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Results for “subspecies separation”

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PubMed1982

NS phosphoprotein of vesicular stomatitis virus: subspecies separated by electrophoresis and isoelectric focusing.

The NS protein of vesicular stomatitis virus is the only phosphorylated nucleocapsid protein. The amount of NS phosphorylation appears to regulate the activity of the protein in the transcription of the virus genome. Several methods have been used to separate NS subspecies containing different amounts of phosphate, but the relationships among the subspecies separated by different workers have been unclear. We report that the isoelectric points of NS molecules were abnormally acidic in some commercial ampholytes, but favorable ampholytes resolved multiple phosphorylated NS subspecies with isoelectric points ranging from pH 6.8 to 7.2. The most highly phosphorylated NS molecules had more acidic isoelectric points, and they exhibited greater electrophoretic mobilities in two previously employed electrophoretic systems.

Capsid↗

PubMed1988

Further resolution of the low density lipoprotein spectrum in normal human plasma: physicochemical characteristics of discrete subspecies separated by density gradient ultracentrifugation.

The molecular basis of the heterogeneity of plasma low density lipoproteins (LDL, d 1.024-1.050 g/ml) was evaluated in 40 normolipidemic male subjects following fractionation by isopycnic density gradient ultracentrifugation into eight major subspecies. The mass profile of our subjects' LDL uniformly displayed single symmetric or asymmetric peaks as a function of density; the peak occurred most frequently (20 subjects) in subfraction 7 (d 1.0297-1.0327 g/ml). Several physicochemical properties (hydrodynamic behavior, electrophoretic mobility, chemical composition, size and particle heterogeneity, and apolipoprotein heterogeneity) of the LDL subfractions were examined. Hydrodynamic analyses revealed unimodal distributions and distinct peak Sf degree rates in individual subfractions. Such behavior correlated well with particle size and heterogeneity data, in which LDL subspecies were typically resolved as unique narrow bands by gradient gel electrophoresis. Subspecies with average densities of 1.024 to 1.0409 g/ml ranged from 229 to 214 A in particle diameter. LDL protein content increased in parallel with density while the proportion of triglyceride diminished; cholesteryl esters predominated, accounting for approximately 40% or more by weight. Distinct differences in net electric charge were demonstrated by electrophoresis in agarose gel, the subspecies with average density of 1.0314 g/ml displaying the lowest net negative charge. ApoB-100 was the major apoprotein in all subspecies, and constituted the unique protein component over the density interval 1.0271-1.0393 g/ml. ApoE and apo[a] were detected at densities less than 1.0271 and greater than 1.0393 g/ml. While apoE was evenly distributed within these two regions, representing up to 2% of apoLDL, the distribution of apo[a] was skewed towards the denser region, in which it amounted to 3-7% of apoLDL. ApoC-III was detectable as a trace component at densities greater than 1.0358 g/ml. Calculation of the number of molecules of each chemical component per LDL subspecies showed the presence of one copy of apoB-100 per particle, in association with decreasing amounts of cholesteryl ester, free cholesterol, and phospholipid. These data indicate that a similar overall molecular organization and structure is maintained in a unimodal distribution of LDL particle subspecies over the density range approximately 1.02 to 1.05 g/ml. In sum, our data may be interpreted to suggest that microheterogeneity in the physicochemical properties of human LDL subspecies reflects dissimilarities in their origins, intravascular metabolism, tissular fate, and possibly in their atherogenicity.

Adult↗

PubMed2006

Polyphasic analysis indicates that Lactobacillus salivarius subsp. salivarius and Lactobacillus salivarius subsp. salicinius do not merit separate subspecies status.

