Pattern of variation of agamospermous Limonium (Plumbaginaceae) in the British Isles

An investigation of cytological, palynological, and taxometric variation in Limonium binervosum (G. E. Sm.) C. E. Salmon has revealed an extensive pattern of hierarchical relationships within this agamospermous group in the British Isles. The group is either triploid (2n = 27) or aneuploid tetraploid (usually 2n = 35) with a highly jumbled karyotype. Pollen is either not produced or of very low stainability (in the range 0–38%). Well stained pollen grains are usually abnormally large resulting from a failure of a meiotic division. These facts as well as the presence of only a single self-incompatible polledstigma morph in the majority of the group suggest that it is obligately agamospermic. The very strong correlation of taxometric relationship and geographical distance between variants suggests that evolution in the group has occurred by the gradual accumulation of mutations giving rise to morphologically and geographically related seed clones. The hierarchical pattern of variation as revealed by cluster analysis has been used as the basis of a hierarchical classification of the group.     

Biosystematic study of the genus Limonium (Plumbaginaceae) in the Aegean area, Greece. EO. Limonium on the islands Kithira and Antikithira and the surrounding islets

The genus Limonium is represented on Kithira, Antikithira and the surrounding islets by the following nine species: L. aphroditae and L. cythereum , recently described from Kithira; L. runemarkii and L. ocymifolium , endemic to Greece; L. graecum and L. sieberi , distributed in E Mediterranean; L. virgatum, L. sinuatum and L. echioides , having a wider Mediterranean distribution. For L. runemarkii , considered so far as endemic to SE Ewia, a new extended distribution range is given from Ewia to NW Kriti, through Peloponnisos and Kithira, showing the phytogeographic relationship of these areas. Moreover, the treatment of L. pigadiense as synonym of L. ocymifolium is proposed. Key and diagnostic characters for the species studied are given, while their affinities to related Aegean and Mediterranean Limonium taxa are discussed. Data on the cytology and breeding system are given. The following chromosome numbers were found: 2n=3x=27 for L. aphroditae and L. virgatum , 2n=6x=52 for L. cythereum , 2n=6x=51 for L. sieberi (firstly reported), 2n=5x=43 for L. runemarkii (firstly reported), L. ocymifolium and L. graecum , 2n=2x=16 for L. sinuatum and 2n=2x=18 for L. echoides. Concerning pollen-stigma combination, L. aphroditae, L. ocymifolium and L. virgatum are monomorphic with the self-incompatible combination B, while L. cythereum and L. runemarkii are also monomorphic with the self-incompatible combination A. According to these data the above species can be considered as apomictic. The facultative apomictic L. graecum was found monomorphic with the combination A, while L. sieberi , has the combination A or B within different populations. The autogamous species L. echioides has the self-compatible combination C, while the allogamous L. sinuatum is dimorphic having both combinations A and B in each population.     

Genome size and karyotype length in some interstitial polychaete species of the genus Ophryotrocha (Dorvilleidae).

Interstitial polychaetes of the genus Ophryotrocha are very small, progenetic, and morphologically very similar. These worms have been widely used in evolutionary biology and sexuality studies. To have a better insight into the karyological evolution of this genus, we measured the total karyotypic length and the 2C nuclear DNA content of the nine best-known species of this genus. No interspecific differences were observed in karyotypic lengths, apart from that of O. gracilis, which was significantly greater than the karyotypic length of five of the nine species. The genome size (i.e., 1C DNA content calculated from 2C DNA content) in eight of the nine species is about 0.4 pg, irrespective of the chromosome number. A group of four gonochoric and morphologically indistinguishable species, with 2n = 6 metacentric chromosomes, appears to be heterogeneous with regard to its DNA content, because one of the species, O. macrovifera, has a genome twice the size of that of the other three species. A hermaphroditic species, O. hartmanni, has a genome three times that size. No correlation has been observed between genome size and body size, egg cell diameter, or time interval from egg fertilization to sexual maturity. The basic genome size of 0.4 pg is among the lowest recorded in invertebrates. Hypotheses about selective pressures that maintain such a low amount of nuclear DNA in this genus are discussed.     

