Phylogeography of the endangered tideland snail Batillaria zonalis in the Japanese and Ryukyu Islands

The phylogeography of the endangered tideland snail Batillaria zonalis in the Japanese and Ryukyu Islands was analyzed on the basis of nucleotide sequences of a mitochondrial gene for cytochrome oxidase c subunit I (COI). Extremely low genetic diversity was found in populations at both the northern and southern boundaries of the geographic distribution of this species in Japan, i.e., Sendai Bay and Iriomotejima Island, respectively, which might be attributed to the population bottleneck due to historical environmental variations and/or the recent foundation of populations in the marginal part of the inhabitable range. Most populations contained unique rare haplotypes, and significant genetic differentiation on the whole was shown, while no clear geographic genetic structure was detected between the Japanese and Ryukyu Islands or over the distribution area of B. zonalis in Japan, with the exception of significant genetic divergences in Ago Bay in the central part of Honshu and the southern part of Okinawajima Island.     

Postural patterns of farmers in the Ryukyu Islands

Postural patterns in everyday life were observed in the Ryukyu Islands. Postures seem to have two dimensions. In one dimension, they consciously changed their posture in the same action according to situations. In the other dimension, they took a particular posture, e.g., sitting with one knee raised, in different actions. The former may be related to the communicative aspect of posture, while the latter to the technical aspect of posture. Further, some postures, e.g., standing while deeply bending forward, could be regarded as techniques peculiar to their culture. The relation between culture and biology is also discussed with respect to postural patterns which may be related to the traditional lifestyle in Okinawa.     

Gliocephalotrichum microchlamydosporum and G. simplex in the Ryukyu Islands, Japan

Seven hyphomycete isolates from forest environments of the Ryukyu Islands, Japan, were identified to Gliocephalotrichum microchlamydosporum and G. simplex. The former species is a new record in Japan. Although the five known species in the genus Gliocephalotrichum including two isolates of G. microchlamydosporum and four of G. simplex in this study are all soilborne, another isolate of G. simplex was first isolated from an unidentified basidiocarp tissue.     

Intersectional gene flow between insular endemics of Ilex (Aquifoliaceae) on the Bonin Islands and the Ryukyu Islands

Hybridization and introgression play important roles in plant evolution, and their occurrence on the oceanic islands provides good examples of plant speciation and diversification. Restriction fragment length polymorphisms (RFLPs) and trnL (UAA) 3'exon-trnF (GAA) intergenic spacer (IGS) sequences of chloroplast DNA (cpDNA), and the sequences of internal transcribed spacer (ITS) of nuclear ribosomal DNA were examined to investigate the occurrence of gene transfer in Ilex species on the Bonin Islands and the Ryukyu Islands in Japan. A gene phylogeny for the plastid genome is in agreement with the morphologically based taxonomy, whereas the nuclear genome phylogeny clusters putatively unrelated endemics both on the Bonin and the Ryukyu Islands. Intersectional hybridization and nuclear gene flow were independently observed in insular endemics of Ilex on both sets of islands without evidence of plastid introgression. Gene flow observed in these island systems can be explained by ecological features of insular endemics, i.e., limits of distribution range or sympatric distribution in a small land area.     

Molecular evolutionary relationships between partulid land snails of the Pacific

Adaptive radiation of partulid land snails in the tropical Pacific has produced an extraordinary array of distinctive morphological, ecological and behavioural types. Here we use part of the nuclear ribosomal RNA gene cluster to investigate the relationships within and between the three partulid genera, Partula, Samoana and Eua. The genera cluster separately, with Samoana and Partula forming monophyletic groups. With one exception, the molecular data generally support the previous generic classification based on genital morphology, even in species that show a number of characteristics otherwise atypical of the genus. Convergent evolution explains morphological similarities between members of different genera. The phylogeny suggests that Samoana has colonized the Pacific from west to east, originating in the area where Eua, believed to be the most ancient partulid genus, is found. An unexplained anomaly is the reported occurrence of a single species of Samoana in the Mariana Islands of the western Pacific. The genus Partula has a disjunct distribution, encompassing islands both to the east and west of the range occupied by Eua. Partula seems to have spread both eastward and westward after the splitting of the Partula lineage.     

