A genetically diverse but distinct North American population of Sarcocystis neurona includes an overrepresented clone described by 12 microsatellite alleles.
نویسندگان
چکیده
The population genetics and systematics of most coccidians remain poorly defined despite their impact on human and veterinary health. Non-recombinant parasite clones characterized by distinct transmission and pathogenesis traits persist in the coccidian Toxoplasma gondii despite opportunities for sexual recombination. In order to determine whether this may be generally true for tissue-cyst forming coccidia, and to address evolutionary and taxonomic problems within the genus Sarcocystis, we characterized polymorphic microsatellite markers in Sarcocystis neurona, the major causative agent of equine protozoal myeloencephalitis (EPM). Bayesian statistical modeling, phylogenetic reconstruction based on genotypic chord distances, and analyses of linkage disequilibrium were employed to examine the population structure within S. neurona and closely related Sarcocystis falcatula isolates from North and South America. North American S. neurona were clearly differentiated from those of South America and also from isolates of S. falcatula. Although S. neurona is characterized by substantial allelic and genotypic diversity typical of interbreeding populations, one genotype occurs with significantly excessive frequency; thus, some degree of asexual propagation of S. neurona clones may naturally occur. Finally, S. neurona isolated from disparate North American localities and diverse hosts (opossums, a Southern sea otter, and horses) comprise a single genetic population. Isolates associated with clinical neurological disease bear no obvious distinction as measured by these presumably neutral genetic markers.
منابع مشابه
Self-Mating in the Definitive Host Potentiates Clonal Outbreaks of the Apicomplexan Parasites Sarcocystis neurona and Toxoplasma gondii
Tissue-encysting coccidia, including Toxoplasma gondii and Sarcocystis neurona, are heterogamous parasites with sexual and asexual life stages in definitive and intermediate hosts, respectively. During its sexual life stage, T. gondii reproduces either by genetic out-crossing or via clonal amplification of a single strain through self-mating. Out-crossing has been experimentally verified as a p...
متن کاملModest genetic differentiation among North American populations of Sarcocystis neurona may reflect expansion in its geographic range.
Sarcocystis neurona is an important cause of neurological disease in horses (equine protozoal myeloencephalitis, EPM) and sea otters in the United States. In addition, EPM-like disease has been diagnosed in several other land and marine mammals. Opossums are its only definitive hosts. Little genetic diversity among isolates of S. neurona from different hosts has been reported. Here, we used 11 ...
متن کاملGenetic structure of Caspian Sea southern area honeybee populations, based on microsatellite polymorphism
Genetic diversity is a key component of ecosystems. The aim of the present study was to evaluate the genetic diversity of Iranian native honeybee colonies (Apis mellifera meda L.) located in the northern region. Colonies from 24 locations have been analyzed using microsatellite markers. Samples were collected from Caspian Sea southern area (north of Iran). Six microsatellite markers (A28, A29, ...
متن کاملMicrosatellite analysis reveals genetically distinct populations of red pine (Pinus resinosa, Pinaceae).
Red pine (Pinus resinosa Ait.) is an ecologically and economically important forest tree species of northeastern North America and is considered one of the most genetically depauperate conifer species in the region. We have isolated and characterized 13 nuclear microsatellite loci by screening a partial genomic library with di-, tri-, and tetranucleotide repeat oligonucleotide probes. In an ana...
متن کاملPrevalence of agglutinating antibodies to Sarcocystis neurona in skunks (Mephitis Mephitis), raccoons (Procyon lotor), and opossums (Didelphis Virginiana) from Connecticut.
Equine protozoal myeloencephalitis is the most important protozoan disease of horses in North America and is usually caused by Sarcocystis neurona. Natural cases of encephalitis caused by S. neurona have been reported in skunks (Mephitis mephitis) and raccoons (Procyon lotor). Opossums (Didelphis spp.) are the only known definitive host. Sera from 24 striped skunks, 12 raccoons, and 7 opossums ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases
دوره 6 5 شماره
صفحات -
تاریخ انتشار 2006