Study of the evolutionary relationships among Limonium species (Plumbaginaceae) using nuclear and cytoplasmic molecular markers

The genus Limonium, due to the patchiness of the natural habitats of its species as well as the high frequency of hybridization and polyploidy and the possibility of reproduction by apomixis, provides an example of all the principal mechanisms of rapid speciation of plants. As an initial study of evolution in this genus, we have analyzed intra- and interspecific variability in 17 species from section Limonium, the largest in the genus, based on RFLPs of cpDNA and nuclear rDNA ITS sequences. In the cpDNA analysis, 21 restriction enzymes were used, resulting in 779 fragments, 490 of which were variable and 339 parsimony informative. L. furfuraceum exhibited two relatively divergent cpDNA haplotypes. The relationships found among the species based on cpDNA restriction fragments were coincident using different methods of phylogenetic analysis. Due to the presumed reticulate evolution in the genus Limonium, the comparison of these results with data from the nuclear DNA was necessary; ITS sequences were analyzed. The final alignment contained 488 characters, of which 198 were variable and 156 parsimony informative. Two relatively divergent ITS types were present at the intraindividual level in L. delicatulum, a triploid species. Each type was related to ITS from different groups of diploid Limonium species, one with a base haploid chromosome number n = 8 (represented by L. cossonianum) and the other with n = 9 (represented by L. minutum). The different phylogenetic inference methods used for the analysis of ITS sequences rendered very similar topologies. In general, the relationships among the species studied were coincident with those obtained with the chloroplast genome. Both nuclear and cytoplasmic markers support the polyphyly of section Limonium, with at least two species, L. narbonense and L. vulgare, clearly divergent from the rest. Moreover, the remaining subsections into which section Limonium is currently divided seem to be artificial.     

四种补血草属植物叶片泌盐结构的扫描电镜观察

利用扫描电镜技术,对4种补血草属植物大叶补血草（Limonium gmelinii (Willd.) Kuntze）、耳叶补血草（Limoniu otolepis (Schrenk) Kuntze）、繁枝补血草（Limonium myrianthum (Schrenk) Kuntze）和簇枝补血草（Limonium auream）的叶表面进行了研究,以探讨植物微形态结构与生态环境的关系。结果表明,这4种植物的上下表皮都分布有盐腺,且上表皮的盐腺密度大于下表皮,盐腺的基本结构相同,多由20个细胞构成,其中4个分泌细胞顶端的角质层中央有一小孔,植物体靠盐腺的泌盐孔泌盐。但4种植物在盐腺的密度、盐腺的大小、盐腺与周围表皮细胞的位置等方面存在差异。植物在对盐碱生境的长期适应过程中,促使其强烈地分化出泌盐结构,因而,具有明显的生态适应性。     

The origin and evolution of Eragrostis tef (Poaceae) and related polyploids: evidence from nuclear waxy and plastid rps16

Tef (Eragrostis tef; Poaceae) is an allotetraploid (2n = 4x = 40) cereal crop whose origin within the large genus Eragrostis is unknown. Previous studies have suggested a total of 14 wild Eragrostis species as potential progenitors. Phylogenetic analysis of sequence data from the nuclear gene waxy and the plastid locus rps16 strongly supports the widely held hypothesis of a close relationship between tef and E. pilosa, a wild allotetraploid. Eragrostis heteromera, another previously proposed progenitor, is shown by the waxy data to be a close relative of one of the tef genomes. Other putative progenitors included in the taxon sample are not supported as closely related to tef. Plastid sequences from five varieties of tef and four E. pilosa accessions are identical and therefore are uninformative with respect to the question of multiple origins of these polyploids. The waxy phylogeny also resolves the relationships among other allopolyploids, supporting a close relationship between the morphologically similar allotetraploids E. macilenta, E. minor, and E. mexicana. Eragrostis cilianensis, another morphologically similar allopolyploid, appears to have shared one diploid progenitor with these species but derived its other genome from an unrelated diploid.     

