An approach to chemotaxonomy of the Asarum subgenus

A survey of chemical composition of 23 species of Asarum subgenus Heterotropa showed that the five groups could be distinguished on the basis of the presence or absence of asatone, phenol ethers and terpenes.     

Cellular fatty acid profiles for the differentiation of Penicillium species

Cellular fatty acid composition of eighteen species of Penicillium was studied to investigate its taxonomic usefulness. Many fungi included in this study displayed the same fatty acid composition but differed in relative concentration. Several test species presented the same fatty acid composition but differed in relative concentration. The principal fatty acids were palmitic (16:0), oleic (18:1) and linoleic (18:2). The amount of unsatured fatty acids varied between 68.5% and 78.5%. Multivariate analyses of data showed that it is possible to differentiate some species that belonged to different Penicillium groups. The level of agreement of long chain fatty acids with morphological taxonomy was acceptable.     

The fatty acid composition of milk fat as influenced by feeding oilseeds

The fatty acid composition of bovine milk fat can be substantially altered by feeding lipid sources which alter the fatty acid profile of lipid entering the intestine from the rumen. As long-chain fatty acids of dietary origin can be incorporated directly into milk fat the opportunity exists to alter the ratio of short and long-chain fatty acids as well as the degree of saturation of milk fat. In practice our ability to alter the fatty acid profile of milk fat is limited not by the synthetic capacity of the mammary gland, but rather by the challenge of achieving effective protection of unsaturated dietary fatty acids from biohydrogenation in the rumen, as well as keeping the level of polyunsaturated fatty acids within the range where the organoleptic quality and shelf-life of milk and dairy products are not compromised. The fatty acid composition of oilseeds such as canola are considered desirable from a human health perspective and thus their inclusion in the diet of dairy cattle as a means of achieving a more desirable fatty acid profile in milk fat may enhance the nutritive quality of milk.     

Laticifers and the classification of Euphorbia: the chemotaxonomy of Euphorbia esula L.

Laticifers and the classification of Euphorbia: the chemotaxonomy of Euphorbia esula L. Articulated and non-articulated laticifer cells represent distinctive cell types of relatively recent origin and occur in only a few families. Both types are of separate phylogenetic origin, reflecting independent evolutionary trends in the Euphorbiaceae. Supra-generic groupings of this family can be segregated into three taxonomic units using the laticifer character; with either articulated laticifers, non-articulated laticifers, or no laticifers. Such units may reflect more natural assemblages than now represented in the classification of this family. Laticifers possess chemical and morphological features of potential application as taxonomic characters to aid in delimiting species and interpreting evolutionary trends. The triterpenoid profile from latex of Euphorbia species has been shown to be diagnostic for a taxon. The qualitative and quantitative composition show a high level of stability under diverse environmental and physiological conditions indicating a genetic basis for triterpenoid synthesis. Triterpenoid profiles of known accessions of European E. esula L. and related presumptive taxa from North America readily separated them into distinctive chemotaxa that include one for E. esula L., whereas morphological features were found inadequate for separating accessions to presumptive taxa. Identification of adventive spurges in North America requires diagnostic analyses of Eurasian leafy spurges for comparison. Laticifer characters used in conjunction with relevant morphological features will provide a broadened insight into phylogenetic relationships with the Euphorbiaceae.     

Adaptive evolution of context-dependent style curvature in some species of the Malvaceae: a molecular phylogenetic approach

The evolution of floral movement responding to pollination environments has long intrigued biologists. This has been mostly demonstrated in different species, but has as yet few explanations at the family level. Style curvature occurs in 23 species of eight genera among our observed and surveyed 52 species of 13 genera in the Malvaceae. To analyze the origin of style curvature in these species, we mapped this and correlated characters onto molecular phylogenetic trees that were constructed using the combination of the chloroplast DNA sequences of ndhF and the rpl16 intron. The results showed that style curvature evolved at least five times in species with herkogamous flowers. The occurrence of style curvature was associated with a shift to annual or perennial herbs with herkogamous flowers, which have similar ecological distributions with unpredictable pollinator environments. Style curvature appears to have evolved to facilitate delayed selfing if outcrossing fails under unpredictable pollination conditions.     

