Population structure of rice (Oryza sativa) landraces from high altitude area of Indian Himalayas

This study examined the genetic diversity in 20 rice landrace populations from parts of traditional farming areas of the Indian Himalayas using 11 mapped simple sequence repeats (SSR) loci. Twenty‐four individuals sampled from each of the 20 landraces (480 individuals), which were collected from farmers from Northwest to Northeast Himalaya, showed that all landraces showed within population variation and none were homogeneous. The number of polymorphic loci in a landrace population ranged from 5 to 11. A total of 71 alleles were recorded of which 58 were common and 13 were rare. Of the 71 alleles, 46 were common to both Northwest and Northeast regions, whereas 9 were unique to the former and 16 were unique to the latter. The mean number of alleles per locus was 6.45 and for landrace populations from Northwest and Northeast regions were 5.0 and 5.64, respectively. Population differentiation, as shown by a high F_ST value (0.61), was greater for Northeast populations. The unweighted pair group method with arithmetic mean (UPGMA) dendrogram classified the populations into three major clusters: cluster I comprised seven populations from the Northwest region, cluster II comprised seven populations from the Northeast region and cluster III comprised populations from both regions. Investigating the population genetic structure can help monitor change in diversity over time and space, and also help devise a rational plan for management of crop landraces on‐farm under farmer management.     

Analysis of polymorphic mitochondrial DNA in the Han population and three other ethnic groups of northeast China

By means of the PCR-RFLP technique the polymorphism of a 465 fragment of mtDNA D loop was analyzed in 36 individuals of the Northeast Han, 30 individuals of the Daur, 32 individuals of the Oroqen and 30 individuals of the Ewenki. All these individuals were randomly selected and are healthy. 27 restriction patterns were obtained by assaying the RFLP fragments of the mtDNA D loop. The mean nucleid acid substitute frequencies at each site are the following: Northeast Han = 0.0291, Oroqen = 0.0477, Ewenki = 0.0563, Daur = 0.0541. The genetic relationship between these four populations was analyzed by the UPG cluster analysis.     

东北地区棕背鼠平种群遗传结构及亚种分类

Using partial sequences of mtDNA control region,we sought genetic diversity,population genetic structure and subspecies classification in 5 populations of Myodes rufocanus from Northeast China and Hokkaido,Japan. After sequencing a 616 bp segment of control region,we detected 45 haplotypes based on 57 variable sites among 55 individuals. Our results revealed that high-level haplotype diversity and slightly less nucleotide diversity occurred in these populations. AMOVA analysis showed that high-level genetic differentiation happened between populations due to 64.70% genetic diversity and Fst ranging from 0. 240 to 0. 814. In a phylogenetic analysis,the haplotypes from Northeast China split into two groups:Daxing’anling-Xiaoxing’anling-Wandashan and Hailin-Dahailin. This suggested that we can separate the populations from Northeast China into two subspecies,M . r. irkutensis and M. r. Changbaishanensis respectively corresponding with the former and latter areas.     

Evaluation of the genetic variability of 13 microsatellite markers in native Indian pigs

We analysed polymorphism of 13 microsatellites in two Indian domesticated pig types (North Indian and Northeast Indian). Heterozygosity, polymorphism information content, and probability of identity of two random individuals were calculated for all microsatellites in both types. The number of alleles observed at a locus varied between five and 12. The evaluated microsatellites exhibited a very high heterozygosity and polymorphism information content. The probability of identity of two random individuals from different populations taking into account all the 13 microsatellites was as low as 3.51 × 10^-19. On the basis of these results, we propose that these microsatellite markers may be used with reliability for studying the genetic diversity and for identification of individuals in Indian pig types.     

