Factors Predicting Bone Mineral Density (BMD) Changes in Young Women over A One-year Study:Changes in Body Weight and Bone Metabolic Markers during the Menstrual Cycle and Their Effects on BMD

Currently, 26% of Japanese women in their twenties are under weight, and therefore at risk of developing various metabolic abnormalities due to an inadequate nutrient intake, which in turn affects the acquisition of a peak bone mineral density (BMD). In this study, we aimed to clarify the effects of menstrual cycle-related changes in body weight and bone metabolic marker levels on the BMD changes. The subjects were 42 women (19.6±0.8 years). The levels of osteocalcin (OC), BAP, s-NTx, u-DPD, and E2 in the menstrual and ovulatory phases were measured. The associations between dependent variables (BMD changes/year in the lumbar spine, femur, femoral neck) and explanatory variables (body weight changes/year, the levels of OC, BAP, s-NTx, u-DPD) were evaluated using multiple regression analysis. Analysis of the correlations between the changes in bone metabolic markers and changes in BMD showed a correlation between the OC level in the menstrual phase and changes in the BMD of the entire femur, suggesting that a high OC level protects against BMD reduction, probably by promoting osteoblast activity, and that bone formation activity suppresses the decrease in BMD. These results suggest that, to predict BMD changes from bone metabolic markers in young women, it is necessary to measure OC levels in the menstrual phase

The exposure of field-grown maize seedlings to weed volatiles affects their growth and seed quality

Plants exposed to volatiles emitted from artificially damaged conspecific or heterospecific plants exhibit increased resistance to herbivorous insects. Here, we examined whether volatiles from artificially damaged weeds affect maize growth and reproduction. Seven days after germination, maize seedlings were exposed to volatiles emitted by artificially damaged mugwort (Artemisia indica var. maximowiczii) or tall goldenrod (Solidago altissima) plants either separately, or as a mixture of the two, for seven days. Unexposed seedlings were used as controls. Treated and control seedlings were cultivated in an experimental field without any insecticides applied. Plants exposed to either of the three volatile treatments sustained significantly less damage than controls. Additionally, seedlings exposed to either goldenrod or mixed volatiles produced more leaves and tillers than control plants. Furthermore, a significant increase in the number of ears was observed in plants exposed to the volatile mixture. In all treated plants, ear sugar content was significantly higher than that in the controls. Further, we cultivated seedlings that were either exposed to the volatile mixture or unexposed, under the conventional farming method using pesticides. Similar significant differences were observed for sugar content, number of tillers, leaves, damaged leaves, and ears. Laboratory experiments were conducted to further evaluate the mechanisms involved in the improved performance of volatile-treated plants. A significant reduction in the growth of common armyworm (Mythimna separata) larvae was observed when maize plants were exposed to the volatile mixture. This treatment did not affect the amount of jasmonic acid in the seedlings, whereas salicylic acid content increased upon exposure. The characteristic differences in chemical composition of mugwort and goldenrod volatiles were confirmed and, in turn, the volatile mixture differed significantly from the volatiles of either species

DNA topoisomerase II interacts with Lim15/Dmc1 in meiosis

Lim15/Dmc1 is a meiosis specific RecA-like protein. Here we propose its participation in meiotic chromosome pairing-related events along with DNA topoisomerase II. Analysis of protein–protein interactions using in vitro binding assays provided evidence that Coprinus cinereus DNA topoisomerase II (CcTopII) specifically interacts with C.cinereus Lim15/Dmc1 (CcLim15). Co-immunoprecipitation experiments also indicated that the CcLim15 protein interacts with CcTopII in vivo. Furthermore, a significant proportion of CcLim15 and CcTopII could be shown to co-localize on chromosomes from the leptotene to the zygotene stage. Interestingly, CcLim15 can potently activate the relaxation/catenation activity of CcTopII in vitro, and CcTopII suppresses CcLim15-dependent strand transfer activity. On the other hand, while enhancement of CcLim15's DNA-dependent ATPase activity by CcTopII was found in vitro, the same enzyme activity of CcTopII was inhibited by adding CcLim15. The interaction of CcLim15 and CcTopII may facilitate pairing of homologous chromosomes

Age-Dependent Contributions of Neck Circumference to Indices of Obesity Among Female College Students Aged 18 to 20 Years

