Later Stages Of Maturation Research Articles

Adaptive Coping Mediates the Relation Between Mothers’ and Daughters’ Depressive Symptoms: A Moderated Mediation Study

Maternal depression is associated with an increased risk for depression in offspring; the factors explaining this association, however, are unclear. We examined coping in a group of 9- to 14-year-old daughters of mothers with and without a history of major depressive disorders. We tested whether daughters’ adaptive coping mediated the association between mothers’ and daughters’ depressive symptoms, and whether these relations were moderated by daughters’ pubertal status. Using moderated mediation analyses, higher levels of maternal depressive symptoms were related to less adaptive coping in daughters, which was related to higher levels of daughters’ depressive symptoms. The mediating effect of coping was evident only for daughters in late stages of pubertal maturation. Early interventions aimed at strengthening coping in girls may have a protective effect on daughters’ risk for depression at later pubertal stages.

Hydrocarbon source potential of Eocene-Miocene sequence of Western Sabah, Malaysia

An evaluation of the petroleum generating potential of onshore Eocene-Miocene sequences of Western Sabah, Malaysia was performed based on organic petrological and geochemical methods. The sequences analysed are the Belait, Meligan, Temburong and West Crocker formations of western Sabah. The Belait Formation which is Stage IV equivalent in the offshore represents one of the major source rock/reservoirs of the petroleum-bearing Sabah Basin. The Eocene-Early Miocene West Crocker and Temburong formations are deepwater turbidites whilst the Miocene Meligan and Belait formations are shallow marine fluvio-deltaic deposits. The vitrinite reflectance and pyrolysis Tmax values show that the Belait samples are generally immature for hydrocarbon generation, whereas the Meligan, Temburong and West Crocker samples are in the mature to late maturity stage of hydrocarbon generation. The overall bulk source rock properties of the Belait and Meligan show fair to good petroleum source rock potential with TOC more than 1 wt %, hydrocarbon yield in the range of 400–1300 ppm and moderately high HI for many of the samples. Most of the samples representing the Temburong and West Crocker formations have TOC less than 1 wt% and have no to fair hydrocarbon generating potential. Interestingly, the samples collected in the West Crocker Formation characterized by slump deposits (MTD) have TOC>2 and possess good to excellent hydrocarbon generating potential. The organic matter present in all of the studied formations is mainly of terrigenous origin based on the abundance of woody plant materials observed under the microscope. Consequently, the analysed sequences are predominantly gas prone, dominated by Type III and Type III-IV kerogen except for minor occurrence of mixed oil-gas prone Type II-III kerogen in the Belait Formation and in the slump mass transport deposits (MTD) of the West Crocker Formation.

Provenance and paleoenvironment of organic matter within the Fika sediments in Chad (Bornu) Basin, northeastern Nigeria: An integrated organic geochemical and palynofacies approach

The Upper Cretaceous Fika sediments in the Chad (Bornu) Basin were characterised to define paleoenvironment and source of the organic matter, using an integration of organic geochemical analyses and palynofacies observations. The present-day TOC contents of the Fika sediments are in the range of 0.41–2.37wt%, while the Hydrogen Index (HI) values are largely below 200mgHC/g TOC, suggesting that the sediments generally have fair to good generative potential and contain mainly Type III and Type IV kerogens. This is supported by palynofacies observations whereby the kerogen is characterised by large amounts AOM and phytoclasts. The Fika sediments have vitrinite reflectance and Tmax values in the range of 0.70–1.34% and 429–465°C, respectively, indicating early-mature to late-mature stage of oil-window. The level of organic maturation in Fika sediments was further supported by the several biomarker maturity indicators.Biomarker distributions and palynofacies data provide evidence for a mixed aquatic algae and terrigenous organic matter input deposited in a marginally marine, moderate salinity, proximal setting with a strong influx of terrestrial plant under environmental conditions that were mostly suboxic. Compound specific isotopic analysis of n-alkanes fraction were also used for the paleoenvironmental inferences. The flat portion pattern of the n-alkane profile between n-C21 and n-C26 in Fika samples is an indication of marine environment and it shows that Fika sediments consist of both terrestrial and marine organic matter deposited in fluvial/deltaic to shallow marine settings.

