Characterization of chloroplast DNA microsatellites from Saccharum spp and related species

Microsatellites, or simple sequence repeats (SSRs), and their flanking regions in chloroplast genomes (plastomes) of some species of the family Poaceae were analyzed in silico to look for DNA sequence variations. Comparison of the complete chloroplast DNA sequences (cpDNAs) of sugarcane (Saccharum hybrid cv. SP-80-3280 and S. officinarum cv. NCo310) and related species, Agrostis stolonifera, Brachypodium distachyon, Hordeum vulgare subsp vulgare, Lolium perenne, Oryza nivara, O. sativa subsp indica, O. sativa subsp japonica, Sorghum bicolor, Triticum aestivum, Zea mays, and Z. mays cv. B73, allowed us to examine the organization of chloroplast SSRs (cpSSRs) in genic and intergenic regions. We identified 204 cpSSRs in the sugarcane cpDNA; 22.5% were in genic regions. The ndh, rps, trn, and rpl gene clusters of the chloroplasts had the most repeats. Mononucleotide repeats were the most abundant cpSSRs in these species; however, di-, tri-, tetra-, penta-, and hexanucleotide repeats were also identified. Many base substitutions and deletions/insertions were identified in the cpSSR loci and their flanking regions. Multiple alignments of all cpSSR sequences of Poaceae species made identification of nucleotide variability possible; repeat motifs are not uniformly distributed across the Poaceae plastomes, but are mostly confined to intergenic regions. Phylogeny was determined by maximum parsimony and neighbor-joining inference methods. The cpSSRs of these species were found to be polymorphic. It appears that individual cpSSRs in the Poaceae are stable, at least over short periods of evolutionary time. We conclude that the plastome database can be exploited for phylogenetic analysis and biotechnological development.     

Characterization of DNA from three nuclear polyhedrosis viruses pathogenic for Choristoneura sp

Three nuclear polyhedrosis viruses isolated from larvae of the insect genus Choristoneura showed polyhedrins of 28–30,000 daltons, genome sizes of 78–82 × 10⁶ daltons, and guanine plus cytosine contents of 47.9–49.4%. It was demonstrated by comparison of restriction endonuclease fragment patterns that two of the viruses are closely related genetically.     

Pollination efficiencies of three bee (Hymenoptera: Apoidea) species visiting rabbiteye blueberry

Inadequate bee pollination limits rabbiteye blueberry, Vaccinium ashei Reade, production in the some areas of the southeastern United States. Honey bees, Apis mellifera L., are currently the only manageable pollinators available for pollinating V. ashei. However, a new adaptable pollinator for rabbiteye blueberry, Osmia ribifloris Cockerell, was successfully reared and flown in captivity. The bee nested successfully in wooden shelters and conferred superior fruit set to 2-yr-old potted, rabbiteye blueberry bushes. Pollination efficiency or the percentage of blueberry flowers to set fruit after being visited once by a female O. ribifloris was comparable to that of the female blueberry bee Habropoda laboriosa (F.) and worker honey bees. Interestingly, honey bees once thought to be inefficient pollinators of rabbiteye blueberry were found to be very efficient, especially for 'Climax' and 'Premier' flowers.     

Sesquiterpenes from three Senecio species

Three succulent Senecio species afforded, in addition to known compounds, two further bisabolene derivatives, a norsesquiterpene and a diol related to β-caryophyllene alcohol, which, however, has a different stereochemistry. Structures were elucidated by spectroscopic methods and some chemical transformations. The chemotaxonomic relevance of the results is discussed briefly.     

Analysis of repetitive DNA in three species of Gossypium

The rate of reassociation of denatured DNA was determined for two selected diploid species, Gossypium thurberi (D genome) and G. arboreum (A genome), and one allotetraploid species, G. hirsutum (AD genome). The relative genome size and DNA content of the chromosomes of the diploids were A greater than D. Renaturation curves indicated that the differences in genome sizes were due primarily to the repetitive DNA content.     