Measurement of neck circumference (NC) is an easy method to assess obesity. Our investigation to estimate risks for metabolic disease in Japanese postmenopausal women indicated that NC is significantly associated with whole-body obesity indices and visceral fat accumulation. To clarify the early stage of metabolic changes and confirm NC validity as a predictor of metabolic syndrome, NC’s association to the four obesity indices, namely, weight, body mass index (BMI), body fat, and waist circumference (WC), was examined in a college student group of 60 females aged 18.7±0.3 years. NC was mainly correlated with weight, followed by BMI, WC, and body fat. It was also significantly associated with weight and BMI, but not with body fat. The participants were divided into two subgroups: “sports-experienced” and “not-sports-experienced,” who had moderate and strong correlation coefficients with NC and WC, respectively. WC value was possibly predicted by NC values using linear functions for the group and its subgroups. The correlation between NC and WC, NC’s association to weight, and substitution of NC to WC were confirmed by the same analyses in another student group composed with 18 females aged 19.7±0.6 years. Our study showed that the distribution of body fat in college students is difficult to assess based on NC alone. Nevertheless, NC measurement is an easy, inexpensive, and reproducible method to assess obesity and a possible predictor to identify the risk for future metabolic diseases in Japanese college students with the four obesity indices, weight, BMI, body fat, and WC

Asymmetrical hybridization between Trillium apetalon and T. tschonoskii for the formation of a hybrid T. miyabeanum (Melanthiaceae)

Trillium apetalon (4x) and T. tschonoskii (4x) hybridize commonly where both species grow sympatrically, leading to the formation of tetraploid T. miyabeanum in Hokkaido, Japan. The present study aimed to determine which isolation factor is responsible for the frequency and asymmetry of hybrid T. miyabeanum formation in a sympatric population of T. apetalon and T. tschonoskii. We examined the contributions and strengths of four reproductive isolation barriers of T. miyabeanum formation: flowering phenology, breeding system, genetic isolation, and hybrid inviability. In addition, we also investigated the effect of flowering phenology on reproductive success (i.e., seed production and outcrossing rates) and outputs (i.e., ovule production) for T. apetalon and T. tschonoskii. We calculated the absolute contribution of each isolation barrier to the total reproductive isolation and found that flowering phenology and differences in breeding systems between the two parental species were more effective when T. apetalon was the maternal parent. Furthermore, hybrids with T. apetalon as the maternal parent had lower viability than those of the reciprocal cross and did not reach the flowering stage. Particularly, absolute contribution of premating isolation, especially by flowering phenology and breeding system, was higher than that of other isolation factors for both crossing directions. For the formation of T. miyabeanum, we concluded that asymmetry of hybridization between T. apetalon and T. tschonoskii would be caused by strong premating isolations. The asymmetry of the isolating barriers may promote T. tschonoskii as the maternal parent of T. miyabeanum

An air transfer experiment confirms the role of volatile cues in communication between plants.

Previous studies reported that sagebrush plants near experimentally clipped neighbors experienced less herbivory than did plants near unclipped neighbors. Blocking air flow with plastic bags made this effect undetectable. However, some scientists remained skeptical about the possibility of volatile communication between plants since the existence and identity of a cue that operates in nature have never been demonstrated. We conducted an air transfer experiment that collected air from the headspace of an experimentally clipped donor plant and delivered it to the headspace of an unclipped assay plant. We found that assay plants treated with air from clipped donors were less likely to be damaged by naturally occurring herbivores in a field experiment. This simple air transfer experiment fulfills the most critical of Koch's postulates and provides more definitive evidence for volatile communication between plants. It also provides an inexpensive experimental protocol that can be used to screen plants for interplant communication in the field

Plant–plant communication and community of herbivores on tall goldenrod

Abstract The volatiles from damaged plants induce defense in neighboring plants. The phenomenon is called plant–plant communication, plant talk, or plant eavesdropping. Plant–plant communication has been reported to be stronger between kin plants than genetically far plants in sagebrush. Why do plants distinguish volatiles from kin or genetically far plants? We hypothesize that plants respond only to important conditions; the induced defense is not free of cost for the plant. To clarify the hypothesis, we conducted experiments and investigations using goldenrod of four different genotypes. The arthropod community on tall goldenrods were different among four genotypes. The response to volatiles was stronger from genetically close plants to the emitter than from genetically distant plants from the emitter. The volatiles from each genotype of goldenrods were different; and they were categorized accordingly. Moreover, the arthropod community on each genotype of goldenrods were different. Synthesis: Our results support the hypothesis: Goldenrods respond to volatiles from genetically close plants because they would have similar arthropod species. These results are important clues elucidating adaptive significance of plant–plant communication.

Airborne signals of communication in sagebrush: a pharmacological approach.

When plants receive volatiles from a damaged plant, the receivers become more resistant to herbivory. This phenomenon has been reported in many plant species and called plant-plant communication. Lab experiments have suggested that several compounds may be functioning as airborne signals. The objective of this study is to identify potential airborne signals used in communication between sagebrush (Artemisia tridentata) individuals in the field. We collected volatiles of one branch from each of 99 sagebrush individual plants. Eighteen different volatiles were detected by GC-MS analysis. Among these, 4 compounds; 1.8-cineol, β-caryophyllene, α-pinene and borneol, were investigated as signals of communication under natural conditions. The branches which received either 1,8-cineol or β-caryophyllene tended to get less damage than controls. These results suggested that 1,8-cineol and β-caryophyllene should be considered further as possible candidates for generalized airborne signals in sagebrush