Genetic similarity among Trifolium species based on isozyme banding pattern

The study deals with similarity among 25 species of the genus Trifolium represented by 134 accessions. Clustering of the species based on isozyme banding pattern of five enzymes revealed that T. repens was distinctly different from other species. T. repens and T. retusum formed independent clusters. The group of species comprising of T. pratense, T. cherleri, T. spumosum, T. subterraneum, T. resupinatum, T. alexandrinum, T. echinatum, T. constantinopolitanum and T. tembense exhibited considerable similarity to the second cluster. This group joined another group of five species, i.e. T. nigrescens, T. glomeratum, T. apertum, T. alpestre and T. hybridum with nearly 50% similarity. T. purpureum, T. hirtum, T. campestre, T. incarnatum, and T. argutum grouped separately. There was no marked difference for banding pattern among T. alexandrinum genotypes. T. alexandrinum showed close affinity with T. subterraneum and T. resupinatum. T. lappaceum, T. diffusum, T. campestre, T. incarnatum and T. argutum showed only 44.8% similarity with other Trifolium species. Grouping together of accessions belonging to individual species indicated that incompatibility among species under study had restricted interspecific hybridization. Species belonging to subgenus Lotoidea clustered with species of subgenus Trifolium. Chonosemium species T. campestre formed one cluster with two Trifolium species T. hirtum and T. incarnatum. T. nigrescens was placed quite apart from the T. repens.     

Tylenchulus graminis n. sp. and T. palustris n. sp. (Tylenchulidae), from Native Flora of Florida,with Notes on T. semipenetrans and T. furcus

Tylenchulus graminis n. sp. and T. palustris n. sp. are described and illustrated from broomsedge (Andropogon virginicus L.) and pop ash (Fraxinus caroliniana Mill.), respectively. T. graminis resembles T. furcus in having a distinct anus, but T. graminis second-stage juveniles (J2) do not have a bifid tail. T. semipenetrans does not have a perceptible anus. The mature female of T. graminis has a mucronate pointed terminus while T. semipenetrans has a smooth and round terminus. T. graminis males have wider stylet knobs and basal bulb and a longer tail than T. semipenetrans males. T. graminis J2 have a longer posterior body portion (without large fat globules) than T. semipenetrans J2. T. palustris resembles T. semipenetrans in having an undetectable anus but differs by the short and conoid mature female postvulval section. The male of T. palustris has larger stylet knobs and basal bulb than those of T. semipenetrans and a bluntly rounded tail terminus, which is tapered in T. semipenetrans. T. palustris differs from T. furcus and T. graminis in having an undetectable anus, by the conoid postvulval section of mature females, by the shorter and rounded tail of males, and the shorter J2 posterior body section without large fat globules. T. graminis and T. palustris are parasites of indigenous flora of Florida.     

New names and combinations in Trixis (Compositae)

Trixis chiapensis, T. grandibracteata, T. mexicana var.auriculata, T. mexicana var.macradenia, andT. parviflora are described as new, and the combinationsT. californica var.peninsularis, T. michuacana var.longifolia, andT. pringlei var.oligantha are proposed. The application of the namesT. inula andT. michuacana is discussed.     

Relatively Recent Evolution of Pelage Coloration in Colobinae: Phylogeny and Phylogeography of Three Closely Related Langur Species

To understand the evolutionary processes leading to the diversity of Asian colobines, we report here on a phylogenetic, phylogeographical and population genetic analysis of three closely related langurs, Trachypithecus francoisi, T. poliocephalus and T. leucocephalus, which are all characterized by different pelage coloration predominantly on the head and shoulders. Therefore, we sequenced a 395 bp long fragment of the mitochondrial control region from 178 T. francoisi, 54 T. leucocephalus and 19 T. poliocephalus individuals, representing all extant populations of these three species. We found 29 haplotypes in T. francoisi, 12 haplotypes in T. leucocephalus and three haplotypes in T. poliocephalus. T. leucocephalus and T. poliocephalus form monophyletic clades, which are both nested within T. francoisi, and diverged from T. francoisi recently, 0.46-0.27 (T. leucocephalus) and 0.50-0.25 million years ago (T. poliocephalus). Thus, T. francoisi appears as a polyphyletic group, while T. leucocephalus and T. poliocephalus are most likely independent descendents of T. francoisi that are both physically separated from T. francoisi populations by rivers, open sea or larger habitat gaps. Since T. francoisi populations show no variability in pelage coloration, pelage coloration in T. leucocephalus and T. poliocephalus is most likely the result of new genetic mutations after the split from T. francoisi and not of the fixation of different characters derived from an ancestral polymorphism. This case study highlights that morphological changes for example in pelage coloration can occur in isolated populations in relatively short time periods and it provides a solid basis for studies in related species. Nevertheless, to fully understand the evolutionary history of these three langur species, nuclear loci should be investigated as well.     