An immunochemical approach to species relationship in Triticum and some related species

Summary An immunological reaction, precipitation in gel, was produced using a rabbit antiserum directed to a specific protein constantly present in bread wheats (T. aestivum, genome AABBDD), but absent in durum wheat (T. durum Desf., genome AABB). This protein was isolated in the soluble-protein fraction of bread wheat caryopses by combined biochemical and immunological techniques.The availability of such a specific anti-bread wheat serum made possible the analysis of a series of varieties and species of wheat and of some closely related (Secale, Aegilops) and less closely related (Hordeum, Haynaldia) taxa to determine whether the protein was present or absent. Hordeum vulgare, Haynaldia villosa, Triticum monoccocum and Triticum turgidum gave a negative result, while positive results were obtained in T. aestivum, T. timopheevi, T. zhukovskyi, Secale cereale, Aegilops speltoides, Ae. mutica, Ae. comosa, Ae. caudata, Ae. umbellulata, Ae. squarrosa, and also in the artificial amphiploids (Ae. speltoides x T. monococcum) and (Ae. caudata x T. monococcum).It is concluded that these results agree closely with the classification of Triticum proposed by MacKey in 1966. The investigated protein not only permits the differentiation of T. aestivum from T. turgidum, but also T. turgidum from T. timopheevi at tetraploid level and T. monococcum from all the diploid species of Aegilops.     

Taxonomy of Pinus species based on the seed oil fatty acid compositions

 The fatty acid compositions of the seed oils from ten pine species have been established by capillary gas-liquid chromatography of the methyl esters. With regard to either normal fatty acids or Δ5-olefinic acids, the general pattern of fatty acids did not differ from that of other pine seed oils reported previously. The main fatty acid was linoleic (9,12–18:2) acid (44.4–57.1%), followed by either oleic (9–18:1) acid (13.4–24.5%) or pinolenic (5,9,12–18:3) acid (1.5–25.2%). When applying multivariate analyses to the chemometric data (13 variables) of 49 pine species (ca. 40% of the living pine species), it was possible to distinguish between several sections: Pinea, Longifolia, Halepensis, Ponderosa-Banksiana, Sylvestris, and Cembra. The latter section was clearly divided into two sub-groups. A few species that presented a low overall content of Δ5-olefinic acids, and that grow in warm-temperate regions, were isolated from the bulk of other pine species. It is hypothesized that Δ5-olefinic acids might be related to cold-acclimation. Received: 5 June 1997 / Accepted: 17 August 1997     

Flavonoids and the chemotaxonomy of three Sophora species

Sophora microphylla, S. prostrata and S. tetraptera are distinguishable from one another by their leaf flavonoids. S. microphylla is distinguished by the present of rhamnosylvitexin and rhamnosylisovitexin and S. tetraptera by the presence of apigenin-7-O-rhamnosylglucoside-4′-O-glucoside and the 7-O-glucosides of apigenin, 7,4′-dihydroxyflavone, luteolin and 7,3′,4′-trihydroxyflavone. Sophora prostrata lacks all these flavonoids, but has several pigments which are common to all three species.     

Effectiveness of the fatty acid and sterol composition of seeds for the chemotaxonomy of Coffea subgenus Coffea

The chemotaxonomic relationships between Coffea (subgenus Coffea) species have been poorly studied to date and the compounds tested so far - chlorogenic acids, diterpenoids and purine alkaloids - did not enable the establishment of phylogenetic relationships analogous to those revealed by chloroplast and nuclear DNA studies. In the present study, the relationships between African Coffea species were assessed on the basis of their seed lipid composition. Fatty acids and sterols were determined in 59 genotypes belonging to 17 distinct Coffea species/origins. Principal Component Analysis of fatty acid and sterol data enabled easy identification of the few species for which one or several compounds could serve as a quantitative signature. Hierarchical Clustering classified the Coffea species in seven groups with both fatty acids and sterols. However, while groupings based on seed fatty acid composition showed remarkable ecological and geographical coherence, no phylogeographic explanation was found for the clusters retrieved from sterol data. When compared with previous phylogenetic studies, the groups deduced from seed fatty acid composition were remarkably congruent with the clades inferred from nuclear and plastid DNA sequences.     