Mhc Class II DNA Polymorphisms within and between Chromosomal Species of the Spalax Ehrenbergi Superspecies in Israel

Restriction fragment length polymorphisms (RFLPs) of two major histocompatibility class II genes (P alpha 1 and Q beta) were studied in 13 populations of four chromosomal species (2n = 52, 54, 58 and 60) of the mole rat, Spalax ehrenbergi superspecies in Israel. A substantial frequency of allelic fragments was found in both genes for all populations, including a desert isolate. In the P alpha 1 gene, one allelic fragment is a result of a deletion mutation which is diagnostic of the 2n = 52 chromosomal species. All other ten allelic variants are the result of point mutations. All mutations are located in a short region flanking the 3' end of the gene. Based on Mhc polymorphisms we confirm earlier evidence that gene flow does not occur between the older chromosomal species (2n = 52, 54, 58), and that reproductive isolation decreases, progressively from the oldest to the youngest species (2n = 60).     

Relationships between four novel ceratomyxid parasites from the gall bladders of labrid fishes from Heron Island, Queensland, Australia

Ceratomyxid parasites from the gall bladder of fishes from the family Labridae were examined for their taxonomic identity and their relatedness to other species of myxozoans. This paper describes four novel species Ceratomyxa choerodonae n. sp. from Choerodon cyanodus; Ceratomyxa cheilinae n. sp. from Cheilinus chlorourus; Ceratomyxa oxycheilinae n. sp. from Oxycheilinus digramma; and Ceratomyxa thalassomae n. sp. from Thalassoma lunare. Each species is characterised morphologically and small subunit (18 S) rDNA sequences were used in molecular phylogenetic analyses. Comparison of the small subunit rDNA sequences revealed four distinct species even though morphological differences indicated the presence of only two morphologically distinctive spore types. Phylogenetic analyses revealed that the ceratomyxids from labrid fishes did not form a clade to the exclusion of all other myxosporeans and provides evidence that host relatedness is not a good character to discriminate between species within the genus Ceratomyxa.     

Genetic differentiation among morphological variants of Acacia saligna (Mimosaceae)

This study investigated the pattern of genetic variation in Acacia saligna (Labill.) H.L. Wendl. to facilitate its development as a crop species for dryland salinity management. A. saligna is a morphologically variable species and four main variants are recognized. The genetic structure within A. saligna was investigated in populations across the geographic range of the species using nuclear restriction fragment length polymorphism loci. The analysis identified considerable genetic variation within A. saligna that was genetically structured into three groups. Two of the three groups corresponded to variants recognized in the field study; the third group encompassed the other two variants which, though morphologically different, were not genetically differentiated. The level of genetic differentiation between the groups suggests they may represent different taxa and a taxonomic revision of the species may be required. Identification of different taxa within A. saligna will have implications for the utilization and domestication of the species, as the taxa will need to be evaluated separately to determine their suitability for agroforestry. The high genetic variation between and within groups suggests there is a large genetic base available for breeding improved cultivars.     

Taxonomic status of a salamander species allied to Hynobius naevius and a reevaluation of Hynobius naevius yatsui (Amphibia, Caudata)

A Japanese small salamander, Hynobius naevius (Temminck and Schlegel, 1838), has recently proven to include two species (larger [A] and smaller [B]) that are reproductively isolated and are genetically and morphologically distinct from each other. Of these two species, Species A is considered to correspond to true H. naevius. To determine the name of Species B, we investigated five specimens stored at Kyushu University and concluded from the locality and date of collection that they represent syntypes of H. n. yatsui Oyama, 1947. Results of morphological comparisons indicated that the syntypes are identical with Species B. Because this species is distinct from Hynobius naevius at the species level, subspecies H. n. yatsui is elevated to full species rank as H. yatsui. To avoid taxonomic confusion, we designated one male among the syntypes as the lectotype and redescribed the species.     

Cytotaxonomic studies of six Indian species of Chlorophytum

Taxonomy of six species of Chlorophytum (Liliaceae) from India has been reassessed in the light of their morphological and cytological characters. C. tuberosum (Roxb.) Baker (2 n = 16), a wide-spread species, is morphologically well defined but C. bharuchae Ansari, Raghavan & Hemadri (2 n = 16) has been confused with C. glaucum Dalz. and C. glaucoides Blatter (both 2 n = 42) by earlier workers. C. malabaricum Baker (2 n = 42) is a delicate species and occurs in the Nilgiris and the Western ghats. Two closely allied species, C. nepalense (Lindley) Baker and C. khasianum Hooker fil. (both 2 n = 56) are distributed in Eastern India. The first two species, with 2 n = 16, have been considered as at the diploid level with base number 8 while the rest of them appear to be autoallopolyploids with base number 7.     