Mammalian enamel maturation: Crystallographic changes prior to tooth eruption.

Using the distal molar of a minipig as a model, we studied changes in the microstructural characteristics of apatite crystallites during enamel maturation (16-23 months of postnatal age), and their effects upon the mechanical properties of the enamel coat. The slow rate of tooth development in a pig model enabled us to reveal essential heterochronies in particular components of the maturation process. The maturation changes began along the enamel-dentine junction (EDJ) of the trigonid, spreading subsequently to the outer layers of the enamel coat to appear at the surface zone with a 2-month delay. Correspondingly, at the distal part of the tooth the timing of maturation processes is delayed by 3-5 month compared to the mesial part of the tooth. The early stage of enamel maturation (16-20 months), when the enamel coat is composed almost exclusively of radial prismatic enamel, is characterized by a gradual increase in crystallite thickness (by a mean monthly increment of 3.8 nm); and an increase in the prism width and thickness of crystals composed of elementary crystallites. The late stage of maturation (the last two months prior to tooth eruption), marked with the rapid appearance of the interprismatic matrix (IPM) during which the crystals densely infill spaces between prisms, is characterized by an abrupt decrease in microstrain and abrupt changes in the micromechanical properties of the enamel: a rapid increase in its ability to resist long-term load and its considerable hardening. The results suggest that in terms of crystallization dynamics the processes characterizing the early and late stage of mammalian enamel maturation represent distinct entities. In regards to common features with enamel formation in the tribosphenic molar we argue that the separation of these processes could be a common apomorphy of mammalian amelogenetic dynamics in general.

Bone Mineral Density, Mechanical, Microstructural Properties and Mineral Content of the Femur in Growing Rats Fed with Cactus Opuntia ficus indica (L.) Mill. (Cactaceae) Cladodes as Calcium Source in Diet.

Mechanical, microstructural properties, mineral content and bone mineral density (BMD) of the femur were evaluated in growing rats fed with Opuntia ficus indica (L.) Mill. (Cactaceae) cladodes at different maturity stages as calcium source. Male weanling rats were fed with cladodes at early maturity stage (25 and 60 days of age, belonging to groups N-60 and N-200, respectively) and cladodes at late maturity stage (100 and 135 days of age, belonging to groups N-400 and N-600, respectively) for 6 weeks. Additionally, a control group fed with calcium carbonate as calcium source was included for comparative purposes. All diets were fitted to the same calcium content (5 g/kg diet). The failure load of femurs was significantly lower (p ≤ 0.05) in groups N-60 and N-200 in comparison to N-400, N-600 and control groups. The cortical width (Ct.Wi) and trabecular thickness (Tb.Th) of the femurs in control and N-600 groups were significantly higher (p ≤ 0.05) than Ct.Wi and Tb.Th of femurs in groups N-60 and N-200. Trabecular separation of the femurs in N-60 and N-200 groups showed the highest values compared with all experimental groups. The highest calcium content in the femurs were observed in control, N-600 and N-400 groups; whereas the lowest phosphorus content in the bones were detected in N-200, N-600 and N-400 groups. Finally, the BMD in all experimental groups increased with age; nevertheless, the highest values were observed in N-600 and control groups during pubertal and adolescence stages. The results derived from this research demonstrate, for the first time, that the calcium found in Opuntia ficus indica cladodes is actually bioavailable and capable of improving mineral density and mechanical and microstructural properties of the bones. These findings suggest that the consumption of cladodes at late maturity stage within the diet might have a beneficial impact on bone health.

Structural snapshot of cytoplasmic pre-60S ribosomal particles bound by Nmd3, Lsg1, Tif6 and Reh1.