Lactobacillus salivarius Rogosa et al. 1953 was described as a homofermentative lactobacillus with two varieties: salivarius, typified inter alia by the ability to ferment rhamnose, and salicinius, characterized by the ability to ferment the glucoside salicin. These varieties have become accepted as subspecies divisions. We have examined the relatedness of 32 L. salivarius strains by a polyphasic approach. Carbohydrate fermentation profile analysis did not support clear distinction of the two subspecies. L. salivarius UCC118 was shown to be facultatively heterofermentative, confirming in silico genome analysis. 16S rRNA gene sequences and 16S-23S rRNA intergenic spacer region sequences provided no discrimination between any of the strains or subspecies. Broad subdivisions were distinguishable by pulsed-field gel genomic digest patterns, but they did not allow subspecific or phenotypic distinctions. A phylogeny based upon groEL gene sequences was discordant with rhamnose or salicin fermentation data for many taxa, and no reliable phenotypic correlations could be established. In the absence of meaningful taxonomic criteria, we therefore propose that Lactobacillus salivarius comprises a single species with no infraspecific taxa. Based on the present study and literature data, an emended description of the species Lactobacillus salivarius is provided.

Aged↗

PubMedDate not supplied

Molecular genetic divergence of orang utan (Pongo pygmaeus) subspecies based on isozyme and two-dimensional gel electrophoresis.

The orang utan (Pongo pygmaeus), as currently recognized, includes two geographically separated subspecies: Pongo pygmaeus pygmaeus, which resides on Borneo, and P. p. abelii, which inhabits Sumatra. At present, there is no known route of gene flow between the two populations except through captive individuals which have been released back into the wild over the last several decades. The two subspecies are differentiated by morphological and behavioral characters, and they can be distinguished by a subspecies specific pericentric chromosomal inversion. Nei-genetic distances were estimated between orang utan subspecies, gorilla, chimpanzee and humans using 44 isozyme loci and using 458 soluble fibroblast proteins which were resolved by two-dimensional gel electrophoresis. Phenetic analysis of both data sets supports the following conclusions: the orang utan subspecies distances are approximately 10 times closer to each other than they are to the African apes, and the orang utan subspecies are approximately as divergent as are the two chimpanzee species. Comparison of the genetic distances to genetic distance estimates done in the same laboratory under identical conditions reveals that the distance between Bornean vs. Sumatran orang utans is 5-10 times the distance measured between several pairs of subspecies including lions, cheetahs, and tigers. Near species level molecular genetic distances between orang utan subspecies would support the separate management of Bornean and Sumatran orang utans as evolutionary significant units (Ryder 1987). Evolutionary topologies were constructed from the distance data using both cladistic and phenetic methods. The majority of resulting trees affirmed previous molecular evolutionary studies that indicated that man and chimpanzee diverged from a common ancestor subsequent to the divergence of gorilla from the common ancestor.

Animals↗

PubMed1987

Characterization of high density lipoprotein subspecies: structural studies by single vertical spin ultracentrifugation and immunoaffinity chromatography.

Affinity columns containing anti-apolipoprotein A-I or A-II were used to fractionate plasma into subpopulations of lipoprotein particles containing: a) apoA-I [Lp(A-I)], b) apoA-I and A-II [Lp(A-I with A-II)], and c) apoA-I but no A-II [Lp(A-I without A-II)]. Single vertical spin and electron microscopy analyses of these HDL subpopulations demonstrated that acid elution from the affinity columns caused no detectable change in size and density of the three subpopulation particles. Analysis by nondenaturing gradient gel electrophoresis of the three subpopulations found in four normal subjects identified nine HDL subspecies, designated [1] through [9] in order of increasing size; [3-7] were the major subspecies. Lp(A-I with A-II) is composed primarily of subspecies [3],[5], and [6], and may contain some subspecies [2] and [7], while Lp(A-I without A-II) represents mainly [4] and [7] and the minor subspecies [1],[2],[8], and [9]. HDL subspecies [4],[5], and [6] are found in the standard sequential flotation density cuts for both HDL3 and HDL2, which illustrates the limitations of the latter terminology. Using single vertical spin ultracentrifugation, HDL fractions were located and isolated for physical and chemical analyses, including immunoassay for apoA-I, A-II, and C-II. The distribution of the Lp(A-I without A-II) particles corresponded closely to the apoC-II distribution. An apoA-I-rich, cholesteryl ester- and phospholipid-poor subspecies was identified in the dense HDL fractions. HDL subspecies [7] was found to contain at least three separate subspecies designated [7a], [7b], and [7c]. Based on these and previously published results (Brouillette, C. G., et al. 1984. Biochemistry. 23: 359-367), we propose that the HDL subspecies adjacent in size generally differ by the association/lack of association of a hinge-like domain of amphipathic helixes in a single molecule of apoA-I.