Phylogenetic relationships in the family Resedaceae L.

A study was made on the phylogenetic relationships of species of the family Resedaceae, based on morphological features, chromosome meiotic behaviour, karyotype features, size and fertility of pollen grains, nucleotypic parameters, seed protein profiles and esterase isozyme patterns.For the comparison of the seed protein profiles among species a method was developed based on the presence or absence of the bands by means of a computer program. The dendrogram obtained by such a method is in line, to a great extent, with the clusters (sections) obtained within the family based on morphological features.Data on meiotic behaviour and on morphology, such as the type of fruit, carpel numbers and others, suggest that x=5 is the primitive basic chromosome number of this family. x₁=6 and x₂=7 are considered as secondary basic numbers derived from x=5 through aneuploid changes.The results support a proposed phylogenetic tree of the genera and sections of the genus Reseda represented in the European Flora.The principal phenomena that have operated in the evolution of the Resedaceae seem to be aneuploid changes, polyploidy and structural rearrangements. A trend towards DNA increase in the evolution of this group is also apparent.     

Phylogenetic relationships between Bryum and supposedly closely related genera

Abstract

The phylogeny of the genus Bryum was studied using cladistic analyses under the maximum parsimony criterion of evolution of anatomical and morphological characters. Three analyses were made with 32 Bryum species plus 20 species from genera supposedly closely related to Bryum, and with Amblyodon dealbatus (Sw. ex Hedw.) Bruch & Schimp., Meesia uliginosa Hedw., and Leptostomum macrocarpum (Hedw.) Bach. Pyl., as outgroups. It is here suggested that under earlier systematic concepts the genus Bryum is paraphyletic. A clade with Bryum billarderi Schwägr., B. capillare Hedw., B. donianum Grev., B. russulum Broth. & Geh., Rhodobryum giganteum (Schwägr.) Paris, and R. keniae (Müll. Hal.) Broth. are circumscribed by spathulate stem leaves that are crowded in the stem apex, suggesting that the rosulate species of Bryum are more closely related to Rhodobryum than to the rest of Bryum. Stem leaf costae without stereids and spores that mature in the winter are synapomorphies for a clade with Anomobryum julaceum (P. Gaertn. et al.) Schimp. and Bryum argenteum (Hedw.). The tropical species B. cellulare Hook. and B. flaccum Wilson ex Mitt. appear in a clade with Plagiobryum zieri (Dicks. ex Hedw.) Lindb. and Synthetodontium pringlei Cardot. In one analysis, B. limbatum Müll. Hal., Epipterygium tozeri (Grev.) Lindb., Leptobryum pyriforme (Hedw.) Wilson, and Roellia roellii (Broth. ex Röll) H.A. Crum came out in a clade with Mniobryum atropurpureum (Wahlenb.) I. Hagen, Mnium hornum Hedw., Pohlia cruda (Hedw.) Lindb., P. longicollis (Hedw.) Lindb., and Pseudopohlia didymodontia (Mitt.) A.L.Andrews. It is here suggested that gametophytic features, such as the orientation and anatomy of the stem leaves and the appearance of vegetative propagules, are important for the internal relationships within the studied ingroup, whereas characters related to the sporophyte, especially those of the peristome, may obscure phylogenetic relationships. Most of the subgenera and the sections of Bryum, as defined by earlier authors, appear to be paraphyletic. However, due to the low stability of most clades it is suggested that analyses including anatomical, morphological, and molecular data are needed.     

