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1.
Since 1983, cases of diseased donkeys and horses with symptoms similar to those produced by alphaviruses were identified in two departments in northern Peru; however serological testing ruled out the presence of those viruses and attempts to isolate an agent were also unproductive. In 1997, also in northern Peru, two new orbiviruses were discovered, each recognized as a causative agent of neurological diseases in livestock and domestic animals and, at the same time, mosquitoes were found to be infected with these viruses. Peruvian horse sickness virus (PHSV) was isolated from pools of culicid mosquitoes, Aedes serratus and Psorophora ferox, and Yunnan virus (YUOV) was isolated from Aedes scapularis in the subtropical jungle (upper jungle) located on the slope between the east side of the Andes and the Amazonian basin in the Department of San Martín. Both viruses later were recovered from mosquitoes collected above the slope between the west side of the Andes and the coast (Department of Piura) in humid subtropical areas associated with the Piura River basin. In this region, PHSV was isolated from Anopheles albimanus and YUOV was isolated from Ae. scapularis. We discuss the ecology of vector mosquitoes during the outbreaks in the areas where these mosquitoes were found.  相似文献   

2.
A purified mitochondrial DNA (mtDNA) probe was used to examine restriction fragment length polymorphisms produced by six restriction enzymes ( Xba I, Eco RV, Ava II, Hinf I, Hae III, Mbo I) in 915 brown trout from western Europe. A total of 20 composite haplotypes were found with one to seven haplotypes in individual populations. Icelandic trout samples from north, south, east, and west coast drainages showed only a single common haplotype in contrast to the high level of polymorphism found in Irish and Scottish populations. The phylogeny of mtDNA haplotypes and the pattern of haplotype distribution suggests that post-glacial colonization of brown trout in NW Europe was more complex than the dual colonization model which has been proposed on the basis of differential LDH-5* allele distribution. For example, Lough Melvin (Ireland) appears to have been independently  相似文献   

3.
We report here the reappearance of Aedes aegypti in the Rimac district, and summarize the history of this mosquito species in Peru since its first detection in 1852. On March 17 2000 were found Ae. aegypti and Culex quinquefasciatus in Mariscal Castilla town, Flor de Amancaes, San Juan de Amancaes, El Altillo and Santa Rosa in the Rimac district, Lima Province.  相似文献   

4.
Abstract The melon fruit fly, Bactrocera cucurbitae (Coquillett) (Diptera: Tephritidae), has been the subject of worldwide quarantine and management efforts due to its widespread agricultural impact and potential for rapid range expansion. From its presumed native distribution in India, this species has spread throughout the hot‐humid regions of the world. We provide information that reveals population structure, invasion history and population connectivity from 23 locations covering nine countries based on DNA sequences of the mitochondrial cytochrome oxidase I (COI) gene. Forty‐two polymorphic sites were described among 38 haplotypes. The most common haplotype, H1, was observed in 73% of the samples distributed among all populations. Highest genetic diversity was seen within populations, and no isolation‐by‐distance was detected. The western regions (Nepal, Bangladesh, Thailand, Burma and China‐west) showed higher haplotype diversity than eastern regions (China‐east). China‐Yunnan showed highest levels of genetic diversity in China. Haplotype diversity decreased with longitude from west to east. Together, these analyses suggest that B. cucurbitae has expanded from west to east within a limited geographic scale and recently invaded China through Yunnan Province.  相似文献   

5.
The pine engraver Ips pini (Say) is known to include three pheromone races, but gene flow between these races has not been investigated. We used maternally inherited mitochondrial DNA (mtDNA) variation to infer gene flow between 22 widely distributed North American populations of I. pini for a total of 217 individuals, based on 354 bp of the cytochrome oxidase I gene. Gene flow was estimated cladistically as migrants per generation (Nm) and as haplotype variation between populations (Nst). Three distinct mtDNA haplotype lineages, generally corresponding to eastern (I), Rocky Mountain (II) and western (III) regions of North America, were resolved with a total of 34 distinct I. pini haplotypes. The distributions of these lineages were largely congruent with the geographical ranges of the ''New York'', ''California'' and ''Idaho–Montana'' pheromone races. Only individuals with lineage I mtDNA were observed among eastern populations, whereas individuals with lineage II or III mtDNA predominated among western populations. Gene flow (Nm and Nst) was generally moderate between all populations. However, the presence of lineage I mtDNA on the eastern side of western North America and the absence of lineage II and III mtDNA in eastern North America suggest directional gene flow from east to west. These results indicate that female-controlled assortative mating among pheromone races may disrupt gene flow between conspecifics, reflecting incomplete pre-mating barriers.  相似文献   