Adult↗

PubMed2007

Multilocus analysis of nucleotide variation of Oryza sativa and its wild relatives: severe bottleneck during domestication of rice.

Varying degrees of reduction of genetic diversity in crops relative to their wild progenitors occurred during the process of domestication. Such information, however, has not been available for the Asian cultivated rice (Oryza sativa) despite its importance as a staple food and a model organism. To reveal levels and patterns of nucleotide diversity and to elucidate the genetic relationship and demographic history of O. sativa and its close relatives (Oryza rufipogon and Oryza nivara), we investigated nucleotide diversity data from 10 unlinked nuclear loci in species-wide samples of these species. The results indicated that O. rufipogon and O. nivara possessed comparable levels of nucleotide variation ((sil) = 0.0077 approximately 0.0095) compared with the relatives of other crops. In contrast, nucleotide diversity of O. sativa was as low as (sil) = 0.0024 and even lower ((sil) = 0.0021 for indica and 0.0011 for japonica), if we consider the 2 subspecies separately. Overall, only 20-10% of the diversity in the wild species was retained in 2 subspecies of the cultivated rice (indica and japonica), respectively. Because statistic tests did not reject the assumption of neutrality for all 10 loci, we further used coalescent to simulate bottlenecks under various lengths and population sizes to better understand the domestication process. Consistent with the dramatic reduction in nucleotide diversity, we detected a severe domestication bottleneck and demonstrated that the sequence diversity currently found in the rice genome could be explained by a founding population of 1,500 individuals if the initial domestication event occurred over a 3,000-year period. Phylogenetic analyses revealed close genetic relationships and ambiguous species boundary of O. rufipogon and O. nivara, providing additional evidence to treat them as 2 ecotypes of a single species. Lowest linkage disequilibrium (LD) was found in the perennial O. rufipogon where the r(2) value dropped to a negligible level within 400 bp, and the highest in the japonica rice where LD extended to the entirely sequenced region ( approximately 900 bp), implying that LD mapping by genome scans may not be feasible in wild rice due to the high density of markers needed.

Base Sequence↗

PubMed1988

The genus Campylobacter: a decade of progress.

In 1977, microbiologists and clinicians were awakened to the importance of the genus Campylobacter when it was learned that one species, Campylobacter jejuni, was a major cause of human enteritis. In the following decade substantial advances were made in diagnosis, isolation technology, identification, classification, serotyping, and epidemiology. The genus has undergone rapid expansion as advantage was taken of the deoxyribonucleic acid-deoxyribonucleic acid hybridization technique in defining new species. The 14 species now included in the genus, however, constitute a widely diverse group, and one species, C. pylori, which is associated with human gastroduodenitis, is under consideration for reassignment to another genus. The nomenclature of the subspecies of C. fetus has been resolved and the role of C. fetus subsp. fetus as an agent of human infections has been more clearly defined. The thermophilic campylobacteria that are etiological agents of human enteritis now include three species, C. jejuni, C. coli, and C. laridis. Recently defined species that have also been implicated as enteritis-causing agents include C. hyointestinalis, "C. upsaliensis," "C. cinaedi," and "C. fennelliae." The aerotolerant campylobacteria are now included in the species C. cryaerophila, and the campylobacteria isolated from salt marshes are included in C. nitrofigilis. The taxonomy and nomenclature of C. sputorum have been revised. C. sputorum now consists of three biovars (biotypes). Two of these, biovar sputorum and biovar bubulus, were previously considered to be separate subspecies and the third, biovar fecalis, was previously regarded as a separate species and known as "C. fecalis." The former subspecies C. sputorum subsp. mucosalis has been elevated to the rank of species. C. mucosalis is metabolically closely related to C. consisus. Human pathogens have not been identified among C. sputorum, C. mucosalis, or C. concisus. The goal of this article is to review developments during the last 10 years with emphasis on changes in taxonomy that are important from the perspective of the clinical microbiologist.

