Animal choice behavior and the evolution of cognitive architecture

Animals process sensory information according to specific computational rules and, subsequently, form representations of their environments that form the basis for decisions and choices. The specific computational rules used by organisms will often be evolutionarily adaptive by generating higher probabilities of survival, reproduction, and resource acquisition. Experiments with enclosed colonies of bumblebees constrained to foraging on artificial flowers suggest that the bumblebee's cognitive architecture is designed to efficiently exploit floral resources from spatially structured environments given limits on memory and the neuronal processing of information. A non-linear relationship between the biomechanics of nectar extraction and rates of net energetic gain by individual bees may account for sensitivities to both the arithmetic mean and variance in reward distributions in flowers. Heuristic rules that lead to efficient resource exploitation may also lead to subjective misperception of likelihoods. Subjective probability formation may then be viewed as a problem in pattern recognition subject to specific sampling schemes and memory constraints.     

DNA分子进化研究进展

分子进化和重组技术在蛋白质体外进化工程中占据着越来越重要的地位,它可以对单一基因、质粒、代谢途径、部分甚至整个基因组进行改造,从而在较短时间内获得漫长自然进化过程无法得到的具有特定性质的基因、蛋白质甚至物种。文章通过综合概括各种DNA分子进化技术的原理、特点,并介绍这些技术的应用研究进展以及最新研究方向,促进其在提高酶活性、蛋白质产量和改善蛋白质（酶）的性能等方面广泛应用。     

Chromosomal speciation and molecular divergence--accelerated evolution in rearranged chromosomes

Humans and their closest evolutionary relatives, the chimpanzees, differ in approximately 1.24% of their genomic DNA sequences. The fraction of these changes accumulated during the speciation processes that have separated the two lineages may be of special relevance in understanding the basis of their differences. We analyzed human and chimpanzee sequence data to search for the patterns of divergence and polymorphism predicted by a theoretical model of speciation. According to the model, positively selected changes should accumulate in chromosomes that present fixed structural differences, such as inversions, between the two species. Protein evolution was more than 2.2 times faster in chromosomes that had undergone structural rearrangements compared with colinear chromosomes. Also, nucleotide variability is slightly lower in rearranged chromosomes. These patterns of divergence and polymorphism may be, at least in part, the molecular footprint of speciation events in the human and chimpanzee lineages.     

A molecular genetic classification of zooxanthellae and the evolution of animal-algal symbioses

Zooxanthellae are unicellular algae that occur as endosymbionts in many hundreds of marine invertebrate species. Because zooxanthellae have traditionally been difficult to classify, little is known about the natural history of these symbioses. Zooxanthellae were isolated from 131 individuals in 22 host taxa and characterized by the use of restriction fragment length polymorphisms (RFLPs) in nuclear genes that encode small ribosomal subunit RNA (ssRNA). Six algal RFLPs, distributed host species specifically, were detected. Individual hosts contained one algal RFLP. Zooxanthella phylogenetic relationships were estimated from 22 algal ssRNA sequences-one from each host species. Closely related algae were found in dissimilar hosts, suggesting that animal and algal lineages have maintained a flexible evolutionary relation with each other.     

Rates of evolution: effects of time and temporal scaling

Rates of morphological evolution documented in laboratory selection experiments, historical colonization events, and the fossil record are inversely related to the interval of time over which they are measured. This inverse relationship is an artifact of comparing a narrow range of morphological variation over a wide range of time intervals, and it is also a product of time averaging. Rates measured over different intervals of time must be scaled against interval length before they can be compared.     

长沙地区南瓜的小西葫芦黄花叶病毒检测及其分子进化分析

对长沙地区160份南瓜疑似病毒病样品进行小西葫芦黄花叶病毒(Zucchini yellow mosaic virus,ZYMV)检测,检出率达46.9%。为进一步明确长沙地区ZYMV分离物的分类地位和分子进化特征,克隆获得了1个长沙地区ZYMV外壳蛋白基因,与Gen Bank已报道的ZYMV外壳蛋白基因比对,并进行基因重组、系统发生、遗传差异、选择压力、种群结构和基因漂流分析。结果显示:长沙地区ZYMV外壳蛋白基因没有发生明显的重组,突变与负选择作用是其进化的主要驱动力,种群结构相对稳定,但正处于扩张的趋势中;ZYMV不同分离物外壳蛋白基因形成3个有明显地理相关性的美洲、欧洲和亚洲种群,美洲和欧洲种群与亚洲种群之间基因交流不频繁,可能受到遗传漂变的影响,而欧洲种群与亚洲种群之间基因交流较频繁。     

