陕西红碱淖普通燕鸥和鸥嘴噪鸥的繁殖生态比较

2009年4～7月,采用定点观察法和逐巢清点法,对陕西省红碱淖地区普通燕鸥(Sterna hirundo)和鸥嘴噪鸥(Gelochelidon nilotica)的繁殖生态进行了比较研究。结果表明,两者都是4月末迁至红碱淖,并于5月中旬进入繁殖期。普通燕鸥和鸥嘴噪鸥都选择在湖心岛上营巢,普通燕鸥巢址沿岛边缘四周呈线状分布,而鸥嘴噪鸥位于岛中央向外扩散呈块状分布。对食物调查发现,两者在食物资源利用上存在部分生态位分离。巢址分布格局差异性和食物资源利用生态位部分分离是两者能在同一领域共存的主要原因。对雏鸟的体重等形态参数进行Gompertz曲线方程拟合,结果表明,两种雏鸟生长状况的差异性从另一面也可以反应二者种间竞争压力的缓和。另外,从一定的角度分析了两者与遗鸥(Larus relictus)的伴生关系。     

利用线粒体Cyt b基因全序列探讨部分鸥类的系统发育关系

利用线粒体细胞色素b(Cyt b)基因全序列,对采自陕西红碱淖湿地繁殖的遗鸥Larus relictus、棕头鸥Larus brunnicephalus、普通燕鸥Sterna hirundo和鸥嘴噪鸥Gelochlidon nilotica的序列特征进行了分析.联合已知该基因全序列的其它32种鸟类,构建了36种鸟类之间的系统发育关系,并确定了4种鸥在系统发育中的地位.结果表明:4种鸥Cytb基因全长均为1 143 bp;MP、ML和Bayes树拓扑结构大致相同,支持遗鸥、渔鸥Larus ichthyaetus和地中海鸥Larus audouinii、Larus melancephalus划归为黑头鸥族;棕头鸥划归为面具族;遗鸥与地中海鸥亲缘关系较近,与渔鸥次之,与棕头鸥亲缘关系较远;普通燕鸥和鸥嘴噪鸥均划归为黑帽族;燕鸥属和凤头燕鸥属亲缘关系较近,噪鸥属较为古老,是较早分化出的一支;鞘嘴鸥科作为单型科,受不同选择压力导致和鸥类亲缘关系甚远;建议将灰头鸥Larus cirrocephalus移人巾头鸥族;鸥科、燕鸥科和剪嘴鸥科的拓扑结构未能准确解析,需要进一步分析研究.     

陕西红碱淖棕头鸥孵卵行为

2014年5—6月,应用e-Science信息技术,对红碱淖棕头鸥的孵卵行为进行了研究。结果表明,不同孵化阶段昼夜间孵卵节律分别为:孵化前期换孵次数7.88±1.08(n=39)、5.00±0.89(n=39),坐巢方向变换27.75±2.04(n=39)、14.37±1.72(n=39),翻卵次数27.13±2.02(n=39)、11.25±1.08(n=39);孵化中期换孵次数3.11±0.19(n=65)、1.32±0.11(n=65),坐巢方向变换23.37±0.91(n=65)、10.95±0.86(n=65),翻卵次数21.11±1.11(n=65)、8.47±0.77(n=65);孵化后期换孵次数3.17±0.22(n=42)、0.95±0.05(n=42),坐巢方向变换20.06±1.46(n=42)、6.62±0.84(n=42),翻卵次数22.39±1.78(n=42)、5.33±0.55(n=42)。当大风或大雨时,对同一孵化阶段的换孵次数、坐巢方向变换和翻卵次数均存在极显著差异(P0.01)。双亲交替换孵主要集中于04:00—10:00、12:00—14:00等时间段内。孵化后期,亲鸟坐巢时长达到(713.29±40.62)min(n=42)。棕头鸥通过调节昼夜间的孵卵节律来控制卵的温度,以保证昼夜间卵胚胎的正常发育。同时与同域分布繁殖的遗鸥的孵卵节律进行了比较。     

