Early Incubation Research Articles

Recalcitrant carbon controls the magnitude of soil organic matter mineralization in temperate forests of northern China

BackgroundThe large potential of the soil organic carbon (SOC) pool to sequester CO2 from the atmosphere could greatly ameliorate the effect of future climate change. However, the quantity of carbon stored in terrestrial soils largely depends upon the magnitude of SOC mineralization. SOC mineralization constitutes an important part of the carbon cycle, and is driven by many biophysical variables, such as temperature and moisture.MethodsSoil samples of a pine forest, an oak forest, and a pine and oak mixed forest were incubated for 387 days under conditions with six temperature settings (5 °C, 10 °C, 15 °C, 20 °C, 25 °C, 30 °C) and three levels of soil moisture content (SMC, 30%, 60%, 90%). The instantaneous rate of mineralized SOC was periodically and automatically measured using a Li-Cor CO2 analyzer. Based on the measured amount of mineralized SOC, carbon fractions were estimated separately via first-order kinetic one- and two-compartment models.ResultsDuring the 387 day incubation experiment, accumulative mineralized carbon ranged from 22.89 mg carbon (C) ·g− 1 SOC at 30 °C and 30% SMC for the mixed forest to 109.20 mg C·g− 1 SOC at 15 °C and 90% SMC for the oak forest. Mineralized recalcitrant carbon varied from 18.48 mg C·g− 1 SOC at 30 °C and 30% SMC for the mixed forest to 104.98 mg C·g− 1 SOC at 15 °C and 90% SMC for the oak forest, and contributed at least 80% to total mineralized carbon.ConclusionsBased on the results of this experiment, the soil organic matter of the pure broadleaved forest is more vulnerable to soil microbial degradation in northern China; most of the amount of the mineralized SOC derived from the recalcitrant carbon pool. Labile carbon fraction constitutes on average 0.4% of SOC across the three forest types and was rapidly digested by soil microbes in the early incubation stage. SOC mineralization markedly increased with soil moisture content, and correlated parabolically to temperature with the highest value at 15 °C. No significant interaction was detected among these variables in the present study.

Optimization of EnBase Fed-Batch Cultivation to Improve Soluble Fraction Ratio of α-Luffin Ribosome Inactivating Protein.

BackgroundThe increase of the protein expression via ribosomal manipulation is one of the suggested cellular mechanisms involved in EnBase fed-batch mode of cultivation. However, this system has not been implemented for cytotoxic proteins.ObjectivesHere, the expression pattern of α-Luffin, a ribosome inactivation protein (RIP) with an innate toxicity, was investigated in EnBase system and the effect of low temperature cultivation on the increase of α-Luffin solubility was determined.Materials and MethodsThe encoding cDNA for mature α-Luffin was synthesized and subcloned into pET28a plasmid under the control of T7 promoter. The E. coli expression yield in EnBase® Flo fed-batch system was compared with traditional batch mode at two temperatures: 25 °C and 30 °C. Sampling was performed at several time intervals and solubility of recombinant-protein was checked on SDS-PAGE in pellet and supernatant samples. The purification of recombinant protein was performed by Ni-NTA column.ResultsIn fed-batch cultivation mode, the early incubation time was desirable at 30 °C whereas the maximum amount of soluble α-Luffin was achieved from the extended protein synthesis period (12 and 24h post induction) at 25 °C.ConclusionsOur founding showed that EnBase had a greater efficacy in producing higher soluble protein ratios compared to batch cultivation growth rate, however for cytotoxic proteins, incubation temperature and time need to be optimized. Owing to the advantages of natural toxins from RIP family for producing anticancer immune-conjugates, well optimization of this protein expression is of importance regarding industrial aspects. The optimized condition proposed here is promising in terms of large scale soluble production of α-Luffin without the need for refolding.