Animals↗

PubMed1996

Genomic differentiation among natural populations of orang-utan (Pongo pygmaeus).

BACKGROUND: Orang-utans exist today in small isolated populations on the islands of Borneo (subspecies Pongo pygmaeus pygmaeus) and Sumatra (subspecies P. p. abelii). Although, on the basis of their morphological, behavioral and cytogenetical characteristics, the Bornean and Sumatran orang-utan populations are generally considered as two separate subspecies, there is no universal agreement as to whether their genetic differentiation is sufficient to consider and manage them as species, subspecies or population level taxonomic units. A more precise phylogenetic description would affect many conservation management decisions about captive and free-ranging orang-utans. RESULTS: We analyzed the amount and patterns of molecular genetic variation in orang-utan populations using cellular DNA from orang-utans from two locations in Sumatra and nine locations-representing four isolated populations-in Borneo. Genetic and phylogenetic analyses of mitochondrial DNA restriction fragment length polymorphisms, nuclear minisatellite (or variable number tandem repeat) loci and mitochondrial 16S ribosomal RNA sequences led to three major findings. First, the genetic distance and phylogenetic differentiation between Sumatran and Bornean orang-utans is large, greater than that between the common chimpanzee, Pan troglodytes, and the pygmy chimpanzee or bonobo, Pan paniscus. The genetic distance suggests that the two island subspecies diverged approximately 1.5-1.7 million years ago, well before the two islands separated and long enough for species-level differentiation. Second, there is considerable endemic genetic diversity within the Bornean and Sumatran orang-utan populations, suggesting that they have not experienced recent bottlenecks or founder effects. And third, there is little genetic differentiation among four geographically isolated populations of Bornean orang-utans, consistent with gene flow having occurred between them until recently. CONCLUSIONS: Our results are consistent with the view that the genetic differentiation between Sumatran and Bornean orang-utans has reached the level of distinct species. Furthermore, our findings indicate that there is not a genetic imperative for the separate management of geographically isolated Bornean populations.

Animals↗

PubMed1990

Primary structures of two protamine 2 variants (St2a and St2b) from stallion spermatozoa.

Protamines were extracted from stallion sperm cell nuclei, alkylated with iodoacetamide and separated by reversed-phase high-performance liquid chromatography. Two main components, protamine 1 and protamine 2, were obtained. The latter contains two subspecies, separable by acetic acid-urea-polyacrylamide gel electrophoresis. The primary structure of protamine 2a (St2a) was determined by analysis of fragments obtained from purified protamine 2 peak by thermolysin digestion. The digested peptides were separated by acetic acid-urea gel electrophoresis and, after electroblotting onto a polyvinylidene difluoride filter, their amino acid sequences were determined by pulse liquid peptide sequencing. The amino acid sequence of protamine 2b was predicted from the double sequence data of protamine 2 peak by eliminating the amino acid of St2a in each cycle. St2a and St2b were found to contain 62 and 58 amino acid residues, respectively, and they seem to be homologous with type 2 protamines from human and mouse spermatozoa.

Alkylation↗

PubMed1986

A study of the structural heterogeneity of low-density lipoproteins in two patients homozygous for familial hypercholesterolaemia, one of phenotype E2/2.