陕西红碱淖同域分布遗鸥与棕头鸥巢址选择比较

2009—2011年4—7月在陕西红碱淖对同域分布的遗鸥和棕头鸥巢参数特征、巢群空间分布和巢址生境选择进行了对比分析。结果表明:巢外径、巢深、巢高等参数均存在显著差异,这主要是与营巢生境和巢址空间分布上有关;从巢群空间分布上来看,两者均选择于湖心岛上营巢繁殖,巢群呈斑块状分布,但彼此没有混巢现象,有时甚至通过压缩种间巢间距来达到共存,由于遗鸥繁殖群体数量占优势,遗鸥总是占据最佳的巢域,棕头鸥巢群通常被排挤至湖心岛边缘部分;在巢址生境选择上,植被类型、植被高度、植被盖度、巢离水面高度和巢距最近水边距离均存在显著差异。这表明两者巢址生境选择上具有特异性,这种特异性使得巢址生境选择上存在生态位差异,促成了遗鸥和棕头鸥能在同一湖心岛上营巢繁殖因素之一。     

基于线粒体ND2基因的直翅目部分种类分子系统发育分析

测定了39种直翅目昆虫线粒体ND2基因全长序列,联合GenBank中41种直翅目昆虫的ND2基因序列,探讨ND2基因在解决直翅目系统发育分析上的功效,为建立直翅目的主要类群之间稳定的系统发育关系提供更多的数据。研究结果表明,直翅目昆虫的ND2基因序列全长为996～1 029 bp,平均长度为1 020 bp,A+T含量平均为73%。用贝叶斯法(Bayesian,BI)、最简约法(maximum parsimony,MP)和最大似然法(maximum likelihood,ML)构建系统树,SH检验显示,RAxML法构建的ML树似然值最大,与PAUP*的ML法构建的ML树差异显著,而与贝叶斯树和简约树没有明显差异。所有系统树都显示直翅目为单系群;而蝗亚目的剑角蝗科、网翅蝗科、槌角蝗科和斑腿蝗科均不是单系群,锥头蝗科与瘤锥蝗科亲缘关系较近,这与Otte分类系统一致。螽亚目基本由两大分支构成,一支是蝼蛄总科和蟋蟀总科聚集而成,且具有很高的置信度;另一大分支由螽斯总科独自构成。     

陕西红碱淖湿地鸥科鸟类组成及分布的研究

2005～2009年,采用路线调查法和定点观察法对陕西红碱淖湿地鸥科鸟类组成及其分布进行了调查研究.结果 表明:红碱淖分布有鸥科鸟类4属10种,在此繁殖的有5种,其中有全球性濒危鸟类--遗鸥的最大种群在此繁殖.记述了鸥科鸟类最早发现时间段、分布状况及迁徙数量情况,也探明了繁殖种群数量.并从植被类型、水位变化、食物因素、湖心岛生境状况和环境气候等因素分析了红碱淖鸥科鸟类迁徙状况、种群数量变化、繁殖情况等.     

鳜类系统发育的线粒体Cytb基因全序列分析

测定了鳜、大眼鳜、斑鳜、暗鳜、波纹鳜、长体鳜、中国少鳞鳜等7种鳜类12个个体的线粒体细胞色素b基因全序列。结合GenBank中的同源序列,共分析了9种鳜类的系统发育关系。序列分析表明,鳜属鱼类属内种间的遗传距离(0.015～0.093)明显小于少鳞鳜属鱼类属内种间的遗传距离(0.152～0.178)。在分子系统发育树上,长体鳜与鳜属的鳜、大眼鳜、斑鳜、波纹鳜、暗鳜聚合成一分支,少鳞鳜属的种类聚成另一分支;支持将长体鳜归入鳜属,鳜类分为鳜属和少鳞鳜属等二个属的分类处理。在鳜属鱼类中,鳜和大眼鳜亲缘关系十分密切;斑鳜与波纹鳜亲缘较近;长体鳜与鳜属其它5个种的亲缘关系较远。在少鳞鳜属鱼类中,中国少鳞鳜和日本少鳞鳜的亲缘关系较远,韩国少鳞鳜的系统位置较不明确。鳜类的单系性及其鳜类的系统位置仍有待进一步研究。     