Degradation profile of synthetic coral scaffold in cell culture media

<p>The scaffold is one of the factors in tissue engineering that determine the success of bone regeneration. The important characteristic of the scaffold is able to degrade gradually. In vitro study using cells, the scaffold will be exposed to culture media. Therefore, degradation profile for scaffold needs to be examined. This study aims to investigate the degradation profile of synthetic coral scaffold in cell culture media using pH measurement. The method used the synthetic coral scaffolds were prepared from denaturalized collagen (gelatin) and calcium carbonate (calcite) with a concentration of 5:5 and 4:6 weight % in aqua dest. The scaffold<span lang="IN" style="">s</span> were fabricated in membrane thick film which was then physically crosslinked.  <span lang="IN" style="">The </span>10 % <span lang="IN" style="">of gelatin scaffold was used as a control.</span>  The scaffolds were incubated in cell culture media (non-phenol red Dulbecco’s Modified Eagle Medium) for 1 until 8 days, and pH changes of the medium were measured. As the result, Profile of degradation on day 1 to day 4 showed the 5:5 scaffold had the smallest degradation. The results indicated the significant different between scaffold concentration in day 1 (p=0.005), 5th(p=0.03), and 6th day (p=0.011). At the end of incubated days, the pH changed but not significantly different. LSD showed the significant differences between scaffold (5:5 and 4:6) with control and no significant difference between 2 concentrations of the scaffold. The conclusion of this study is the synthetic coral scaffold degraded gradually until the end incubation time and between concentration had different degradation profile in the early incubation time using pH measurement.<br></p>

Incubation and hatch management: consequences for bone mineralization in Cobb 500 meat chickens

From ~35 days of age fast growing meat chickens spend extended periods sitting or lying and less time standing. In a fast-feathering parent line lower early incubation temperatures which delayed chick hatch time, improved bone ash and extended their standing time. This incubation study assessed the consequences of incubation temperatures, hatch time and chick management at hatch/take off on femoral bone ash (BA) in Cobb 500 meat chickens. Embryos were incubated under either Control (between 37.8°C and 38.2°C egg shell temperature (EST)) or a Slow start (from 37.2°C at sett (the start of incubation), reaching 37.8°C EST at day 13 incubation), temperatures. Hatched chicks were identified at 492 h (20.5 days of incubation – classified as early (E)) or, between >492 and ⩽516 h (>20.5 and ⩽21.5 days of incubation – classified as late (L)), from setting. The E hatch chicks were allocated across three post-hatch treatments; treatment 1: E hatch chicks that were sampled E at 492 h from setting; treatment 2: E hatch chicks that were fed for a further 24 h in a floorpen before being sampled L at 516 h from setting; treatment 3: E hatch chicks that spent a further 24 h in the incubator before being sampled L at 516 h from setting. All L hatch chicks formed one treatment group which was sampled L at 516 h (i.e. L hatch chicks sampled L). It is not possible to sample L hatching chicks E hence this treatment is absent from the experimental design. Slow start incubation resulted in a higher total hatch percentage with a greater proportion of chicks hatching L, compared with the Control incubation. The L hatching chicks had significantly higher BA than the E hatching chicks. Of the E hatching chicks, those sampled both E and L had significantly lower BA than E hatching chicks fed for 24 h before L sampling. The E hatch, fed and sampled L chicks had the numerically highest BA, which was not significantly different from the BA of the L hatching chicks sampled L These results demonstrate that BA at hatch can be improved, either by extending the incubation period through a Slow start incubation profile, inducing L hatch, or alternatively, via the prompt provision of feed to E hatching chicks.

Exogenous Nitrogen Addition Reduced the Temperature Sensitivity of Microbial Respiration without Altering the Microbial Community Composition.

Atmospheric nitrogen (N) deposition is changing in both load quantity and chemical composition. The load effects have been studied extensively, whereas the composition effects remain poorly understood. We conducted a microcosm experiment to study how N chemistry affected the soil microbial community composition characterized by phospholipid fatty acids (PLFAs) and activity indicated by microbial CO2 release. Surface and subsurface soils collected from an old-growth subtropical forest were supplemented with three N-containing materials (ammonium, nitrate, and urea) at the current regional deposition load (50 kg ha-1 yr-1) and incubated at three temperatures (10, 20, and 30°C) to detect the interactive effects of N deposition and temperature. The results showed that the additions of N, regardless of form, did not alter the microbial PLFAs at any of the three temperatures. However, the addition of urea significantly stimulated soil CO2 release in the early incubation stage. Compared with the control, N addition consistently reduced the temperature dependency of microbial respiration, implying that N deposition could potentially weaken the positive feedback of the warming-stimulated soil CO2 release to the atmosphere. The consistent N effects for the surface and subsurface soils suggest that the effects of N on soil microbial communities may be independent of soil chemical contents and stoichiometry.