The structural heterogeneity of the low-density lipoproteins (d 1.019-1.063 g ml-1) in two female patients homozygous for familial hypercholesterolaemia, one of phenotype E2/2, has been evaluated using a new ultracentrifugal density gradient procedure. The mass distribution, chemical composition, particle size and heterogeneity, hydrated density and apolipoprotein content of 16 LDL subfractions were determined. By gradient gel electrophoresis, the lighter LDL subfractions (d 1.016-1.037 g ml-1) displayed a single particle species which progressively diminished in size from 24.8 to 22.0 nm with increase in density. By contrast, subfractions of higher density (d greater than 1.037 g ml-1) exhibited two LDL particle species of distinct size; one component decreased in size from 21.8 to 20.4 nm with increase in density, while the second maintained an essentially constant diameter (between 22.5 and 23.5 nm) across these LDL subfractions. Immunoblotting with anti-apo-B100 of LDL subspecies separated by gradient gel electrophoresis showed all particles to contain apo-B100. However, dot-blots and immunoblotting with a monoclonal antibody to lipoprotein (a) (Lp(a)) revealed that the LDL particle subspecies of greatest diameter (22.5-23.5 nm) present in the denser subfractions (d greater than 1.037 g ml-1) also contained the Lp(a) antigen. These findings, taken together with the high plasma Lp(a) levels (greater than 60 mg dl-1) in our patients, raise the possibility that Lp(a) may contribute in a significant manner to the atherogenic process in homozygous familial hypercholesterolaemia.

Adolescent↗

PubMed1975

Dependence of pathogenic properties of leptospires on animal subspecies.

1. Leptospires of mozdok serotype of the Pomona serogroup possessed specific pathogenic properties for a definite subspecies of Apodemus agrarius. They caused carriership in rodents of a European population, but were unable to cause such a process in Far East mice. However, leptospires of monjakov and pomona types were also unable to provoke leptospiruria in these small mammals. 2. The intensity of the formation of antibody to leptospires in different subspecies of Apodemus agrarius was dependent on the degree of their susceptibility, determined by the presence of renal leptospirosis. Leptospira-carriers among animals reacted by antibody formation 6-40 times more intensive than in those not susceptible to the infection. 3. Leptospires of pomona, monjakov and mozdok serotypes of the Pomona group taxonomically can be designated as separate subspecies, on the basis of differences in biological properties as related to their natural animal reservoirs.

Animals↗

PubMed1993

Anticoagulant activity of tissue factor pathway inhibitor in human plasma is preferentially associated with dense subspecies of LDL and HDL and with Lp(a).

Human plasma contains a multivalent, Kunitz-type proteinase inhibitor termed tissue factor pathway inhibitor (TFPI), which specifically inhibits the action of the factor VII(a)-tissue factor complex in coagulation. In the present study, we examined the distribution and anticoagulant activity of TFPI among plasma lipoprotein subspecies separated by isopycnic density gradient ultracentrifugation; this procedure permitted the simultaneous fractionation of the major lipoprotein classes (very-low-density lipoprotein [VLDL], intermediate-density lipoprotein [IDL], low-density lipoprotein [LDL], high-density lipoprotein [HDL] 2 and 3, and very-high-density lipoprotein [VHDL]). Studies of eight normolipidemic subjects revealed two major lipoprotein carriers of TFPI activity: dense LDL subspecies (d = 1.039 to 1.063 g/mL) and both dense HDL particles and VHDL (d = 1.133 to 1.190 g/mL), representing 33.8% and 35.9%, respectively, of the total lipoprotein-associated TFPI activity in plasma. TFPI activity was also associated with lipoprotein(a) (Lp[a]), whose density distribution (d = 1.044 to 1.100 g/mL) overlapped that of LDL and HDL2; such association was related to Lp(a)'s particle size and phenotype. VLDL, IDL, and LDL1 through LDL3 (d = 1.019 to 1.039 g/mL), HDL2 (d = 1.063 to 1.100 g/mL), and light subfractions of HDL3 (d = 1.100 to 1.167 g/mL) conveyed only 1.8%, 10%, and 18.5%, respectively, of lipoprotein-associated TFPI activity. Such anticoagulant activity was dependent on the presence of TFPI protein. The dense subspecies of HDL3 (d = 1.133 to 1.167 g/mL) with which TFPI was preferentially associated were small, displayed a cholesteryl ester to protein ratio of approximately 0.2, and were deficient in phospholipid (13.6% to 18.3%). HDL subspecies of d = 1.110 to 1.167 g/mL mainly contained the higher relative molecular mass form of TFPI of 41 kD (a form that is known to be covalently associated with apolipoprotein [apo] A-II) and minor bands of the 35- and 52-kD forms. The second major localization of TFPI was within the hydrated density range of small, dense LDL particles (d = 1.033 to 1.063 g/mL), which in comparison with light LDL (d = 1.019 to 1.033 g/mL) exhibited a markedly lower proportion of triglyceride and enrichment in cholesteryl ester.(ABSTRACT TRUNCATED AT 400 WORDS)

