表型可塑性变异的生态-发育机制及其进化意义

表型可塑性赋予生物个体在不同环境条件下通过产生不同表型来维持其适合度的能力。研究结果显示多数可塑性变异的产生是基于对环境变异信号的响应、改变基因表达式样并调整发育轨迹的结果,表观遗传调控体系在基因选择性表达和可塑性变异的跨世代传递过程中发挥了重要作用。不同物种和种群对环境变化的敏感性、发生可塑性变异的能力以及可塑性反应模式不尽相同,预示着控制可塑性能力并独立于控制性状的可塑性基因的存在,这些基因是直接响应环境信号并控制表型表达的调控基因。表型可塑性不仅是物种适应性进化的一个重要方面,也是选择进化的产物,物种的表型可塑性变异对其生态适应和进化模式有深远的影响。

The View of Educational Purpose under the Infiltration of Post-modernism

Some of the characteristics of post-modernism, such as opposition centers, denial of holism, identity, differences and uncertainties, have had a great impact on the view of education. Because the purpose of education is the starting point and end-result of education, which is related to the general orientation of education development, we have to re-examine the concept of modem educational purpose in the post-modernism thought. The author holds that compared with the modem education view, the educational purpose view of the post-modem period shows the following characteristics： Maintaining the diversification and difference of individuahty, paying attention to cultivating social consciousness and critical ability, learning to understand and respect ecological harmony.

Association of Polymorphisms of Leptin Gene with Body Weight and Body Sizes Indexes in Chinese Indigenous Cattle

PCR-SSCP was used to analyze the polymorphism of leptin gene in 539 samples of six cattle breeds, namely Nanyang （NY）, Qinchuan （QC）, Jiaxianred （JXR）, Xizhen （XZ）, Luxi （LX）, and Holstein cow （HOL） breeds. PCR products with a 330 bp were amplified and sequenced. The results showed that the frequencies of alleles A/B of NY, QC, JXR, XZ, LX, and HOL breeds were 0.558/0.442, 0.492/0.508, 0.571/0.429, 0.658/0.342, 0.591/0.409, and 0.615/0.385, respectively. The association of variations of leptin gene with growth traits in NY, QC, JXR breeds was analyzed. Some indexes of the individuals with genotype BB were higher than that with genotype AA and AB in NY breed, such as the indexes of body length, heart length, body weight, hucklebone width, body height, and average day gain. The height at hip cross of the individuals with genotype BB was higher than that of those with genotype AA and AB in QC breed （P 〈 0.05）. So leptin gene may be one of the candidate genes for growth traits with height at hip cross, but not for body weight, heart length, and body length trait. However, the height at hip cross and hucklebone width of the individuals with genotype AB and BB were higher than that of those with genotype AA in JXR breed （P 〈 0.05）, but the difference was not statistically significant in body weight and body sizes （body height, body length, and heart length）. And the polymorphisms in leptin gene were caused by G→T transversion at the 66th bp position, A→C transversion at the 67th bp position and G→T transversion at the 299th bp position. These results may be applied to marker-assisted selection of Chinese cattle breeds.

Dynamic Characteristics of Growth and Development of Xiangsha Taro in Jingjiang

The growth and development of Jingjiang Taro [Colocasia esculenta（L.） Schott] were observed, laying foundation for highly-yielding cultivation technology system of Xiangsha taro. The results indicate that germination of the second taro happened from 46 d after sprouting （7-8 leaves）; the first taro began to expand, from 125 d after sprouting （12 leaves） when the the second taro was been formed; the third taro began to form from 141 to 150 d after sprouting （15-16 leaves）. The fresh weight of the second and third taros quickly increased from the time of 15 leaves to harvest. Early September is a transformation term of Xiangsha taro from vegetative body dominant to corm growth dominant.

Ontogenetic Changes in Meristic Measurements of Silver Carp and Bighead Carp

The study analyzed 30 exterior meristic characters for 255 silver and bighead carp samples of 1- to 5-year-old collected from the National Primary Breeding Farm at Laojianghe Lake at the Middle Reach of the Yangtze River. Multivariate analysis was performed. In silver carp, the Euclidean distance was the greatest between the 1-year-old group and other age groups. Silver carp individuals were correctly classified at 98.0% accuracy with a discriminant function established by discriminant analysis based on meristic measurements. Similarly, bighead carp had the greatest distance between 1- to 2-year-old group and other age groups. Individuals of bighead carp were correctly classified at 90.7% accuracy by the discrimination function. The data showed that morphological transformation occurred during the life history of silver and bighead carp development. Eighteen meristic measurements showed highly significant differences, while four showed a significant difference between the two silver carp groups. Ten parameters decreased, while twelve measurements increased during development. In bighead carp, fourteen parameters were significantly different, while three parameters were significantly different between the two groups. Twelve parameters were significantly decreased and another five were increased during development. The results suggest allometric growth should be taken into account when identifying species, analyzing population differences and establishing germplasm standards based on morphology.