6.
To investigate the mtDNA variation and origin of maternal lineages in South American donkeys and to reassess the domestication of donkeys in northeast Africa, we analyzed sequences (489 bp of the D‐loop) from 323 domestic donkeys sampled from Peru, Brazil, Ethiopia and Egypt. Altogether, the 323 sequences displayed 53 different haplotypes (45 in Ethiopia, 14 in Egypt, eight in Peru and six in Brazil). Among the four populations, Egyptian donkeys possessed the highest haplotype diversity (0.910 ± 0.032), followed by Brazilian donkeys (0.879 ± 0.060). The Clade I haplotypes dominated in Peruvian donkeys (65%), whereas Clade II haplotypes dominated in Brazilian donkeys (67%). Estimates of FST values showed a high genetic differentiation between Peruvian and Brazilian donkey populations (FST = 0.4066), which could be explained by the complex introduction history of South American donkeys. Phylogeographic analysis indicates that northeast Africa could be the most probable domestication center for Clade I donkeys. Analysis of molecular variance confirmed a weak genetic structure in domestic donkey populations among four continents (Europe, Asia, Africa and South America).  相似文献   

7.
Mitochondrial DNA variation in cattle of South China: origin and introgression   总被引:21,自引:0,他引:21  
Y Yu  L Nie  Z Q He  J K Wen  C S Jian  Y P Zhang 《Animal genetics》1999,30(4):245-250
Ten restriction endonucleases were used to investigate the mitochondrial DNA restriction fragment length polymorphism (mtDNA RFLP) of 11 native cattle breeds and one cultivated cattle breed in South China. Twenty-three restriction morphs were detected, which can be sorted into five haplotypes. A phylogenetic tree of the haplotypes was constructed by using the 'upgMa' method. Our study showed that haplotype I and II are identical to the zebu (Bos indicus) and taurine (Bos taurus) haplotypes, respectively. Zebu and taurine were the two major origins of cattle populations in South China, and the zebu probably had more influence on the native cattle population than taurine did. Haplotype III is identical to haplotype I of yak (Bos grunniens), which was only detected in the Diqing cattle breed. Haplotype IV was detected for the first time. This haplotype, found only in Dehong cattle, might be from an independent domestication event, probably from another Bos indicus population. Divergence of haplotypes I and IV occurred about 268,000-535,000 years ago, much earlier than the 10,000-year history of cattle husbandry. Our results also suggest a secondary introgession of mtDNA from yak to Diqing cattle.  相似文献   

8.
Echinococcus granulosus sensu stricto is a cosmopolitan parasite causing cystic echinococcosis in humans and livestock. Recent molecular phylogeographic studies suggested the rapid dispersal of the parasite by the anthropogenic movement of domestic animal hosts. In the present study, genetic polymorphism of E. granulosus s. s. in the Middle East, where the domestication started, was investigated to validate the dispersal history of the parasite. Thirty-five and 26 hydatid cysts were collected from Iran and Jordan, respectively, and mitochondrial cytochrome c oxidase subunit I (cox1) gene was sequenced. Chinese and Peruvian specimens were also analyzed for comparison. Haplotype network analysis demonstrated the existence of a common haplotype EG01 in all populations. Although EG01 and its one-step neighbors were the majority in all regions, most of the neighboring haplotypes were unique in each locality. Haplotype diversity was high but nucleotide diversity was low in Iran, Jordan and China. Both diversities were lowest and only a few haplotypes were found in Peru. Neutrality indices were significantly negative in Iran, Jordan and China, and positive but not significant in Peru. Pairwise fixation index was significant for all pairwise comparisons, indicating genetic differentiation among populations. These results suggest a evolutionary history of E. granulosus s. s. in which a genetic subgroup including EG01 was selected at the dawn of domestication, and then it was rapidly dispersed worldwide through the diffusion of stock raising. To approach the origin of the ancestral strain, extensive sampling is needed in many endemic regions. To evaluate the hypothetical evolutionary scenario, further study is needed to analyze specimens from diverse host species in wider regions.  相似文献   

