Developmentally regulated expression of type XV collagen correlates with abnormalities in Col15a1(-/-) mice.

Lack of type XV collagen in mice results in mild skeletal myopathy and increases vulnerability to exercise-induced skeletal muscle and cardiac injury [Proc. Natl. Acad. Sci. USA 98 (2001), 1194]. The expression of type XV collagen was studied during murine fetal development from 10.5 to 18.5 dpc using immunofluorescence. The first sign of type expression was seen in the capillaries of many tissues at 10.5 dpc, some of them showing developmental transitions in the expression. Interestingly, capillaries forming the blood-brain barrier and those of the sinusoidal type were essentially lacking in this collagen. Early expression was also detected in the skeletal muscle and peripheral nerves, while expression in the heart, kidney and lung appeared to be developmentally regulated. In addition, distinct staining was found in the perichondrium of the cartilage. Collectively, the dynamics of its expression during development, its localization in the basement membrane--fibrillar matrix interface and the consequences of its absence in mice suggest a structural role in providing stability at least in skeletal muscle and capillaries. The early prominent expression of type XV collagen in newly forming blood vessels could also indicate a possible role in angiogenic processes.     

The effect of temperature on male mating signals and female choice in the red mason bee,Osmia bicornis (L.)

Climate change and the resulting changes in air temperature are known to have a major influence on most animals, especially poikilothermic insects, because they depend on the high enough temperatures to function. Previous studies have shown that various signals can be affected by changes in temperature. However, research into the effect of temperature on mating signals and subsequently communication between mates and on female choice is still rare. In the red mason bee, Osmia bicornis, which emerges early in spring and is therefore subject to extensive temperature changes, females choose suitable males based on, among other criteria, their thorax vibrations and odor. So far there has been no research into the effect of temperature changes on these signals. We therefore investigated whether the environmental temperature has an influence on the male's mating signals by measuring vibrations using a laser vibrometer and collecting male and female odor at different temperatures. Furthermore, we performed behavioral experiments in order to show whether there is an effect of temperature‐induced changes and female choice. Our results showed that rejected males differed in their vibrations between the two temperature settings but accepted ones did not. Temperature changes therefore seem to have a stronger effect on those males that are rejected by the females, whereas the accepted males are the ones that can produce desirable signals despite temperature fluctuations. Furthermore, we found that the differences in odor profiles were greater between temperature settings than between the sexes and that females change their preference for odor with temperature. We conclude that temperature strongly influences the male mating signals and therefore may have a major impact on sexual selection in this species. This is an important aspect to consider, not only in future studies on mating behavior, but also in view of our ever raising temperatures.     

Heritability of maximal isometric muscle strength in older female twins.

The purpose of the present study was to examine genetic and environmental effects on maximal isometric handgrip, knee extension, and ankle plantar flexion strength. In addition, we wanted to investigate whether the strength of these three muscle groups shares a genetic component or whether the genetic effect is specific for each muscle group. Muscle strength was measured as part of the Finnish Twin Study on Aging in 97 monozygotic (MZ) and 102 dizygotic (DZ) female twin pairs, aged 63-76 yr. The MZ and DZ individuals did not differ from each other in age, body height, weight, or self-related health. The age-adjusted pairwise (intraclass) correlations of the MZ and DZ twins were, respectively, 0.462 and 0.242 in knee extension, 0.435 and 0.345 in handgrip, and 0.512 and 0.435 in ankle plantar flexion strength. The multivariate genetic analysis showed that handgrip and knee extension strength shared a genetic component, which accounted for 14% (95% confidence interval: 4-28%) of the variance in handgrip strength and 31% (95% confidence interval: 18-45%) in knee extension strength. The influence of genetic effects on ankle plantar flexion strength was minor and not significant. Furthermore, these three muscle groups had a nongenetic familial effect in common and nonshared environmental effects in common. The results suggested that muscle strength is under a genetic regulation, but also environmental effects have a significant role in explaining the variability in the muscle strength.     

Contribution of genetic and environmental effects to postural balance in older female twins.

The aim of the present study was to determine the relative roles of genetic and environmental influences on postural balance in older women. The participants were 97 monozygotic (MZ) and 102 dizygotic (DZ) female twins, aged 64-76 yr. Postural sway was measured during side-by-side stance with eyes open and eyes closed, and during semitandem stance with eyes open on a force platform. Sway data were condensed into four first-order and one second-order latent factors. The second-order factor, named balance, incorporates sway data from multiple tests and thus best describes the phenotype of postural balance. The contribution of genetic and environmental influences on the variability of the latent factors was assessed by using structural equation modeling. Additive genetic influences accounted for 35% and shared environmental influences accounted for 24% of the total variance in the balance factor. In the present study, postural balance in older women had a moderate genetic component. Genetic influences on postural balance may be mediated through gene variation in the systems that control posture. The finding that individual environmental influences accounted for almost one-half of the variance in postural balance points to the potential of targeted interventions to maintain and improve balance control in older persons.     

