PISTIL DEVELOPMENT AND PARIETAL PLACENTATION IN THE PSEUDOMONOMEROUS OVARY OF ZELKOVA SERRATA (ULMACEAE)

Development of female flowers in Zelkova serrata was observed using epi-illuminated microscopy and scanning electron microscopy, with particular attention given to placentation. After the inception of staminodial primordia, the floral apex becomes flat, and the first and subsequently the second carpel primordia appear at opposite comers of the pistil primordium. Inside each carpel primordium a fossette forms. Through differential growth this depression becomes clear and the carpel wall encircles one side of the future placental region. The placental region is detectable even in early stages, but clear signs of ovule inception appear late when the placental region is elevated onto one side of the ovary wall by intercalary growth. Although the relative size of the two carpels varies among flowers, the placental position always appears to be the border between the two carpels and the floral apex. This suggests that the placentation of Zelkova is parietal. The ovule position in tricarpellate ovaries also suggests an evolutionary derivation from ovaries with parietal placentation. Parietal placentation appears to be the original condition in Urticales.     

Establishing a new genus,Chiharadinium gen. nov. (Peridiniales,Dinophyceae) for a tidal pool dinoflagellate formerly known as Scrippsiella hexapraecingula

To determine its accurate taxonomic position, a tidal pool bloom-forming dinoflagellate, Scrippsiella hexapraecingula was re-investigated using light, scanning and transmission electron microscopy together with a phylogenetic analysis based on concatenated ribosomal DNA sequences. The culture strains used in this study were established from intertidal rock pool samples taken from Jogashima, Kanagawa prefecture and Heisaura, Chiba prefecture, Japan and were identified as S. hexapraecingula originally described by Horiguchi and Chihara from a tidal pool in Hachijo Island, Tokyo, Japan in 1983. The thecal plate arrangement was determined as Po, X, 4′, 3a, 6″, 6c, 5s, 5″′, 2″″. The internal structure was investigated for the first time. The organism has typical dinoflagellate cellular organelles such as a dinokaryotic nucleus, mitochondria with tubular cristae, trichocysts and pusule. The chloroplast was single and connected to the central pyrenoid (stalked type). The eyespot found in the sulcus is of the B type with two rows of superficial intraplastidal lipid globules directly overlain by an extraplastidal single layer of crystalline bricks enveloped by a common membrane. The apical pore is plugged by a double-layered stub-like structure. Stalk building material for attachment covered the apical pore. Phylogenetic analysis indicated that S. hexapraecingula was most closely related to a freshwater dinoflagellate, Peridiniopsis borgei, the type species of the genus Peridiniopsis. However, clear differences exist between these two organisms, including their thecal plate arrangement, habitat and habit. As a result, a new genus, Chiharadinium Dawut & T. Horiguchi gen. nov. has been proposed rather than attempting to accommodate S. hexapraecingula in the genus Peridiniopsis. The new combination, Chiharadinium hexapraecingulum (T. Horiguchi & Chihara) Dawut & T. Horiguchi comb. nov. has been proposed.     

Chemotaxis of Pseudomonas syringae subsp. savastanoi Virulence Mutants

Several mutants of Pseudomonas syringae subsp. savastanoi were tested for their ability to sense and respond to a chemotactic gradient in low concentrations of yeast extract. The mutants were deficient in one or both of the genes coding for the synthesis of the plant hormones indole-3-acetic acid (IAA) and isopentenyl adenosine. Mutations which resulted in the loss of IAA production were due to the loss of the entire plasmid containing the iaa operon or to an 18-kb deletion of the iaa region. Additional mutants tested were deficient in their ability to produce isopentenyl adenosine as a result of the loss of the ptz-bearing plasmid. In all cases, strains which had lost the ability to produce IAA exhibited enhanced motility of up to 2.5 times that of the wild type (IAA⁺) in medium containing 0.01% yeast extract. No differences in motility were observed on medium containing lower concentrations of yeast extract. The presence or absence of the cytokinin plasmid and the presence or absence of inorganic nitrogen in the medium had no effect on the relative mobility of the strains.     

Studies on Flavor Components of Foodstuffs

Distribution of tetramethylpyrazine (T.M.P.) in Japanese fermented foodstuffs was investigated by more accurate analytical method.

Namely, the method was successful when trapping T.M.P. with picric acid after flash evaporation of the foodstuffs, followed by analysis with gas chromatography.

T.M.P. was detected in many Japanese fermented foodstuffs, especially in Miso, Soy sause and Natto, which suggests that alkylpyrazines may play an important role as flavor of those foodstuffs.     

The Epidemiology of HIV and HSV-2 Infections among Women Participating in Microbicide and Vaccine Feasibility Studies in Northern Tanzania

Objectives

To prepare for future HIV prevention trials, we conducted prospective cohort studies among women working in food and recreational facilities in northern Tanzania. We examined the prevalence and incidence of HIV and HSV-2, and associated risk factors.