Cloning and molecular evolution research of porcine GAD65 gene

Glutamate decarboxylase (GAD) has been found in animal and higher plant tissues as well as in yeasts and microorganisms. In animals the enzyme plays an important role in central nervous system activity because the enzyme substrate glutamic acid is a mediator of excitation process and the product, gamma-aminobutyric acid, is the most important mediator of inhibition process in the central nervous system. GAD65 is one form of the glutamate decarboxylases (GAD), GAD65 has been identified as a major autoantigen in type 1 diabetes, so the GAD65 gene of porcine was cloned by RT-PCR method to construct phylogenetic tree, the homology of 13 glutamate decarboxylases (GAD) of different origin was analyzed by multiple alignment.     

Genome-wide identification,molecular evolution,and expression divergence of the hexokinase gene family in apple

Hexokinase(HXK) is the first irreversible catalytic enzyme in the glycolytic pathway, which not only provides energy for plant growth and development but also serves as a signaling molecule in response to environmental changes. However, the evolutionary pattern of the HXK gene family in apple remains unknown. In this study, a total of nine HXK genes were identified in the Malus×domestica genome GDDH13 v1.1. The physiological and biochemical properties, exonintron structures, conserved motifs, and cis-elements of the MdHXK genes were determined. Predicted subcellular localization indicated that the MdHXK genes were mainly distributed in the mitochondria, cytoplasm, and nucleus. Gene duplication revealed that whole-genome duplication(WGD) and segmental duplication played vital roles in MdHXK gene family expansion. The ω values of pairwise MdHXK genes indicated that this family was subjected to strong purifying selection during apple domestication. Additionally, five subfamilies were classified, and recent/old duplication events were identified based on phylogenetic tree analysis. Different evolutionary rates were estimated among the various HXK subfamilies. Moreover, divergent expression patterns of the Md HXK genes in four source-sink tissues and at five different apple fruit developmental stages indicated that they play vital roles in apple fruit development and sugar accumulation. Our study provides a theoretical basis for future elucidation of the biological functions of the MdHXK genes during apple fruit development.     

安徽省畜禽养殖业粪便成分调查及排放量估算

通过调查采样及测试分析的方法,分析了安徽省主要畜禽养殖品种粪便中的氮、磷、钾养分含量,以及Pb、Cd、Cr、Cu、Zn、Hg、As等重金属的含量,根据安徽省统计年鉴中的数据对2008年安徽省畜禽养殖业粪便总排放量进行估算,结果表明:2008年安徽省畜禽养殖业产生的粪便中纯氮、磷、钾养分的排放量分别约为113 235、58 441和80 573 t,相当于24.62万t尿素、111.59万t过磷酸钙和16.18万t氯化钾,以总氮量计算占安徽省耕地最大氮承载量的18.20%。Pb、Cd、Cr、Cu、Zn、As等重金属的产生量分别为72.59、2.30、125.97、977.96、1 123.98、32.67 t,Hg为171.41 kg,畜禽粪便长期大量施用于农田存在着一定的重金属累积超标风险。     

Contingency and determinism in replicated adaptive radiations of island lizards

The vagaries of history lead to the prediction that repeated instances of evolutionary diversification will lead to disparate outcomes even if starting conditions are similar. We tested this proposition by examining the evolutionary radiation of Anolis lizards on the four islands of the Greater Antilles. Morphometric analyses indicate that the same set of habitat specialists, termed ecomorphs, occurs on all four islands. Although these similar assemblages could result from a single evolutionary origin of each ecomorph, followed by dispersal or vicariance, phylogenetic analysis indicates that the ecomorphs originated independently on each island. Thus, adaptive radiation in similar environments can overcome historical contingencies to produce strikingly similar evolutionary outcomes.     

Animal Manure Components and Production of the Animal Husbandry in Anhul Province

通过调查采样及测试分析的方法,分析了安徽省主要畜禽养殖品种粪便中的氮、磷、钾养分含量,以及Pb、Cd、Cr、Cu、Zn、Hg、As 等重金属的含量,根据安徽省统计年鉴中的数据对2008年安徽省畜禽养殖业粪便总排放量进行估算,结果表明:2008年安徽省畜禽养殖业产生的粪便中纯氮、磷、钾养分的排放量分别约为113 235、58 441和80 573t,相当于24.62万t尿素、111.59万t过磷酸钙和16.18万t氯化钾,以总氮量计算占安徽省耕地最大氮承载量的18.20％.Pb、Cd、Cr、Cu、Zn、As等重金属的产生量分别为72.59、2.30、125.97、977.96、1 123.98、32.67 t,Hg为171.41 kg,畜禽粪便长期大量施用于农田存在着一定的重金属累积超标风险.     

