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1. Analysis of mitochondrial and nuclear DNA (microsatellites) in 379 individuals, collected from 15 localities in northern Australia and Papua New Guinea (PNG), demonstrated that wild redclaw crayfish ( Cherax quadricarinatus ) populations consist of two highly divergent Australian lineages and two PNG lineages.
2. The disjunction between the two Australian lineages occurs over a distance of approximately 200 km in the south-western corner of the Gulf of Carpenteria. These data conflict with an earlier study that detected no significant differentiation in 23 variable allozyme loci in redclaw sampled from northern Australia, but concur broadly with the previous recognition of two morphologically distinct species ( C. quadricarinatus and C. bicarinatus ) across northern Australia, and a third species in PNG ( C. albertsii ).
3. The inferred timing and patterns of divergence evident in the molecular data presented here closely align with a similar pattern reported in a co-distributed freshwater decapod crustacean, and broadly reflect patterns in some vertebrate taxa with similar distributions across northern Australia and PNG.
4. These congruent patterns most probably reflect periodic Plio-Pleistocene land and freshwater connections between Australia and New Guinea.  相似文献   
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We report the presence, in the mitochondrial DNA (mtDNA) of all of the sexual species of the salamander family Ambystomatidae, of a shared 240- bp intergenic spacer between tRNAThr and tRNAPro. We place the intergenic spacer in context by presenting the sequence of 1,746 bp of mtDNA from Ambystoma tigrinum tigrinum, describe the nucleotide composition of the intergenic spacer in all of the species of Ambystomatidae, and compare it to other coding and noncoding regions of Ambystoma and several other vertebrate mtDNAs. The nucleotide substitution rate of the intergenic spacer is approximately three times faster than the substitution rate of the control region, as shown by comparisons among six Ambystoma macrodactylum sequences and eight members of the Ambystoma tigrinum complex. We also found additional inserts within the intergenic spacers of five species that varied from 87-444 bp in length. The presence of the intergenic spacer in all sexual species of Ambystomatidae suggests that it arose at least 20 MYA and has been a stable component of the ambystomatid mtDNA ever since. As such, it represents one of the few examples of a large and persistent intergenic spacer in the mtDNA of any vertebrate clade.   相似文献   
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Six microsatellite loci were identified and characterized in the eastern form of the widespread and commercially important giant freshwater prawn (Macrobrachium rosenbergii). The loci were detected by randomly screening for dinucleotide and trinucleotide repeat units within a partial genomic library developed for the species. In a sample of 29 prawns, number of alleles and heterozygosity per locus ranged from 12 to 18 and from 0.66 to 0.90, respectively. These markers provide powerful tools for the conservation and management of wild stocks, the improvement of cultured stocks of M. rosenbergii, and for investigating evolutionary processes underlying genetic divergence among populations.  相似文献   
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Mumps is one of the most common viruses to affect the central nervous system and should be given primary consideration in the differential diagnosis of aseptic meningitis. Many cases of numps infection do not involve the salivary glands. The course of numps meningoencephalitis is usually benign, with fever and signs of meningeal irritation lasting less than five days. The findings in the cerebrospinal fluid are usually distinctive, with leukocyte content greater than 200 per milliliter, of which 80 per cent or more are lymphocytes. Sequelae, even of a minor nature, are rare. Death is extremely rare in recorded literature. A fatal case of numps meningoencephalitis is described herein.  相似文献   
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Dage  JL; Ackermann  BL; Halsall  HB 《Glycobiology》1998,8(8):755-760
A simple, fast and sensitive method was developed to verify the presence of the sialyl Lewis(x) antigen on an N-linked glycoprotein. High performance liquid chromatography-electrospray mass spectrometry (HPLC-ESI/MS) was used to identify which of the five N-linked glycosylation sites of human plasma alpha1-acid-glycoprotein (orosomucoid, OMD) contain the sialyl Lewis(x) antigen. OMD was digested with proteolytic enzymes and analyzed by reversed phase chromatography coupled with on-line ESI/MS. A tandem mass spectrometry experiment was designed to detect the presence of the sialyl Lewis(x) antigen based on the observation of an 803 mass to charge ratio ( m/z ) ion produced in the intermediate pressure region of the ESI interface. The ESI/MS signal at m/z 803 is consistent with an oxonium ion for a glycan structure containing NeuAc, Gal, GlcNAc, and Fuc. The identity of the m/z 803 ion was confirmed by ESI/MS/MS analysis of the m/z 803 fragment ion and comparison with a sialyl Lewis(x) standard. The stereochemistry and linkage positions were assigned using previous NMR analysis but could be determined with permethylation analysis if necessary. The analysis of OMD gave a pattern showing signal for the sialyl Lewis(x) antigen coeluting with each of the five N-linked glycopeptides. The ability to monitor sialyl Lewis(x) expression at each of the five sites is of interest in the study of OMD's role in inflammatory diseases.   相似文献   
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