A key step in ribosome biogenesis is the nuclear export of pre-ribosomal particles. Nmd3, a highly conserved protein in eukaryotes, is a specific adaptor required for the export of pre-60S particles. Here we used cryo-electron microscopy (cryo-EM) to characterize Saccharomyces cerevisiae pre-60S particles purified with epitope-tagged Nmd3. Our structural analysis indicates that these particles belong to a specific late stage of cytoplasmic pre-60S maturation in which ribosomal proteins uL16, uL10, uL11, eL40 and eL41 are deficient, but ribosome assembly factors Nmd3, Lsg1, Tif6 and Reh1 are present. Nmd3 and Lsg1 are located near the peptidyl-transferase center (PTC). In particular, Nmd3 recognizes the PTC in its near-mature conformation. In contrast, Reh1 is anchored to the exit of the polypeptide tunnel, with its C terminus inserted into the tunnel. These findings pinpoint a structural checkpoint role for Nmd3 in PTC assembly, and provide information about functional and mechanistic roles of these assembly factors in the maturation of the 60S ribosomal subunit.

成熟後期でのアブシジン酸含有肥料処理によるブドウ ‘安芸クイーン’ および ‘ルビーロマン’ の着色特性の差異

無核栽培における四倍体の赤色系ブドウ品種‘安芸クイーン’および‘ルビーロマン’に対する成熟後期（ベレゾーン25～40日後）でのABA含有肥料処理が着色と果実品質へ及ぼす影響を調査した．本処理がベレゾーン期処理の際に生じる深色化，糖度の低下を発生させずにアントシアニン蓄積を増加させたことから，成熟後期におけるABA含有肥料処理の着色促進効果の有効性が確認された．本処理による着色促進効果は‘ルビーロマン’と比べ‘安芸クイーン’でより顕著に現れた．アントシアニンの蓄積およびその生合成に関わる転写調節因子VlMybA1-2およびVlMybA1-3と生合成酵素UFGTの遺伝子発現パターンを経時的に調査したところ，品種間差異がみられた．すなわち，‘ルビーロマン’は，‘安芸クイーン’と比較してこれらの遺伝子発現が成熟後期において高く推移しておりアントシアニンをより蓄積しやすい品種であることが示唆された．

Analysis of Sugarcane Juice Quality Indexes

The analysis of the quality indexes of sugarcane juice plays a vital role in the process of refining sugarcane, breeding, cultivation, and production management. The paper analyzes the dynamic laws of five quality indexes (i.e., brix, purity, polarization, sucrose content, and reducing sugar) combined with graphs over time along the course of crushing season (December–March) in Guangxi province of China. During this time, the sugarcane is in the mature stage and hypermature stage. At the beginning of December to early January, during which sugarcane is in the later stage of maturity, the nutrients are accumulating, causing brix, purity, polarization, and sucrose content increase. At the beginning of January to mid-February, due to low temperature and insufficient light, it is not conducive to accumulation of nutrients. However, there is the so-called “sugar back” phenomenon and reducing sugar rises gradually in March, leading to deterioration of the quality of sugarcane juice. The results show that timely harvest of sugarcane is beneficial for sugar making. The regression analysis results show that some of quality indexes have strong correlation between them and the regression models are extremely significant, indicating that the prediction results are ideal.

Hemangioblast, hemogenic endothelium, and primitive versus definitive hematopoiesis.

The types of progenitors generated during the successive stages of embryonic blood development are now fairly well characterized. The terminology used to describe these waves, however,can still be confusing. What is truly primitive? What is uniquely definitive? These questions become even more challenging to answer when blood progenitors are derived invitro upon the differentiation of embryonic stem cells or induced pluripotent stem cells. Similarly, the cellular origin of these blood progenitors can be controversial. Are all blood cells, including the primitive wave, derived from hemogenic endothelium? Is the hemangioblast an invitro artifact or is this mesoderm entity also present in the developing embryo? Here, we discuss the latest findings and propose some consensus relating to these controversial issues.