Incubation onset maintains survival of most embryos and growth and survival of late-hatched young

Hatching asynchrony occurs primarily as a consequence of the timing of embryonic development. Despite over 50 years of study, it is unclear why, ultimately, most birds initiate embryonic development (incubation) before all eggs are laid. One hypothesis focuses on prehatching (embryo) survival and predicts that early incubation maximizes embryo survival by reducing exposure of unincubated eggs (egg viability hypothesis). Another set of hypotheses focuses on posthatching growth and survival and predicts that females time incubation to maximize the number or quality of hatched offspring that fledge (adaptive hatching pattern hypotheses). I experimentally manipulated when females could begin incubation to test how timing of embryonic development influences prehatching survival and posthatching growth and survival in the house sparrow, Passer domesticus. Despite high embryo survival in both naturally asynchronous and experimentally synchronized nests, early incubation appeared to maximize embryo survival in all but the earliest-laid eggs, suggesting that house sparrows begin incubation too late to maximize survival of all embryos. Early incubation had little effect on overall (i.e. mean) patterns of posthatching growth and survival. However, early incubation increased the initial variation in offspring size because last-hatched young were relatively small when all eggs had completed hatching. Nestlings that were small at hatch completion grew slowly and exhibited a reduced probability of survival, suggesting that house sparrows begin incubation too early to maximize growth and survival of hatched offspring. These results suggest that timing of incubation neither maximizes embryo survival nor maximizes posthatching growth and survival. Instead, early incubation appears to be a trade-off between maintaining both embryo survival and growth and survival of late-hatched offspring. Thus, house sparrow females likely time incubation as an adaptive strategy to maximize the number of embryos that survive the incubation and nestling periods to fledge.

Gold Nanoparticle Size and Shape Effects on Cellular Uptake and Intracellular Distribution of siRNA Nanoconstructs.

Gold nanoparticles (AuNPs) show potential for transfecting target cells with small interfering RNA (siRNA), but the influence of key design parameters such as the size and shape of the particle core is incomplete. This paper describes a side-by-side comparison of the in vitro response of U87 glioblastoma cells to different formulations of siRNA-conjugated gold nanoconstructs targeting the expression of isocitrate dehydrogenase 1 (IDH1) based on 13 nm spheres, 50 nm spheres, and 40 nm stars. 50 nm spheres and 40 nm stars showed much higher uptake efficiency compared to 13 nm spheres. Confocal fluorescence microscopy showed that all three formulations were localized in the endosomes at early incubation times (2 h), but after 24 h, 50 nm spheres and 40 nm stars were neither in endosomes nor in lysosomes while 13 nm spheres remained in endosomes. Transmission electron microscopy images revealed that the 13 nm spheres were enclosed and dispersed within endocytic vesicles while 50 nm spheres and 40 nm stars were aggregated, and some of these NPs were outside of endocytic vesicles. In our comparison of nanoconstructs with different sizes and shapes, while holding siRNA surface density and nanoparticle concentration constant, we found that larger particles (50 nm spheres and 40 nm stars) showed higher potential as carriers for the delivery of siRNA.

Ectoparasites as developmental stressors: Effects on somatic and physiological development.

Developmental stress can alter resource allocation in early life, and in altricial birds with rapid developmental trajectories and high resource demands, nestlings may adjust early resource partitioning to cope with challenging environments. We experimentally manipulated ectoparasite levels in nests and assessed whether ectoparasites affected somatic and physiological development in European starling (Sturnus vulgaris) nestlings. We hypothesized that mites act as developmental stressors in nestlings and predicted that nestlings from infested nests would exhibit either reduced somatic growth, or reduced physiological development, including impaired innate immunity, and would have elevated corticosterone concentrations. We either added ≈200 mites to nests during early incubation, or treated nests with a pesticide, permethrin, to reduce mites and possibly other arthropods. We assessed treatment effects on egg spottiness and mite abundance, and monitored offspring hatching and survival. We also measured somatic growth (mass, tarsus length, and feather growth), hematocrit, immune-related metrics (bacterial killing ability [BKA] and spleen mass), and baseline corticosterone concentrations in response to treatment. Compared with mite treatment, permethrin reduced egg spottiness and mite abundance in nests. Relative to nestlings in mite-reduced nests, nestlings in mite-enhanced nests had lower survival, hematocrit, and corticosterone concentrations. Early in development, nestlings from both treatments exhibited similar rapid somatic growth, yet mite-treated nestlings exhibited lower BKA. Nestlings in both treatments increased BKA across development, despite nestlings in mite-treated nests exhibiting lower mass as nest leaving neared. Overall, we found evidence that mites can act as development stressors, but contrary to our prediction, mites decreased corticosterone concentrations.