Genus-wide Bacillus species identification through proper artificial neural network experiments on fatty acid profiles

Gas chromatographic fatty acid methyl ester analysis of bacteria is an easy, cheap and fast-automated identification tool routinely used in microbiological research. This paper reports on the application of artificial neural networks for genus-wide FAME-based identification of Bacillus species. Using 1,071 FAME profiles covering a genus-wide spectrum of 477 strains and 82 species, different balanced and imbalanced data sets have been created according to different validation methods and model parameters. Following training and validation, each classifier was evaluated on its ability to identify the profiles of a test set. Comparison of the classifiers showed a good identification rate favoring the imbalanced data sets. The presence of the Bacillus cereus and Bacillus subtilis groups made clear that it is of great importance to take into account the limitations of FAME analysis resolution for the construction of identification models. Indeed, as members of such a group cannot easily be distinguished from one another based upon FAME data alone, identification models built upon this data can neither be successful at keeping them apart. Comparison of the different experimental setups ultimately led to a few general recommendations. With respect to the routinely used commercial Sherlock Microbial Identification System (MIS, Microbial ID, Inc. (MIDI), Newark, Delaware, USA), the artificial neural network test results showed a significant improvement in Bacillus species identification. These results indicate that machine learning techniques such as artificial neural networks are most promising tools for FAME-based classification and identification of bacterial species.     

Characterization of the hydroxy fatty acid content ofBasidiomycotina

Fatty acids (FA) of nine fungal species belonging to the subphylumBasidiomycotina were identified by using capillary GC-MS, MS and HPLC. The identified fatty acids included 45 saturated (iso-, anteiso-, and 19 hydroxy acids) and 42 monoenoic acids (including 14 hydroxy acids); dienes and polyenes were represented by 13 fatty acids. The proportion of hydroxy acids in the total fatty acids in the fungal species ranged from 4.3 to 10.2%. Very long-chain fatty acids (C₂₄-C₃₀) were also determined. Four fatty acids 16:0 (8.8–14.3%), 18:1(11) (3.9–14.9%), 18:1(9) (7.7–19.0%) and 18:2(6) (7.6–19.4%), were found as major acids. Of the identified acids, 17 were detected inBasidiomycotina for the first time.     

Lipid content and fatty acid composition in hypogeous organs ofHelleborus species (Ranunculaceae)

Root and rhizome of fourHelleborus species:H. viridis, H. odorus, H. niger, H. foetidus were examined throughout a two-year period in order to determine the variation of lipid content and fatty acid composition during the ontogenetic cycle. In the deciduous geophytesH. viridis andH. odorus subsp.laxus the lipid content reaches its maximum during the quiescent phase, whereas in the evergreen geophyteH. niger the lipid content is highest during the main growth period. In the chamaephyteH. foetidus lipid content is always very low and it does not show variation throughout the year. In all species the fatty acids detected in the neutral fraction are myristic, palmitic, stearic, oleic and linoleic acid. Palmitic and linoleic acid are always present in larger quantities. The pattern of the relative content of saturated/unsaturated fatty acids seems to be linked to the life form of these species.     

The fatty acid content of the Bordetella pertussis endotoxin

The fatty acid content of Bordetella pertussis endotoxin has been estimated by several methods. Expressed as 3-hydroxytetradecanoic acid, it was 0.74 mumol (mg lyophilized material)-1, 0.38 mumol being ester-bound, and 0.32 mumol in amide linkage. Reported molar ratios of ester-bound to amide-bound fatty acids in endotoxins of various bacterial species range from 2.4 to 2 in B. pertussis, to 5 to 2 in Salmonella minnesota; according to these figures large differences must exist in the degree of substitution, and the substitution pattern of the glucosaminyl-beta-1,6-glucosamine unit present in the hydrophobic region of endotoxins. When fatty acids, released by acid and alkaline hydrolyses of the B. pertussis endotoxin, were extracted into chloroform, unidentified chromogenic substances appearing in the extract interfered with their colorimetric estimation; no interference was observed when hexane was used instead of chloroform.     

Mortierella sugadairana,a new homothallic species related to the firstly described heterothallic species in the genus

A new species, Mortierella sugadairana, is described for a fungus forming homothallic zygospores with a club-shaped macrosuspensor and a microsuspensor originating from the macrosuspensor. The species was isolated from cool regions in Japan and morphologically and phylogenetically close to a heterothallic species M. parvispora, which is the first species reported as a heterothallic species in the genus. Mycelial growth of the species was limited at 30 °C, whereas two isolates of M. parvispora can grow. This may indicate that the species and M. parvispora adapted to different climates from a common ancestor involving differentiation of the manner of reproduction.     

