Norimasa Matsuoka

Biochemical phylogeny of the sea-urchins of the family toxopneustidae

Abstract 1. 1. The family Toxopneustidae in the seas around Japan is represented by four species of sea-urchins. They are Toxopneustes pileolus , Tripneustes gratilla , Pseudoboletia maculata and Pseudocentrotusdepressus . 2. 2. The phylogenetic relationships among these four members of this family were investigated by electrophoretic analyses of 13 enzymes. 3. 3. The biochemical phylogenetic tree for these species constructed from these electrophoretic data suggests that Pseudoboletia maculata is closely related to Toxopneustes pileolus , and that Pseudocentrotus depressus is strongly differentiated from the other three species. 4. 4. These results agree with the phylogenetic relationships of these species inferred from morphological, zoogeographical and immunological evidence and show the phylogenetic value of electrophoretic data at the genus level.

Phylogenetic relationships among five species of starfish of the genus, Asterina: an electrophoretic study

Abstract 1. 1. Variations and similarities of seven different enzyme systems were analysed electrophoretically in and among five species of starfish belonging to the genus Asterina, and the dendrogram showing their phylogenetic relationships was constructed. 2. 2. Electrophoretic data thus obtained agrees well with the phyletic relationships inferred from the immunological, morphological and embryological evidence.

Further immunological study on the phylogenetic relationships among sea-urchins of the order echinoida

Abstract 1. 1. In a previous study, I examined immunologically the phylogenetic relationships among 10 sea-urchin species belonging to the four families of the order Echinoida by the enzyme inhibition method with anti-Strongylocentrotus intermedius G6PD antibody (Matsuoka, 1980). The results suggested the close affinity between the two families, Strongylocentrotidae and Toxopneustidae of this order. 2. 2. In order to extend the previous immunological study, the immunological cross-reactions of the antibody to G6PDs from nine sea-urchin species collected thereafter were also examined by the enzyme inhibition method. 3. 3. The further immunological results thus obtained confirmed the suggestion that the family Strongylocentrotidae might be closely related to the family Toxopneustidae.

Immunological relatedness of sea-urchin glucose 6-phosphate dehydrogenases: Phylogenetic implication

Abstract 1. 1. G6PD was purified from eggs of the sea-urchin, Strongylocentrotus intermedius and its specific antibody was raised in a rabbit. 2. 2. Immunological cross-reactions of the antibody to G6PDs of 10 species of sea-urchins of the order Echinoida were examined by the enzyme inhibition test. 3. 3. The immunological data thus obtained strongly suggest a close affinity between the two families, Strongylocentrotidae and Toxopneustidae of this order.

Biochemical systematics of four sea-urchin species of the family diadematidae from Japanese waters

Abstract The poisonous sea-urchins of the family Diadematidae commonly found in the seas around southern Japan comprise four species belonging to two different genera. They are Diadema setosum (Leske), Diadema savignyi (Audouin), Echinothrix calamaris (Pallas) and Echinothrix diaderna (Linnaeus). The genetic relationships and genetic variation within their populations were investigated by electrophoretic analyses of 15 different enzymes. The amount of genetic variation within populations was considerably lower (the mean H is 3.7%) than that of echinoderms from the deep-sea, but compareble to that of other echinoderms living in shallow water as well as the diadematids. The biochemical dendrogram for these four species constructed from the Neis genetic distances by using the UPGMA clustering method showed that the four species of the family Diadematidae are divided into two groups: one consists of two Diadema species and the other of the two Echinothrix species. The biochemical result is therefore consistent with the generally accepted taxonomic system established by morphological studies. The present electrophoretic results also strongly suggested that the four species of the Diadematidae are closely related to one another and their evolutionary divergences occurred in the relatively recent geological age of the Pleistocene (1.2–2.0 million years ago).