Individual variation of persistent organic pollutants in relation to stable isotope ratios, sex, reproductive phase and oxidative status in Scopoli's shearwaters (Calonectris diomedea) from the Southern Mediterranean

Little is known about the accumulation of persistent organic pollutants (POPs) and its consequences for seabirds in the Mediterranean basin. We characterised the plasma contaminant profile (polychlorinated biphenyls ΣPCBs; organochlorine pesticides ΣOCPs; polybrominated diphenyl ethers ΣPBDEs) of a population of the seabird Scopoli's shearwater (Calonectris diomedea) that breeds in the southern Mediterranean (Linosa Island) and investigated (i) whether sex, stable isotope ratios (related to diet), reproductive phase (early incubation vs. late breeding season) and body mass explained variation in contaminant burden and (ii) whether they predict health-related variables. The predominant category of POPs was ΣPCBs contributing between 53.0 and 92.4% of the total POPs in each shearwater. The percentage contribution of ΣOCPs to total POPs ranged between 7.6 and 47.0%, while that of ΣPBDEs ranged between <1% and 22.1%. Near the end of the breeding season, concentrations of ΣPCBs, ΣOCPs and ΣPOPs were significantly higher than at the beginning of the incubation period. ΣPBDEs were higher in males than females near the end of the breeding season, while they were higher in females than males at the beginning of the egg incubation period. Carbon- and nitrogen isotope ratios and individual body mass were not significantly associated with any contaminant class. Mates differed in the concentration of POPs, but they had similar stable isotope values. There was little evidence for a connection between contaminants and blood-based markers of oxidative balance. None of the contaminants predicted the probability of a bird being resighted as a breeder the following year. Thus, although POPs were present at high concentrations in some individuals, our study suggests little concern regarding POP exposure for this shearwater population.

Incubation and embryonic development affect the color of eggs of Mountain Bluebirds

Technological and theoretical advances over the past two decades have allowed researchers to quantify eggshell color in ways that were not previously possible. However, differences among studies in the timing of color measurements during laying or incubation and inclusion of data from inviable eggs may affect the results of these studies as well as conclusions based on comparisons among studies. To determine the effect of the timing of color measurements, we compared the color of the eggs of Mountain Bluebirds (Sialia currucoides) during both laying/early incubation and late incubation. We also assessed the influence of egg viability on eggshell color by comparing viable and inviable eggs from the same clutch. We found that all color metrics investigated (blue-green and UV chroma, brightness, and hue) were significantly different between early and late incubation, and viable and inviable eggs. However, color metrics of eggs measured during early and late incubation and of viable and inviable eggs in the same clutch were correlated. Our results suggest that the timing of color measurements and the viability of eggs have important effects on eggshell color and, therefore, in future studies, investigators should always provide information about the timing of measurements and the viability of eggs measured. Our results also suggest that comparisons among studies where eggshell color was measured at different times and/or the viability of eggs was not determined or reported are possible, given that the color metrics of viable and inviable eggs and of eggs measured at different times in our study were correlated, but those comparisons should be interpreted with caution.

Data loggers in artificial eggs reveal that egg-turning behavior varies on multiple ecological scales in seabirds

ABSTRACT In most avian species, egg-turning behavior during incubation is vital for proper embryonic development and hatching success. However, changes in turning behaviors are rarely studied across different temporal scales (e.g., day–night or across incubation phases), though the timing of incubation behaviors affects reproductive success. We used data loggers encapsulated in artificial eggs to measure turning rates and angle changes of eggs in Western Gull (Larus occidentalis) and Laysan Albatross (Phoebastria immutabilis) nests. We examined diurnal and daily cycles in egg-turning behaviors across early, middle, and late incubation phases. Our results indicate that (1) egg-turning behaviors remain similar throughout incubation, resulting in a consistent environment for developing chicks; (2) egg-turning rates and angle changes vary according to diurnal cycles and day length in each species; and (3) egg-turning rates, but not angle changes, were similar between species. Egg-turning behaviors may vary am...