Anticoagulants↗

PubMed2006

Reclassification of Paenibacillus larvae subsp. pulvifaciens and Paenibacillus larvae subsp. larvae as Paenibacillus larvae without subspecies differentiation.

A polyphasic taxonomic study of the two subspecies of Paenibacillus larvae, Paenibacillus larvae subsp. larvae and Paenibacillus larvae subsp. pulvifaciens, supported the reclassification of the subspecies into one species, Paenibacillus larvae, without subspecies separation. Our conclusions are based on the analysis of six reference strains of P. larvae subsp. pulvifaciens and three reference strains and 44 field isolates of P. larvae. subsp. larvae. The latter originated from brood or honey of clinically diseased honey bee colonies or from honey of both clinically diseased and asymptomatic colonies from Sweden, Finland and Germany. Colony and spore morphology, as well as the metabolism of mannitol and salicin, did not allow a clear identification of the two subspecies and SDS-PAGE of whole-cell proteins did not support the subspecies differentiation. For genomic fingerprinting, repetitive element-PCR fingerprinting using ERIC primers and PFGE of bacterial DNA were performed. The latter method is a high-resolution DNA fingerprinting method proven to be superior to most other methods for biochemical and molecular typing and has not previously been used to characterize P. larvae. ERIC-PCR identified four different genotypes, while PFGE revealed two main clusters. One cluster included most of the P. larvae subsp. larvae field isolates, as well as all P. larvae subsp. pulvifaciens reference strains. The other cluster comprised the pigmented variants of P. larvae subsp. larvae. 16S rRNA gene sequences were determined for some strains. Finally, exposure bioassays demonstrated that reference strains of P. larvae subsp. pulvifaciens were pathogenic for honey bee larvae, producing symptoms similar to reference strains of P. larvae subsp. larvae. In comparison with the type strain for P. larvae subsp. larvae, ATCC 9545T, the P. larvae subsp. pulvifaciens strains tested were even more virulent, since they showed a shorter LT100. An emended description of the species is given.

Animals↗

PubMed1995

Genetic diversity and population structure of Trypanosoma brucei: clonality versus sexuality.

Genomic fingerprinting by arbitrarily primed PCR was used to analyze the genetic variability among 59 Trypanosoma brucei stocks representing the three T. brucei subspecies isolated from various hosts and different countries in Africa. 14 oligonucleotide primers revealed 355 polymorphic binary characters which were used for phenetic and phylogenetic analysis and to perform recombination tests exploring the linkage disequilibrium in the sample. There was good concordance between arbitrarily primed PCR polymorphisms and isoenzyme data previously collected for many of the same strains [1]. However, the arbitrarily primed PCR typing was more discerning than multilocus enzyme electrophoresis typing. Phenetic and phylogenetic analysis using arbitrarily primed PCR markers did not confirm T. brucei brucei and T. brucei rhodesiense as separate subspecies, but T. brucei gambiense group I was monophyletic, confirming this group as suitable for the subspecies status. With this exception, there were no clear lineages among the sample, other than clustering of East African stocks and clustering of West African stocks. Some features of the phylogenetic analysis suggested that the population structure was not strictly clonal though recombination tests showed linkage disequilibrium, even in the absence of repeated genotypes. While genotypes appear stable enough for tracking in applied studies, sexuality will impact at the evolutionary time scale, and may be more frequent under some ecological conditions. The arbitrarily primed PCR approach should be an effective and simple approach to follow epidemics and to quantify the role of sexuality in T. brucei populations.