三种摇蚊幼虫RAPD扩增条件的优化及在昆虫系统发育分析中的应用

为了研究摇蚊科昆虫种群遗传的多样性,以促进对其资源的合理保护,以萨摩亚摇蚊Chironomus samoensisEdwards基因组DNA为模板,对摇蚊幼虫的RAPD扩增条件进行优化,建立了摇蚊幼虫RAPD扩增反应的最佳体系:按照利用优化的RAPD扩增条件进行研究,实验有着良好的重现性。用16个随机引物对3种摇蚊幼虫类群各10个个体进行RAPD扩增,其中萨摩亚摇蚊共扩增出78个条带,多态座位率为41.03%,Shannon遗传多样性指数为0.2570,群体内相似度为0.8730;红裸须摇蚊Propsilocerus akamusi(Tokunaga)共75个条带,多态座位率为44.0%,Shannon遗传多样性指数为0.2472,群体内相似度为0.8731;刺铗长足摇蚊Tanypus punctipennis(Fabricius)共67个条带,多态座位率为41.79%,Shannon遗传多样性指数为0.1943,群体内相似度为0.9066。聚类分析结果表明,刺铗长足摇蚊与红裸须摇蚊的亲缘关系较近。     

Characterization of the macronuclear DNA of different species ofTetrahymena

Summary The macronuclear DNAs from 20 different species ofTetrahymena were characterized using alternating Orthogonal Field (AOF) gel electrophoresis. Each species has approximately 300 different macronuclear DNA molecules that range in size from about 100–2000 kb pairs. Although the individual macronuclear DNA molecules are not well resolved on an AOF gel, most species have a unique profile of macronuclear DNA. The sequences that hybridize with histone H4 (Tetrahymena) and ubiquitin (yeast) genes were identified on the separated macronuclear DNA molecules of the different species. All species have 2 histone H4 genes located on macronuclear DNA molecules of different sizes. This is consistent with the duplication of the histone H4 gene prior to the speciation events leading to the various species ofTetrahymena. The number and sizes of the macronuclear DNA molecules that hybridize with the ubiquitin probe vary from species to species. A grouping of the different species ofTetrahymena based on this hybridization pattern paralels groupings of the species based on ribosomal RNA sequences and isoenzymes. Some intraspecific variation among different strains ofTetrahymena thermophila was detected using ubiquitin and 5S ribosomal RNA as probes.Presented at the FEBS Symposium on Genome Organization and Evolution, held in Crete, Greece, September 1–5, 1986     

Genetic differentiation of three sympatric charr species from genus Salvelinus inferred from PCR-RFLP analysis of mitochondrial DNA

We examined differentiation of three sympatric charr species Dolly Varden charr Salvelinus malma Walbaum, white-spotted charr S. leucomaenis Pallas, and Levanidov charr S. levanidovi Chereshnev, Scopetz, Gudkov. Using restriction fragment length polymorphism analysis (RFLP), three mitochondrial DNA fragments (ND1/ND2, ND5/ND6, and Cytb/D-loop) amplified in PCR were compared. The divergence of mtDNA nucleotide sequences between S. levanidovi and S. leucomaenis was about 9.7%, between S. levanidovi and S. malma, 8.7%, and between S. malma and S. laecomaenis, 7.5%. These results indicate genetic isolation of the species examined and support the earlier suggestion on closeness of Levanidov charr to the common ancestor of the genus Salvelinus.     

Seven furanoeremophilanes from three Senecio species

The investigation of two further Senecio species and the re-investigation of S. inaequidens afforded, in addition to known compounds, seven new furanoeremophilane derivatives. Six of these are closely related to cacalol, a sesquiterpene type which predominates in the species investigated.     

New peltogynoids from three Peltogyne species

Two novel peltogynoids, 7-O-methylpeltogynol and 4-O-methyl-4′,5′-O,O-methylidenemopanol were isolated respectively from the trunk     

Gum polysaccharides from three Parkia species

Nigerian gum exudates from Parkia bicolor and P. biglobosa, and gum from the seed pods of P. pendula growing in Costa Rica have been analysed. The two gum exudates are proteinaceous and have closely similar physicochemical properties and compositions, with galactose, arabinose, glucuronic acid and 4-O-methylglucuronic acid as their constituent sugars; rhamnose is absent, and they are dextrorotatory. The gum from the seed pods of P. pendula contains the same constituent sugars in different proportions, and is laevorotatory. These data may be of interest in the continuing studies of plant-animal interactions and mechanisms of seed dispersal associated with the genus Parkia.     

Characterization of the salivary apyrase activity of three rodent flea species

1. Salivary gland lysates of the adult female fleas Oropsylla bacchi, Orchopea howardi and Xenopsylla cheopis hydrolyse ATP and ADP, but not AMP, thus characterizing the existence of a salivary apyrase activity. 2. In all species Mg++ or Ca++ function as activators, and a pH optimum between 7 and 8 is observed. 3. Salivary gland lysates of male fleas contain significantly smaller amounts of the enzyme activity than do those of female fleas. 4. Immediately following a blood meal, apyrase activity and protein content of female X. cheopis salivary glands are 2-3-fold less than that of unfed fleas, indicating that salivary apyrase activity is secreted during feeding. 5. It is suggested that, as in other arthropods, salivary apyrase may facilitate blood location and blood feeding by preventing ADP-induced platelet aggregation at the site of the bite.     