Phylogenetic relationships of Japanese species of Heterobasidion--H. annosum sensu lato and an undetermined Heterobasidion sp

The phylogenetic relationships of two Japanese Heterobasidion species, H. annosum sensu lato and an undetermined species, were revealed based on three gene loci, glyceraldehyde 3-phosphate dehydrogenase (gpd), heat shock protein (hsp) and elongation factor 1-alpha (ef). The tree, based on combined data of gpd, hsp and ef, showed that Japanese H. annosum s.l. was close to the European S-group, forming a subclade. The results of this study also provided strong support for the recognition of the undetermined Heterobasidion sp. as a distinct phylogenetic species closely related to H. araucariae.     

Dispersal ecology of the maritime plants in the Ryukyu Islands,Japan

The dispersal ecology of seventeen maritime species, which are dominant and/or characteristic species of coastal communities on the Ryukyu Islands, was studied. The species wereCalophyllum inophyllum, Canavalia maritima, Clerodendron inerme, Guettarda speciosa, Hernandia sonora, Hibiscus tiliaceus, Ipomoea gracilis, I. pes-caprae, Messerschmidia argentea, Pandanus odoratissimus, Pongamia pinnata, Scaevola frutescens, Sophora tomentosa, Terminalia catappa, Thespesia populnea, Vigna marina andWedelia biflora. The structure and size of disseminules and their buoyancy and viability in seawater were examined in the laboratory. The disseminules of these seventeen species have morphological characteristics for buoyancy, and tests showed that these species could be dispersed by sea currents. Drift disseminules on the drift line, seedlings on the hightide line, and young plants of woody species in the herb zone were observed, being abundant on the coasts of the Ryukyu Islands. The Kuroshio Current carries these disseminules from islands where these species form part of the tropical coastal vegetation.     

Reproductive and sexual characteristics in five Lethrinus species in waters off the Ryukyu Islands

Gonads of five lethrinids, viz., Lethrinus harak, L. miniatus, L. obsoletus, L. ornatus, and L. sp. 2, were collected monthly in waters off the Ryukyu Islands and observed histologically to reveal their spawning periods and size at sexual maturation and sexual transition. The spawning period was from April to November for L. harak, from April to July for L. miniatus, from April to October for L. obsoletus, from May to November for L. ornatus, and from April to October for L. sp. 2. Sexual patterns in the five species were determined by fork length at both sexual maturation and sexual transition. The body size (fork length, FL) and sex ratio (% of female) at 90% maturity in L. harak were 21.1 cm FL and 90%, respectively; those of L. miniatus were 42.2 cm FL and 80%; 25.7 cm FL and 60% for L. obsoletus; about 20 cm FL and 90% for L. ornatus; and about 26 cm FL and 90% for L. sp. 2. Because the sex ratios decreased to 0% at the maximum size classes in L. miniatus, L. ornatus, and L. sp. 2, the sexual patterns in these species were considered to be protogynous hermaphrodite. Although the sex ratio (% of female) once decreased to about 30% at 28 cm FL, rapid increase occurred in the larger size class in L. harak. However, the increase did not result from sexual transition. Hence, the sexual pattern of L. harak was considered to be protogynous hermaphrodite. Because the sex ratio (% of female) at body sizes larger than 23 cm FL was stable at about 60% in L. obsoletus, the sexual pattern was determined to be one of juvenile hermaphrodites.     

The evolution of narrow reef flats at high-latitude in the Ryukyu Islands

This paper describes a Holocene reef structure observed from a cutting in a modern reef on Okierabu Island in the Ryukyu Islands and proposes a process for the initiation and formation of narrow, lagoon-less fringing reef flats. Reef formation began around 7050 yBP at 11 m below present sea level. The reef was constructed by a uniform facies of in situ tabular corals and kept up with sea level rise. Geomorphological zonation has been restricted by the lack of a cross-reef energy gradient during reef formation. Sediment trapped by limestone caves abutting the shore has contributed to this characteristic. The slope break around-10 m and steep scarp of the shore create a narrow substrate that is responsible for the development of an equally narrow reef flat.     

