Two New Halogenated Compounds from the Marine Red Alga Laurencia nipponica Yamada from the Kunashiri and Etorofu Islands

The red alga Laurencia nipponica comprises various chemical races distributed relative to the ocean current in Japanese coastal areas. We investigated the chemical compositions and chemical races of L. nipponica distributed from the Kunashiri and Etorofu Islands, the confluence of the Soya warm current and Oya-shio cold current. Two new halogenated secondary metabolites, deacetylneonipponallene ( 1 ) and neopacifenol ( 2 ), along with four known compounds, deoxyprepacifenol ( 3 ), pacifenol ( 4 ), halo-chamigrene diether ( 5 ), and isolaurallene ( 6 ) were isolated from L. nipponica collected at Chikappunai, Kunashiri Island, while Zaimokuiwa (Kunashiri Island) and Sana (Etorofu Island) populations contained 3 , 7-hydroxylaurene ( 7 ), 2,10-dibromo-3-chloro-9-hydroxy-α-chamigrene ( 8 ), and (3Z)-laurefucin ( 9 ). The structures of 1 and 2 were established using spectroscopic methods. The chemical races of L. nipponica distributed in this area were divided into 6 - and 9 -producing races. Interestingly, both races contained 4 as an additional race-index, as well as its derivatives, 2 and 5 . To the best of our knowledge, this is the first example of a race comprising a mixture of two race-index compounds, suggesting that the convergence of two currents causes the production of new and diverse chemical races in this species.     

Cloning and characterization of an allene oxide cyclase,PpAOC3, in <Emphasis Type="Italic">Physcomitrella patens</Emphasis>

Allene oxide cyclase (AOC) is a key enzyme in the octadecanoid pathway of flowering plants that synthesizes 12-oxo-phytodienoic acid (OPDA), which is a biosynthetic precursor of the signal molecule jasmonic acid (JA). A database search of the Physcomitrella patens genome revealed the presence of an AOC gene unique from the two previously reported AOC genes, PpAOC1 and PpAOC2. After cloning the identified AOC gene, designated PpAOC3, the obtained cDNA sequence (897 bp) was larger than the predicted AOC gene (765 bp) in the database because a speculated intron was not fully deleted. Although PpAOC3 did not display high similarity with AOC proteins from other species, recombinant PpAOC3 exhibited AOC activity and translocated to chloroplasts, as is observed for other AOC proteins. Notably, the expression profile of PpAOC3 differed from the other PpAOCs, as its expression in protonemata was higher than that in gametophores. Although the function of oxylipins such as OPDA and JA remains elusive in P. patens, further characterization of the enzymes in the octadecanoid pathway and the role of oxylipin will aid in the elucidation of physiological processes in this model bryophyte.     

Morphological study of the ovary in Hanseniella caldaria (Myriapoda; Symphyla): The position of oocyte-growth and evolution of ovarian structure in Arthropoda

In Arthropoda, the ovary is classified into Chelicerata-type and Mandibulata-type, based on the oocyte-growth position within the ovary. By contrast, oocytes of Diplopoda and Chilopoda grow within the hemocoelic space. However, as the position of oocyte-growth in Symphyla and Pauropoda has not been confirmed, whether the hemocoelic nature of oocyte-growth is common among myriapods remains ambiguous. This study described the ovarian structure of Hanseniella caldaria to reveal the oocyte-growth position in Symphyla. The oocyte is surrounded by the follicle epithelium, and the inner surface of the follicle epithelium, i.e., the space between follicle cells and oocytes, is lined with a basement membrane. The follicle epithelial layer continues to the ovarian epithelium via the follicle extension with a continuous layer of basement membrane. Data on the architecture of the follicle suggest that the follicle pouch opens to the hemocoel. Hence, the oocyte of H. caldaria grows within the hemocoelic space. Based on our findings in H. caldaria and previous studies in a millipede and in centipedes, the hemocoelic nature of oocyte-growth is considered as a common feature among myriapods and a synapomorphy of the Myriapoda for which morphological synapomorphies have been ambiguous.     

On some basic laws in physiological systems

Summary By the application of a new concept of activity, which is an extension of excitability in physiology, it was possible to establish the activity cycle in relation to the interstimulus interval as an extension of excitability cycle. It was proved also that the response area and audiogram in the auditory system, as well as the spectral response curve in the visual system can be described in uniform fashion as a special situation of activity.It was further found that Fechner's law and Stevens' power function are none other than one of the laws of activity in the semi-logarithmic and in the double logarithmic domains, respectively.