Effects of Light Intensity on Growth, Development and Formation on Fagopyrum cymosum

Effects of light intensity on growth, development and formation on Fagopy- rum cymosum were explored with natural light intensities at 100%（A）, 85.2%（B）, 75.8%（C） and 59.7%（D）. The results showed that the decline of light intensity re- duced nutrient growth period, so that plant growth stage entered in advance and extended, which indicated that the decline of light intensity would lower leaf number and area, the number of twigs from the stem, as well as photosynthate. Further- more, the reduction degree increased upon light intensity decrease degree, and the proper shading improved stem height and leaf area enhanced before growth term.

Comparative Study of Rice Morphogenesis with Different Cultivation Methods

[Objective] The aim of this study was to compare the morphological char- acteristics of rice （Oryza sativa L.） with different cultivation methods and investigate the dynamics of organ growth and development characteristics of different rice culti- vars. [Method] Based on continuous field observation and destructive sampling over a growing season, detailed organ morphological data were obtained including leaf length, node number, plant height, tiller number, leaf angle, leaf area and specific leaf weight, to compare organ morphological differences among 4 rice cultivars of Baidao （indica）, Jinnanfeng （japonica）, 9325 （japonica） and 9915 （japonica） with 3 cultivation methods of field planting in Weigang, pot planting in Weigang, and field planting in Jiangpu. [Result] Maximum leaf length of each node gradually increased at the early growth stage and decreased at the later growth stage, the relationship between maximum leaf length and node position can be described by the equations y=a,,-~ and y=ax＋b; node number, growth duration, leaf length and plant height of pot planting rice in Weigang were smaller than that of the other two field planting meth- ods; the relationship between plant height and sunshine duration, plant height and GDD （growing degree days） can be described by the equation y=ax＋b, 19.23 ℃.d of GDD （≥10 ≥-d） and 8.12 h of sunshine duration were required to increase 1 cm of plant height; plant height, tiller number, and leaf area of Baidao were higher than that of the other 3 laponica rice cultivars, but the specific leaf weight and leaf angle were smaller. [Conclusion] Comparison of morphological characteristic differ- ences among rice cultivars is an important way to select water-saving and drought- tolerant rice varieties. In this study, the experimental results can be integrated into a rice functional-architectural model to simulate rice organ growth dynamics in a three- dimensional space, thereby providing reference for selecting water-saving and drought-tolerant rice cultivars.

Developmental ecology of the American horseshoe crab Limulus polyphemus

During spawning events, horseshoe crab eggs are released from the female＇s oviducts, and fertilized by one or more males. Eggs are shaped by the female into discrete clutches deposited in nests at depths of 10-20 cm on intertidal estuarine beaches. Distinguishing between fxesh eggs and the early developmental stages is obfuscated by the large amount of dense, opaque yolk. The first unambiguous confirmation of development is the formation of the rudimentary prosomatie appendages at the ＂limb bud＂ stage. Several days thereafter, the outer chorion is shed and the developing embryo expands and undergoes a series of molts within the clear inner egg membrane. The trilobite （first iustar） stage thus attained may remain within the beach sedi- ments for several more weeks, until hatching is facilitated by environmental factors such as hydration, agitation, and osmotic shock that accompany the infiltration of seawater into the nests. Trilobites exhibit endogenous eirgatidal swimming rhythms that are entrained by mechanical agitation, suggesting that peaks in larval swimming are timed to coincide with periods of high water and the inundation of the nests. Larval swimming is limited and does not appear to result in long-distance dispersal. The limited dispersal of the larvae has important implications for the population dynamics of relatively isolated populations. The rate of larval development is highly plastic and is influenced by temperature, salinity, dissolved oxygen, and the presence of pollutants. The broad environmental tolerances of horseshoe crab embryos and larvae are important in understanding their current geographic distribution and their evolutionary persistence

Posterior gut development in Drosophila:a model system for identifying genes controlling epithelial morphogenesis

The posterior gut of the Drosophila embryo, consisting of hindgut and Malpighian tubules, provides a simple,well-defined system where it is possible to use a genetic approach to define components essential for epithelial morphogenesis.We review here the advantages of Drosophila as a model genetic organism, the morphogenesis of the epithelial structures of the posterior gut, and what is known about the genetic requirements to form these structures.In overview, primordia are patterned by expression of hierarchies of transcription factors; this leads to localized expression of cell signaling molecules, and finally, to the least understood step: modulation of cell adhesion and cell shape. We describe approaches to identify additional genes that are required for morphogenesis of these simple epithelia, particularly those that might play a structural role by affecting cell adhesion and cell shape.