Productivity, chemical composition and ruminal degradability of irrigated Napier grass leaves harvested at three stages of maturity

The effect of the stage of maturity on the productivity, chemical composition, and ruminal degradability of Napier grass ( Pennisetum purpureum ) leaves under irrigation was studied. Samples were collected at three stages of maturity, at intervals of four weeks starting from the fourth week until the twelfth week (April–July) after sprouting and then harvested to determine biomass. The stages of maturity had significant effects on longest leaf length per plant and plant height, but had no effect on number of leaves per plant and number of tillers. Dry matter (DM) increased significantly with maturity, while crude protein (CP) and fat content decreased significantly, with no significant effect on acid detergent lignin (ADL), ash, acid detergent fibre (ADF) and neutral detergent fibre (NDF). Maturity significantly decreased potassium, copper and sodium, while calcium and zinc increased significantly up to the intermediate stage, then declined toward the late stage of maturity. Maturity did not affect the magnesium, phosphorus, manganese and iron contents of the forage. Ruminal degradability of CP at 48, 72, 96 and 120 incubation hour decreased significantly with maturity, with no effect on all other incubation times for DM and CP. Maturity significantly decreased the soluble fraction (a) of DM, with no significant effect on other fractions of DM and CP. Effective degradability (%) of DM and CP decreased with maturity when the rate of passage increased from 2% to 8%. Napier forage should be harvested before maturity to retain its high nutrient content, and the degradability of DM and CP. Keywords: mineral composition, in sacco, dry matter, crude protein disappearance

Stat5 and Stat3 Differentially Regulate Early and Late Stages of Primary Embryonic Erythroid Cell Maturation

Erythropoietin is the critical regulator of adult (definitive) red cell production, acting through its cognate receptor (EpoR) and downstream Janus kinase (Jak)2 and signal transducer and activator of transcription (Stat)5 signaling. Mutant JAK2 activation causes hyperproliferation of erythroid precursors in polycythemia vera, highlighting the importance of Jak2-STAT signaling in pathologic states in addition to normal development. EpoR-null mouse embryos die at midgestation of profound anemia and we have recently determined that EpoR signaling is also specifically required for the survival and terminal maturation of primitive erythroblasts. Unlike definitive erythropoiesis, Stat3 is significantly expressed in primitive erythroblasts but its function in erythropoiesis remains poorly understood. We find that Stat3, in addition to Stat5, is phosphorylated downstream of EpoR in primitive erythroblasts. Interestingly, phospho-Stat5 intensity decreases during primitive erythroblast maturation while phospho-Stat3 levels remain constant, resulting in an increase in relative phospho-Stat3 in late-stage primitive erythroblasts. Knockdown of Jak2 and Stat5 each results in accelerated maturation, decreased cell size, and increased apoptosis of primary primitive erythroblasts. In contrast, Stat3 knockdown results in delayed maturation and increased cell size of late-stage primary primitive erythroblasts, consistent with an increased role of phospho-Stat3 once phospho-Stat5 signal intensity has diminished. Stat3 knockdown, both in vitro and in vivo, also increased apoptosis of late-stage primitive erythroblasts. While Stat3 and Stat5 bind many apoptosis-related genes in common, Stat3 specifically binds several caspase genes and their regulators. We find that activated caspase3 levels increase in late-stage primitive erythroblasts, and that knockdown of Stat3 results in decreased levels of caspases and their regulators. In addition, caspase inhibition, like Stat3 knockdown, results in delayed maturation of late-stage primitive erythroblasts. Taken together, our data support a model where Stat3 and Stat5 differentially regulate erythroid maturation and Stat3 preferentially regulates terminal stages of primitive erythropoiesis through its activation and regulation of apoptotic machinery. Disclosures No relevant conflicts of interest to declare.

Phagocytosis: Hungry, Hungry Cells.