Survey and census of the hoolock gibbon in West Garo Hills,Northeast India

During a long-term study on the hoolock gibbon in Northeast India, a detailed survey was made in West Garo Hills District of the Meghalaya, India from July 1985 to March 1987. Approximately 5,075 km² of the area was covered. Groups and individuals were counted in 32 localities (812 km²). Interestingly only 1,395 ha was the actual forest area occupied by these gibbons. Forty-two family groups and four floating individuals of gibbons made up the total count. Of these the adult males and females comprised of nearly 67% while the sub-adults, juveniles, and infants were 6%, 12%, and 15%, respectively. Each family group's territory ranged from 14 to 55 ha. Of the 32 localities only 6 had more than one family group. The present paper deals with the diminishing habitats for these gibbons. The discussion is based on the available small forest patches throughout the district (a common feature for the whole of Northeast India) surrounded by bare hills due to shifting cultivation. A strategy for conservation is also outlined.     

Defence, intrusion and the evolutionary stability of territoriality

Territorial behaviour can only be adaptive if its costs are outweighed by its benefits. Territorial individuals incur costs by defending their territories against intruders. Usually these intruders are assumed to be non-territorial floaters attempting to take over the whole territory or neighbours trying to extend the borders of their own territory. We instead investigate how costs and benefits of territorial behaviour are affected by neighbours which invade to steal resources on a territory.We show analytically that in the absence of defence intrusion into neighbouring territories always pays and that even if territories are defended intrusion levels can still be high. Using a more detailed simulation model we find that territory defence usually disappears from the population even if owners have a strong advantage over intruders in terms of fighting costs or foraging efficiency. Defence and thus territoriality can only be evolutionarily stable if fighting costs for the intruder relative to the productivity of the territory are very high or if crossing the borders between territories carries additional costs.Our results show that stealing of resources by neighbours can have a considerable effect on the evolutionary stability of territory defence and thus territoriality itself. A more mechanistic model of territorial behaviour is needed to incorporate these kinds of mechanisms into a general theory on the evolution of territoriality.     

Do great tits assess rivals by combining direct experience with information gathered by eavesdropping?

Animals frequently use signals that travel further than the spacing between individuals. For every intended recipient of a given signal there are likely to be many other individuals that receive information. Eavesdropping on signalling interactions between other individuals provides a relatively cost-free method of assessing future opponents or mates. Male great tits (Parus major) extract relative information from such interactions between individuals unknown to them. Here, we show that male great tits can take information gathering a stage further and obtain more information about a previously unencountered intruder, by the hitherto unknown capability of combining information gathered by eavesdropping with that derived from their own direct interaction with an individual. Prior experience with an intruder (A) was achieved by subjecting a focal male to different levels of intrusion simulated using interactive playback. This intruder (A) then took part in a simulated interaction with an unknown male (B) outside the territorial boundary of the focal males. In response to subsequent intrusion by the second male (B), focal males showed low song output in response to males that had lost to a male that the subject was able to beat. Males of known high quality, or those about which information was ambiguous, elicited a high level of song output by focal males. We discuss the implications of this finding for the evolution of communication and social behaviour.     

Patterns of mtDNA diversity in northwestern North America

The mitochondrial DNA (mtDNA) haplogroups of 54 full-blooded modern and 64 ancient Native Americans from northwestern North America were determined. The control regions of 10 modern and 30 ancient individuals were sequenced and compared. Within the Northwest, the frequency distribution for haplogroup A is geographically structured, with haplogroup A decreasing with distance from the Pacific Coast. The haplogroup A distribution suggests that a prehistoric population intrusion from the subarctic and coastal region occurred on the Columbia Plateau in prehistoric times. Overall, the mtDNA pattern in the Northwest suggests significant amounts of gene flow among Northwest Coast, Columbia Plateau, and Great Basin populations.     