基于线粒体COI基因全序列的直翅目部分类群系统发育关系分析

该研究基于直翅目56种昆虫的COI基因全序列构建了该目部分类群间的系统发育关系,同时也分析了COI基因编码的氨基酸序列构建直翅目系统发育关系的可靠性。将COI序列按照密码子一、二、三位点划分,分别计算PBS(partioned Bremer support)值,评估蛋白质编码基因密码子不同位点的系统发生信号强度。分析结果支持螽亚目和蝗亚目的单系性;剑角蝗科、斑腿蝗科、斑翅蝗科、网翅蝗科和槌角蝗科5科均不是单系群,科间的遗传距离在0.107~0.153之间变化,与其他科相比遗传距离较小,符合将这5科合并为一科(即蝗科)的分类系统,瘤锥蝗科和锥头蝗科归为锥头蝗总科,癞蝗科单独成为一科,这也与Otte(1997)系统的划分一致。根据PBS值的大小推断密码子第三、第一位点对系统树分支的贡献比第二位点大,并且较长的序列含有较多的信息位点。研究也证实将各物种COI基因之间的遗传距离作为直翅目划分科级阶元的工具是可行的。     

基于线粒体Cyt b基因的全长序列探讨闭壳龟类的系统进化

采用PCR技术对淡水龟科具闭壳结构的黄缘盒龟、黄额盒龟、金头闭壳龟、潘氏闭壳龟、锯缘龟和白腹摄龟的线粒体Cytb基因的全长序列进行了PCR扩增和序列测定,并结合GenBank中16种淡水龟科物种的同源序列,进行了序列变异和系统发生分析。经C lustalX1.8软件对位排列后共有1154个位点,其中可变位点413个,简约信息位点301个;A＋T的平均含量（56.5%）高于G＋C（43.5%）。在氨基酸密码子中,第一位富含A,第二位富含T,第三位富含C;碱基转换/颠换率为5.97,碱基替换多发生在密码子第三位。以中华鳖和马来鳖为外群,通过最大简约法,最大似然法和贝叶斯法重建了分子系统树,均具有一致的拓扑结构,结果表明：金头闭壳龟和潘氏闭壳龟最先聚成一支,再和三线闭壳龟聚成一组,说明形态上相似的三种闭壳龟亲缘关系最近;闭壳龟属、盒龟属和单种锯缘龟属聚成一个单系的闭壳龟群,建议合并为闭壳龟属;齿缘龟属和果龟属聚为一支,它们与新的闭壳龟属关系较远,揭示闭壳结构的形成不是由一个共同祖先分化而来;乌龟属、花龟属和拟水龟属三属为并系起源,建议三属可以合并为一属。     

基于核基因RAG1部分序列探讨菊头蝠科和蹄蝠科的系统发育关系

应用核基因重组激活基因1(Recombination activating gene,RAG1)部分序列对贵州9种菊头蝠和5种蹄蝠的系统发育关系进行了研究,运用贝叶斯法(Bayesian inference,BI)、最大似然法(Maximum likelihood,ML)和邻接法(Neighbor-joining,NJ)构建了系统进化树。研究结果表明:1.菊头蝠科和蹄蝠科形成两个平行的分支,支持它们是两个平行科的结论。2.马铁菊头蝠是菊头蝠科中第一个独立出来的亚分支,与其余8种菊头蝠的亲缘关系最远;Rhinolophus sp.与大菊头蝠聚合为一支,推测Rhinolophus sp.可能是大菊头蝠,或者是大菊头蝠的近缘种,它们是继马铁菊头蝠之后分离出来的第二亚分支;中华菊头蝠、栗黄菊头蝠、中菊头蝠聚合为第三亚分支,贵州菊头蝠、大耳菊头蝠、菲菊头蝠聚合为第四亚分支,此两分支形成姊妹群。3.在蹄蝠科的亚分支中,三叶蹄蝠、小蹄蝠、普氏蹄蝠依次分离出来,最后分出的是大蹄蝠和中蹄蝠。     

