Population genetical study of natural hybridization betweenPapio anubis andP. hamadryas

The natural hybridization betweenPapio anubis andP. hamadryas in central Ethiopia was studied from a population genetical perspective. Studies were made using electrophoretical blood protein variations as markers in order to clarify the genetic relationship between them. A total of 563 samples from ten populations which were collected in the field studies with a socioecologist in 1976 and 1979 were examined for 34 blood protein loci. Ten of the 34 loci showed polymorphism. The Tf, PA-2 and Es were found to be effective for discriminating between the anubis and hamadryas. Genetic variability, hybridization rate, genetic distance, migration rates and correlations between genetical and morphological and between genetical and behavioral indices were computed and analyzed. The results of the present genetic survey revealed that most of the populations from which the author collected blood samples were more or less hybridized. The Nei's (1975) genetic distance between the two species was estimated to be 0.0679 at most. As this value is too small to consider these species as real biological species, it is supposed that the natural hybrid zone is fairly wide and still expanding now. This work was supported in part by Grants in aid for scientific research (Overseas scientific research, 1975) and of the Overseas Special Research Programme of the Primate Research Institute, Kyoto University in 1978 by Ministry of Education, Science and Culture.     

Metabolism of non-phenolic diarylpropane lignin substructure model compound by Coriolus versicolor

Abstract A lignin substructure model, 1-(4-ethoxy-3,5-dimethoxyphenyl)-2-(4-ethoxy-3-methoxyphenyl)-propane-1,3-diol(I), was actively metabolized by a white-rot fungus Coriolus versicolor in low nitrogen stationary cultures favouring the ligninolytic activity in the fungus. Cleavage of the dimer I between C_α and C_β of the propanoid side chain was the major degradative reaction by the fungus.     

Novel histone modifications in microglia derived from a mouse model of chronic pain

As the resident immune cells in the central nervous system, microglia play an important role in the maintenance of its homeostasis. Dysregulation of microglia has been associated with the development and maintenance of chronic pain. However, the relevant molecular pathways remain poorly defined. In this study, we used a mass spectrometry-based proteomic approach to screen potential changes of histone protein modifications in microglia isolated from the brain of control and cisplatin-induced neuropathic pain adult C57BL/6J male mice. We identified several novel microglial histone modifications associated with pain, including statistically significantly decreased histone H3.1 lysine 27 mono-methylation (H3.1K27me1, 54.8% of control) and H3 lysine 56 tri-methylation (7.5% of control), as well as a trend suggesting increased H3 tyrosine 41 nitration. We further investigated the functional role of H3.1K27me1 and found that treatment of cultured microglial cells for 4 consecutive days with 1–10 μM of NCDM-64, a potent and selective inhibitor of lysine demethylase 7A, an enzyme responsible for the demethylation of H3K27me1, dose-dependently elevated its levels with a greater than a two-fold increase observed at 10 μM compared to vehicle-treated control cells. Moreover, pretreatment of mice with NCDM-64 (10 or 25 mg/kg/day, i.p.) prior to cisplatin treatment prevented the development of neuropathic pain in mice. The identification of specific chromatin marks in microglia associated with chronic pain may yield critical insight into the contribution of microglia to the development and maintenance of pain, and opens new avenues for the development of novel nonopioid therapeutics for the effective management of chronic pain.     

Changes in intracellular pH during repeated exercise

The rates of change in intracellular pH during repeated exercise sessions with rest periods was determined by 31 phosphorus-nuclear magnetic resonance spectroscopy (³¹P-MRS). Five long-distance runners and six healthy male subjects as controls performed a 2-min femoral flexion at 20 kg · m · min^–1 in a 2.1 T superconducting magnet with a 67-cm bore and repeated this exercise four times with 2-min rest periods intervening. In all cases during exercise the inorganic phosphate (P_i) peak split into two, the earlier increased rapidly (high-pH P_i) and the later (low-pH P_i) increased more slowly. The P_i peaks were separated by a fitting procedure using the least square mean method. The high-pH P_i area during exercise decreased as the number of repeated exercise periods increased, while the low-pH P_i area gradually increased. Although the total P_i area decreased exponentially during the recovery period, the high-pH P_i area decreased first and then the low-pH P_i area reduced gradually. The pH values were estimated from the chemical shift between the phosphocreatine peak and each split peak in the P_i. The high-pH in pooled data ranged from 6.6 to 7.0 during exercise and recovery, while the low pH decreased to 6.2 during exercise. As the number of exercise periods increased, each pH value gradually became less acidic, although there was a tendency to more acidity in the control subjects than in the long-distance runners. In conclusion, it was possible to obtain by non-invasive, continuous³¹P-MRS, a split pattern of P_i peaks during exercise and there were at least tow different intracellular pH values during exercise, suggesting that each P_i peak might be attributed to the types of muscle fibre recruited.     