Methods

Women aged 18–44 years working in food and recreational facilities were screened to determine their eligibility for the studies. Between 2008–2010, HIV-negative women were enrolled and followed for 12 months. At enrolment and 3-monthly, we collected socio-demographic and behavioural data, and performed clinical examinations for collection of biological specimens that were tested for reproductive tract infections. Risk factors for HIV and HSV-2 incidence were investigated using Poisson regression models.

Results

We screened 2,229 and enrolled 1,378 women. The median age was 27 years (interquartile range, IQR 22, 33), and median duration working at current facility was 2 years. The prevalences of HIV at screening and HSV-2 at enrolment were 16% and 67%, respectively. Attendance at the 12-month visit was 86%. HIV and HSV-2 incidence rates were 3.7 (95% confidence interval, CI: 2.8,5.1) and 28.6 (95% CI: 23.5,35.0)/100 person-years, respectively. Women who were separated, divorced, or widowed were at increased risk of HIV (adjusted incidence rate ratio, aRR = 6.63; 95% CI: 1.97,22.2) and HSV-2 (aRR = 2.00; 95% CI: 1.15,3.47) compared with married women. Women reporting ≥3 partners in the past 3 months were at higher HIV risk compared with women with 0–1 partner (aRR = 4.75; 95% CI: 2.10,10.8), while those who had reached secondary education or above were at lower risk of HSV-2 compared with women with incomplete primary education (aRR = 0.42; 95% CI: 0.22,0.82).

Conclusions

HIV and HSV-2 rates remain substantially higher in this cohort than in the general population, indicating urgent need for effective interventions. These studies demonstrate the feasibility of conducting trials to test new interventions in this highly-mobile population.     

Abstracts of papers read at the Winter Meeting, 1961

Herdmania litoralis is a heterotrophic, sand-dwelling dinoflagellate with morphological characters that do not provide clear evidence for its systematic position in any existing family of dinoflagellates. Protoperidinium minutum is a heterotrophic, planktonic species that has a typical tabulation for the genus Protoperidinium. In order to infer the phylogenetic positions of these two species more confidently, we characterized the thecal plate patterns and determined small-subunit and large-subunit ribosomal DNA sequences (SSU rDNA and LSU rDNA, respectively) from both species. Intraindividual and intraspecific diversity of SSU and LSU rDNA data were characterized in H. litoralis using a combination of single-cell PCR approaches and analyses of PCR clones derived from multi-cell DNA extractions. The results of the molecular phylogenetic analyses demonstrated a novel, well-supported clade comprising both sand-dwelling species (H. litoralis and Thecadinium dragescoi) and planktonic species (P. minutum). Because the establishment of this clade also demonstrated that P. minutum is not a member of Protoperidinium, we reinstated and emended the genus Archaeperidinium Jörgensen 1912 Jörgensen, E. 1912. Bericht über die von der schwedischen hydrographisch-biologischen Kommission in den schwedischen Gewässern in den Jahren 1909–10 eingesammelten Planktonproben. Svenska Hydrograph.-Biol. Komm. Skr., 4: 1–20.  [Google Scholar].     

Flavor Constituents of Pouchong Tea and a Comparison of the Aroma Pattern with Jasmine Tea

The aroma constituents of the highest quality pouchong tea were characterized by GC–MS. Forty-eight components, including five newly identified compounds were characterized. GC peak area percentages of the main components in pouchong tea were compared with those of jasmine tea to differentiate compounds contributing to the aroma characteristics of pouchong tea with superior floral elegant flavor. Nerolidol, jasmine lactone, methyl jasmonate, indole, benzyl cyanide and linalool oxides were found in much higher concentration in pouchong tea than in jasmine tea. These compounds seemed to contribute to the aroma characteristics of the highest quality pouchong tea.     

Studies on the Pungent Principle of Capsicum

The chemical constitutions of the pungent principle of Capsicum were investigated. These principles are assumed to consist of capsaicin, dihydrocapsaicin, nordihydrocapsaicin, homodihydrocapsaicin and two or more analogues of these materials. Thin-layer chromatography and open tubular gas chromatography showed that the natural pungent mixture contains no cis-isomer of capsaicin. The chemical structure of nordihydrocapsaicin was determined as N-(4-hydroxy-3-methoxybenzyl)-7-methyloctanamide by gas chromatography, infrared spectroscopy, mass spectrometry and nuclear magnetic resonance spectroscopy. In addition, homodihydrocapsaicin was identified as N-(4-hydroxy-3-methoxybenzyl)-9-methyl-decanamide. These identities were also proven by comparison with synthetic samples.