Phagocytosis is the cellular internalization and sequestration of particulate matter into a `phagosome, which then matures into a phagolysosome. The phagolysosome then offers a specialized acidic and hydrolytic milieu that ultimately degrades the engulfed particle. In multicellular organisms, phagocytosis and phagosome maturation play two key physiological roles. First, phagocytic cells have an important function in tissue remodeling and homeostasis by eliminating apoptotic bodies, senescent cells and cell fragments. Second, phagocytosis is a critical weapon of the immune system, whereby cells like macrophages and neutrophils hunt and engulf a variety of pathogens and foreign particles. Not surprisingly, pathogens have evolved mechanisms to either block or alter phagocytosis and phagosome maturation, ultimately usurping the cellular machinery for their own survival. Here, we review past and recent discoveries that highlight how phagocytes recognize target particles, key signals that emanate after phagocyte-particle engagement, and how these signals help modulate actin-dependent remodeling of the plasma membrane that culminates in the release of the phagosome. We then explore processes related to early and late stages of phagosome maturation, which requires fusion with endosomes and lysosomes. We end this review by acknowledging that little is known about phagosome fission and even less is known about how phagosomes are resolved after particle digestion.

Application of rice microspore-preferred promoters to manipulate early pollen development in Arabidopsis: a heterologous system.

Rice microspore-promoters. Based on microarray data analyzed for developing anthers and pollen grains, we identified nine rice microspore-preferred (RMP) genes, designated RMP1 through RMP9. To extend their biotechnological applicability, we then investigated the activity of RMP promoters originating from monocotyledonous rice in a heterologous system of dicotyledonous Arabidopsis. Expression of GUS was significantly induced in transgenic plants from the microspore to the mature pollen stages and was driven by the RMP1, RMP3, RMP4, RMP5, and RMP9 promoters. We found it interesting that, whereas RMP2 and RMP6 directed GUS expression in microspore at the early unicellular and bicellular stages, RMP7 and RMP8 seemed to be expressed at the late tricellular and mature pollen stages. Moreover, GUS was expressed in seven promoters, RMP3 through RMP9, during the seedling stage, in immature leaves, cotyledons, and roots. To confirm microspore-specific expression, we used complementation analysis with an Arabidopsis male-specific gametophytic mutant, sidecar pollen-2 (scp-2), to verify the activity of three promoters. That mutant shows defects in microspore development prior to pollen mitosis I. These results provide strong evidence that the SIDECAR POLLEN gene, driven by RMP promoters, successfully complements the scp-2 mutation, and they strongly suggest that these promoters can potentially be applied for manipulating the expression of target genes at the microspore stage in various species.

Novel hydrolytic extremely halotolerant alkaliphiles from mature landfill leachate with key involvement in maturation process

ABSTRACTMature landfill leachate is a heavily-polluted wastewater due to its recalcitrant nature of organic matter, and high ammonia and salt content. Despite the moderate saline and alkaline nature of this habitat, no attention has been paid to the isolation and functional role of extremophiles in such environment. In this work, a total of 73 and 29 bacterial strains were isolated by using alkaline and saline media, respectively, while bacteria from mature landfill leachate growing in these media were enumerated as 1.5 ± 0.1 (×108) and 5.8 ± 0.9 (×108) cfu/L. Based on their pH and salt ranges and optima for growth, all bacterial isolates were halotolerant alkaliphiles (either facultative or obligate), with the majority of them being extremely halotolerant bacteria. These halotolerant alkaliphiles were classified into 14 operational taxonomic units (OTUs). Of these, 12 are placed within known halophilic and alkaliphilic species of the genera Dietzia, Glycocaulis, Halomonas, Marinobacter, Piscibacillus and Rhodobacter, while the remaining OTUs represented two novel phylogenetic linkages among the families Cyclobacteriaceae and Rhodobacteraceae. Examination of their hydrolytic ability through the performance of lipase, protease and β-glucosidase assays using landfill leachate as the growth substrate revealed that all halotolerant alkaliphiles isolated exhibited extremely high lipolytic activities (up to 78,800 U g−1 protein), indicating a key involvement of extremophilic microbiota at the late landfill maturation stage. The wide extremely lipolytic halotolerant alkaliphilic community identified also makes mature landfill leachate an ideal microbial pool for the isolation of novel extremophiles of biotechnological interest.