Population Response to Temperature in the Subfamily Tylenchorhynchinae

The effects of temperature on population development of 11 species of stunt nematodes in the subfamily Tylenchorhynchinae were compared on red clover or Kentucky bluegrass in constant-temperature tanks at 5-degree intervals from 10 to 35 C. The optimum temperature for population increase on red clover in 90 days was 30 C for Tylenchorhynchus agri, T. nudus, T. martini, and T. clarus, 25 C for T. sylvaticus and T. dubius, and 20 C for T. canalis, Merlinius brevidens, and Quinisulcius capitatus. The optimum was 30 C for T. robustoides and 25 C for T. maximus on Kentucky bluegrass. The temperature range for population increase was 20-35 C for T. agri, T. nudus, T. martini, and T. clarus, 20-30 C for T. sylvaticus and T. robustoides, 15-25 C for T. maximus, 10-25 C for T. dubius, and 10-20 C for M. brevidens and Q. capitatus. T. canalis increased only at 20 C. All species were recovered in numbers near their inoculum level at 10 C. There was no survival of T. sylvaticus, T. dubius, T. canalis, T. robustoides, T. maximus, M. brevidens, and Q. capitatus at 35 C, or of the last three of these species at 30 C. Temperature had no effect on sex ratio in final populations. Population increase was greatest in T. martini and least in T. canalis.     

Studies on California ants: a review of the genus Temnothorax (Hymenoptera,Formicidae)

The following ten new species of the ant genus Temnothorax are described and illustrated: T. anaphalantus (California, Baja California), T. arboreus (California), T. caguatan (Oregon, California, Baja California), T. morongo (California, Baja California), T. myrmiciformis (California, Baja California), T. nuwuvi (Nevada), T. paiute (California, Nevada), T. pseudandrei (Arizona, California), T. quasimodo (California) and T. wardi (California). A key to workers of the twenty-two Temnothorax species known or expected to occur in California is provided.     

Floral morphology and systematics of the genus Thottea Rottb. (Aristolochiaceae) from the Western Ghats, India

The medicinal genus Thottea (Aristolochiaceae) is represented in the Western Ghats, India, by eight species, seven of which are endemic to this region. In the present study, diversity in floral structure and organization of these eight species was analyzed from a systematic perspective. Floral morphology was thoroughly studied and discussed with emphasis on 16 qualitative and 11 quantitative characters. Statistical tools such as UPGMA cluster analysis, PCoA, PCA, and one-way ANOVA were used for elucidating species boundaries and inter-relationships. Significance of the selected qualitative and quantitative characters for species level systematics was revealed by the PCA and one-way ANOVA. Based on the nature of sepals (free/fused), two species groups were identified (first group with T. duchartrei and T. idukkiana, and the second group with the remaining six species). By considering the number and arrangement of stamens, yet another species grouping was proposed (one with T. abrahamii and T. dinghoui, and the other with the remaining six species). The UPGMA phenogram and the PCoA scatter plot clearly pointed out the existence of two species groups: the first group with T. abrahamii, T. barberi, T. dinghoui, T. ponmudiana, T. siliquosa, and T. sivarajanii, and the second one with T. duchartrei and T. idukkiana. With regard to the morphometric tools and the taxonomic key, it does not seem possible to distinguish T. abrahamii from T. dinghoui, and T. idukkiana from T. duchartrei.     

