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1.
mtDNA diversity in rhesus monkeys reveals overestimates of divergence time and paraphyly with neighboring species 总被引:4,自引:0,他引:4
Reconstructions of the human-African great ape phylogeny by using
mitochondrial DNA (mtDNA) have been subject to considerable debate. One
confounding factor may be the lack of data on intraspecific variation. To
test this hypothesis, we examined the effect of intraspecific mtDNA
diversity on the phylogenetic reconstruction of another Plio- Pleistocene
radiation of higher primates, the fascicularis group of macaque (Macaca)
monkey species. Fifteen endonucleases were used to identify 10 haplotypes
of 40-47 restriction sites in M. mulatta, which were compared with similar
data for the other members of this species group. Interpopulational,
intraspecific mtDNA diversity was large (0.5%- 4.5%), and estimates of
divergence time and branching order incorporating this variation were
substantially different from those based on single representatives of each
species. We conclude that intraspecific mtDNA diversity is substantial in
at least some primate species. Consequently, without prior information on
the extent of genetic diversity within a particular species, intraspecific
variation must be assessed and accounted for when reconstructing primate
phylogenies. Further, we question the reliability of hominoid mtDNA
phylogenies, based as they are on one or a few representatives of each
species, in an already depauperate superfamily of primates.
相似文献
2.
The ITS sequences of Acropora spp. are the shortest so far identified in
any metazoan and are among the shortest seen in eukaryotes; ITS1 was 70-80
bases, and ITS2 was 100-112 bases. The ITS sequences were also highly
variable, but base composition and secondary structure prediction indicate
that divergent sequence variants are unlikely to be pseudogenes. The
pattern of variation was unusual in several other respects: (1) two
distinct ITS2 types were detected in both A. hyacinthus and A. cytherea,
species known to hybridize in vitro with high success rates, and a putative
intermediate ITS2 form was also detected in A. cytherea; (2) A. valida was
found to contain highly (29%) diverged ITS1 variants; and (3) A.
longicyathus contained two distinct 5.8S rDNA types. These data are
consistent with a reticulate evolutionary history for the genus Acropora.
相似文献
3.
Squirrell J Hollingsworth PM Bateman RM Tebbitt MC Hollingsworth ML 《Molecular ecology》2002,11(10):1957-1964
The genus Epipactis contains a problematical complex of autogamous taxa among which species limits are difficult to define. Different authors have treated these plants in different ways, some recognizing the different taxa as distinct species, others considering them as minor intraspecific variants. These contrasting treatments have a direct impact on the conservation resources and status such plants command; 'endemic orchid species' are perceived as having high conservation value, 'localized minor variants' are not. We used allozyme and chloroplast restriction fragment length polymorphism (RFLP) and sequencing analyses to investigate patterns of population genetic structure underlying the taxonomic complexity in this group. Populations of E. dunensis, E. leptochila and E. muelleri were homozygous and uniform for all loci studied here. There were, however, fixed genetic differences among these taxa. Comparisons with published data from the putative progenitor species for the autogamous taxa (the widespread, allogamous E. helleborine) suggest iterative origins of autogamy, rather than the self-pollinating taxa all being merely mutational variants of a single autogamous lineage. 相似文献
4.
P Fuentes-Utrilla M Venturas P M Hollingsworth J Squirrell C Collada G N Stone L Gil 《Heredity》2014,112(2):105-113
Conservation policies usually focus on in situ protection of native populations,
a priority that requires accurate assessment of population status. Distinction between
native and introduced status can be particularly difficult (and at the same time, is most
important) for species whose natural habitat has become both rare and highly fragmented.
Here, we address the status of the white elm (Ulmus laevis Pallas), a European
riparian tree species whose populations have been fragmented by human activity and is
protected wherever it is considered native. Small populations of this species are located
in Iberia, where they are unprotected because they are considered introductions due to
their rarity. However, Iberia and neighbouring regions in southwestern France have been
shown to support discrete glacial refuge populations of many European trees, and the
possibility remains that Iberian white elms are native relicts. We used chloroplast RFLPs
and nuclear microsatellites to establish the relationship between populations in Iberia
and the Central European core distribution. Bayesian approaches revealed significant
spatial structure across populations. Those in Iberia and southwestern France shared
alleles absent from Central Europe, and showed spatial population structure within Iberia
common in recognized native taxa. Iberian populations show a demographic signature of
ancient population bottlenecks, while those in Central European show a signature of recent
population bottlenecks. These patterns are not consistent with historical introduction of
white elm to Iberia, and instead strongly support native status, arguing for immediate
implementation of conservation measures for white elm populations in Spain and contiguous
areas of southern France. 相似文献
5.
Muma JB Lund A Siamudaala VM Munang'andu HM Munyeme M Matope G Nielsen K DJønne B Godfroid J Tryland M Skjerve E 《Journal of wildlife diseases》2010,46(4):1063-1069
One of the diseases of veterinary and public health importance affecting the Kafue lechwe (Kobus leche kafuensis) on the Kafue flats is brucellosis, for which only scant information is available. During the 2003 (October), 2004 (December), and 2008 (July-December) hunting seasons in the Kafue flats, we conducted a study to determine the seroprevalence of Brucella spp. in the Kafue lechwe and to evaluate serologic tests for detection of Brucella spp. antibodies in lechwe. The Rose Bengal Test (RBT), competitive enzyme-linked immunosorbent assay (cELISA), and fluorescence polarization assay (FPA) were used. A total of 121 Kafue lechwe were hunted for disease investigations in 2003, 2004, and 2008 in the Kafue Flat Game Management Area. Of these, 21.6%, (95% confidence interval [CI]: 14.2-29.1%) had detectable antibodies to Brucella spp. The Kafue lechwe in Lochnivar National Park had higher antibody results than those in Blue Lagoon National Park (odds ratio=3.0; 95% CI: 0.94-9.4). Infection levels were similar in females (21.6%) and males (21.7%). Results were similar among RBT, FPA, cELISA tests, suggesting that these could effectively be used in diagnosing brucellosis in the Kafue lechwe. Our study demonstrates the presence of Brucella infections in the Kafue lechwe in two national parks located in the Kafue flats and further highlights the suitability of serologic assays for testing the Kafue lechwe. Because the Kafue lechwe is the most hunted wildlife species in Zambia, hunters need to be informed of the public health risk of Brucella spp. infection. 相似文献
6.