NMR metabolomics demonstrates phenotypic plasticity of sea buckthorn (Hippophaë rhamnoides) berries with respect to growth conditions in Finland and Canada.

The berries of sea buckthorn (Hippophaë rhamnoides ssp. rhamnoides) cultivars 'Terhi' and 'Tytti' were studied with respect to their growth location, 60° and 68°N latitude in Finland and 46°N in Canada, using 1H NMR metabolomics. The berries of 'Terhi' were characterised by stronger signals of quinic acid, while 'Tytti' had higher levels of O-ethyl β-d-glucopyranoside. The metabolic profile of the northernmost berries was distinctly different from those grown in southern Finland or Canada. Berries from northern Finland had relatively higher levels of quinic acid, glucose, l-quebrachitol and ascorbic acid. Ethyl glucoside was shown to accumulate by several fold at the late stage of maturation in the south as it correlated with degree days (r=0.63) and global radiation (r=0.59), but not in the north. The variance in the composition of the sea buckthorn berries demonstrates plasticity in the acclimatisation to growth environments.

The Contents of Ustiloxins A and B along with Their Distribution in Rice False Smut Balls

Ustiloxins are cyclopeptide mycotoxins isolated from rice false smut balls (FSBs), the ball-like colonies transformed from the individual grains through the filament infection by the fungal pathogen Villosiclava virens. There were no obvious relations between ustiloxin content and any of the collection areas, collection times, or average weight of each FSB. The rice false smut balls at early, middle, and late maturity stages were respectively divided into different parts (glume, chlamydospores, mycelia, and pseudoparenchyma). The highest content of ustiloxins A and B of rice FSBs was found at the early maturity stage. Both ustiloxins A and B were mainly distributed in the middle layer containing mycelia and immature chlamydospores of the FSBs. When the rice FSBs were at the early maturity stage, the total yield of ustiloxins A and B in the middle layer of each ball was 48.3 µg, which was 3.20-fold of the yield (15.1 µg) of the inner part of the ball. The rice FSBs at the early maturity stage are the appropriate materials for the production of ustiloxins A and B.

Evolution of cherries texture in brine: Impact of harvest conditions during long-time storage

Texture is a primary quality attribute of brined sweet cherries (Prunus avium L.) and its preservation is a major objective for candying industry. In order to identify the harvest factors influencing textural changes during long period brine storage, different itineraries were applied: harvest at two different maturity stages, treatment or not with ethephon, manual or mechanical harvest, removal or not of peduncles. The cherries were immersed in brine and examined over a 12-months period for firmness, calcium and total soluble solids diffusion and cytohistological remodelling. Mechanical harvesting, harvest at late maturity stage and storage with peduncle decreased firmness while ethephon treatment had no effect. However, only presence or absence of peduncles influenced salt and total soluble solids diffusion, suggesting that peduncle removal promotes osmotic exchanges.Brine storage led to a texture gain in the first two months in most cases compared to fresh cherries, as confirmed by a beneficial reshuffle at cytohistological level. This explains why it can allow storage of cherries for candying over the whole duration between two harvest seasons.