Nuclear DNA content variation within the genusTaraxacum (Asteraceae)

Nuclear DNA content was estimated using flow cytometry in 13 sections represented by 18 species of the genusTaraxacum using propidium iodide as the DNA stain. Investigated plants represented diploid, triploid and tetraploid species from sections considered both primitive and advanced, i.e.,T. sect.Dioszegia, Piesis, Glacialia, Mongolica, Scariosa, Obovata, T. pyrenaicum group,T. sect.Coronata, Palustria, Taraxacum (=Crocea),Kashmirana, Ruderalia andErythrosperma. Estimated nuclear 2C DNA content ranged from 1.74 pg in diploidT. linearisquameum (T. sect.Ruderalia) to 6.91 pg in tetraploidT. albidum (T. sect.Mongolica), demonstrating 3.97-fold variation. The lowest monoploid genome size 1C_x=0.87 pg was recorded inT. linearisquameum (T. sect.Ruderalia) together withT. brachyglossum (T. sect.Erythrosperma), and the highest one (1.73 pg) was recorded inT. albidum (T. sect.Mongolica), giving a 1.99-fold difference in the genus. No significant differences in genome size were observed withinT. sect.Ruderalia, similarly no intraspecific variation was observed inT. paludosum (T. sect.Palustria) andT. serotinum (T. sect.Dioszegia). These results indicate a high intraspecific stability of the trait. Preliminary comparisons of genome size in species/sections considered to be close relatives were made. These data give tentative additional evidence for the close phylogenetic relationship between sectionsPalustria andPiesis and against the close relationship between sectionsPiesis andDioszegia.     

Molecular-genetics study of entomophages of the genus Trichogramma Westw.

Studies of the genetic structure of the internal noncoding transcribed spacer region 2 (ITS2) of the ribosomal DNA of five entomophage species of the genus Trichogramma, i.e., T. pintoi Voeg., T. evanescens Westw., T. dendrolimi Mats., T. cacoeciae Meyer, and T. semblidis Auriv., are performed. A PCR analysis with subsequent determination of the nucleotide sequence of the ITS2 regions made it possible to identify essential inter-species differences. The data may be used for the identification of the species T. pintoi, T. dendrolini, and T. semblidis.     

Human and Animal Trypanosomes in C?te d'Ivoire Form a Single Breeding Population

Background

Trypanosoma brucei is the causative agent of African Sleeping Sickness in humans and contributes to the related veterinary disease, Nagana. T. brucei is segregated into three subspecies based on host specificity, geography and pathology. T. b. brucei is limited to animals (excluding some primates) throughout sub-Saharan Africa and is non-infective to humans due to trypanolytic factors found in human serum. T. b. gambiense and T. b. rhodesiense are human infective sub-species. T. b. gambiense is the more prevalent human, causing over 97% of human cases. Study of T. b. gambiense is complicated in that there are two distinct groups delineated by genetics and phenotype. The relationships between the two groups and local T. b. brucei are unclear and may have a bearing on the evolution of the human infectivity traits.

Methodology/Principal Findings

A collection of sympatric T. brucei isolates from Côte d’Ivoire, consisting of T. b. brucei and both groups of T. b. gambiense have previously been categorized by isoenzymes, RFLPs and Blood Incubation Infectivity Tests. These samples were further characterized using the group 1 specific marker, TgSGP, and seven microsatellites. The relationships between the T. b. brucei and T. b. gambiense isolates were determined using principal components analysis, neighbor-joining phylogenetics, STRUCTURE, F_ST, Hardy-Weinberg equilibrium and linkage disequilibrium.

Conclusions/Significance

Group 1 T. b. gambiense form a clonal genetic group, distinct from group 2 and T. b. brucei, whereas group 2 T. b. gambiense are genetically indistinguishable from local T. b. brucei. There is strong evidence for mating within and between group 2 T. b. gambiense and T. b. brucei. We found no evidence to support the hypothesis that group 2 T. b. gambiense are hybrids of group 1 and T. b. brucei, suggesting that human infectivity has evolved independently in groups 1 and 2 T. b. gambiense.     

