culture, from depths ranging from 500 to 2,379 m below the surface. These strains appear morphologically, physiologically, biochemically, and phylogenetically similar to Citromicrobium bathyomarinum strain JF-1, a bacterium previously isolated from hydrothermal vent plume waters.

An obligately photosynthetic bacterial anaerobe from a deep-sea hydrothermal vent.

The abundance of life on Earth is almost entirely due to biological photosynthesis, which depends on light energy. The source of light in natural habitats has heretofore been thought to be the sun, thus restricting photosynthesis to solar photic environments on the surface of the Earth. If photosynthesis could take place in geothermally illuminated environments, it would increase the diversity of photosynthetic habitats both on Earth and on other worlds that have been proposed to possibly harbor life.

GTX(4) imposters: characterization of fluorescent compounds synthesized by Pseudomonas stutzeri SF/PS and Pseudomonas/Alteromonas PTB-1, symbionts of saxitoxin-producing Alexandrium spp.

Saxitoxins, the etiological agent of paralytic shellfish poisoning, are synthesized by dinoflagellates and cyanobacteria. Several reports indicate that bacteria are capable of saxitoxin synthesis. Two bacterial strains were isolated from saxitoxin-producing dinoflagellates, Alexandrium tamarense and A.

Contribution of aerobic photoheterotrophic bacteria to the carbon cycle in the ocean.

The vertical distribution of bacteriochlorophyll a, the numbers of infrared fluorescent cells, and the variable fluorescence signal at 880 nanometers wavelength, all indicate that photosynthetically competent anoxygenic phototrophic bacteria are abundant in the upper open ocean and comprise at least 11% of the total microbial community. These organisms are facultative photoheterotrophs, metabolizing organic carbon when available, but are capable of photosynthetic light utilization when organic carbon is scarce. They are globally distributed in the euphotic zone and represent a hitherto unrecognized component of the marine microbial community that appears to be critical to the cycling of both organic and inorganic carbon in the ocean.

Comparison of spectrofluorometric and HPLC methods for the characterization of fecal porphyrins in river otters.

A spectrofluorometric method (B. Grandchamp et al., 1980, Biochem.

Oxygen-evolving diatom thylakoid membranes.

Two protocols were developed that yielded purified oxygen-evolving thylakoid membranes from the diatom Cylindrotheca fusiformis. One protocol employed sonication, while the second involved French press lysis of protoplasts formed by brief culture of cells in a cation-depleted medium. Regardless of the method of cell breakage, some damage to electron transport components occurred.

One-step extraction and concentration of pigments and acyl lipids by sec-butanol from in vitro and in vivo samples.

Photosynthetic pigments and acyl lipids were simultaneously extracted and concentrated by sec-butanol. Pigments extracted with sec-butanol were indistinguishable from those extracted using acetone as determined by quantitative and qualitative HPLC. Use of sec-butanol has several advantages over conventional extraction solvents: (1) pigments are extracted directly from polyacrylamide gel slices without an elution step; (2) pigments in dilute, isolated pigment-protein complexes are extracted and concentrated without first concentrating the sample; (3) when necessary, the concentration factor is readily increased by addition of water; (4) sec-butanol extracts acyl lipids and vitamin K1 as effectively, but much quicker, than chloroform:methanol; (5) sec-butanol rapidly extracts and concentrates pigments from thylakoids of all plant species tested and even directly from many algal/higher plant cells, facilitating analysis of pigment biosynthetic pathways using radioactive substrates; and (6) pigments are stable in sec-butanol for several days at room temperature in the dark or for many weeks if stored at -20 degrees C in darkness.

Nitrogen-dependent regulation of photosynthetic gene expression.

Nitrogen-limited Chlamydomonas reinhardtii is chlorotic and very deficient in chlorophyll a/b light-harvesting complexes (LHC). Rates of synthesis of photosynthetic proteins, but especially the LHC apoproteins, are reduced 10- to 40-fold. Moderately high levels of chloroplast transcripts accumulate in nitrogen-limited cells, and there is a correlation between chloroplast DNA levels and chloroplast mRNA abundance.