Diet dichotomy between two migrant seabirds breeding near a high Arctic polynya.

High Arctic polynyas are predictable areas of open water, which offer long-distance migrant seabirds a reliable source of food during a period when they have to replenish and accumulate energy for reproduction. Investigating the interaction between species nesting sympatrically in the vicinity of polynyas should provide insights into the role that such oceanographic features play for pre-breeding seabirds. We used stable isotopes (δ13C and δ15N) to compare the diet of two ground-nesting seabirds, Sabine's gull (Xema sabini) and Arctic tern (Sterna paradisaea), nesting on an island adjacent to a recurring polynya in the Canadian high Arctic in 2008 and 2009. We show that, unlike Arctic terns, the diet of Sabine's gulls appears to include a non-negligible amount of terrestrially derived prey during early incubation, and that overall both species segregate their dietary niche during pre-laying and early incubation.

Visible marking of wader nests to avoid damage by farmers does not increase nest predation

SummaryOnly a few studies have assessed the predation risk on artificially marked nests, or have examined ways of marking nests to avoid destruction by machinery. Until now, however, neither type of study has directly addressed this apparent trade-off experimentally. The impact of marking the nests of Northern Lapwing Vanellus vanellus with thin 2 m-long conspicuous bamboo poles with the top end highlighted with reflective red or orange spray has been tested for three years in two breeding areas of waders in the Czech Republic. A total of 52 pairs of nests on agricultural land, with each pair consisting of one marked nest and one unmarked reference counterpart nest, were monitored for 2004 nest-days until hatching, agricultural operations or failure. The results proved that marking itself does not result in increased nest predation. The nests found in the early incubation stage were under higher threat of depredation, irrespective of the presence of marking. Our results show that it is possible to find a finely-tuned trade-off in nest marking of ground-nesting birds between risk of damage by agricultural machinery and risk of increased nest predation. Our positive experience with Northern Lapwing, and episodically with three other wader species in the Czech Republic, suggests that this direct nest protection could be used effectively for a wider variety of ground-nesting birds.

Effects of Lactobacillus acidophilus supplementation for improving in vitro rumen fermentation characteristics of cereal straws

We explored and compared the effects of four doses (0, 0.25 × 107, 0.50 × 107, and 0.75 × 107 cfu/mL) of Lactobacillus acidophilus supplementation on ruminal fermentation characteristics of maize stover and rice straw. The maximum gas production (Vf) for maize stover and the rate of gas production during early incubation (FRD0) for rice straw were quadratic (p < .05) and linear (p < .01), respectively, and increased when supplemented with L. acidophilus. The L. acidophilus supplementation increased ruminal NH3-N concentration for maize stover (p < .01) and rice straw (p < .05), respectively. The supplementation level of L. acidophilus did not affect the production of volatile fatty acids (VFAs) except for valeric acid, nor did it affect CH4 production, IVDMD, IVNDFD, ruminal pH value, total volatile fatty acids (TVFAs) or the ratio of acetic to propionic acid (A:P). As a fermentation substrate, when compared to rice straw, maize stover increased in vitro gas production parameters (e.g. Vf, k, FRD0 and t0.5), IVDMD, IVNDFD, ruminal NH3-N concentration and TVFAs, whereas there was no (p > .05) difference in CH4 production, ruminal pH value or A:P between the two substrates. The results indicate that L. acidophilus increase in vitro gas production and ruminal NH3-N concentration when using either fermentation substrate, with the greatest increase observed at a dosage of 0.75 × 107 cfu/mL. Additionally, maize stover is superior to rice straw as a fermentation substrate or forage for ruminants. The present positive in vitro results should be tested using in vivo experiments in future.