基于微卫星标记的中国东北地区灰飞虱遗传变异及种群遗传结构分析

【目的】本研究旨在明确我国东北地区灰飞虱Laodelphax striatellus种群遗传变异及种群遗传结构,阐明种群间遗传分化与基因流。【方法】利用9对微卫星引物对采自我国东北地区15个地理种群的375头灰飞虱样品进行测序与分析;利用GeneAlex6.51, GENEPOP4.0.9和STRUCTURE 2.3.4等软件分析灰飞虱地理种群间的遗传多样性、遗传分化、基因流及种群遗传结构。【结果】在所分析的375头灰飞虱个体中,各位点平均有效等位基因数Na=6.898;总体上,灰飞虱不同地理种群遗传多样性较高(平均观测杂合度Ho=0.548;平均期望杂合度He=0.582),各种群间基因流较低(Nm=0.660)。UPGMA聚类树、PCoA及STRCTURE分析结果表明,东北地区灰飞虱种群分为两分支:吉林(JL)和沈阳(SY2012,SY2013和SY2014)种群聚为一支;其余种群聚为一支。AMOVA分析结果表明,灰飞虱遗传变异主要来自种群内(87%),种群间变异水平较低(13%)。【结论】中国东北地区灰飞虱遗传多样性较高,不同地理种群存在一定程度的遗传分化,且基因交流较低,存在一...     

BsaH Ⅰ对猪激素敏感脂肪酶基因外显子Ⅰ的PCR-RFLP分析

以华北野猪、东北野猪和山西黑猪、长白猪、大白猪、马身猪共计287头猪作为研究对象,对其HSL基因外显子Ⅰ区域进行了PCR-RFLP多态性研究,发现不同品种猪间存在多态性。瘦肉型大白猪、长白猪全部表现为GG基因型;山西黑猪表现为AA、AG和GG三种基因型;脂肪型地方猪种马身猪为单一的AA基因型;华北杂种野猪、东北纯种野猪及杂种野猪表现为AG和GG两种基因型。等位基因A、G及三种基因型的频率在不同猪种中不同。该研究首次对华北及东北野猪HSL基因进行了多态性研究,丰富了国内外对野猪的分子生物学研究,为野猪遗传资源的合理开发利用提供了依据。     

利用RAPD 标记技术对白桦种源遗传变异的分析及种源区划

用随机扩增多态DNA(RAPD)分子标记方法对白桦17 个种源152 个个体进行了遗传变异的比较分析, 通过14 个随机引物扩增共检测到233 个位点, 各种源多态位点百分率差异明显, 范围在20.17%~32.19%之间, 多态位点百分率最高的是帽儿山种源和清源种源, 最低的是绰尔种源。遗传变异在种源间占43.53%, 在种源内个体间占56.47%。根据种源间的遗传距离, 构建了白桦17 个种源的遗传关系聚类图, 结果将东北地区的白桦聚为一类, 华北、西北地区的白桦聚为另一类。同时根据地理气候因子和遗传距离对白桦群体进行了种源区的划分。     

A Single Nucleotide Polymorphism of Chicken Acetyl-CoA Carboxylase A Gene Associated with Fatness Traits

Acetyl-CoA carboxylase α (ACCα) is a major rate-limiting enzyme in the biogenesis of long-chain fatty acids. It can catalyze the carboxylation of acetyl-CoA to form malonyl-CoA that plays a key role in the regulation of fatty acid metabolism. The objective of the present study was to investigate the associations of ACCα gene polymorphisms with chicken growth and body composition traits. The Northeast Agricultural University broiler lines divergently selected for abdominal fat content and the Northeast Agricultural University F₂ Resource Population were used in the current study. Body weight and body composition traits were measured in the aforementioned two populations. A synonymous mutation was detected in the exon 19 region of ACCα gene, then polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was developed to genotype all the individuals derived from the aforementioned populations. Association analysis revealed that the polymorphism was associated with abdominal fat weight and percentage of abdominal fat in the two populations. The results suggested that ACCα gene could be a candidate locus or linked to a major gene that affects abdominal fat content in the chicken.     