Fractionation and characterization of histones from barley (Hordeum vulgare) leaves

Histones were extracted from purified nuclei isolated from four cereals,viz. barley (Hordeum vulgare), wheat(Triticum aestivum), Aegilops squarrosa and corn (Zea mais), and from tobacco (Nicotiana tabacum). Analysis of the histones on SDS gels showed complex electrophoretic patterns with one species of both H3 and H4, one to three species of H1 and two to five species of H2. Judged from the electrophoretic patterns, the histones from barley, wheat and Aegilops are identical but different from those of corn with respect to H2. Like tobacco, corn showed two H2 components, whereas barley, wheat and Aegilops showed five H2 components. SDS gel electrophoresis of histones extracted from buds and roots of germinating seeds at different steps of germination and from different parts of ten-day-old leaves revealed that the existence in barley of multiple histone 2 variants is not restricted to any particular stage of differentiation of barley. Histones from barley leaves were resolved into four fractions by Biogel P-100 gel filtration and histones 2 were further fractionated by their differential solubility in HCl-ethanol. Each of these five fractions (H1, H3, H4, H2A and H2B, respectively) were characterized by electrophoresis on SDS or Triton-acid-urea gels and by their amino acid compositions as compared with the homologous histones of calf thymus and chicken erythrocytes. This revealed the following:

1. H3 and H4 are strictly analogous to their animal counterparts. However, H4 has an unexplained lower electrophoretic mobility in Triton-containing acid-urea gels.
2. H1 contains three components with lower electrophoretic mobilities than H1 from erythrocytes, contains more alanine than lysine and has a lower ratio of basic to acidic residues.
3. Both H2A and H2B contain at least four variants each, with higher molecular weights than in animals and higher lysine to arginine ratios. H2A variants comigrate in acid-urea-Triton gels with chicken erythrocytes H2A, whereas H2B migrate much slower.

It was concluded that the presence of multiple major variants of H2A and H2B is a frequent but not universal feature in cereals. The existence of these variants is not restricted to the embryonic stage as previously suggested for wheat (31).     

Chromosome banding in three species of <Emphasis Type="Italic">Hypsiboas</Emphasis> (Hylidae,Hylinae), with special reference to a new case of B-chromosome in anuran frogs and to the reduction of the diploid number of 2n = 24 to 2n = 22 in the genus

The chromosomes of hylids Hypsiboas albopunctatus, H. raniceps, and H. crepitans from Brazil were analyzed with standard and differential staining techniques. The former species presented 2n = 22 and 2n = 23 karyotypes, the odd diploid number is due to the presence of an extra element interpreted as B chromosome. Although morphologically very similar to the small-sized chromosomes of the A complement, the B was promptly recognized, even under standard staining, on the basis of some characteristics that are usually attributed to this particular class of chromosomes. The two other species have 2n = 24, which is the chromosome number usually found in the species of Hypsiboas karyotyped so far. This means that 2n = 22 is a deviant diploid number, resulted from a structural rearrangement, altering the chromosome number of 2n = 24 to 2n = 22. Based on new chromosome data, some possibilities were evaluated for the origin of B chromosome in Hypsiboas albopunctatus, as well as the karyotypic evolution in the genus, leading to the reduction in the diploid number of 2n = 24 to 2n = 22.     

Molecular phylogenetics of Limonium and related genera (Plumbaginaceae): biogeographical and systematic implications

Phylogenetic relationships within Limonium (Plumbaginaceae) are evaluated using sequence data from three plastid regions (rbcL, the trnL intron, and the trnL-trnF intergenic spacer). Sixty-six species representing the major genera of Staticoideae, including representatives of all sections and genera formerly included in Limonium, have been analyzed using four species of Plumbaginoideae as an outgroup. Analyses of each separate and combined data set yield similar results. Afrolimon is embedded in Limonium and related to L. vulgare, the type of Limonium. Limonium is split into two major clades corresponding to subgenera, but otherwise the current infrageneric classification proved to be artificial. Some groups restricted to particular areas can be recognized, and their synapomorphies are discussed. The presence of an isolated taxon in the Canary Islands is used as a calibration point for age estimates of the major events in the genus, including migrations to the Southern Hemisphere, the Canary Islands, and Asia. The rapid radiation of Limonium in the Mediterranean basin appears to coincide with the desiccation of the Mediterranean Sea in the Messinian (late Miocene).     