Body fat and mobility are explained by common genetic and environmental influences in older women

In older adults, mobility limitations often coexist with overweight or obesity, suggesting that similar factors may underlie both traits. This study examined the extent to which genetic and environmental influences explain the association between adiposity and mobility in older women. Body fat percentage (bioimpedance test), walking speed over 10 m, and distance walked in a 6-min test were evaluated in 92 monozygotic (MZ) and 104 dizygotic (DZ) pairs of twin sisters reared together, aged 63-76 years. Genetic and environmental influences on each trait were estimated using age-adjusted multivariate genetic modeling. The analyses showed that the means (and s.d.) for body fat percentage, walking speed, and walking endurance were 33.2+/-7.3%, 1.7+/-0.3 m/s and 529.7+/-75.4 m, respectively. The phenotypic correlation between adiposity and walking speed was -0.32 and between adiposity and endurance it was -0.33. Genetic influences explained 80% of the association between adiposity and speed, and 65% of adiposity and walking endurance. Cross-trait genetic influences accounted for 12% of the variability in adiposity, 56% in walking speed, and 34% in endurance. Trait-specific genetic influences were also detected for adiposity (54%) and walking endurance (13%), but not speed. In conclusion, among community-living older women, an inverse association was found between adiposity and mobility that was mostly due to the effect of shared genes. This result suggests that the identification of genetic variants for body fat metabolism may also provide understanding of the development of mobility limitations in older women.     

Catechol-o-methyltransferase gene polymorphism is associated with skeletal muscle properties in older women alone and together with physical activity

Background

Muscle strength declines on average by one percent annually from midlife on. In postmenopausal women this decrement coincides with a rapid decline in estrogen production. The genetics underlying the effects of estrogen on skeletal muscle remains unclear. In the present study, we examined whether polymorphisms within COMT and ESR1 are associated with muscle properties and assessed their interaction and their combined effects with physical activity.

Methodology/Principal Findings

A cross-sectional data analysis was conducted with 434 63-76-year-old women from the population-based Finnish Twin Study on Aging. Body anthropometry, muscle cross-sectional area (mCSA), isometric hand grip and knee extension strengths, and leg extension power were measured. COMT Val158Met and ESR1 PvuII genotypes were determined by the RFLP method. mCSA differed by COMT genotypes (p = 0.014) being significantly larger in LL than HL individuals in unadjusted (p = 0.001) and age- and height-adjusted model (p = 0.004). When physical activity and age were entered into GEE model, COMT genotype had a significant main effect (p = 0.038) on mCSA. Furthermore, sedentary individuals with the HH genotype had lower muscle mass, strength and power, but they also appeared to benefit the most from physical activity. No association of ESR1 PvuII polymorphism with any of the muscle outcomes was observed.

Conclusions/Significance

The present study suggests that the COMT polymorphism, affecting the activity of the enzyme, is associated with muscle mass. Furthermore, sedentary individuals with potential high enzyme activity were the weakest group, but they may potentially benefit the most from physical activity. This observation elucidates the importance of both environmental and genetic factors in muscle properties.     

Life Course Trajectories of Labour Market Participation among Young Adults Who Experienced Severe Alcohol-Related Health Outcomes: A Retrospective Cohort Study

BackgroundLong-term employment trajectories of young problem drinkers are poorly understood.MethodsWe constructed retrospective labour market participation histories at ages 18–34 of 64 342 persons born in 1969–1982. Beginning from the year of each subject’s 18^th birthday, we extracted information from the records of Statistics Finland on educational attainment, main type of economic activity, months in employment, and months in unemployment for a minimum of seven years (range 7–16 years). We used information on the timing of alcohol-related hospitalizations and deaths in the same period to define problem drinkers with early onset limited course, early onset persistent course, and late onset problem drinking.ResultsEarly onset limited course problem drinkers improved their employment considerably by age, whereas early onset persistent problem drinkers experienced a constant decline in their employment by age. From the age of 18 to 34, early onset persistent problem drinkers were in employment merely 12% of the time, in comparison with 39% among the early onset limited course problem drinkers, and 58% among the general population.ConclusionsThese results indicate that young adults who were retrospectively defined as having early onset persistent course problem drinking were extensively marginalized from the labour market early on during their life course, and that their employment trajectory was significantly worse compared to other problem drinkers.     

The oxidation of veratryl alcohol, dimeric lignin models and lignin by lignin peroxidase: The redox cycle revisited

Abstract: The mechanism of oxidation of veratryl alcohol and β-0–4 dimeric lignin models is reviewed. Veratryl alcohol radicals are intermediates in both oxidation pathways. The possible role of the veratryl alcohol radical cation as a mediator is discussed. The lignin peroxidase (LIP) redox cycle is analyzed in terms of the Marcus theory of electron transfer. Reduction of both LiP-Compound I (LiP-I) and LiP-Compound II (LiP-II) by veratryl alcohol occurs in the endergonic region of the driving force. The reduction of LiP-II has a higher reorganization energy due to the change in spin state and the accompanying conformational change in the protein. It is suggested that a reversible nucleophilic addition of a carbohydrate residue located at the entrance of the active site channel plays a key role in the LiP redox cycle. Moreover. (polymeric) hydroxysubstituted benzyl radicals may reduce LiP-II via long-range electron transfer.