Sunflower seed yield estimation under the interaction of soil salinity and nitrogen application

Understanding the interaction effects of salinity and fertilizer is of great economic and environmental importance for improving crop yield and fertilizer used efficiency. The present study established a sunflower seed yield prediction model for saline soils directly from soil salinity (S) and nitrogen application (N) and related the results to the optimum N rate in saline soils. Two years of field trial data on sunflower growth under different S levels and N rates were collected at the Yichang Experimental Station in the Hetao Irrigation District of Inner Mongolia, China. Statistical techniques, including bootstrap resampling and artificial neural network (ANN) analysis, were used for data analysis and model establishment. The results indicated that sunflower crop characteristics varied in relation to S and N rates. The changes in plant height (H) with time before the late mature stage could be fitted with a linear function under different S and N treatments. Furthermore, the leaf area index (LAI) varied from the day after sowing and was expressed using a quadratic polynomial. The salt tolerance threshold (ECth) values for sunflower at the seedling, bud, flowering, and mature stages were 6.93, 14.46, 14.46, and 17.26dSm−1, respectively. When S was smaller than ECth, relative evapotranspiration (RET) fluctuated with S and was estimated using an artificial neural network (ANN); moreover, when S was larger than ECth, RET decreased with S and was simulated using linear regression. In addition, effective nitrogen application (ENA) was determined coupled with S, and the positive and negative effects of ENA on RET were expressed as a quadratic polynomial. The sunflower seed yield was estimated using a modified Jensen model (SNJ model) (R2=0.51). The maximum relative seed yield (MRSY) decreased rapidly with soil salinity until 12dSm−1; when the soil salinity level was below 18dSm−1, the optimal N application rate fluctuated from 100 to 160kgha−1.

Myostatin in black Muscovy duck (Cairina moschata): full-length cDNA cloning and age-dependent mRNA expression compared with IGF-I

Insulin-like growth factor-I (IGF-I) and myostatin (MSTN) are a pair of critical positive and negative growth regulators. The aim of the current study was to examine the age-dependent and muscle-specific expression of IGF-I and MSTN mRNAs in black Muscovy ducks in order to understand their roles in regulating the postnatal muscle growth of domestic ducks.The full-length cDNA of the black Muscovy duck MSTN gene was cloned and the age-dependent mRNA expression profile was compared with that of the IGF-I mRNA in skeletal muscles.The cDNA sequence of the MSTN gene was 1128 bp in length and encodes 375 amino acids, with more than 94.9% homology with poultry MSTN genes, and 83.0–92.0% homology with that of human and mammals (accession: KR006339.1).The IGF-I and MSTN mRNA expression exhibited opposite trends in age-dependency and in different muscles: IGF-I mRNA level was high in the early postnatal stage and low in the late mature stage, corresponding positively to growth; while the MSTN mRNA was low in the early stage, increased gradually and reached the highest level in mature muscles, and was negatively related to muscle growth. In the breast muscles, IGF-I mRNA was much higher than in the leg muscles; the opposite effect was seen in MSTN mRNA.These data suggest that the relative expression levels of IGF-I and MSTN are essential determinants in the temporal and muscle-specific regulation of postnatal skeletal muscle growth in Muscovy duck and possibly in other poultry species as well.

Septin/anillin filaments scaffold central nervous system myelin to accelerate nerve conduction.

Myelination of axons facilitates rapid impulse propagation in the nervous system. The axon/myelin-unit becomes impaired in myelin-related disorders and upon normal aging. However, the molecular cause of many pathological features, including the frequently observed myelin outfoldings, remained unknown. Using label-free quantitative proteomics, we find that the presence of myelin outfoldings correlates with a loss of cytoskeletal septins in myelin. Regulated by phosphatidylinositol-(4,5)-bisphosphate (PI(4,5)P2)-levels, myelin septins (SEPT2/SEPT4/SEPT7/SEPT8) and the PI(4,5)P2-adaptor anillin form previously unrecognized filaments that extend longitudinally along myelinated axons. By confocal microscopy and immunogold-electron microscopy, these filaments are localized to the non-compacted adaxonal myelin compartment. Genetic disruption of these filaments in Sept8-mutant mice causes myelin outfoldings as a very specific neuropathology. Septin filaments thus serve an important function in scaffolding the axon/myelin-unit, evidently a late stage of myelin maturation. We propose that pathological or aging-associated diminishment of the septin/anillin-scaffold causes myelin outfoldings that impair the normal nerve conduction velocity.