Feeding ecology of hairtail Trichiurus margarites and largehead hairtail Trichiurus lepturus in the Beibu Gulf, the South China Sea

We evaluated the feeding ecology of largehead hairtail (Trichiurus lepturus) and hairtail (T. margarites). We collected specimens from fishing ports in the Beibu Gulf (Gulf of Tonkin) from October 2008 to September 2009 and analyzed their gut contents. We collected 857 T. lepturus and 666 T. margarites samples. The number of stomachs examined in this study was sufficient to describe the monthly and ontogenetic diet shifts for the two species, as indicated by the trophic diversity curves. T. lepturus was a general omnivore, feeding primarily on Bregmaceros rarisquamosu, Decapterus maruadsi, and Acetes chinensis. Conversely, T. margarites preyed primarily on D. maruadsi, B. rarisquamosus, B. nectabanus, and A. chinensis. Both species exhibited distinct ontogenetic diet shifts. Although the two hairtail specie fed on similar sources in the same habitat, the diet overlap was relatively low. Our results suggest that hairtail play an important role in controlling small pelagic and benthic fish populations in the gulf. This trophic correlation shall be used for developing a marine ecosystem model for the Beibu Gulf.

The Appearance of Ulva laetevirens(Ulvophyceae, Chlorophyta) in the Northeast Coast of the United States of America

Introduced species may outcompete or hybridize with native species, resulting in the loss of native biodiversity or even alteration of ecosystem processes. In this study, we reported an alien distromatic Ulva species, which was found in an embayment(Holly Pond) connected with Long Island Sound, USA. The morphological and anatomical observations in combination with molecular data were used for its identification to species. Anatomy of collected specimens showed that the cell shape in rhizoidal and basal regions was round and the marginal teeth along the basal and median region were not found. These characteristics were primarily identical to the diagnostic characteristics of Ulva laetevirens Areschoug(Chlorophyta). The plastid-encoding tufA and nucleus-encoding ITS1 were used for its molecular identification. Phylogenetic analysis for the tufA gene placed the specimens from Holly Pond in a well-supported clade along with published sequences of U. laetevirens identified early without any sequence divergence. In ITS tree, the sample also formed well-supported clades with the sequences of U. laetevirens with an estimated sequence divergence among the taxa in these clades as low as 1%. These findings confirmed the morpho-anatomical conclusion. Native to Australia, this species was reported in several countries along the Mediterranean coast after the late of 1990 s. This is the first time that U. laetevirens is found in the northeast coast of United States and the second record for Atlantic North America.

Morphogenesis of Oil Palm Fruit （Elaeis guineensis Jacq.） in Mesocarp and Endocarp Development

This work aims to study the development of the pericarp of the fruit of Elaeis guineensis Jacq. var. dura. The thickness, the water and the oil contents of its tissues are evaluated every two weeks, from pollination to the maturity of the fruit. The development of the oil palm fruit takes 5.5 months. The endocarp reaches its maximum thickness at the 70th DPP （day post-pollination）, with a water content of 72%. It then starts its dehydration, while sclerifying. It therefore isolates the seed at start and later protects it. The mesocarp is visible at anthesis and its water content is close to 92%. From the 100th DPP, it begins a continuous dehydration associated, from the 130th DPP, with an active lipids biosynthesis. Ultimately, the pericarp of the oil palm fruit fulfills both functions, namely to protect the seed by early sclerification of the endocarp and ensure the dissemination of the species by the high oil content of the mesocarp. A comparative anatomy of the pericarp tissues of the three genotypes.of E. guineensis Jacq., during the first three weeks of fruit development, will enhance the understanding of the primary effect of sh gene.