Electrophoretic study on the taxonomic relationship of the two morphologically very similar sea-urchins, Echinostrephus aciculatus and E. molaris

1. 1. The taxonomic relationship of two morphologically very similar sea-urchins, Echinostrephus aciculatus A. Agassiz and E. molaris (Blainville), was examined by means of gel electrophoresis of 18 different enzyme systems. 2. 2. The results demonstrated that the two species shared common allozymes at 25 of the 26 genetic loci studied here and that the Neis genetic identity value (I = 0.963) obtained between the two species was comparable to those already reported between conspecific local populations of many other animals. 3. 3. Their genetic similarity verified by the present electrophoretic study and their morphological and ecological similarity strongly suggest that E. aciculatus and E. molaris may belong to one and the same species.

Genetic variation in northern Japanese populations of the starfish Asterina pectinifera.

Abstract The starfish Asterina pectinifera of the family Asterinidae is endemic Japanese species and commonly found in Japanese waters. In order to examine the degree of genetic variation and the main-tenace mechanism of polymorphism within population, we studied the allozyme variation in five northern Japanese local populations of the starfish by electrophoresis. The species showed much higher genetic variability than many other shallow water echinoderms. Based on other allozyme studies and the ecological data, it was suggested that the high genetic variation of the starfish was closely related to the population size. Additionally, the relation between the degree of enzyme variation and the quaternary structure of enzymes was also examined, and the results suggested the close relation between the enzyme variability and functional constraints.

Genetic distance and protein polymorphism in two sea-urchin species of the order arbacioida and implications for their evolution

Abstract 1. 1. Protein polymorphism and genetic relationship were investigated in two sea-urchin species, Glyptocidaris crenularis and Stomopneustes variolaris belonging to the order Arbacioida by enzyme electrophoresis. 2. 2. The degree of genetic variation was comparable to that observed in many other echinoderms from shallow water, but was considerably lower than that from deep-sea water. The glucose metabolizing enzymes were on average less variable than the non-glucose enzymes. 3. 3. Neis genetic distance between the two species of the different families was 1.417, and comparable to the D values between closely related families of the order Echinoida. This suggests that the two species have the more recent evolutionary origin.

Genetic variation and differentiation in six local Japanese populations of the sea-urchin, Anthocidaris crassispina: electrophoretic analysis of allozymes

Abstract 1. 1. Protein variation, levels of heterozygosity, and inter-locality genetic differentiation were studied in six local Japanese populations of the sea-urchin, Anthocidaris crassipina, by electrophoretic analysis of 18 different enzymes. 2. 2. The proportion of polymorphic loci (P) was in the range 7.7–23.1% with a mean of 19.2%, and the average heterozygosity per locus (H) in the range 2.8–8.8% with a mean of 6.3%. These values are comparable to those observed in marine invertebrates from shallow water, but are considerably lower than those from the deep-sea. 3. 3. Of 18 enzymes examined, the glucose metabolizing enzymes were less variable than the non-glucose metabolizing enzymes, as already observed in many other animal species. 4. 4. The Neis genetic identity values between six local populations of the species ranged from 0.933 to 0.992 with a mean of 0.963. These values fall within the range of those observed in conspecific local populations of various animal species. 5. 5. The biochemical dendrogram showing genetic relationships among six local populations of the species demonstrated that the marginal populations are a little genetically differentiated from the populations in the middle zones of distribution.

Genetic variation in the starfish Coscinasterias acutispina

Abstract 1. 1. Protein variation was studied in the population of the starfish, Coscinasterias acutispina, of the family Asteriidae by enzyme electrophoresis as a preliminary study of the molecular systematics of the asteroids. 2. 2. The proportion of polymorphic loci (P) was 16.7% and the average heterozygosity per locus (H) was 6.1%. These values were comparable to those observed in many other echinoderm populations living in shallow water as well as C. acutispina, but were considerably lower than those from dee-sea water. 3. 3. Of 15 enzymes analyzed, the glucose metabolizing enzymes of more strictly functional constraint were, on average, less variable than the non-glucose metabolizing enzymes, as observed in many other echinoderms.