Phylogenetic relationships of the Chalcides skink species from the Chafarinas Islands with those from mainland North Africa

Species whose geographical distribution encompasses both mainland and island populations provide ideal systems for examining potential isolation and genetic divergence. This has also interest from a conservationist point of view, as it is important to protect “evolutionarily significant units”. We report a phylogenetic mitochondrial DNA analysis comparing the populations of the three Chalcides skink species from the Chafarinas Islands (NW Africa) with specimens of the same species from the nearest mainland. We tested for the potential genetic distinctiveness of the skink island populations. However, the results of the comparison of the genetic variability of the mitochondrial coding gene cytb were conclusive showing that the genetic divergence between continental and island Chalcides species was either non-existent or extremely low. We discuss how genetic divergence may be lower than expected if separation time of the islands with the mainland has not been long enough or if the island skink populations were currently communicated via ocean rafting with individuals coming from the mainland ones.     

Phylogenetic relationships based on morphology among the Diospyros (Ebenaceae) species endemic to the Mascarene Islands

The Diospyros (Ebenaceae) species which colonized the Mascarene Islands, namely Mauritius, Reunion and Rodrigues, have been decimated over the years by human settlements. Of the 14 endemic species that have been described and collected for herbaria, Diospyros angulata is now believed to be extinct in Mauritius. The phylogenetic relationships of the 14 Diospyros species were determined using maximum parsimony analysis of 35 morphological characters. This analysis separated the Mascarene Diospyros into two major clades, with D. revaughanii , D. egrettarum and D. leucomelas grouped in the same strongly supported most basal clade while the rest of the species formed the other major clade. High bootstrap values were obtained for the sister species D. angulata and D. boutonania , and the clade clustering the upland species D. neraudii , D. nodosa and D. pterocalyx . There was also relatively strong support for the clade comprising D. hemiteles and D. melanida , which are located in mid altitude regions. These results indicate that Diospyros species most probably colonized the coastal areas of Mauritius and then moved to mid altitude habitats before finally reaching the upland regions. There are also strong indications that D. borbonica and D. diversifolia , endemic to Reunion and Rodrigues, respectively, resulted from migrations from Mauritius.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 150 , 307–313.     

Fine-Scale Genetic Structure and Demographic History in the Miyako Islands of the Ryukyu Archipelago

The Ryukyu Archipelago is located in the southwest of the Japanese islands and is composed of dozens of islands, grouped into the Miyako Islands, Yaeyama Islands, and Okinawa Islands. Based on the results of principal component analysis on genome-wide single-nucleotide polymorphisms, genetic differentiation was observed among the island groups of the Ryukyu Archipelago. However, a detailed population structure analysis of the Ryukyu Archipelago has not yet been completed. We obtained genomic DNA samples from 1,240 individuals living in the Miyako Islands, and we genotyped 665,326 single-nucleotide polymorphisms to infer population history within the Miyako Islands, including Miyakojima, Irabu, and Ikema islands. The haplotype-based analysis showed that populations in the Miyako Islands were divided into three subpopulations located on Miyakojima northeast, Miyakojima southwest, and Irabu/Ikema. The results of haplotype sharing and the D statistics analyses showed that the Irabu/Ikema subpopulation received gene flows different from those of the Miyakojima subpopulations, which may be related with the historically attested immigration during the Gusuku period (900 − 500 BP). A coalescent-based demographic inference suggests that the Irabu/Ikema population firstly split away from the ancestral Ryukyu population about 41 generations ago, followed by a split of the Miyako southwest population from the ancestral Ryukyu population (about 16 generations ago), and the differentiation of the ancestral Ryukyu population into two populations (Miyako northeast and Okinawajima populations) about seven generations ago. Such genetic information is useful for explaining the population history of modern Miyako people and must be taken into account when performing disease association studies.     