Phosphorylation of Photosystem II Components, CP43 Apoprotein, D1, D2, and 10 to 11 Kilodalton Protein in Chloroplast Thylakoids of Higher Plants.

Phosphorylated thylakoid proteins of spinach (Spinacia oleracea L.) and pea (Pisum sativum L.) were solubilized, fractionated by sucrose density gradient centrifugation, and analyzed by gel electrophoresis and crossed immunoelectrophoresis to identify the phosphoproteins.

Chlorophyll antenna proteins of photosystem I: topology, synthesis, and regulation of the 20-kDa subunit of Chlamydomonas light-harvesting complex of photosystem I.

The light-harvesting complex of photosystem I (LHCI) was isolated from wild-type cells of Chlamydomonas reinhardtii; the Chl a/b-protein complex contains four major polypeptides of approximately 27, 26, 24, and 20 kDa (polypeptides 14, 15, 17.2, and 22, respectively, in the nomenclature for Chlamydomonas thylakoid proteins). Antiserum against the 20-kDa subunit of LHCI was prepared and used to determine the membrane topology, subcellular site of synthesis, and cell-cycle regulation of this polypeptide.

Reconstitution of chlorophyll a/b light-harvesting complexes: Xanthophyll-dependent assembly and energy transfer.

A method for in vitro reconstitution of the chlorophyll a/b light-harvesting complex from LiDodSO(4)/heat-denatured or acetone-extracted photosynthetic membranes has been developed. Characterization of the minimum components necessary for the functional organization of pigments in these membrane complexes reveals that xanthophylls are essential structural components.

Biogenesis of photosystem II complexes: transcriptional, translational, and posttranslational regulation.

The integral membrane proteins of photosystem II (PS II) reaction center complexes are encoded by chloroplast genomes. These proteins are absent from thylakoids of PS II mutants of algae and vascular plants as a result of either chloroplast or nuclear gene mutations. To resolve the molecular basis for the concurrent absence of the PS II polypeptides, protein synthesis rates and mRNA levels were measured in mutants of Chlamydomonas reinhardtii that lack PS II.

The Water Oxidation Complex of Chlamydomonas: Accumulation and Maturation of the Largest Subunit in Photosystem II Mutants.

Photosystem II particles of Chlamydomonas reinhardtii contain three extrinsic polypeptides of 29, 20, and 16 kilodaltons, whose functions are incompletely defined. We prepared a monospecific polyclonal antibody against the 29 kilodalton protein and determined that it also specifically recognizes a protein of approximately 33 kilodaltons in thylakoid membrane fractions of several vascular plants, eukaryotic algae, and a cyanobacterium. The cross-reacting 33 kilodalton protein of pea was removed from inverted thylakoid vesicles by CaCl(2) washes demonstrating the structural relationship between the Chlamydomonas polypeptide and the largest subunit of the water oxidation complex of vascular plants.

Ribulose Bisphosphate Carboxylase from Three Chlorophyll c-Containing Algae : Physical and Immunological Characterizations.

Distinctive properties are identified in the molecular structure of ribulose, 1,5-bisphosphate carboxylase/oxygenase (RuBPCase) in chlorophyll c-containing algae (i.e., chromophytes).

Rocket and crossed immunoelectrophoresis of proteins solubilized with sodium dodecyl sulfate.

A method for the immunoelectrophoretic analysis of both hydrophilic and hydrophobic proteins from whole-cell extracts solubilized with 2% (w/v) sodium dodecyl sulfate (SDS) is described. For rocket immunoelectrophoresis, Triton X-100 is added to the sample before electrophoresis to sequester non-protein-bound SDS, and polyethylene glycol (PEG) is added to the antibody gel to enhance precipitin formation. With the optimal ratio of Triton X-100 to PEG, the quantitative determination of 5 ng of protein is possible.