Woodhead M Russell J Squirrell J Hollingsworth PM Mackenzie K Gibby M Powell W 《Molecular ecology》2005,14(6):1681-1695
To examine the performance and information content of different marker systems, comparative assessment of population genetic diversity was undertaken in nine populations of Athyrium distentifolium using nine genomic and 10 expressed sequence tag (EST) microsatellite (SSR) loci, and 265 amplified fragment length polymorphism (AFLP) loci from two primer combinations. In range-wide comparisons (European vs. North American populations), the EST-SSR loci showed more reliable amplification and produced more easily scorable bands than genomic simple sequence repeats (SSRs). Genomic SSRs showed significantly higher levels of allelic diversity than EST-SSRs, but there was a significant correlation in the rank order of population diversities revealed by both marker types. When AFLPs, genomic SSRs, and EST-SSRs are considered, comparisons of different population diversity metrics/markers revealed a mixture of significant and nonsignificant rank-order correlations. However, no hard incongruence was detected (in no pairwise comparison of populations did different marker systems or metrics detect opposingly significant different amounts of variation). Comparable population pairwise estimates of F(ST) were obtained for all marker types, but whilst absolute values for genomic and EST-SSRs were very similar (F(ST) = 0.355 and 0.342, respectively), differentiation was consistently higher for AFLPs in pairwise and global comparisons (global AFLP F(ST) = 0.496). The two AFLP primer combinations outperformed 18 SSR loci in assignment tests and discriminatory power in phenetic cluster analyses. The results from marker comparisons on A. distentifolium are discussed in the context of the few other studies on natural plant populations comparing microsatellite and AFLP variability. 相似文献
7.
Susan DJ Chapple Anna M Crofts S Paul Shadbolt John McCafferty Michael R Dyson 《BMC biotechnology》2006,6(1):49-15
Background
A variety of approaches to understanding protein structure and function require production of recombinant protein. Mammalian based expression systems have advantages over bacterial systems for certain classes of protein but can be slower and more laborious. Thus the availability of a simple system for production and rapid screening of constructs or conditions for mammalian expression would be of great benefit. To this end we have coupled an efficient recombinant protein production system based on transient transfection in HEK-293 EBNA1 (HEK-293E) suspension cells with a dot blot method allowing pre-screening of proteins expressed in cells in a high throughput manner. 相似文献8.
JM Squirrell JJ Fong CA Ariza A Mael K Meyer NK Shevde A Roopra GE Lyons TJ Kamp KW Eliceiri BM Ogle 《PloS one》2012,7(8):e43708
The therapeutic potential of stem cells is limited by the non-uniformity of their phenotypic state. Thus it would be advantageous to noninvasively monitor stem cell status. Driven by this challenge, we employed multidimensional multiphoton microscopy to quantify changes in endogenous fluorescence occurring with pluripotent stem cell differentiation. We found that global and cellular-scale fluorescence lifetime of human embryonic stem cells (hESC) and murine embryonic stem cells (mESC) consistently decreased with differentiation. Less consistent were trends in endogenous fluorescence intensity with differentiation, suggesting intensity is more readily impacted by nuances of species and scale of analysis. What emerges is a practical and accessible approach to evaluate, and ultimately enrich, living stem cell populations based on changes in metabolism that could be exploited for both research and clinical applications. 相似文献
9.
Study design
A prospective treatment study with a new brace was conducted Objective. To evaluate radiological and subjective clinical results after one year conservative brace treatment with pressure onto lordosis at the thoracolumbar joint in children with scoliosis and kyphosis.Summary of background data
Conservative brace treatment of adolescent scoliosis is not proven to be effective in terms of lasting correction. Conservative treatment in kyphotic deformities may lead to satisfactory correction. None of the brace or casting techniques is based on sagittal forces only applied at the thoracolumbar spine (TLI= thoracolumbar lordotic intervention). Previously we showed in patients with scoliosis after forced lordosis at the thoracolumbar spine a radiological instantaneous reduction in both coronal curves of double major scoliosis.Methods
A consecutive series of 91 children with adolescent scoliosis and kyphosis were treated with a modified symmetric 30 degrees Boston brace to ensure only forced lordosis at the thoracolumbar spine. Scoliosis was defined with a Cobb angle of at least one of the curves [greater than or equal to] 25 degrees and kyphosis with or without a curve <25 degrees in the coronal plane. Standing radiographs were made i) at start, ii) in brace at beginning and iii) after one year treatment without brace.Results
Before treatment start ??in brace?? radiographs showed a strong reduction of the Cobb angles in different curves in kyphosis and scoliosis groups (sagittal n = 5 all p < 0.001, pelvic obliquity p < 0.001). After one year of brace treatment in scoliosis and kyphosis group the measurements on radiographs made without brace revealed an improvement in 3 Cobb angles each.Conclusion
Conservative treatment using thoracolumbar lordotic intervention in scoliotic and kyphotic deformities in adolescence demonstrates a marked improvement after one year also in clinical and postural criteria. An effect not obtained with current brace techniques. 相似文献10.