Factors Affecting Interspecific Aggression in a Year‐Round Territorial Species,the Jewel Damselfish

Vertebrates live in complex species networks in which interspecific interactions are common. In some contexts, the aggressive behaviours shown in these interspecific interactions are very similar to those shown in intraspecific interactions. It is still an open question whether intra‐ and interspecific aggression share common causality. We studied a year‐round territorial species the jewel damselfish, (Plectroglyphidodon lacrymatus), which cultivate algae they feed on. Territory holders aggressively defend these algae that are an attractive resource for many other species. In this study, we recorded territorial aggression in free‐living individuals and recorded aggressive responses to a standardized territorial intrusion test in captive individuals. Field observations indicated that territorial aggression was selectively targeted towards food competitors. Independent of the size of the species, aggression was more frequent towards common species around their territories. This relationship was confirmed experimentally by confronting the jewel damselfish with novel objects to which the subjects were exposed either frequently or rarely. We suggest that jewel damselfish have to learn which species are competitors and therefore should be chased. In a standardized intrusion test with captive individuals, no significant differences were found in territorial responses towards intra‐ or interspecific intruders. Neither territorial aggression nor the intrusion showed any relationship with plasma androgen levels. Together, these data suggest that experience might be more important in non‐seasonal territorial aggression than circulating hormonal factors.     

Genetic structure of two urban afro-brazilian populations

A total of 218 individuals living in the Brazilian cities of Porto Alegre (in the South) and Salvador (in the Northeast) were variously studied in relation to nine erythrocyte and four plasma protein systems. The results were compared with previous studies in some of these systems, and estimates of interethnic admixture obtained in subsamples according to morphological appearance. As a whole, Afro-Brazilians from Salvador show 42% of non-African genes, the corresponding figure for Porto Alegre being 59%. The Amerindian contribution to these individuals was estimated as null or negligible. Average heterozygosities are similar to those obtained for African groups, but the gene differentiation coefficient (GST') is small. The phylogenetic tree indicates a closer relationship of Salvador with the African subcluster, as would be expected by the admixture and istorical data. Analyses such as this one are important for the unraveling of the complex networks responsible for the present variability of human populations, and for the dispelling of racist concepts.     

Effects of Pleistocene climate change on genetic structure and diversity of <Emphasis Type="Italic">Shorea macrophylla</Emphasis> in Kalimantan Rainforest

The island of Borneo is the diversity center of the Dipterocarpaceae, the most important family of tropical rainforest trees in Southeast Asia. However, changes in land use and climate have affected dipterocarp distributions on the island, raising concerns about the vulnerability (inter alia) of the endemic riparian species Shorea macrophylla. Thus, to aid conservation efforts, we have investigated the genetic diversity, structure, and demographic history of S. macrophylla. The species’ genetic diversity and structure in Kalimantan (part of Indonesia, covering 75% of the island) were explored by examining genotypes of 377 individuals representing 13 populations in three regions (Northeast, Central, and West Kalimantan) using 14 newly developed microsatellite loci. Higher genetic diversity was found, at all loci, in samples from Northeast Kalimantan than in samples from the other regions. Moderate genetic differentiation between populations was detected (F_ST 0.093). Bayesian clustering, principal coordinate, and neighbor joining tree analyses of the population structure consistently identified two genetically distinct groups, one in the Northeast and the other in the Central and West regions. The higher diversity of the diverged populations in Northeast Kalimantan indicates that the region may have hosted rainforest refugia during the ice age. Accordingly, analysis using DIY ABC software indicated that the Northeast and Central-West Kalimantan groups diverged 194,000 years ago. We conclude that global climate change during the Pleistocene strongly influenced the genetic diversity and structure of S. macrophylla populations in Kalimantan.     

Cement flow during impaction allografting: a finite element analysis

Cement intrusion into cancellous or impacted bone is not well understood. We adopted an engineering mechanics approach to predict the effect of surgical variables on the cement intrusion into impacted cancellous bone, used for the revision of failed total hip replacement with the impaction allografting technique. Specifically, a three-dimensional finite element model was used to determine the effects of cement viscosity, the magnitude and duration of pressurization, and the distribution of the porosity along the femur on cement intrusion. The overall averaged mean intrusion depth difference between the finite element model prediction and the cadaveric measurements was 1.1mm. The depth of penetration increased with higher pressurization pressure, duration of pressurization, and earlier stem insertion (lower viscosity), but maintained a similar profile. The distribution of the porosity along the femur determined the intrusion profile. Cement viscosity, the applied pressure or the duration of the pressurization can be adjusted to limit the cement volume injected into the medullary canal and therefore prevent the cement from reaching the endosteal surface.     