Chromosomal nucleolar organizer regions in four sturgeon species as markers of karyotype evolution in Acipenseriformes (Pisces).

Nucleolar organizer regions in Acipenser ruthenus (2n = 118 +/- 4) are localized on the telomeric regions of two morphologically different pairs of chromosomes. In A. baeri (2n = 250 +/- 8), A. transmontanus (2n = 248 +/- 8), and A. naccarii (2n = 246 +/- 8) they are localized on eight chromosomes arranged in two quadruplets. Contrary to what is commonly accepted, such distribution suggests that species with 120 chromosomes should be considered diploids and species with 240-250 chromosomes should be considered tetraploid.     

Exome sequencing and subsequent association studies identify five amino acid-altering variants influencing human height

Height is a highly heritable trait that involves multiple genetic loci. To identify causal variants that influence stature, we sequenced whole exomes of four children with idiopathic short stature. Ninety-five nonsynonymous single-nucleotide polymorphisms (nsSNPs) were selected as potential candidate variants. We performed association analysis in 740 cohort individuals and identified 11 nsSNPs in 10 loci (DIS3L2, ZBTB38, FAM154A, PTCH1, TSSC4, KIF18A, GPR133, ACAN, FAM59A, and NINL) associated with adult height (P < 0.05), including five novel loci. Of these, two nsSNPs (TSSC4 and KIF18A loci) were significant at P < 0.05 in the replication study (n = 1,000) and five (ZBTB38, FAM154A, TSSC4, KIF18A, and FAM59A loci) were significant at P < 0.01 in the combined analysis (n = 1,740). Together, the five nsSNPs accounted for approximately 2.5% of the height variation. This study demonstrated the utility of next-generation sequencing in identifying genetic variants and loci associated with complex traits.     

The ‘Pseudorhabdosynochus cupatus group’ (Monogenea: Diplectanidae) on Epinephelus fasciatus, E. howlandi, E. rivulatus and E. merra (Perciformes: Serranidae) off New Caledonia, with descriptions of Pseudorhabdosynochus cyathus n. sp. and P. calathus n. sp.

Pseudorhabdosynochus cupatus (Young, 1969) is characterised by small lamellosquamodiscs made up of central telescopic rings and peripheral rows of rodlets, and a sclerotised vagina in the shape of a thin-walled coiled tube with three accessory chambers. Two new species of Pseudorhabdosynochus are herein described from epinepheline fish off New Caledonia, South Pacific, and are considered part of the 'P. cupatus group'. P. cyathus n. sp. from Epinephelus howlandi has lamellosquamodiscs made up of four telescopic rings and four rows of separate rodlets; there are dorsal tegumental scales. This species was found only in young hosts; older hosts harbour P. venus Hinsinger & Justine, 2006. P. calathus n. sp. from Epinephelus rivulatus has lamellosquamodiscs made up of four telescopic rings and five rows of separate rodlets; the tegument is smooth. The three species, P. cupatus, P. calathus and P. cyathus, are strictly species specific; although morphologically very similar, they can be distinguished by features of the tegumental scales and measurements of the vagina and haptoral hard parts. P. melanesiensis (Laird, 1958) from E. merra is close to the 'P. cupatus group' according to the morphology of its sclerotised vagina but is distinguished by its squamodiscs which lack telescopic rings. Rare specimens found in E. merra are tentatively attributed to P. coioidesis Bu et al., 1999. A paratype of P. coioidesis is figured for comparison. E. merra, E. fasciatus, E. rivulatus and E. howlandi each have a Pseudorhabdosynochus species of the P. cupatus lineage: these are the dominant species in each host. In addition, E. merra, E. fasciatus and E. howlandi harbour a rare species of Pseudorhabdosynochus, respectively P. cf. coioidesis, P. caledonicus Justine, 2005 and P. venus; these rare species are morphologically unrelated to each other and to the 'P. cupatus group'.