Structure,expression,and developmental function of early divergent forms of metalloproteinases in Hydra

Metalloproteinases have a critical role in a broad spectrum of cellular processesranging from the break-down of extracellular matrix to the processing of signaltransduction-related proteins.These hydrolytic functions underlie a variety of mechanisms related to developmental processes as well as disease states.Structural analysis of metalloproteinases from both invertebrate and vertebrate species indicates that these enzymes are highly conserved and arose early during metazoan evolution.In this regard,studies from vari-ous laboratories have reported that a number of classes of metalloproteinases are found in hydra,a member of Cnidaria,the second oldest of existing animal phyla.These studies demonstrate that the hydra genome contains at least three classes of metalloproteinases to include members of the 1)astacin class,2)matrix met-alloproteinase class,and 3)neprilysin class.Functional studies indicate that these metalloproteinases play diverse and important roles in hydra morphogenesis and cell differentiation as well as specialized functions in adult polyps.This article will review the structure,expression,and function of these metalloproteinases in hydra.

Microcosm Study： Effect of Fe（II） Addition in Sawdust for Phosphorous Recovery from Eutrophic Aquatic Ecosystems

The recovery of phosphorus in eutrophic water bodies adsorption in sawdust can be promoted by Fe（III） oxide-hydroxides is important to ensure water and food security, phosphorus biofllms. The main objective of this study was to analyze the influence of iron addition in sawdust on phosphorus adsorption. The microcosm experiment was performed with water and sediment samples from a eutrophic reservoir located in Barra Bonita/SP. Three control flasks （without bags） and 18 others as treatments （with two bags filled with sawdust, with or without previous Fe（II） addition） were assembled. The addition of iron did not promote greater phosphorus adsorption, the sawdust without previous iron addition had a total phosphorus concentration of 49μg·P·g^-1, while the sawdust with previous iron addition had 14.4μg.p.g^-1. The use of sawdust for the remediation of eutrophic water bodies is interesting, especially considering the low-cost and possibility of reuse as fertilizer in agriculture.

Dental Variation Among Asian Colobines, with Specific Reference to the Macaques on the Same Continent

In order to discern dental morphometric variations among the Asian colobines, residuals of the colobines, derived from allometric baselines formed by the Asian macaques （Macaca）, were analyzed with Principal Components Analysis and Euclidean Distances. Results indicated that the widely accepted view that the colobines possess relatively smaller front teeth than the macaques is only the case for the first incisors. The colobines show relatively smaller molars than the macaques. Such profiles may be related to the differences in dietary preferences between the two major groups of the Asian Old World monkeys. The magnitude of such differences is not as great as usullay assumed for the two groups that contain both African and Asian taxa. In other words, the two Asian cercopithecoid groups may have homogenously been shaped by the tectonic modifications and climate alterations in the past five million years. There exist marked differences among the Asian colobines when each of the genera is compared with macaques; the dental profile reflects not only the variation in geographic distribution but also in phylogenetic divergence. Thus, the snub-nosed monkeys （Rhinopithecus） and the gray langurs （Semnopithecus） are characterized by relatively larger molars than the other colobines - larger even than those of the macaques. The differences among Asian colobines, depicted by Euclidean Distances, seems to reflect the relationship of the phylogeny and evolution between colobines and cercopithecines.

Mentoring as an Interaction System, Providing Teachers＇ Readiness to Integrate Into the School Environment

The sustainable development of today＇s society can be promoted by providing the educational sustainability. The education of prospective teachers should be based on ecological approach, which ensures the ecological perspective and an opportunity for students to develop their readiness to integrate into the school environment. The main aim of the author＇s research is to substantiate mentoring as an interaction system for the facilitation of the prospective teachers＇ readiness to integrate into the school environment. The author of this paper offers the results of her theoretical research： substantiation of mentoring＇s importance in teachers＇ education, substantiation of mentors＇ roles and functions, and substantiation of ecological approach in teachers＇ education. Ecological approach in teachers＇ education facilitates the formation of friendly attitude toward a school as an educational environment. Mentoring provides the prospective teachers＇ readiness to the professional activity and ability to successful integration in various types of school environment, considering their specificity. The author applied the following research methods： experience reflection, studying, analysing, and evaluating of scientific literature.