9.
We describe patterns of tree community change along a 700-km transect through terra firme forests of western Amazonia, running from the base of the Andes in Ecuador to the Peru–Brazil border. Our primary question is whether floristic variation at large scales arises from many gradual changes or a few abrupt ones. Data from 54 1-ha tree plots along the transect support the latter model, showing two sharp discontinuities in community structure at the genus level. One is located near the Ecuador–Peru border, where the suite of species that dominates large areas of Ecuadorean forest declines abruptly in importance to the east. This discontinuity is underlain by a subterranean paleoarch and congruent with a change in soil texture. A second discontinuity is associated with the shift from clay to white sand soils near Iquitos. We hypothesize that the first discontinuity is part of an edaphic boundary that runs along the Andean piedmont and causes a transition from tree communities preferring richer, younger soils near the base of the Andes to those preferring poorer, older soils farther east. Because the floristic changes observed at this discontinuity are conserved for large distances to the east and west of it, the discontinuity is potentially key for understanding floristic variation in western Amazonia. The significant floristic turnover at the Ecuador–Peru border suggests that the only large protected area in the region—Ecuador's Yasuní National Park—is not adequate protection for the very diverse tree communities that cover vast areas of northern Peru.  相似文献   

10.
Summary The incidence of phenylketonuria (PKU) in the western part of Poland is 1 in 5000 live births. Restriction fragment length polymorphism (RFLP) haplotypes at the phenylalanine hydroxylase locus have been analysed in 46 Polish families with PKU. Among 43 fully-informative families 16 RFLP haplotypes were identified. Haplotype 2 is the most frequently (62%) associated with Polish PKU alleles, and the codon 408 mutation is in complete linkage disequilibrium with this haplotype in Poland. This finding is in agreement with observations in other eastern European countries (German Democratic Republic, Czechoslovakia, and Hungary) and in contrast to the genotype distribution observed in western European countries. The present observation suggests the spread of classical PKU, due to the codon 408 mutation associated with haplotype 2, from east to west in European populations. Perhaps more important for genetic counselling, 62% of all PKU chromosomes in the Polish population can now be detected using only one mutantspecific oligonucleotide probe.  相似文献   

11.
Ips typographus populations were analysed by enzyme electrophoresis and by sequence analysis in order to quantify the degree of population differentiation. Enzyme electrophoresis showed a high gene flow among all European populations. Analysis of single loci showed that aspartate aminotransferase-2 ( Aat-2 ) clustered the Scandinavian populations apart from the other populations whereas other enzyme loci showed no significant pattern. Analysis of mitochondrial DNA revealed eight haplotypes. The populations from Italy, Croatia and Belgium were the most polymorphic. Two haplotypes (I and II) were found in the majority of Central European populations. In the northern populations only one haplotype (I) was found. The Russian and Lithuanian populations had a particular haplotype (IV) that was not found in any of the other populations. In view of these data it is suggested that the population structure of I. typographus has been influenced by events which took place during and after the last ice age. Populations were forced into refugial areas in the south and in the area north of Moscow along with the host tree, Picea abies . P. abies had four refugial areas: the Apennine Alps, the Dinaric Alps, the Carpathian Alps and Kostroma, an area north of Moscow. With amelioration of the temperature, beetles spread after P. abies . According to the data presented here, I. typographus migrated from the Apennine and/or Dinaric Alps to the north. Whilst there is evidence for high gene flow among populations, bottleneck effects can still be detected in the north and also in the east. Beetles from the refugial area north of Moscow did not spread to Scandinavia or to the west like the host tree.  相似文献   

12.
Abstract 1 The red turpentine beetle, Dendroctonus valens LeConte, is a recent New World introduction to the People's Republic of China. An outbreak of these beetles has infested over 0.5 million hectares of pine forests. 2 Efforts are underway to suppress this outbreak using biological control measures. However, the wide distribution in the native range of D. valens suggests regional variation of the beetle's biology, predators, and parasitoids. Thus, knowledge of the origin of these beetles can help devise precise and effective control measures. 3 A portion of the mitochondrial cytochrome oxidase subunit I gene was sequenced for 218 individuals from 32 populations throughout the native range of D. valens and in China. 4 Haplotype diversity was high. A total of 131 haplotypes were found and Jukes–Cantor corrected nucleotide difference ranged from 0 to 16%. Haplotype diversity ranged from 0.53 to 0.98 and unique haplotypes were found in most populations. 5 Parsimony and statistical parsimony analyses of these haplotypes support the hypothesis that the introduction of D. valens to China was recent and originated from the Pacific North‐west of the U.S.A. 6 In addition, the high haplotype diversity also suggests a large or multiple introductions. However, based on the genetics of the beetle's reproductive behaviour, this diversity may also be explained by a limited number of individuals or introductions.  相似文献   

