Willow tit Parus montanus extrapair offspring are more heterozygous than their maternal half‐siblings

Through extrapair matings, males can sire additional offspring with low cost and females may look for direct benefits in form of food or additional paternal care or gain genetic benefits that increase offspring fitness. We studied the patterns of female mate choice and frequency of extrapair paternity in the socially monogamous willow tit Parus montanus using microsatellites. We also examined the effect of heterozygosity on the growth rate and survival of the chicks. We found 25 mixed‐paternity broods out of 117 broods of which both parents were sampled. Altogether, 6.7% of sampled chicks were classified as extrapair young. The pairwise relatedness of social pairs did not correlate with the percentage of extrapair young in the brood and there was no difference in heterozygosity between promiscuous and monogamous parents. However, the extrapair young were more heterozygous than the within‐pair young in the mixed‐paternity broods. The maternal half‐siblings in mixed paternity broods were similar in body size. Thus, there was no indication for different growth rate between the siblings, but there were indications that heterozygosity affects survival.     

Identification in the mould Hypocrea jecorina of a gene encoding an NADP(+): d-xylose dehydrogenase

A gene coding for an NADP(+)-dependent d-xylose dehydrogenase was identified in the mould Hypocrea jecorina (Trichoderma reesei). It was cloned from cDNA, the active enzyme was expressed in yeast and a histidine-tagged enzyme was purified and characterized. The enzyme had highest activity with d-xylose and significantly smaller activities with other aldose sugars. The enzyme is specific for NADP(+). The K(m) values for d-xylose and NADP(+) are 43 mM and 250 microM, respectively. The role of this enzyme in H. jecorina is unclear because in this organism d-xylose is predominantly catabolized through a path with xylitol and d-xylulose as intermediates and the mould is unable to grow on d-xylonic acid.     

Production in <Emphasis Type="Italic">Trichoderma reesei</Emphasis> of three xylanases from <Emphasis Type="Italic">Chaetomium thermophilum</Emphasis>: a recombinant thermoxylanase for biobleaching of kraft pulp

Three endoxylanase genes were cloned from the thermophilic fungus Chaetomium thermophilum CBS 730.95. All genes contained the typical consensus sequence of family 11 glycoside hydrolases. Genomic copies of Ct xyn11A, Ct xyn11B, and Ct xyn11C were expressed in the filamentous fungus T. reesei under the control of the strong T. reesei cel7A (cellobiohydrolase 1, cbh1) promoter. The molecular masses of the Ct Xyn11A, Ct Xyn11B, and Ct Xyn11C proteins on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) were 27, 23, and 22 kDa, respectively. Ct Xyn11A was produced almost as efficiently as the homologous xylanase II from a corresponding single-copy transformant strain. Ct Xyn11B production level was approximately half of that of Ct Xyn11A. The amount of Ct Xyn11C was remarkably lower. Ct Xyn11A had the highest temperature optimum and stability of the recombinant xylanases and the highest activity at acid-neutral pH (pH 5–7). It was the most suitable for industrial bleaching of kraft pulp at high temperature.     

Fast but ephemeral effects of ecological restoration on forest beetle community

Many protected areas have a long history of human intervention before being protected. In protected forests, the past land use has reduced the amount of natural structures, which are crucial substrates for thousands of species. We evaluate the short-term ecological effect of forest restoration (dead wood creation) on conifer-associated saproxylic (dead-wood dependent) beetles. More specifically, we analyze the effect of dead wood creation on the number of beetle species and individuals 1 and 5 years after restoration in spruce and pine forests, using a large-scale monitoring network over Finland. The number of saproxylic beetle species and individuals was larger at restored than at control plots both 1 and 5 years after restoration in both spruce and pine forests. Community composition in restored plots was different from control plots 1 year after restoration, but had returned towards the control plot composition 5 years after restoration, while control plots remained largely unchanged. Both in spruce and pine forests, there were more red-listed and rare saproxylic beetles in restored than in control plots 1 and 5 years after restoration. Our results indicate that restoration has an overall positive influence on saproxylic beetle diversity immediately after dead wood creation, but this effect is rather short-lived. Long term monitoring of restored dead wood is crucial in investigating successional pathways as well as biotic communities in advanced decay stages, and in fully evaluating the ecological effect of dead wood creation as a forest restoration measure.     