Functional implication of nucleolin in the mouse first molar development

We examined the functional implication of nucleolin in the mouse first molar development. Both the nucleolin mRNA and protein expressions were demonstrated in the odontogenic epithelial cells in the early stage and in the inner enamel epithelial layer in the late stage. The expression pattern of nucleolin corresponded to the proliferating cells in the tooth germ, thus showing that nucleolin could possibly be related to cell proliferation. No in situ signal of nucleolin was found in the primary enamel knot (PEK). Furthermore, nucleolin protein was demonstrated in the PEK by immunohistochemistry. The existence of nucleolin protein in the PEK may possibly be related to the apoptosis in the PEK cells. An inhibition assay using the hemagglutinating virus of Japan-liposome containing nucleolin antisense phosphorothioated oligonucleotide (AS S-ODN) in cultured mouse mandibles at embryonic day (E) 11.0 showed a marked growth inhibition of tooth germ. Moreover, no developmental arrest was found in the cultured tooth germ at E15.0 treated with nucleolin AS S-ODN. Real time PCR was performed to examine the mRNA expression of nucleolin-related genes, and a significant reduction in the midkine mRNA expression was thus observed in the mouse mandible after being treated with nucleolin AS S-ODN. This inhibition assay indicated that nucleolin could thus be involved in the early stage of tooth germ initiation and morphogenesis, possibly by regulating the midkine expression.     

Contribution of the Cell Wall Component Teichuronopeptide to pH Homeostasis and Alkaliphily in the Alkaliphile Bacillus lentus C-125

A teichuronopeptide (TUP) is one of major structural components of the cell wall of the facultative alkaliphilic strain Bacillus lentus C-125. A mutant defective in TUP synthesis grows slowly at alkaline pH. An upper limit of pH for growth of the mutant was 10.4, while that of the parental strain C-125 was 10.8. Gene tupA, directing synthesis of TUP, was cloned from C-125 chromosomal DNA. The primary translation product of this gene is likely a cytoplasmic protein (57. 3 kDa) consisting of 489 amino acid residues. Introduction of the tupA gene into the TUP-defective mutant complemented the mutation responsible for the pleiotropic phenotypes of the mutant, leading to simultaneous disappearance of the defect in TUP synthesis, the diminished ability for cytoplasmic pH homeostasis, and the low tolerance for alkaline conditions. These results demonstrate that the acidic polymer TUP in the cell wall plays a role in pH homeostasis in this alkaliphile.     

Alien pollen grains interfere with the reproductive success of native congener

The effects of invasive species on native species comprise important conservation issues. Determining the mechanisms by which invasives exclude natives is indispensable to efficiently control their impact, but most invasives remain poorly studied. The purpose of this study was to elucidate potentially important but neglected mechanisms, reproductive interference, in wild Taraxacum systems, in which invasive Taraxacum officinale has displaced its native congener T. japonicum in Japan. Hand-pollination of mixed pollen grains significantly reduced the native seed-set compared to conspecific-only pollination. Moreover, natives with a high ratio of invasive pollen on their stigmas suffered severe seed-set reduction, and the proportion of invasive pollen on native stigmas increased as frequencies of the alien neighbor increased. These results, combined with those of previous studies, revealed that depositing invasive pollen on native stigmas contributes to the observed alien-frequency-dependent reduction of native seed-set, and strongly suggest that reproductive interference was the primary cause of displacement in the Taraxacum systems.     

Growth strategy of an emergent macrophyte, Typha orientalis Presl, in comparison with Typha latifolia L. and Typha angustifolia L.

The growth strategy of an emergent plant, Typha orientalis Presl, was examined in experimental ponds in comparison with two other Typha species distributed in Japan, Typha latifolia L. and Typha angustifolia L. T. orientalis showed the greatest ability of vegetative reproduction at the expense of growth in height. T. orientalis started to produce new ramets earlier than T. latifolia and T. angustifolia. These results suggest that T. orientalis should be a rather pioneer-like species and would be restricted to disturbed habitats.     

Developmental expression of HpNanos, the Hemicentrotus pulcherrimus homologue of nanos

The Hemicentrotus pulcherrimus homologue of nanos (HpNanos), that encodes a protein containing two CCHC zinc finger motifs, was isolated from a gastrula cDNA library. The accumulation of HpNanos mRNA during embryonic development and the spatial expression pattern are reported. Developmental northern blot analysis revealed that HpNanos mRNA markedly accumulated during the blastula stages, and then decreased in abundance at the mesenchyme blastula stage. The second phase of HpNanos mRNA expression occurred during gastrulation, after which the expression returned to a low level. Whole-mount in situ hybridization showed that the HpNanos was exclusively expressed in four to six small micromere-descendant cells at the blastula stage. The expression of HpNanos was restricted to the coelomic pouch, which gives rise to the mesoderm of the ventral surface of the adult rudiment, at the prism stage. These results suggest that HpNanos expression will be instrumental for future analyses of the function of small micromere-descendant cells and of the origin of germ cells during sea urchin development.