Rates of molecular evolution are linked to life history in flowering plants

Variable rates of molecular evolution have been documented across the tree of life, but the cause of this observed variation within and among clades remains uncertain. In plants, it has been suggested that life history traits are correlated with the rate of molecular evolution, but previous studies have yielded conflicting results. Exceptionally large phylogenies of five major angiosperm clades demonstrate that rates of molecular evolution are consistently low in trees and shrubs, with relatively long generation times, as compared with related herbaceous plants, which generally have shorter generation times. Herbs show much higher rates of molecular change but also much higher variance in rates. Correlates of life history attributes have long been of interest to biologists, and our results demonstrate how changes in the rate of molecular evolution that are linked to life history traits can affect measurements of the tempo of evolution as well as our ability to identify and conserve biodiversity.     

乌苏里貉MC4R基因的克隆及分子进化分析

对乌苏里貉MC4R基因进行克隆测序,并与GenBank中其他物种的相应基因编码区核苷酸序列进行比较分析,采用邻接法构建貉与其他物种间分子系统进化树.结果表明,乌苏里貉MC4R基因与貉、犬、赤狐、北极狐、人、黑猩猩、牛、非洲象、猪、大鼠、小鼠在该编码区核苷酸序列上的同源性大小分别为99.7%、98.7%、98.7%、98.8%、88.9%、88.7%、88.1%、89.5%、87.4%、87.4%、86.2%,不同物种间在该基因核苷酸序列上有较高的保守性.利用MEGA生物学软件基于Mc4R核苷酸序列对20种脊椎动物进行的聚类分析结果显示,犬科动物与哺乳动物为一紧密类群,鸡与斑马鱼为一松散类群,该聚类结果与公认的动物分类及进化关系拟合.     

植酸酶在单胃和水产动物生产中的应用

植酸酶是能将植酸分解为肌醇和无机磷的一类酶。饲料中添加植酸酶对提高畜禽业生产效益及降低植酸磷对环境的污染有重要意义。文章对植酸及植酸的抗营养特性、来源、分类、作用机理及其在单胃和水产动物生产中的应用作以概述。     

Amino acid composition of proteins as a product of molecular evolution

The average amino acid composition of proteins is determined by the genetic code and by random base changes in evolution. Small but significant deviations from expected composition can be explained by selective constraint on amino acid substitutions. In particular, the deficiency of arginine in proteins has been caused by constraint, during evolution, on fixation of mutations substituting arginine for other amino acids.     

鸡杆菌河南分离株的分子进化分析

【目的】确定鸡杆菌河南分离株的具体种属和进化地位。【方法】以9株鸡杆菌河南分离株为研究对象,根据GenBank上登录的相关序列,针对鸡杆菌3个管家基因rpoB、infB和atpD设计引物,并进行PCR扩增、克隆和序列测定分析;将9株鸡杆菌的3个管家基因部分核苷酸序列,与已知的鸡杆菌属和巴氏杆菌科其他属相关参考株的相应基因序列进行比较分析并构建进化树。【结果】扩增出rpoBi、nfB和atpD3个管家基因部分序列,长度分别为566,531和1 441 bp,将测序结果登陆到GenBank。鸡杆菌分离株间的同源性分别为98.3%~100%(rpoB)、90.5%~100%(infB)和98.3%~100%(atpD);分离株与国外鸭源鸡杆菌分离株间的同源性分别为97.1%~98.5%(rpoB)8、5.2%~93.2%(infB)和98.3%~98.8%(atpD);分离株与国外鸡杆菌属其他种的同源性分别为84.3%~86.8%(rpoB),83.1%~86.7%(infB);鸡杆菌分离株与巴氏杆菌科其他代表属的同源性分别为77.4%~79.3%(rpoB)、78.2%~79.7%(infB)和83.5%~84.1%(atpD)。遗传进化分析显示,9株鸡杆菌河南分离株与鸭源鸡杆菌处于同一大分支之中。【结论】9株鸡杆菌河南分离株均为鸭源鸡杆菌。