Association of VO2 and VCO2 rate variability with serum glucose, insulin, and glucose intolerance

Changes in the cellular metabolism assessed by the variability of oxygen consumption (VO(2) ) and carbon dioxide production (VCO(2) ) as well as the association of serum glucose and insulin to energy spectral density (ESD) of VO(2) and VCO(2) were evaluated. Ten nonglucose intolerant and 10 glucose intolerant subjects, aged 21-70 years, were included. Glucose and insulin concentrations and VO(2) and VCO(2) records were collected every 10 min during 3 h. ESD of VO(2) and VCO(2) was estimated and associated with glucose and insulin concentrations. Statistical significance in glucose levels, insulin, and ESD of VO(2) and VCO(2) among nonglucose intolerant subjects and glucose and insulin among glucose intolerance subjects at postload glucose (PLG) state compared with basal state was found. Moreover, glucose was significantly higher in glucose intolerance subjects than nonglucose intolerant subjects for basal and PLG states. These results show an increment in ESD of VO(2) and VCO(2) at PLG state among nonglucose intolerant subjects and suggest that their measurement may be a key indicator of the variability of cellular metabolic activity and contribute to confirm disturbances in glucose metabolism.     

Cloning, expression, and characterization of novel thermostable family 7 cellobiohydrolases

As part of the effort to find better cellulases for bioethanol production processes, we were looking for novel GH-7 family cellobiohydrolases, which would be particularly active on insoluble polymeric substrates and participate in the rate-limiting step in the hydrolysis of cellulose. The enzymatic properties were studied and are reported here for family 7 cellobiohydrolases from the thermophilic fungi Acremonium thermophilum, Thermoascus aurantiacus, and Chaetomium thermophilum. The Trichoderma reesei Cel7A enzyme was used as a reference in the experiments. As the native T. aurantiacus Cel7A has no carbohydrate-binding module (CBM), recombinant proteins having the CBM from either the C. thermophilum Cel7A or the T. reesei Cel7A were also constructed. All these novel acidic cellobiohydrolases were more thermostable (by 4-10 degrees C) and more active (two- to fourfold) in hydrolysis of microcrystalline cellulose (Avicel) at 45 degrees C than T. reesei Cel7A. The C. thermophilum Cel7A showed the highest specific activity and temperature optimum when measured on soluble substrates. The most effective enzyme for Avicel hydrolysis at 70 degrees C, however, was the 2-module version of the T. aurantiacus Cel7A, which was also relatively weakly inhibited by cellobiose. These results are discussed from the structural point of view based on the three-dimensional homology models of these enzymes.     

Matrix dimensionality in demographic analyses of plants: when to use smaller matrices?

Large data requirements may restrict the use of matrix population models for analysis of population dynamics. Less data are required for a small population matrix than for a large matrix because the smaller matrix contains fewer vital rates that need to be estimated. Smaller matrices, however, tend to have a lower precision. Based on 37 plant species, we studied the effects of matrix dimensionality on the long-term population growth rate (λ) and the elasticity of λ in herbaceous and woody species. We found that when matrix dimensionality was reduced, changes in λ were significantly larger for herbaceous than for woody species. In many cases, λ of woody species remained virtually the same after a substantial decrease in matrix dimensionality, suggesting that woody species are less susceptible to matrix dimensionality. We demonstrated that when adjacent stages of a transition matrix are combined, the magnitude of a change in λ depends on the distance of the population structure from a stable stage distribution, and the difference in the combined vital rates weighted by their reproductive values. Elasticity of λ to survival and fecundity usually increased, whereas elasticity to growth decreased both in herbaceous and in woody species with reduced matrix dimensionality. Changes in elasticity values tended to be larger for herbaceous than for woody species. Our results show that by reducing matrix dimensionality, the amount of demographic data can be decreased to save time, money, and field effort. We recommend the use of a small matrix dimensionality especially when a limited amount of data is available, and for slow-growing species having a simple matrix structure that mainly consists of stasis and growth to the next stage.     

Enhanced procollagen processing in skeletal muscle after a single bout of eccentric loading in humans.

Increases in procollagen processing within skeletal muscle have previously been reported in small animal models only. While indirect measurements in humans have suggested an increase procollagen processing, no intra-skeletal muscle measurements have confirmed these findings. In this study, eight young healthy male subjects performed a single bout of unaccustomed high intensity eccentric exercise on one leg, with the contralateral leg being the control. A significant increase in the muscle interstitial concentration of the N-terminal propeptide of procollagen type I (PINP) was observed (day 0: 1.96 +/- 0.44 ng ml(-1), day 2: 1.94 +/- 0.32 ng ml(-1), day 4: 3.90 +/- 1.03 ng ml(-1), day 8: 7.23 +/- 2.34 ng ml(-1)*, *P < 0.05 vs. basal and control) with no change being noted in the control leg. By day 2 post-exercise, an increase in the histological immunoreactivity of PINP and the N-terminal propeptide of procollagen type III (PIIINP) was also shown in the exercising leg only. Further, from day 2 post-exercise, immunoreactivity for tenascin C and reactive macrophages (CD68+ cells) was seen within the perimysial and endomysial connective tissue of the exercising leg only, indicating a high mechanical load and inflammation. This study shows that following a single bout of high intensity eccentric exercise there is an increase in procollagen processing within skeletal muscle in humans.