Genetic relationships between Bidens forbesii and six species in the Hawaiian and the Marquesas Islands

A crossing program was carried out between the Kauai endemicB. forbesii and six other Polynesian species, five of which are Hawaiian and one Marquesan. All crosses produced vigorous F₁ hybrids, portraying a strong genetic relationship betweenB. forbesii and the other species. The results indicate a close systematic relationship among the Polynesian species ofBidens placed by Sherff in sect.Campylotheca and strengthen the argument that this group dispersed from North America to the Hawaiian Islands, then from Hawaii to the Marquesas Islands.     

Phylogenetic relationships between the families of recent Thysanoptera (Insecta)

One family, the Phlaeothripidae, is recognized in the suborder Tubulifera, whereas extant species of Terebrantia are classified into seven families: Uzelothripidae, Merothripidae, Aeolothripidae, Adiheterothripidae, Fauriellidae (stat. n.), Heterothripidae and Thripidae. A phylogenetic analysis of the relationships between these families is given, based on consideration of 35 imaginal characters; however, the relationships of Uzelothripidae and Phlaeothripidae to the rest of the Thysanoptera remain equivocal. The Phlaeothripidae are either derived independently from Protothysanoptera, or else are the sister-group of the Thripidae, the most specialized family of Terebrantia.
Diagnostic characters, diversity, distribution and relationships of each family are discussed. Keys to family and, in Fauriellidae, to genus are provided. Holarthrothrips Bagnall (= Adiheterothrips Ramakrishna, syn. n.) and Oligothrips Moulton are removed from Heterothripidae to Adiheterothripidae and Fauriella Hood, Opisthothrips Hood and Ropotamothrips Pelikan (= Osmanothrips Priesner, syn. n.) from Heteromripidae to Fauriellidae (stat. n.). These transfers leave Aulacothrips Hood, Heterothrips Hood and Scutothrips Stannard as the only genera in Heterothripidae.     

Molecular phylogeny of the genus Pieris (Ericaceae) with special reference to phylogenetic relationships of insular plants on the Ryukyu Islands

Phylogenetic relationships within the genus Pieris (Ericaceae) were investigated based on the rbcL and matK genes along with five spacer sequences of chloroplast DNA to address questions regarding the phylogeography of the genus in association with insular plants on the Ryukyu Islands. The most parsimonious trees indicated that P. floribunda from eastern North America is a sister taxon to the remaining taxa examined, and suggested that the East Asian taxa examined are monophyletic. A morphologically cohesive group, section Pieris, was revealed to be paraphyletic. Within the East Asian clade, insular endemics from the Ryukyu Islands, Taiwan, and mainland Japan formed a sister group to P. formosa from the Himalayas and southern China. Our data suggest that the insular endemics of the Ryukyu Islands and Taiwan arose via allopatric divergence as a result of a paleogeographical land configuration of a landbridge during the early–middle Pleistocene in the Quaternary Period.     

Phenol Ethers and Terpenes of Six Heterotropa Species Distributed in the Ryukyu Islands and Formosa

A new intracellular peptidase, which we call “d-peptidase S,” was purified from Nocardia orientalis IFO 12806 (ISP 5040). The purified enzyme was homogeneous on disc gel electrophoresis. The molecular weight and the isoelectric point were estimated to be 52,000 and 4.9, respectively. The optimum pH for the hydrolysis of d-leucyl-d-leucine was 8.0 to 8.1, and the optimum temperature was 36°C. The purified enzyme usually hydrolyzed the peptide bonds preceding the hydrophobic D-amino acids of dipeptides. Tri- and tetra-peptides extending to the amino terminus of such peptides were also hydrolyzed. Therefore, the enzyme is a carboxylpeptidase-like peptidase specific to d-amino acid peptides. The Km values for d-leucyl-d-leucine and l-leucyl-d-leucine were 0.21 × 10^-3 and 0.44 × 10^-3 m respectively. The activity was inhibited by several sulfhydryl reagents and two chelators, 8-hydroxyquinoline and o-phenanthroline.