Bio-active molecules modified surfaces enhanced mesenchymal stem cell adhesion and proliferation

Surface modification of the substrate as a component of in vitro cell culture and tissue engineering, using bio-active molecules including extracellular matrix (ECM) proteins or peptides derived ECM proteins can modulate the surface properties and thereby induce the desired signaling pathways in cells. The aim of this study was to evaluate the behavior of human bone marrow mesenchymal stem cells (hBM-MSCs) on glass substrates modified with fibronectin (Fn), collagen (Coll), RGD peptides (RGD) and designed peptide (R-pept) as bio-active molecules. The glass coverslips were coated with fibronectin, collagen, RGD peptide and R-peptide. Bone marrow mesenchymal stem cells were cultured on different substrates and the adhesion behavior in early incubation times was investigated using scanning electron microscopy (SEM) and confocal microscopy. The MTT assay was performed to evaluate the effect of different bio-active molecules on MSCs proliferation rate during 24 and 72 h. Formation of filopodia and focal adhesion (FA) complexes, two steps of cell adhesion process, were observed in MSCs cultured on bio-active molecules modified coverslips, specifically in Fn coated and R-pept coated groups. SEM image showed well adhesion pattern for MSCs cultured on Fn and R-pept after 2 h incubation, while the shape of cells cultured on Coll and RGD substrates indicated that they might experience stress condition in early hours of culture. Investigation of adhesion behavior, as well as proliferation pattern, suggests R-peptide as a promising bio-active molecule to be used for surface modification of substrate in supporting and inducing cell adhesion and proliferation.

Improved transient production of a cellulase enzyme in detached sunflower leaves using plant hormones

A synthetic endoglucanase E1 was transiently expressed in detached whole sunflower leaves using recombinant Agrobacterium tumefaciens. As a means to increase protein accumulation, the effect of plant hormones on E1 production was investigated using six different hormones: methyl jasmonic acid (JA), gibberellin A3 (GA), indole acetic acid (IAA), 2,4-dichlorophenoxyacetic acid (2,4-D), kinetin (CK), and salicylic acid (SA). Among the six hormones, JA was best at boosting E1 concentrations, increasing yields as much as six-fold and the JA treatment was especially effective at an early phase of leaf incubation likely by enhancing T-DNA transfer at an early leaf incubation phase. Finally, co-infiltrating combinations of two different hormones revealed an antagonistic interaction between JA and SA in A. tumefaciens-mediated transient expression.

Differences in accumulation and the transport mechanism of l- and d-methionine in high- and low-grade human glioma cells

IntroductionAlthough [S-methyl-11C]-labeled L-methionine and D-methionine (11C-L-MET and 11C-D-MET) are useful radiotracers for positron emission tomography imaging of brain tumors, it is not known whether the accumulation and transport mechanisms underlying uptake of 11C-D-MET and 11C-L-MET are the same. 11C-L-MET is mainly taken up by the amino acid transport system L. We evaluated accumulation and the transport mechanism of D-MET in high- and low-grade human glioma cells in vitro. MethodsThe expression of transport system genes in high- (A172 and T98G) and low-grade (SW1088 and Hs683) glioma cells was quantitatively analyzed. Accumulation of [S-methyl-3H]-L-MET (3H-L-MET) and [S-methyl-3H]-D-MET (3H-D-MET) in these cells was compared during 60min of incubation. The transport mechanism of 3H-L-MET and 3H-D-MET was investigated by incubating the cells with these compounds and examining the effect of the inhibitors 2-amino-2-norbornane-carboxylic acid or α-(methylamino) isobutyric acid. ResultsAbsolute expression levels of system L and system alanine–serine–cysteine (ASC) in high-grade glioma cells were higher than in low-grade cells. In high-grade glioma cells, expression of system ASC genes was higher than that of system L genes. 3H-D-MET, which is transported by systems L and ASC, accumulated at higher levels than 3H-L-MET at all incubation times because 3H-D-MET is more sensitive to system ASC than 3H-L-MET. Conversely, in low-grade glioma cells with lower expression of system L and ASC, 3H-D-MET accumulated at higher levels than 3H-L-MET in early incubation times because 3H-D-MET may be more sensitive to system ASC than system L. Conclusion3H-D-MET was mainly transported by systems L and ASC and sensitive to system ASC, whereas 3H-L-MET was transported by system L in human glioma cells. In vitro, the accumulation of 3H-D-MET was significantly higher than that of 3H-L-MET during the entire incubation time in high-grade glioma cells, and in early incubation times in low-grade glioma cells.

Transient Shifts of Incubation Temperature Reveal Immediate and Long-Term Transcriptional Response in Chicken Breast Muscle Underpinning Resilience and Phenotypic Plasticity.

