Conchospore germlings of Porphyra yezoensis were stained with a fluorescent dye for DNA and observed with confocal laser scanning microscopy (CLSM). Relative DNA values of the germling nuclei were obtained by measuring fluorescence intensities of nuclear regions of the optically sliced specimens, using the mean value of the smallest blade cells as a reference of the genomic n value. Such quantification revealed that the nuclear DNA amounts of the one-cell, two-cell, and four-cell-stage germlings are approximately 4×n, 2×n, and n ∼2×n values respectively; these values agreed well with the expected ones from the hypothesis that meiosis corresponds to the first successive cell divisions after the conchospore germination. These results are consistent with a previous study on cytogenetic analysis of the chimaera blade formation (Ohme and Miura 1988, Plant Sci 57:135-140) and not consistent with a recent microscopic study (Wang et al. 2006, Phycol Res 54:201-207) which proposed that the first meiotic division occurs at the conchospore formation and the second division at the germination.

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Lipases (triacylglycerol acylhydrolase, EC 3.1.1.3) were purified from Aspergillus repens and Euro tium herbariorum NU-2 strain by using a DEAE-Sephadex A-50 column and preparative electrophore sis. The purified enzymes from A. repens and NU-2 had molecular weights estimated by SDS-PAGE to be 38,000 and 65,000, respectively. Lipase from A. repens had a pH optimum of 5.3 and a temperature optimum of 27•Ž, while for the NU-2 strain corresponding values were pH 5.2 and 37•Ž. The specific activity of NU-2 was about twice that of A. repens. Substrate specificity toward olive oil or triolein and positional specificity for hydrolyzing the 1 (3)-position ester bonds of triacylglycerol are discussed for both enzymes.

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KEY WORDS: amino acid, bulbus arteriosus, collagen, desmosine, elastin, isodesmosine, skin.Collagen, hyaluronic acid, and elastin are contained in the extracellular matrix. They function in metabolism, multiplication, differentiation, and maintenance of cells in vivo . 1 Elastin is a protein found in the lung, skin, ligaments, and arteries. It has been shown to be important as a construction material for the cell, like collagen, and is used in diverse fields including cosmetics, food, and medicine. Elastin for commercial use has been produced from bovine ligaments; however, bovine spongiform encephalopathy (BSE) has led to concern regarding the use of elastin of bovine origin. However, elastin from fish raw materials is expected to maintain social acceptability since fishes from natural sources are free from BSE.We attempted to manufacture elastin peptides from aquatic resources such as fish bulbus arteriosus and skin, which were excised easily from fish; however, they have been rarely used industrially and are discarded. The properties of these peptides were evaluated by the fluorescence intensity and the amino acid composition.Raw materials were selected from yellowtail Seriola quinqueradiata (2.0 kg body weight), skipjack Katsuwonus pelamis (2.2 kg), bluefin tuna Thunnus thynnus (1.8 kg), salmon Salmo salar (2.0 kg), and walleye pollock Theragra chalcogramma (0.7 kg). These species have constantly supported major fisheries in Japan.First, tissue section of the bulbus arteriosus and skin from these fishes was performed by routine histological methods to confirm the elastin distribution in the organ. They were fixed in 10% formaldehyde in 0.1 M sodium phosphate at pH 7.0, then materials were embedded in paraffin, sectioned, and stained by Elastica Van Gieson (EVG) stain. 2 Tissues from the bulbus arteriosus and skin, and also dark, heart, and ordinary muscle, intestine, kidney, liver, ovary, pyloric cecum, spleen, and stomach from fresh fish were analyzed for amino acid desmosine (Des) and isodesmosine (Ide) contents. The tissues were washed with 1% NaCl and cut into small pieces. The pieces were lyophilized, then tissue samples were hydrolyzed in 6 M HCl under nitrogen at 110 ° C for 20 h in sealed glass tubes. The hydrolyzates were dried and diluted in 0.02 M HCl. Amino acid analysis was carried out on a JLC-500/V instrument (JEOL, Tokyo, Japan) with the buffer system modified for separation of free amino acids.Second, soluble elastin peptide was prepared at the commercial production scale from bulbus arteriosus and skin by the following methods. Bulbus arteriosus (3.0 g) were dissected from fresh yellowtail (4.5 kg average body weight), which was obtained in Kumamoto. They were washed and kept frozen at − 20 ° C until use. Thawed bulbus arteriosus (100 kg) was defatted in 0.01 M NaOH at 4 ° C, and washed with distilled water. To remove the collagen, the materials were boiled at 95 ° C for 5 min and ground mechanically. The fragments were hydrolyzed at 50 ° C for 8 h at pH 8.5 by two kinds of commercial protea...