Cryptic species diversity in a widespread bumble bee complex revealed using mitochondrial DNA RFLPs

Cryptic species diversity is thought to be common within the class Insecta, posing problems for basic ecological and population genetic studies and conservation management. Within the temperate bumble bee (Bombus spp.) fauna, members of the subgenus Bombus sensu stricto are amongst the most abundant and widespread. However, their species diversity is controversial due to the extreme difficulty or inability morphologically to identify the majority of individuals to species. Our character-based phylogenetic analyses of partial CO1 (700 bp) from 39 individuals spread across their sympatric European ranges provided unequivocal support for five taxa (3–22 diagnostic DNA base pair sites per species). Inclusion of 20 Irish specimens to the dataset revealed ≥2.3% sequence divergence between taxa and ≤1.3% within taxa. We developed a PCR-RFLP based method for unequivocally distinguishing amongst the four cryptic European taxa of this subgenus, B. cryptarum, B. lucorum, B. magnus and B. terrestris, and used it to analyse 391 females of the former three species collected across Ireland, all of which could be unambiguously assigned to species. Bombus lucorum was the most widely distributed and abundant of the cryptarum–lucorum–magnus species complex, comprising 56% of individuals, though it was significantly less abundant at higher altitudes (>200 m) whilst B. cryptarum was relatively more abundant at higher altitudes. Bombus magnus was rarely encountered at urban sites. Both B. lucorum and B. terrestris are nowadays reared commercially for pollination and transported globally. Our RFLP approach to identify native fauna can underpin ecological studies of these important cryptic species as well as the impact of commercial bumble bees on them.     

Chromosomes and DNA of Mus: Terminal DNA synthetic sequences in three species

The DNA replication patterns of the terminal S phase of three species of Mus were analyzed by tritiated thymidine autoradiography. The centromeric heterochromatin of M. fulvidiventris is the latest component to finish DNA synthesis. The Y chromosome finishes replication earlier than the centromeric heterochromatin. The centromeric heterochromatin of M. musculus, on the other hand, is not the latest component to finish DNA synthesis. At the very late S phase, grains are found in the euchromatic arms instead of the heterochromatic areas. The hot X and the hot Y can be identified in the majority of, but not all, cases. The heterochromatic short arms of the autosomes in M. dunni finish DNA replication earlier than many areas in the euchromatic long arms and the heterochromatin of the sex chromosomes. This indicates that in M. dunni there are at least two types of heterochromatin. The late-replicating zones in the euchromatic long arms are distinctly banded. This banded grain pattern can be seen in all Mus species observed, but in M. dunni it is most exaggerated. Late-replicating chromosome segments can be demonstrated also by 2+ cycles of BUdR incorporation and Giemsa staining.     

Karyotypes of three Garra species from Ethiopia

Three cyprinid species from Ethiopia, Garra dembeensis, G. makiensis , and G. quadrimaculata , were found to be characterized by the chromosome numbers (2n) of 50 and by the arm numbers of 82, 84, and 88, respectively.     

Nuclear DNA content variation of three Miscanthus species in China

In order to estimate the variation in nuclear genome size in Miscanthus, flow cytometry of nuclei stained by propidium iodide was carried out using 36 populations of three Miscanthus species: M. lutarioriparius, M. sacchariflorus and M. sinensis, which were sampled from cold northern to warm and humid southern and central China, as well as near the sea level in eastern China to mountains in western China. The DNA content of diploid was 4.37 ± 0.02 pg/2C in M. lutarioriparius, 4.37 ± 0.01 pg/2C in M. sacchariflorus, and 5.37 ± 0.03 pg/2C in M. sinensis, respectively. There was no intraspecific variation in the three Miscanthus species at the diploid level, suggesting that the genome size was stable within species and the diverse environments did not induce variation in genome size at the diploid level. However, tetraploid populations were found in M. lutarioriparius and M. sacchariflorus, and their genome sizes were 8.56 and 8.54 pg, respectively, which are lower than expected values (8.74 pg), indicating the genome downsizing after polyploidization in the genus. Our results showed that the plant height of M. lutarioriparius was the highest one among the three species and the species was more closely related to M. sacchariflorus than M. sinensis. The intra-species genomic variation and inter-species differentiation in Miscanthus species provide important genetic and genomic information for the development of Miscanthus, especially for the endemic species, M. lutarioriparius, (together with Miscanthus × giganteus) which are now emerging as a key bio-energy crop because of their high yields and strong adaptability.