972 resultados para Microbial diversity


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Genetic variation of 31 blood protein loci in 236 cattle from eight South China populations (including mithan, Bos frontalis) and a Holstein population was investigated by means of horizontal starch gel electrophoresis. Thirteen loci (ALB, CAR, Hb-b, Np, PGM, Amy-I, PEP-B, AKP, 6PGD, Cp, Pa, EsD, and TF) were found to be polymorphic. The comparison of average heterozygosities (H) shows that all the native cattle embrace a rich genetic diversity Our results on protein polymorphism suggest that cattle in China originated mainly from Bos indicus and Bos taurus; Xuwen, Hainan, Wenshan, and Dehong cattle and the Dehong zebu are close to zebu-type cattle, and Diqing and Zhaotong cattle are close to the taurine. The mithan was very different from other native cattle, and we suggest that its origin was complicated and may be influenced by other cattle species.

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We examined protein polymorphism of 20 native pig breeds in China and 3 introduced pig breeds. Thirty loci have been investigated, among which six loci were found to be polymorphic. Especially, the polymorphism of malate dehydrogenase (MDH), adenylate kinase (AK), and two new alleles of adenosine deaminase (ADA) had not been reported in domestic pigs and wild pigs. The percentage of polymorphic loci (P), the mean heterozygosity (H), and the mean number of alleles (A) are 0.200, 0.065, and 1.300, respectively. The degree of genetic variability of Chinese pigs as a whole was higher than that of goats, lower than that of cattle and horses, and similar to that of sheep. Using the gene frequencies of the 30 loci, Nei's genetic distance among the 20 native breeds in China and 3 introduced pig breeds was calculated by the formula of Nei. The program NEIGHBOR in PHYLIP 3.5c was chosen to construct an UPGMA tree and a NJ tree. Our results show that, of the total genetic variation found in the native pig breeds in China, 31% (0.31) is ascribable to genetic differences among breeds. About 69% of the total genetic variation is found within breeds. Most breeds are in linkage disequilibrium. The patterns of genetic similarities between the Chinese native pig breeds were not in agreement with the proposed pig type classification.

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Random amplified polymorphic DNA (RAPD) markers are used to investigate genetic variation and evolutionary relationships of 29 samples of Cordyceps sinensis from different geographical populations on the Qinghai-Tibet plateau. Out of 137 RAPD bands scored, 100 are polymorphic. A correlation is revealed between geographical distance and genetic distance. The molecular phylogenetic tree suggests that the 29 samples are divided into three notable clusters, corresponding to the geographical populations, i.e., the north population (NP), middle population (MP), and south population (SP). The NP consists of 7 northern samples from Menyuan, Maqu, and Luqu, the MP consists of 8 samples from Yushu and Chengduo, and the SP consists of 14 samples from Byma Snow Mountain, Renzhi Snow Moutain, Chongcaoxiwa, and Dacaodi. It is demonstrated that extensive genetic diversity is found among different geographical populations of C. sinensis. The genetic diversity pattern of C. sinensis may be caused by the founder effects. The taxonomic status of NP, MP, and SP populations should be that they are different subspecies rather than different species.

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Partial sequences of the mitochondrial cytochrome b gene of the Korean hare (Lepus coreanus) were analyzed to determine the degree of genetic diversity. Nine haPlotyes were observed, and the maximum Tamura-Nei nucleotide distance among them was 2.8%, indicating that genetic diversity of L. coreanus is moderate. In order to clarify the Korean hare's taxonomic status and relationship with the Manchurian hare (L. mandshuricus) and the Chinese hare (L. sinensis), these nine haplotypes of the Korean hare were compared with 13 haplotypes from five other species of eastern Asian Lepus including L. mandshwicus and L. sinensis. The Korean hare was distinct in its cytochrome b gene, and it is confirmed that L. coreanus is a valid species, as noted by Jones and Johnson (1965, Univ. Kansas Publ. (Mus. Nat. Hist.) 16:357). Further analyses of mtDNA cytochrome b gene with additional specimens of L. coreanus from North Korea and other species of Lepus from eastern Asia are needed to clarify the taxonomic status of the divergent mtDNA clades of L. mandshuricus and L. sinensis.

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The loss of biodiversity resulting from extinctions is receiving increasing attention. Over several thousands of animal species have been evaluated and recognized as endangered species. Inbreeding depression has been demonstrated in many wild animal speci

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The first 539 bases of mitochondrial DNA D-loop region of six Chinese native chicken breeds (Gallus gallus domesticus) were sequenced and compared to those of the red junglefowl (Gallus gallus), the gray junglefowl (Gallus sonneratii), the green junglefow

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The origin and demographic history of the ethnic populations of China have not been clearly resolved. In this study, we examined the hypervariable segment I sequences (HVSI) of the mitochondrial DNA control region in 372 individuals from nine Chinese popu

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Golden monkey (Rhinopithecus roxellana), namely the snub-nosed monkey, is a well-known endangered primate, which distributes only in the central part of mainland China. As an effort to understand the current genetic status as well as population history of this species, we collected a sample of 32 individuals from four different regions, which cover the major habitat of this species. Forty-four allozyme loci were surveyed in our study by allozyme electrophoresis, none of which was found to be polymorphic. The void of polymorphism compared with that of other nonhuman primates is surprising particularly considering that the current population size is many times larger than that of some other endangered species. Since many independent loci are surveyed in this Study, the most plausible explanation for our observation is that the population has experienced a recent bottleneck. We used a coalescent approach to explore various scenarios of population bottleneck and concluded that the most recent bottleneck could have happened within the last 15,000 years. Moreover, the proposed simulation approach could be useful to researchers who need to analyze the non- or low-polymorphism data.