A comparison of impoundments and natural drainage lakes in the Northeast USA*

We classified 235 randomly selected lentic waterbodies (>1 ha) in the Northeast USA as human created, or natural. We compared geographic extent and distribution, morphology and hydrology, trophic state, and fish assemblage metrics of impoundments and natural drainage lakes. We estimated that 46% of the 10 608 (±1695; 95% CI) lentic waterbodies in the region were impoundments or quarries; 68% of Uplands lakes and 26% of Lowlands lakes were natural. Impoundments were smaller, shallower, had shorter water residence times, and were in watersheds with greater human activity than were natural drainage lakes. More than half (55%) of Lowlands impoundments were eutrophic, accounting for 67% of eutrophic or hypereutrophic lentic waterbodies in the Northeast. An estimated 90% of eutrophic lakes and impoundments were <23 ha. Impoundments had greater proportions of fish species and individuals tolerant of human disturbance, and greater proportions of non-native species and individuals than did natural drainage lakes. We discuss some management implications of the differences between impoundments and natural drainage lakes.     

Genetic markers among Meiteis and Brahmins of Manipur, India

Genetic polymorphism of 16 red-cell antigens, enzymes, serum proteins and Hb variants was investigated in 214 male and female individuals belonging to the Meiteis and a Brahmin caste group living in Imphal (Manipur, Northeast India). Ethnohistorical records suggest that the Meiteis are of Mongoloid origin, while the original Brahmin settlers represent the easternmost part of the so-called Caucasoids. The markers studied are: A1A2BO, MNSs, Rh-system, Duffy, Diego; Gm, Km, Gc, Hp, Tf, Cp; Hb; aP, AK, EsD and LDH. The comparison between the two groups on the basis of the markers studied showed that the Meiteis and Brahmins are very close to each other with respect to most of the loci except Gm, EsD and Hb, where significant statistical differences were found.     

Female song sparrow, Melospiza melodia, response to simulated conspecific and heterospecific intrusion across three seasons

To investigate female responses to territorial intrusion I presented female song sparrows with either a simulated female song sparrow intrusion or a simulated spotted towhee, Pipilo maculatus, intrusion as a control during either the prebreeding, breeding or postmoult seasons. Aggressive and nonaggressive behaviours and vocalizations were compared between intrusion types and across seasons. Principle components analysis suggested that female responses fell into three categories: (1) responses directed towards the intruder, mostly aggressive; (2) responses directed towards the mate; and (3) lack of response to the intruder. In every season, females responded more aggressively to simulated female song sparrow intrusion than simulated towhee intrusion. Responses directed towards female song sparrow intruders dropped across the three seasons and were significantly higher in the prebreeding season than in the breeding or postmoult seasons. Copyright 2000 The Association for the Study of Animal Behaviour.     

Enigmatic septa in shells of some Middle Jurassic Pholadomya (Bivalvia) from Poland

The interior of 36 specimens of Pholadomya Sowerby (Bivalvia) from the Middle Jurassic of Poland reveals the presence of unusual septa that separate sediment‐filled chambers from the shell interior. The septa occupy one or several recurrent loci in shells of various individuals, that is within umbones, in pallial sinuses and along the shell margins. Based on the location and shape of the septa, eight forms grouped into types and varieties are identified. A possible cause for the formation of septa is sediment toxicity, but intrusion of sediment to the shell interior must have been linked to shell breakage or rupture of the free periostracum. One form of septa occurs in perforated umbones, common in Pholadomya; other forms occur in intact shells, which suggest damage to free periostracum. The most likely cause for the latter is the presence of parasites, especially digenean trematodes, for which clams were intermediate hosts. The morphological aberrations presented here were hitherto unknown in both fossil and extant bivalves. This study is also the first report of pathologies in Anomalodesmata.