13.
Leishmania (Viannia) peruviana was isolated from 1/75 Lutzomyia peruensis captured during May 2006 in an endemic cutaneous leishmaniasis region of the Peruvian Andes (Chaute, Huarochiri, Lima, Peru). Sand fly gut with promastigotes was inoculated into a hamster and the remaining body was fixed in ethanol. L. (Viannia) sp. was determined by polymerase chain reaction (PCR), and Leishmania species through molecular genotyping by PCR-restriction fragment length polymorphism analyses targeting the genes cpb and hsp70, resulting L. (V.) peruviana. The infected sand fly appeared 15 days after the rains finished, time expected and useful real time data for interventions when transmission is occurring.  相似文献   

14.
Gracilaria vermiculophylla (Ohmi) Papenf., an agar‐producing red alga introduced from northeast Asia to Europe and North America, is often highly abundant in invaded areas. To assay its genetic diversity and identify the putative source of invasive populations, we analyzed the mitochondrial cytochrome c oxidase subunit I (cox1) gene from 312 individuals of G. vermiculophylla collected in 37 native and 32 introduced locations. A total of 19 haplotypes were detected: 17 in northeast Asia and three in Europe and eastern and western North America, with only one shared among all regions. The shared haplotype was present in all introduced populations and in ~99% of individuals in the introduced areas. This haplotype was also found at three native locations in east Korea, west Japan, and eastern Russia. Both haplotype and nucleotide diversities were extremely low in Europe and North America compared to northeast Asia. Our study indicates that the East Sea/Sea of Japan is a likely donor region of the invasive populations of G. vermiculophylla in the east and west Atlantic and the east Pacific.  相似文献   

15.
ABSTRACT

The little-known Alucita danunciae Vargas, 2011 (Lepidoptera: Alucitidae) is recorded for the first time from Peru, expanding its altitudinal, geographic and host plant ranges. Its larvae were found on fruits of Tecoma fulva arequipensis (Bignoniaceae) at 2900 m elevation in Pocsi, Arequipa, on the western slopes of the Andes of southern Peru. Genetic divergence between the Chilean (type locality) and Peruvian DNA barcode haplotypes was 0.6–0.9% K2P.  相似文献   

16.
10个牛品种线粒体12S rRNA基因多态性分析   总被引:3,自引:0,他引:3  
孟彦  许尚忠  昝林森  高雪  陈金宝  任红  王兴平 《遗传》2006,28(4):422-426
以鲁西牛、渤海黑牛、大别山牛、南阳牛、晋南牛、秦川牛、中国西门塔尔牛、日本和牛、海福特牛和安格斯牛10个牛品种共计353头牛为研究对象,利用单链构象多态性(SSCP)分子标记方法对其线粒体DNA 12S rRNA基因进行了多态性分析,结果发现该基因出现分布频率不同的3种单倍型(Ⅰ、Ⅱ、Ⅲ),其中单倍型Ⅰ出现的频率最低,仅在晋南牛1个个体中发现;单倍型Ⅱ在中国本地黄牛中都存在,在中国西门塔尔牛中的分布频率很低,但在3个国外品种海福特牛、安格斯牛和日本和牛中不存在;单倍型Ⅲ在这10个牛品种中均有分布,但以国外品种最丰富。计算平均多态信息含量,发现我国地方品种在0.232~0.423之间,基本属于中度多态,说明我国地方黄牛品种在12S rRNA上多态性比较丰富,国外品种较为贫乏;但是单倍型Ⅰ频率很低有丢失的趋势,需要对其进行保护。  相似文献   

