Population structure
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... One Reason 68 Photo Captions and Credits 120 Editorial Team 120 -- Selected Indicators for Less-Populous ... ... PALACKÉHO V OLOMOUCI -- & 1 -- Sign. 43- 6/ 04y - Knihovna katedry 7 2 / 4/37 -- THE STATE OF WORLD POPULATION ...
State of world population ; Y. 2005
iii, 119 s. : il.
- MeSH
- altruismus MeSH
- chudoba MeSH
- dorostové lékařství MeSH
- lidská práva MeSH
- násilí MeSH
- reprodukční zdraví MeSH
- sociální spravedlnost MeSH
- socioekonomické faktory MeSH
- zdravotní politika MeSH
- ženská práva MeSH
- Konspekt
- Demografie. Populace
- NLK Obory
- demografie
- veřejné zdravotnictví
- sociologie
- demografie
- veřejné zdravotnictví
- sociologie
- NLK Publikační typ
- ročenky
BACKGROUND: Cryptosporidium parvum is a zoonotic pathogen worldwide. Extensive genetic diversity and complex population structures exist in C. parvum in different geographical regions and hosts. Unlike the IIa subtype family, which is responsible for most zoonotic C. parvum infections in industrialized countries, IId is identified as the dominant subtype family in farm animals, rodents and humans in China. Thus far, the population genetic characteristics of IId subtypes in calves in China are not clear. METHODS: In the present study, 46 C. parvum isolates from dairy and beef cattle in six provinces and regions in China were characterized using sequence analysis of eight genetic loci, including msc6-7, rpgr, msc6-5, dz-hrgp, chom3t, hsp70, mucin1 and gp60. They belonged to three IId subtypes in the gp60 gene, including IIdA20G1 (n = 17), IIdA19G1 (n = 24) and IIdA15G1 (n = 5). The data generated were analyzed for population genetic structures of C. parvum using DnaSP and LIAN and subpopulation structures using STRUCTURE, RAxML, Arlequin, GENALEX and Network. RESULTS: Seventeen multilocus genotypes were identified. The results of linkage disequilibrium analysis indicated the presence of an epidemic genetic structure in the C. parvum IId population. When isolates of various geographical areas were treated as individual subpopulations, maximum likelihood inference of phylogeny, pairwise genetic distance analysis, substructure analysis, principal components analysis and network analysis all provided evidence for geographical segregation of subpopulations in Heilongjiang, Hebei and Xinjiang. In contrast, isolates from Guangdong, Shanghai and Jiangsu were genetically similar to each other. CONCLUSIONS: Data from the multilocus analysis have revealed a much higher genetic diversity of C. parvum than gp60 sequence analysis. Despite an epidemic population structure, there is an apparent geographical segregation in C. parvum subpopulations within China.
- MeSH
- Cryptosporidium parvum genetika izolace a purifikace MeSH
- Cryptosporidium genetika izolace a purifikace MeSH
- fylogeneze MeSH
- fylogeografie MeSH
- genetická variace MeSH
- genotyp MeSH
- kryptosporidióza epidemiologie MeSH
- lidé MeSH
- multilokusová sekvenční typizace MeSH
- nemoci skotu epidemiologie parazitologie MeSH
- populační genetika MeSH
- protozoální geny MeSH
- skot MeSH
- zoonózy epidemiologie parazitologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- skot MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Čína MeSH
In order to disentangle the contribution of host and parasite biology to host specificity, we compared the structure and population dynamics of the Gyrodactylus (von Nordmann, 1832) flatworm community living on sympatric three-spined Gasterosteus aculeatus L. and nine-spined Pungitius pungitius (L.) stickleback. Between April 2002 and March 2003, a small lowland creek was sampled monthly. Species identity of about 75% of the worms per host was determined with a genetic nuclear marker (ITS1). Each stickleback species hosted a characteristic gill- and fin-parasitic Gyrodactylus: G. arcuatus Bychowsky, 1933 and G. gasterostei Gläser, 1974 respectively infecting the three-spined stickleback, with G. rarus Wegener, 1910 and G. pungitii Malmberg, 1964 infecting the nine-spined stickleback. Host size and seasonal dynamics were strong determinants of parasite abundance. A strong interaction between host and parasite species determined infection levels and affected three levels of parasite organisation: community structure, population structure and topographical specialisation. Community and population structure were shaped by asymmetric cross-infections, resulting in a net transmission of the Gyrodactylus species typical of the nine-spined stickleback towards the three-spined stickleback. Host density was not a major determinant of parasite exchange. Aggregation and topographical specialisation of the Gyrodactylus species of the three-spined stickleback were more pronounced than that of the nine-spined stickleback.
- MeSH
- časové faktory MeSH
- druhová specificita MeSH
- ekosystém MeSH
- infekce červy třídy Trematoda parazitologie veterinární MeSH
- nemoci ryb parazitologie MeSH
- pohlavní dimorfismus MeSH
- populační dynamika MeSH
- roční období MeSH
- Smegmamorpha genetika klasifikace parazitologie MeSH
- Trematoda klasifikace parazitologie MeSH
- velikost těla MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
BACKGROUND: Detailed knowledge of spatial and temporal variation in the genetic population structure of hosts and parasites is required for understanding of host - parasite coevolution. As hot-spots of contemporary coevolution in natural systems are difficult to detect and long-term studies are restricted to few systems, additional population genetic data from various host - parasite systems may provide important insights into the topic. This is particularly true for parasites, as these players have been under-investigated so far due to the lower availability of suitable molecular markers. Here, we traced genetic variation (based on sequence variants in the internal transcribed spacer region, ITS) among seven geographically isolated populations of the ichthyosporean Caullerya mesnili, a common microparasite of the cladoceran Daphnia (here, the D. longispina hybrid complex). At three sites, we also studied parasite genetic variation over time (three to four sampling points) and tested for associations between parasite genotypes and host species. RESULTS: Parasite (and host) populations were significantly structured across space, indicating limited dispersal. Moreover, the frequency of parasite genotypes varied significantly over time, suggesting rapid evolutionary change in Caullerya. However, the distribution of parasite genotypes was similar across different host species, which might in turn have important consequences for parasite epidemiology. CONCLUSIONS: The approach proposed here can be applied to track spatial and temporal changes in the population structure of other microparasite species for which sequence variation in the ITS or other highly variable genome regions has been documented but other types of polymorphic markers are lacking. Screening of parasite sequence variants allows for reliable detection of cross-species infections and, using advanced sequencing techniques in the near future, for detailed studies of parasite evolution in natural host - parasite systems.
- MeSH
- biologická evoluce MeSH
- Daphnia parazitologie MeSH
- Eukaryota klasifikace genetika MeSH
- genetická variace MeSH
- mezerníky ribozomální DNA genetika MeSH
- molekulární sekvence - údaje MeSH
- sladká voda MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
- MeSH
- adaptace psychologická MeSH
- dospělí MeSH
- lidé MeSH
- osobnost MeSH
- psychický stres MeSH
- srovnání kultur MeSH
- životní změny MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- Geografické názvy
- Česká republika MeSH
- Spojené státy americké MeSH