Variations in egg incubation temperatures can have acute or long-term effects on gene transcription in avian species. Altered gene expression may, in turn, affect muscle traits in poultry and indirectly influence commercial production. To determine how changes in eggshell temperature affect gene expression, incubation temperatures were varied [36.8°C (low), 37.8°C (control), 38.8°C (high)] at specific time periods reflecting two stages of myogenesis [embryonic days (ED) 7–10 and 10–13]. Gene expression was compared between interventions and matching controls by microarrays in broiler breast muscle at ED10 or ED13 and post-hatch at day 35. Early (ED7-10) high incubation temperature (H10ΔC) resulted in 1370 differentially expressed genes (DEGs) in embryos. Ingenuity pathway analysis revealed temporary activation of cell maintenance, organismal development, and survival ability genes, but these effects were not maintained in adults. Late high incubation temperature (ED10-13) (H13ΔC) had slightly negative impacts on development of cellular components in embryos, but a cumulative effect was observed in adults, in which tissue development and nutrition metabolism were affected. Early low incubation temperature (L10ΔC) produced 368 DEGs, most of which were down-regulated and involved in differentiation and formation of muscle cells. In adults, this treatment down-regulated pathways of transcriptional processes, but up-regulated cell proliferation. Late low temperature incubation (L13ΔC) produced 795 DEGs in embryos, and activated organismal survival and post-transcriptional regulation pathways. In adults this treatment activated cellular and organ development, nutrition and small molecule activity, and survival rate, but deactivated size of body and muscle cells. Thermal interventions during incubation initiate immediate and delayed transcriptional responses that are specific for timing and direction of treatment. Interestingly, the transcriptional response to transiently decreased incubation temperature, which did not affect the phenotypes, prompts compensatory effects reflecting resilience. In contrast, higher incubation temperature triggers gene expression and has long-term effects on the phenotype. These mechanisms of considerable phenotypic plasticity contribute to the biodiversity and broaden the basis for managing poultry populations.

Carbon budget by priming in a biochar-amended soil

Understanding the balance between the priming effect and the retention of added organic carbon (C) in soil is important in evaluating the role of specific practices for terrestrial C sequestration. However, knowledge about the effects of biochar addition on soil net C accumulation following various C input patterns remains limited. We incubated soil with aged and fresh biochar, and added 14C-labeled glucose at three frequencies over 120 days: single, repeated, and continuous additions. Regardless of glucose addition, the presence of aged or fresh biochar reduced the accumulative CO2 emissions, by 23% on average, relative to the soil without biochar addition. Compared with the soil without biochar addition, glucose mineralization significantly increased by 1.4–2.0% in the soils with aged biochar, but decreased by 0.1–1.9% in the soils with fresh biochar. Relative to repeated and continuous glucose additions, the single addition may slightly overestimate priming effects, especially during the early incubation period. At the end of incubation, repeated and continuous additions showed a higher net C accumulation than the single addition. Regardless of the glucose addition frequency, net C accumulation was lower in soils with aged or fresh biochar than in the control. In summary, biochar amendment has an interactive effect with glucose addition frequency and thus affects the direction and magnitude of priming. Despite the direct contribution of biochar to C sequestration in soil, the low net C accumulation from glucose in the biochar-amended soil highlights the necessity of C balance accounting.

The effect of pelleting onin siturumen degradability of compound feed containing brown rice for dairy cows

This study was conducted to determine the effect of pelleting on in situ dry matter degradability of pelleted compound feed containing brown rice for dairy cows. Mash feed of the same composition was used as a control and the in situ study was conducted using three non-lactating Holstein steers fitted with a rumen cannula. The feeds contained 32.3% brown rice, 19.4% rapeseed meal, 11.4% wheat bran and 10.6% soybean meal (fresh weight basis). Except for moisture content, the chemical composition of the feed was not affected by pelleting. In situ dry matter disappearance of the feed increased from 0 to 2 h and after 72 h of incubation with pellet processing. Integration of the dry matter disappearance values over time revealed that degradability parameter a (soluble fraction) increased with pellet processing, whereas parameter b (potentially degradable fraction) decreased. Parameter c (fractional rate of degradation) and effective degradability (5% passage rate) were not affected by pellet processing. We concluded that pellet processing promotes rumen degradability at early incubation hours when the pelleted feed contains brown rice.