Africa↗

PubMed2002

Phylogeography of the African buffalo based on mitochondrial and Y-chromosomal loci: Pleistocene origin and population expansion of the Cape buffalo subspecies.

Population genetics and phylogeography of the African buffalo (Syncerus caffer) are inferred from genetic diversity at mitochondrial D-loop hypervariable region I sequences and a Y-chromosomal microsatellite. Three buffalo subspecies from different parts of Africa are included. Nucleotide diversity of the subspecies Cape buffalo at hypervariable region I is high, with little differentiation between populations. A mutation rate of 13-18% substitutions/million years is estimated for hypervariable region I. The nucleotide diversity indicates an estimated female effective population size of 17 000-32 000 individuals. Both mitochondrial and Y-chromosomal diversity are considerably higher in buffalo from central and southwestern Africa than in Cape buffalo, for which several explanations are hypothesized. There are several indications that there was a late middle to late Pleistocene population expansion in Cape buffalo. This also seems to be the period in which Cape buffalo evolved as a separate subspecies, according to the net sequence divergence with the other subspecies. These two observations are in agreement with the hypothesis of a rapid evolution of Cape buffalo based on fossil data. Additionally, there appears to have been a population expansion from eastern to southern Africa, which may be related to vegetation changes. However, as alternative explanations are also possible, further analyses with autosomal loci are needed.

Africa↗

PubMed1995

PAF-degrading acetylhydrolase is preferentially associated with dense LDL and VHDL-1 in human plasma. Catalytic characteristics and relation to the monocyte-derived enzyme.

In human plasma, platelet activating factor (PAF)-degrading acetylhydrolase (acetylhydrolase) is principally transported in association with LDLs and HDLs; this enzyme hydrolyzes PAF and short-chain forms of oxidized phosphatidylcholine, transforming them into lyso-PAF and lysophosphatidylcholine, respectively. We have examined the distribution, catalytic characteristics, and transfer of acetylhydrolase activity among plasma lipoprotein subspecies separated by isopycnic density gradient ultracentrifugation; the possibility that the plasma enzyme may be partially derived from adherent monocytes has also been evaluated. In normolipidemic subjects with Lp(a) levels < 0.1 mg/mL, acetylhydrolase was associated preferentially with small, dense LDL particles (LDL-5; d = 1.050 to 1.063 g/mL) and with the very-high-density lipoprotein-1 subfraction (VHDL-1; d = 1.156 to 1.179 g/mL), representing 23.9 +/- 1.7% and 20.6 +/- 3.2%, respectively, of total plasma activity. The apparent Km values for PAF of the enzyme associated with such lipoproteins were 89.7 +/- 23.4 and 34.8 +/- 4.5 mumol/L for LDL-5 and VHDL-1, respectively: indeed, the Km value for LDL-5 was some 10-fold higher than that of the light LDL-1, LDL-2, and LDL-3 subspecies, whereas the Km of VHDL-1 was some twofold greater than those of the HDL-2 and HDL-3 subspecies. Furthermore, when expressed on the basis of unit plasma volume, the Vmax of the acetylhydrolase associated with LDL-5 was some 150-fold greater than that in LDL-1 (d = 1.019 to 1.023 g/mL). No significant differences in the pH dependence of enzyme activity or in sensitivity to protease inactivation, sulfydryl reagents, the serine protease inhibitor Pefabloc, or the PAF antagonist CV 3988 could be detected between apo B-containing and apo A-I-containing lipoprotein particle subspecies. Incubation of LDL-1 (Km = 8.4 +/- 2.6 mumol/L) and LDL-2 (d = 1.023 to 1.029 g/mL; Km = 8.4 +/- 3.3 mumol/L) subspecies with LDL-5, in which acetylhydrolase had been inactivated by pretreatment with Pefabloc, demonstrated preferential transfer of acetylhydrolase to LDL-5. Acetylhydrolase transferred to LDL-5 from the light LDL subspecies exhibited a Km of 9.4 +/- 2.2 mumol/L, a value characteristic of the particle donors. Finally, acetylhydrolase (Km = 23.4 +/- 7.6 mumol/L) released by adherent human monocytes in culture was found to bind preferentially to small, dense LDL subspecies upon incubation of Pefabloc-inactivated plasma with monocyte supernatant.(ABSTRACT TRUNCATED AT 400 WORDS)