17.
Generally, oaks dominate the broadleaf deciduous forests in Japan. The genetic variation in 6 cpDNA regions (trnT-trnL, trnL-trnF, atpB-rbcL, and trnH-psbA speacers, trnL intron, and matK gene) with regard to the Japanese oak (Quercus mongolica var. crispula) and 3 related species in the section Prinus (Q. serrata, Q. dentata and Q. aliena) was investigated in 598 trees belonging to 44 populations distributed throughout the Japanese archipelago. Additional samples were collected from Korea, China, and Russia (Sakhalin). Thirteen haplotypes (I to XIII) were identified on the bases of 15 nucleotide substitutions and 3 indels. Haplotypes I and II were discovered in northeastern Japan, whereas haplotypes III to IX were distributed in southwestern Japan. The boundary distinguishing these 2 groups was located in central Japan coincident with the Itoigawa-Shzuoka tectonic line. Haplotype I was also found in Sakhalin, whereas haplotypes VI, VII, VIII, X, XI, XII, and XIII were found in Korea and China. Four oak species in the same location shared identical haplotypes, suggesting cpDNA introgression by occasional hybridization. Both the values of total haplotype diversity (HT) and haplotype diversity within populations (HS) in Q. mongolica var. crispula were higher in the southwestern populations than in the northeastern populations. A haplotype network indicated that haplotype VI is the ancestral haplotype. The presence of identical haplotypes in Korea, China, and Japan suggested that the haplotypes diversified on the Eurasian continent before the last glacial period. The difference in genetic structure between the northeastern and southwestern regions indicates a difference in the history of migration and recolonization in Japan during the last glacial period.  相似文献   

18.
Mitochondrial DNA variability has been analyzed in the primary screwworm fly (Cochliomyia hominivorax) using restriction endonuclease fragment patterns and restriction site mapping. A total of 30 different screwworm lines originating from Texas to Costa Rica and the Island of Jamaica was examined using 15 restriction endonucleases. Eleven of the restriction enzymes revealed polymorphism and yielded 16 mitochondrial genotypes or haplotypes. Two of the haplotypes were widely distributed, haplotype 1 being found scattered across southern Mexico and haplotype 2 along the west coast of Mexico. Haplotype 1 also appeared paired with several other haplotypes in mixed lines that were most likely the result of collecting an egg mass to which more than one female had contributed or to some form of contamination by haplotype 1 after introduction into the laboratory. These lines became fixed before single insects were examined and thus it is impossible to rule out heteroplasmy. The other 14 haplotypes were found in only a single locale and 12 of these were found in only one line. The average sequence diversity among 27 mainland lines was about 0.5%. The two Jamaican lines and one east coast mainland line differed from the others by greater than 2%. The pattern of geographical distribution, a small number of apparently recurring haplotypes and a substantial number (75%) of the haplotypes unique, bears similarities to patterns observed in other insects such as Drosophila. The high frequency of unique genotypes in southern Mexico suggests a population with a very reduced gene flow, which may have had a positive effect on the sterile male release control program.  相似文献   

19.
Sixty‐four samples from 46 salmon populations totalling 2369 specimens were used for polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) analysis of the mitochondrial ND1 region. The final analyses included 3095 specimens from 60 populations in Northern Europe. A subsample was analysed by RFLP of ND3/4/5/6. Representative RFLP haplotypes from different parts of the distribution area were sequenced and the phylogeny of European haplotypes and their relations to the North American lineage was described. The four common European haplotypes derive from the ancestral ND1‐BBBA (rooting the European clade to the North American) by one‐step substitutions: AAAA < AABA < BBBA > BBBB. The Swedish west‐coast populations differ from the geographically close southern Baltic, indicating absence of inward and limited outward gene flow through the Danish straits during the last 8000 years. Within the Baltic Sea, only three ND1 haplotypes were detected and there was no variation for ND3/4/5/6. In the whole southern Baltic and in lakes Vänern, Ladoga and Onega the haplotype AABA dominated. Proposed postglacial colonization routes to the Baltic Sea are discussed in relation to the haplotype distribution pattern.  相似文献   

20.
Testudo graeca is an endangered species of tortoise that inhabits Mediterranean areas of Africa, Asia, and Europe. Western populations are found on both sides of the Straits of Gibraltar. The effects of geographical isolation on genetic divergence were assessed by the sequence analysis of two mitochondrial DNA regions of the 12S rRNA and cytochrome b genes. Four different haplotypes were identified. A single haplotype was shared by all Spanish and some east Moroccan specimens. Two haplotypes were unique to the west Moroccan T. graeca populations and allowed the clear discrimination between individual specimens found west of the Moulouya River. Phylogenetic analysis based on the estimation of nucleotide sequence distances of the haplotypes suggests an African origin for the Spanish populations and a subspecies status for the west Moroccan pool.  相似文献   

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