Acetylcholinesterase secretion by parasitic nematodes. II. Trichostrongylus spp

Unusually high levels of acetylcholinesterase (AChE) were found in the nematode parasites Trichostrongylus axei, T. colubriformis and T, retortaeformis. In T. colubriformis the enzyme was located in the oesophageal and excretory glands of the parasitic stages. The highest level/unit wt was found in the fourth-stage larvae, which per worm had a comparable level to that in adult worms because the excretory gland was fully developed in the fourth-stage larvae. In acrylamide gel electrophoresis, T. axei and T. colubriformis AChE and esterases were similar but differed from those present in T. retortaeformis. Globulins prepared from the sera of sheep and guinea-pigs infected with T. colubriformis complexed with T. colubriformis and T. axei AChE, but not with esterases nor with AChE from T. retortaeformis, Nippostrongylus brasiliensis, Oesophagostomum radiatum or O. venulosum. Complexing of AChE to globulins did not inhibit the enzymic function of this enzyme.     

Isoflavone synthase (IFS) gene phylogeny in Trifolium species associated with plant isoflavone contents

This study presents the results of the identification and quantification of 12 isoflavones (prunetin, irilone, pseudobaptigenin, glycitein, daidzin, genistin, daidzein, pratensein, puerarin, biochanin A, formononetin and genistein) in 23 species of Trifolium (T. arvense, T. pratense, T. ligusticum, T. striatum, T. lappaceum, T. angustifolium, T. hirtum, T. subterraneum, T. isthmocarpum, T. stellatum, T. mutabile, T. strictum, T. fragiferum, T. alexandrinum, T. tomentosum. T. nigrescens subsp. petrisavii, T. nigrescens, T. glomeratum, T. subterraneum subsp. brachycalycinum, T. cherleri, T. resupinatum, T. campestre and T. repens). Isoflavones were extracted by an MSPD method and analyzed with HPLC coupled with a diode-array detector. The evaluation of molecular phylogeny of the IFS gene and the relation with isoflavone content was also performed. Five species (T. subterraneum subsp. brachycalycinum, T. alexandrinum, T. pratense, T. subterraneum and T. lappaceum) were identified with high levels of biochanin A (431–83 mg/kg), formononetin (72–365 mg/kg) and genistein (9–509 mg/kg), which could be utilized as alternative sources for the nutraceutical industry. Genetic phylogeny for the IFS gene was found in the species studied, with 20 out of 23 species having been divided into two clades, while the remaining three were genetically distant. Based on our results, we confirm the direct correlation between IFS gene polymorphism and isoflavones content in species of Trifolium particularly noted for formononetin. Therefore, the IFS gene can be utilized for screening Trifolium genotypes for formononetin. The relation of the three isoflavones' contents and the molecular phylogeny of plants determined by the IFS sequences, as a screening marker for plants with high isoflavone contents in Trifolium species, are to the best of our knowledge described for the first time.     

Host performance of Trichogramma species on Opisina arenosella,and evaluation of their biological control efficacy

Five candidate species for biocontrol of Opisina arenosella Walker, a destructive pest of palm trees, were evaluated. To compare host performance, 5 Trichogramma species were allowed to parasitize O. arenosella eggs of different ages and egg densities. The parasitization capacity of two species, T. embryophagum and T. japonicum, were evaluated with respect to adult age. Treatments consisted of field with releases of T. embryophagum or T. japonicum set up in Danzhou, Hainan, and the pest densities was recorded periodically. The results showed that T. embryophagum, T. chilonis, and T. dendrolimi had a strong parasitic ability on 0-day-old O. arenosella eggs. In species comparisons, the parasitism rates of T. embryophagum on 1-day-old and 4-day-old eggs, and T. japonicum on 2-day-old, 3-day-old, and 5-day-old eggs of O. arenosella were significantly higher than those of other Trichogramma species. At densities of 40 and 35 eggs/tube (84.8 cm³), the numbers of eggs parasitized by T. embryophagum and T. japonicum were the highest, at 29.9 and 24.6, respectively. During the first 24-h, the numbers of eggs parasitized by T. embryophagum and T. japonicum were 110.6 and 82.2, accounting for 84.7% and 59.5%, respectively, of the total parasitized eggs. After 2 months releases, the larvae and pupa density of O. arenosella under T. embryophagum and T. japonicun treatment were 0.95 and 0.94 individuals/leaflet, respectively, were significantly lower than untreated control (1.6 individuals/leaflet). These findings encouraged that T. embryophagum and T. japonicun are able to be used for biological control for O. arenosella.     