Cells, Cultured↗

PubMed2002

Phylogenetic relationships between Hapalemur species and subspecies based on mitochondrial DNA sequences.

BACKGROUND: Phylogenetic relationships of the genus Hapalemur remains controversial, particularly within the Hapalemur griseus species group. In order to obtain more information on the taxonomic status within this genus, and particularly in the cytogenetic distinct subspecies group of Hapalemur griseus, 357 bp sequence of cytochrome b and 438 bp of 12S mitochondrial DNAs were analyzed on a sample of animals captured in areas extending from the north to the south-east of Madagascar. This sample covers all cytogenetically defined types recognized of the genus Hapalemur. RESULTS: Phylogenetic trees and distances analyses demonstrate a first emergence of Hapalemur simus followed by H. aureus which is the sister clade of the H. griseus subspecies. Hapalemur griseus is composed of 4 subspecies separated into two clades. The first contains H. g. griseus, H. g. alaotrensis and H. g. occidentalis. The second consists of H. g. meridionalis. A new chromosomal polymorphic variant from the region of Ranomafana, H. griseus ssp, has been analysed and was found in both clades. CONCLUSIONS: Our results support the raising of H. g. meridionalis to the specific rank H. meridionalis, while neither cytogenetic nor molecular evidences support the raising of H. g. alaotrensis to a species rank despite its morphological characteristics. The new cytotype H. g. ssp which has been previously characterized by cytogenetic studies contains animals clustering either with the group of Hapalemur griseus griseus or with that of Hapalemur meridionalis. This suggests the existence of an ancestral polymorphism or an introgression of mitochondrial DNA between subspecies.

Animals↗

PubMed2006

Phylogeny of primate T lymphotropic virus type 1 (PTLV-1) including various new Asian and African non-human primate strains.

To further unravel intra- and interspecies PTLV-1 evolution in Asia and Africa, we phylogenetically analysed 15 new STLV-1 LTR and env sequences discovered in eight different Asian and African non-human primate species. We show that orang-utan STLV-1s form a tight, deeply branching monophyletic cluster between Asian STLV-1 macaque species clades, suggesting natural cross-species transmission. Novel viruses of Macaca maura, Macaca nigra and siamang cluster with other Sulawesian STLV-1s, demonstrating close relatedness among the STLV-1s in these insular species and suggesting cross-species transmission to a siamang in captivity. Viruses from Western chimpanzees and a Western lowland gorilla cluster within the HTLV-lb/STLV-1 clade, the latter close to a human strain, indicative of zoonosis. A new STLV-1 from Cercopithecus ascanius differs from the published STLV-Cas57, explainable by the existence of five geographically separated subspecies. Barbary macaques, not yet described to be STLV-infected, carry a relatively recent acquired, typical African STLV-1, giving us no clue on the phylogeographical origin of PTLV-1.

Africa↗