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In this paper we examine the use of electronic patient records (EPR) by clinical specialists in their development of multidisciplinary care for diagnosis and treatment of breast cancer. We develop a practice theory lens to investigate EPR use across multidisciplinary team practice. Our findings suggest that there are oppositional tendencies towards diversity in EPR use and unity which emerges across multidisciplinary work, and this influences the outcomes of EPR use. The value of this perspective is illustrated through the analysis of a year-long, longitudinal case study of a multidisciplinary team of surgeons, oncologists, pathologists, radiologists, and nurse specialists adopting a new EPR. Each group adapted their use of the EPR to their diverse specialist practices, but they nonetheless orientated their use of the EPR to each others' practices sufficiently to support unity in multidisciplinary teamwork. Multidisciplinary practice elements were also reconfigured in an episode of explicit negotiations, resulting in significant changes in EPR use within team meetings. Our study contributes to the growing literature that questions the feasibility and necessity of achieving high levels of standardized, uniform health information technology use in healthcare.

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This report briefly describes the microbial status and storage properties of fish raised under composite fish culture in sewage fed ponds.

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In this study, random amplified polymorphic DNA (RAPD) analysis was used to estimate genetic diversity and relationship in 134 samples belonging to two native cattle breeds from the Yunnan province of China (DeHong cattle and DiQing cattle) and four intro

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China has numerous native domestic goat breeds, but so far there has been no extensive study on genetic diversity, population demographic history, and origin of Chinese goats. Here, we examined the genetic diversity and phylogeographic structure of Chinese domestic goats by determining a 481-bp fragment of the first hypervariable region of mitochondrial DNA (mtDNA) control region from 368 individuals representing 18 indigenous breeds. Phylogenetic analyses revealed that there were four mtDNA lineages (A-D) identified in Chinese goats, in which lineage A was predominant, lineage B was moderate, and lineages C and D were at low frequency. These results further support the multiple maternal origins of domestic goats. The pattern of genetic variation in goat mtDNA sequences indicated that the two larger lineages A and B had undergone population expansion events. In a combined analysis of previously reported sequences and our sequences belonging to lineage B, we detected two subclades, in which one was unique to eastern Asia and another was shared between eastern and southern Asia. A larger genetic variation in eastern Asia than southern Asia and the pattern of phylogeographic variation in lineage B suggest that at least one subclade of lineage B originated from eastern Asia. There was no significant geographical structuring in Chinese goat populations, which suggested that there existed strong gene flow among goat populations caused by extensive transportation of goats in history. (c) 2005 Elsevier Inc. All rights reserved.

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A total of 38 Amiota (s. str.) species (about 40% of the world total) are reported from southern China, with descriptions of 23 new species, i.e. sinuata species-group: aculeata Chen and Aotsuka, sp. nov., subsinuata Chen and Aotsuka, sp. nov., xishuangbanna Chen and Aotsuka, sp. nov.; basdeni species-group: brevipartita Chen and Gao, sp. nov., curvispina Chen and Gao, sp. nov., lipingae Chen and Gao, sp. nov., huae Chen and Gao, sp. nov., longispina Chen and Gao, sp. nov.; taurusata species-group: asymmetrica Chen and Takamori, sp. nov.; femorata Chen and Takamori, sp. nov., yixiangensis Chen and Takamori, sp. nov.; alboguttata species-group: ailaoshanensis Chen and Watabe, sp. nov., arcuata Chen and Watabe, sp. nov., dehiscentia Chen and Watabe, sp. nov., jizushanensis Chen and Watabe, sp. nov., latitabula Chen and Watabe, sp. nov., luguhuensis Chen and Watabe, sp. nov., nozawai Chen and Watabe, sp. nov., paraspinata Chen and Watabe, sp. nov., shangrila Chen and Watabe, sp. nov.; and ungrouped: fuscicata Chen and Zhang, sp. nov., wangi Chen and Zhang, sp. nov., wuyishanensis Chen and Zhang, sp. nov. A key to all species from southern China is provided. The Amiota fauna of southern China at the species-group level is compared with that of six geographic regions. The subgenus Amiota is assumed to have originated and produced many species-groups in the Oriental region of East Asia, and then the basdeni, alboguttata and rufescens species-groups might have spread to Europe and North-Central America throughout the Palearctic region of East Asia and both the apodemata, sinuata and nagatai species-groups to tropical regions of South-East Asia.

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To characterize the origin, genetic diversity, and phylogeographic structure of Chinese domestic sheep, we here analyzed a 531-bp fragment of mtDNA control region of 449 Chinese autochthonous sheep from 19 breeds/populations from 13 geographic regions, to