陕西红碱淖遗鸥育雏行为和雏鸟生长

2012年5～7月,应用e-Science信息技术和标记法,对陕西神木县红碱淖(N 38°13′～ 39°27′,E 109°42′～110°54′)遗鸥(Larus relictus)的育雏行为和雏鸟生长发育进行了研究.结果表明,雏鸟由双亲共同承担喂食.育雏前期,亲鸟采取直接喂食、食物呕吐于巢边和在巢中间断性喂食这3种喂食模式;亲鸟昼间平均喂食(0.706±0.036)次/h,夜间平均喂食(0.469±0.024)次/h,双亲在喂食频次上无显著差异(F=32.54,P＞0.05).育雏后期,主要采取双亲直接喂食和亲鸟把食物呕吐于地面上,由雏鸟自己取食的喂食模式;亲鸟昼间平均喂食(0.416±0.021)次/h,夜间平均喂食(0.331±0.018)次/h,亲鸟喂食次数与雏鸟的日龄存在相关性(r =0.074,P＜0.05).随着雏鸟日龄的增长,暖雏次数趋于减少,而在炎热晴天、降雨和大风等天气状况下,暖雏时间和护雏行为都增强.雏鸟20日龄后未再观察到暖雏行为.雏鸟体长及外部器官的形态学参数适合用Gompertz曲线方程拟合.同时,与其近缘种黑嘴鸥(L.saundersi)的育雏行为和雏鸟生长进行了比较.     

Prospectors' colony attendance is sex-specific and increases future recruitment chances in a seabird

In most long-lived vertebrates, including seabirds, young non-breeders often attend potential breeding sites. In seabird colonies, this prospecting behaviour has nearly never been studied with respect to potential sex-specific benefits, and its fitness consequences are largely unknown. We compared attendance patterns of sexed common tern prospectors at six subcolonies with future breeding status and nesting site choice. We also tested for potential effects of population density. Birds that arrived earlier at the colony were recorded more often along the season. This arrival effect was stronger in males, which generally spent more time at the colony. Birds prospecting for two consecutive years attended the colony more intensively in the second year. A high colony attendance enhanced recruitment probability in both sexes, but only in females, it was linked with a higher probability to return. Attendance at a preferred subcolony increased during the season. For first breeding, individuals favoured the subcolony where they had prospected most intensively in the previous season. In males, this subcolony fidelity was stronger and increased simultaneously to breeding pair density. We conclude that prospecting is a process of integration into the community of breeders, and that benefits are higher for males, the more territorial sex in this species.     

陕西定边苟池湿地发现遗鸥繁殖群分布

2013年5月23日,在陕西省定边苟池湿地发现遗鸥 (Larus relictus) 繁殖群,统计结果为434巢。分为南、北两个巢群,南部巢群341巢,北部巢群93巢,南、北两个巢群间距8 m。遗鸥筑巢于坑洼相连的盐碱沼泽中一处较大\"岛屿\"上,巢址高出水面30~50 cm。定边苟池湿地是我国又一处新的遗鸥繁殖地。     

Individual changes underlie age-specific pattern of laying date and egg-size in female common terns Sterna hirundo

It has been suggested that breeding performance differs between young and old birds due to the appearance and disappearance of phenotypes through differential survival (selection hypothesis) or differential recruitment (delayed breeding hypothesis) of high-quality individuals, but each bird may show constant breeding performance over its life. We tested constant egg-volume and laying date by modelling their variability on the basis of the 109 known-age females of common tern Sterna hirundo with data available from 1 to 9 years. Longitudinal analyses showed a significant advancement of laying date, as well as a steady increase in egg-volume, in young age classes from 2 to 5–7 years old, indicating individual intrinsic changes in performance with age. In our model, female effect accounted for 74% and 8% of variance in egg-volume and laying date, respectively, suggesting that if correlation between breeding performance and survival or recruitment exists, population patterns of age-specific performance may emerge. However, we found no evidence that birds that did not return to breed during young age classes laid later or smaller eggs than returned breeders. Likewise, we found no evidence that recruiting birds laid earlier or larger eggs than same aged birds recruited in preceding years. Thus, this study shows that age-specific patterns in timing of breeding and egg-size in common terns result from individuals intrinsic changes, and we reject the selection and the delayed breeding hypotheses as a major factor shaping age-specific patterns at population level.Communicated by F. Bairlein     

Comparative virulence phenotypes and molecular genotypes of Puccinia striiformis f. sp. tritici, the wheat stripe rust pathogen in China and the United States