New species and new records of Tinodes Curtis (Trichoptera: Psychomyiidae) from Dabie Mountains,East-central China

We describe a new Tinodes, Tinodes stamen sp. nov., collected in the Dabie Mountains, East-central China and report four new records, T. ventralis Li & Morse, 1997; T. cryptophallicata Li & Morse, 1997; T. harael Malicky, 2017; and T. sartael Malicky, 2017, from Dabie Mountains. Moreover, we illustrate infraspecific variability in T. ventralis, and the recently described T. harael, and T. sartael from the Dabie Mountains region.     

A type VII secretion system of Streptococcus gallolyticus subsp. gallolyticus contributes to gut colonization and the development of colon tumors

Streptococcus gallolyticus subspecies gallolyticus (Sgg) has a strong clinical association with colorectal cancer (CRC) and actively promotes the development of colon tumors. However, the molecular determinants involved in Sgg pathogenicity in the gut are unknown. Bacterial type VII secretion systems (T7SS) mediate pathogen interactions with their host and are important for virulence in pathogenic mycobacteria and Staphylococcus aureus. Through genome analysis, we identified a locus in Sgg strain TX20005 that encodes a putative type VII secretion system (designated as SggT7SS^T05). We showed that core genes within the SggT7SS^T05 locus are expressed in vitro and in the colon of mice. Western blot analysis showed that SggEsxA, a protein predicted to be a T7SS secretion substrate, is detected in the bacterial culture supernatant, indicating that this SggT7SS^T05 is functional. Deletion of SggT7SS^T05 (TX20005Δesx) resulted in impaired bacterial adherence to HT29 cells and abolished the ability of Sgg to stimulate HT29 cell proliferation. Analysis of bacterial culture supernatants suggest that SggT7SS^T05-secreted factors are responsible for the pro-proliferative activity of Sgg, whereas Sgg adherence to host cells requires both SggT7SS^T05-secreted and bacterial surface-associated factors. In a murine gut colonization model, TX20005Δesx showed significantly reduced colonization compared to the parent strain. Furthermore, in a mouse model of CRC, mice exposed to TX20005 had a significantly higher tumor burden compared to saline-treated mice, whereas those exposed to TX20005Δesx did not. Examination of the Sgg load in the colon in the CRC model suggests that SggT7SS^T05-mediated activities are directly involved in the promotion of colon tumors. Taken together, these results reveal SggT7SS^T05 as a previously unrecognized pathogenicity determinant for Sgg colonization of the colon and promotion of colon tumors.     

Effect of gut bacterial isolates from Apis mellifera jemenitica on Paenibacillus larvae infected bee larvae

The probiotic effects of seven newly isolated gut bacteria, from the indegenous honey bees of Saudi Arabia were investigated. In vivo bioassays were used to investigate the effects of each gut bacterium namely, Fructobacillus fructosus (T1), Proteus mirabilis (T2), Bacillus licheniformis (T3), Lactobacillus kunkeei (T4), Bacillus subtilis (T5), Enterobacter kobei (T6), and Morganella morganii (T7) on mortality percentage of honey bee larvae infected with P. larvae spores along with negative control (normal diet) and positive control (normal diet spiked with P. larvae spores). Addition of gut bacteria to the normal diet significantly reduced the mortality percentage of the treated groups. Mortality percentage in all treated groups ranged from 56.67% up to 86.67%. T6 treated group exhibited the highest mortality (86.67%), whereas T4 group showed the lowest mortality (56.67%). Among the seven gut bacterial treatments, T4 and T3 decreased the mortality 56.67% and 66.67%, respectively, whereas, for T2, T6, and T7 the mortality percentage was equal to that of the positive control (86.67%). Mortality percentages in infected larval groups treated with T1, and T5 were 78.33% and 73.33% respectively. Most of the mortality occurred in the treated larvae during days 2 and 3. Treatments T3 and T4 treatments showed positive effects and reduced mortality.