Nuclear DNA content of some important plant species

Nuclear DNA contents of more than 100 important plant species were measured by flow cytometry of isolated nuclei stained with propidium iodide.Arabidopsis exhibits developmentally regulated multiploidy and has a 2C nuclear DNA content of 0.30 pg (145 Mbp/1C), twice the value usually cited. The 2C value for rice is only about three times that ofArabidopsis. Tomato has a 2C value of about 2.0 pg, larger than commonly cited. This survey identified several horticultural crops in a variety of families with genomes only two or three times as large asArabidopsis; these include several fruit trees (a pricot, cherry, mango, orange, papaya, and peach). The small genome sizes of rice and the horticultural plants should facilitate molecular studies of these crops.     

Intraparticulate localization of some peroxisomal enzymes related to fatty acid beta-oxidation

Male Wistar rats were given a diet containing 0.05% (w/w) LK-903 (alpha-methyl-p-myristyroxycinnamic acid 1-monoglyceride) for 2 weeks. The activities of four hepatic peroxisomal enzymes involved in the fatty acyl-CoA beta-oxidizing system were determined. The activities of fatty acyl-CoA oxidase, crotonase, beta-hydroxybutyryl-CoA dehydrogenase and thiolase were all increased about three times by administration of LK-903. The intraparticulate localizations of the four enzymes were then investigated by treatment of the purified peroxisomes with Triton X-100, by sonication, and by sucrose-density-gradient centrifugation after Triton X-100 treatment. The results suggest that thiolase is localized in the matrix of peroxisomes, that crotonase and beta-hydroxybutyryl-CoA dehydrogenase are located in the core, and that all or at least part of fatty acyl-CoA oxidase is associated with the core, though its association is weak.     

Cuticular hydrocarbon pattern as a chemotaxonomy marker to assess six species of thrips

Thrips constitute several families of slender insects with fringed wings and unique asymmetrical mouthparts. They have become globally important pests, infesting a variety of agriculturally important crops. Species of thrips are difficult to identify due to their small size and similarities in morphology. Recently, in addition to morphology, both molecular and non-molecular taxonomic tools have been used to identify species differences. Insect cuticular hydrocarbons have been widely used in chemotaxonomy. In this study, a Thermal Separation Probe was used to identify the cuticular hydrocarbons of Frankliniella occidentalis, Frankliniella intonsa, Thrips palmi, Thrips hawaiiensis, Haplothrips chinensis and Gynaikothrips ficorum. We analyzed the hydrocarbon composition of adults in all 6 species, and in the larvae of F. occidentalis, T. hawaiiensis and T. palmi. The results showed that the composition of cuticular hydrocarbons differed between species. All 6 species of adults and 3 species of larvae were easily distinguishable by quantitative analysis of hydrocarbon profiles. These results provide a possible method for the identification of thrips.     

An in vitro reversible interconversion of rat liver fatty acid binding protein having different isoelectric points by virtue of the fatty acid content.

Rat liver fatty acid binding protein (FABP) was purified to homogeneity by procedures including Sephadex G-100 and DEAE-cellulose column chromatographies. FABP was resolved into two major peaks, A and B, by the first DEAE-cellulose column chromatography. Each of these two fractions exhibited apparent homogeneity upon polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate with a molecular weight of 14,000 Da and amino acid analysis of these fractions has revealed that they are virtually identical or closely resemble each other. However, their fatty acid content was significantly different and heterogeneity was clearly demonstrated in the patterns of isoelectric focusing. In this communication, a single isoform (pI 5.0) from peak B FABP was further purified by successive DEAE-cellulose column chromatography and used as the final preparation. When the final FABP was partly freed of fatty acids by a mild delipidation technique using Lipidex 1,000, the pI shifted upward from 5.0 to 7.0. However, the pI of the delipidated FABP returned to its original pI of 5.0 after recombining fatty acids. These in vitro manipulations of bound fatty acid content made clear its possible cause of the microheterogeneity of FABP.