Stripe rust (yellow rust) of wheat, caused by Puccinia striiformis f. sp. tritici, is one of the most important diseases in both China and the United States. The Chinese and US populations of the stripe rust fungus were compared for their virulence phenotypes on wheat cultivars used to differentiate races of the pathogen in China and the US and molecular genotypes using simple sequence repeat (SSR) markers. From 86 Chinese isolates, 54 races were identified based on reactions on the 17 Chinese differentials and 52 races were identified based on the 20 US differentials. The selected 51 US isolates, representing 50 races based on the US differentials, were identified as 41 races using the Chinese differentials. A total of 132 virulence phenotypes were identified from the 137 isolates based on reactions on both Chinese and US differentials. None of the isolates from the two countries had identical virulence phenotypes on both sets of differentials. From the 137 isolates, SSR markers identified 102 genotypes, of which 71 from China and 31 from the US. The virulence data clustered the 137 isolates into 20 virulence groups (VGs) and the marker data clustered the isolates into seven molecular groups (MGs). Virulence and SSR data had a low (r = 0.34), but significant (P = 0.01) correlation. Principal component analyses using either the virulence data or the SSR data separated the isolates into three groups: group a consisting of only Chinese isolates, group b consisting of both Chinese and US isolates and group c consisting of mostly US isolates. A neighbour-joining tree generated using the molecular data suggested that the P. striiformis f. sp. tritici populations of China and the US in general evolved independently.     

The little-known Dipteropeltis hirundo Calman, 1912 (Crustacea, Branchiura): SEM investigations of paratype material in light of recent phylogenetic analyses

The Branchiura are fish ectoparasites which include the well-known and very commonly found genus Argulus. But the Branchiura also contains the monotypic genus Dipteropeltis, about which only very little is known. In this investigation of two female paratype specimens we describe for the first time the external morphology of Dipteropeltis based on Scanning Electron Microscopy. We show that Dipteropeltis has a pre-oral spine, unique suction disc support structures, an Argulus-like mouth cone and second maxillae with a combination of features seen in both Argulus and Chonopeltis. These data are compared with data from the three remaining branchiuran genera Dolops, Chonopeltis and Argulus and discussed in a phylogenetic context based on a recently proposed phylogeny of the group.     

Phylogenetic analysis of Cystoisospora species at the rRNA ITS1 locus and development of a PCR-RFLP assay

The ITS1 sequences for C. suis, C. belli, C. rivolta, C. felis, and C. ohioensis-like oocysts were determined and a diagnostic PCR-RFLP assay specific for Cystosisopora species was developed. Phylogenetic analysis of ITS1 sequences of Cystosisopora species along with ITS1 sequences for Toxoplasma, Neospora, Sarcocystis and Eimeria spp. using distance, minimum evolution and parsimony-based methods confirmed previous studies, which suggested that the genus Cystoisospora does not belong to the family Eimeriidae, but should be classified together with the cyst-forming coccidia in the family Sarcocystidae.     

Phylogenetic analysis of Nosema ceranae isolated from European and Asian honeybees in Northern Thailand

Nosema ceranae was found to infect four different host species including the European honeybee (A. mellifera) and the Asian honeybees (Apis florea, A. cerana and Apis dorsata) collected from apiaries and forests in Northern Thailand. Significant sequence variation in the polar tube protein (PTP1) gene of N. ceranae was observed with N. ceranae isolates from A. mellifera and A. cerana, they clustered into the same phylogenetic lineage. N. ceranae isolates from A. dorsata and A. florea were grouped into two other distinct clades. This study provides the first elucidation of a genetic relationship among N. ceranae strains isolated from different host species and demonstrates that the N. ceranae PTP gene was shown to be a suitable and reliable marker in revealing genetic relationships within species.     

Dissection of cis-regulatory elements in the C. elegans Hox gene egl-5 promoter

Hox genes are highly conserved segmental identity genes well known for their complex expression patterns and divergent targets. Here we present an analysis of cis-regulatory elements in the Caenorhabditis elegans Hox gene egl-5, which is expressed in multiple tissues in the posterior region of the nematode. We have utilized phylogenetic footprinting to efficiently identify cis-regulatory elements and have characterized these with gfp reporters and tissue-specific rescue experiments. We have found that the complex expression pattern of egl-5 is the cumulative result of the activities of multiple tissue or local region-specific activator sequences that are conserved both in sequence and near-perfect order in the related nematode Caenorhabditis briggsae. Two conserved regulatory blocks analyzed in detail contain multiple sites for both positively and negatively acting factors. One of these regions may promote activation of egl-5 in certain cells via the Wnt pathway. Positively acting regions are repressed in inappropriate tissues by additional negative pathways acting at other sites within the promoter. Our analysis has allowed us to implicate several new regulatory factors significant to the control of egl-5 expression.