Modeling of Organ Morphology and Biomass Dynamics in Rice

Physiological processes governing rice plant light capture and subsequent crop growth and development are intimately tied to canopy architecture. Conversely, the production and spatial orientation of organs are dependent on the underlying physiological processes. An integrated functional-architectural modeling system would allow greater refinement of intra- and inter-plant interactions, facilitate the incorporation of additional mechanistic processes, allow greater integration of processes across multiple structural scales, and improve the accuracy of predictions. The objective of this study is to quantify the physiological bases for organ morphological development of 3 rice cultivars （Banks, IR68886B, and their hybrid Banks × IR68886A）. Detailed organ morphological data were obtained through repeated field observations and destructive samplings over the growing season, including leaf length, width, area, mass, and leaf phyllochron; sheath length, diameter and mass; internode length, diameter and mass; panicle length; stem and tiller number. The result showed that the plant age （GDD, 〉 10 ℃ d） at the first full leaf initiation （node = 2） was 147.92, 154.35, 166.23 for Banks, IR68886B, and Banks × IR68886A respectively. Banks × IR68886A produced 18 nodes, while IR68886B produced 17 nodes, and Banks 16 nodes. The Specific Leaf Weight （SLW, mg cm2） was fairly constant （about 6 mg cm2） during the growing season for the 3 cultivars, and appears to slowly increase for the latter nodes. The leaf length and SLW of Banks × IR68886A was more than Banks and IR68886B. Specific internodes weight of Banks x IR68886A was higher than IR68886B ×and Banks. Growing duration for Banks × IR68886A is longer than Banks and IR68886B. Banks × IR68886A shows positive heterosis,, and the mid-parent heterosis （MPH） for panicle length was 26.74% and that for stem and tiller number was 135.00%. Results from the experiments were used to parameterize a rice functional-architectural model that simulates organ dynamics and renders organ growth in a 3-dimensional space over the rice growing season.

Correlation of expression of preprothyrotropin-releasing hormone and receptor with rat testis development

Objective To investigate the expression regulation of thyrotrophin-releasing hormone (TRH) and TRH receptor (TRH-R), and their role in the development of rat testis.Methods Oligonucleotide primers were designed from the sequences of rat hypothalamus prepro TRH (ppTRH) and pituitary TRH-R cDNA for reverse transcription polymerase chain reaction (RT-PCR). Specific fragments of ppTRH and TRH-R cDNA were cloned and sequenced. Expression plasmids containing ppTRH and TRH-R genes were then constructed, and expression was found in E.coli DH5-α. ppTRH and TRH-R mRNA in the testis was quantitated in RNA samples prepared from rats at different developmental stages by real time quantitative RT-PCR.Results The quantitative analyses demonstrated that no ppTRH and TRH mRNA could be detected at the earliest stage (day 8). ppTRH and TRH mRNA signals were detected on day 15 and increased progressively on days 20, 35, 60 and 90. Conclusion Our results suggest that rat testis could specifically express TRH and TRH-R, and the transcriptions of ppTRH and TRH-R genes in the rat testis were development-dependent. The acquirement of expressed products for ppTRH and TRH-R can be used for further research on the physiological significance of TRH and TRH-R expression in rat testis.

Testing three pipelines for 18S rDNA-based metabarcoding of soil faunal diversity

A number of basic and applied questions in ecology and environmental management require the characterization of soil and leaf litter faunal diversity. Recent advances in high-throughput sequencing of barcode-gene amplicons ('metabarcoding') have made it possible to survey biodiversity in a robust and efficient way. However, one obstacle to the widespread adoption of this technique is the need to choose amongst many candidates for bioinformatic processing of the raw sequencing data. We compare three candidate pipelines for the processing of 18S small subunit rDNA metabarcode data from solid substrates: (i) USEARCH/CROP, (ii) Denoiser/UCLUST, and (iii) OCTUPUS. The three pipelines produced reassuringly similar and highly correlated assessments of community composition that are dominated by taxa known to characterize the sampled environments. However, OCTUPUS appears to inflate phylogenetic diversity, because of higher sequence noise. We therefore recommend either the USEARCH/CROP or Denoiser/UCLUST pipelines, both of which can be run within the QIIME (Quantitative Insights Into Microbial Ecology) environment.

Archaeal viruses-novel,diverse and enigmatic

Recent research has revealed a remarkable diversity of viruses in archaeal-rich environments where spindles, spheres, fila- ments and rods are common, together with other exceptional morphotypes never recorded previously. Moreover, their dou- ble-stranded DNA genomes carry very few genes exhibiting homology to those of bacterial and eukaryal viruses. Studies on viral life cycles are still at a preliminary stage but important insights are being gained especially from microarray analyses of viral transcripts for a few model virus-host systems. Recently, evidence has been presented for some exceptional archaeal- nspecific mechanisms for extra-cellular morphological development of virions and for their cellular extrusion. Here we sum- marise some of the recent developments in this rapidly developing and exciting research area.