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PubMed1994

A species-specific antigen of Trypanosoma (Duttonella) vivax detectable in the course of infection is encoded by a differentially expressed tandemly reiterated gene.

A monoclonal antibody that is used as a Trypanosoma vivax species-specific diagnostic reagent on antigen-trapping enzyme-linked immunosorbent assay recognized an 8-kDa peptide on western blots. The 8-kDa species-specific antigen was isolated and employed in raising rabbit polyclonal antibodies, which were used in the immunoscreening of a T. vivax cDNA library in lambda gt11.2. A clone containing a 0.8-kb insert was isolated. The cloned gene is tandemly repeated, with a monomeric unit length of 900 bp, in the genomes of all T. vivax isolates from diverse geographic locations in Africa and South America. The gene is differentially expressed, since both the transcript and antigen are present in bloodstream-stage parasites, but not in the epimastigotes of T. vivax. Although the gene is found in all T. vivax isolates so far tested, it either exists in low copy number or in a divergent form in one isolate from Kilifi at the Kenya Coast. Sequence translation revealed a remarkable degree of bias in codon usage with preference for G and C (82%) in the wobble position. Using the deduced amino acid sequence to search the databases for any structurally related peptides, revealed no significant identity with any known proteins. The function of the species-specific antigen of T. vivax is thus unknown. Nevertheless the identification and characterization of proteins released into the circulation of protozoan parasite-infected animals is important and should allow the determination of what role such molecules may play in the modulation of disease pathology.

Amino Acid Sequence↗
PubMed1993

Social experience with siblings fosters species-specific responsiveness to maternal visual cues in bobwhite quail chicks (Colinus virginianus).

We examined the role of visual and social experience with siblings in the development of bobwhite quail (Colinus virginianus) chicks' preference for species-specific maternal visual cues. Chicks were reared in 1 of 4 conditions: group, isolation, partial isolation, and heterospecific group. They were tested in simultaneous choice tests with species-typical and species-atypical audiovisual stimuli. Results revealed that only subjects that were reared in a group with same-aged conspecifics preferred the visual features of a bobwhite hen model. Subjects in the other 3 conditions did not exhibit species-specific visual preference. The findings suggest that visual experience and direct social interaction with siblings facilitate the development of bobwhite chicks' species-specific responsiveness to static maternal visual cues and illustrate the important influence of experience with conspecifics in the development of early perceptual preferences.

Aging↗
PubMed1997

Synergistic cofactor function of factor V and protein S to activated protein C in the inactivation of the factor VIIIa - factor IXa complex -- species specific interactions of components of the protein C anticoagulant system.

Human factor V has been shown not only to be a precursor to procoagulant factor Va but also to express anticoagulant properties. Thus, factor V was recently found to potentiate the effect of protein S as cofactor to activated protein C (APC) in the inactivation of the factor VIIIa-factor IXa complex. The purpose of this study was to determine whether the APC-cofactor function of factor V was also expressed in the bovine protein C system and to elucidate the molecular background for the species specificity of APC. For this purpose, the effects of protein S and factor V on APC-mediated inactivation of factor VIIIa were studied using purified APC, protein S and factor V of human and bovine origin. The factor VIIIa investigated here was part of a Xase complex (i.e. factor IXa, factor VIIIa, phospholipid and calcium) and the APC-mediated inhibition of factor VIIIa was monitored by the ability of the Xase complex to activate factor X. Synergistic APC-cofactor function of factor V and protein S was demonstrated in the bovine system. The effect of bovine APC was potentiated by bovine protein S but not by human protein S, whereas both human or bovine protein S stimulated the function of human APC. Factor V did not express species specificity in its APC-cofactor activity even though bovine factor V was more potent than its human counterpart. Recombinant human/bovine protein S chimeras were used to demonstrate that the thrombin sensitive region and first epidermal growth factor-like module of protein S determine the species specificity of the APC-protein S interaction. In conclusion, both human and bovine factor V were found to express APC-cofactor activity which depends on the presence of protein S. The species specificity of APC was shown to be caused by the interaction between APC and protein S.

Animals↗
PubMed1994

Isolation and characterization of a gene encoding a Chlamydia pneumoniae 76-kilodalton protein containing a species-specific epitope.

Chlamydia pneumoniae is a human respiratory pathogen. Unlike the other two Chlamydia species, no species-specific antigen has been defined for C. pneumoniae. An immunoreactive clone containing a 0.8-kb fragment was isolated from a C. pneumoniae (AR-39) genomic library by using anti-C. pneumoniae rabbit immune serum. By Southern hybridization analysis of chromosomal digests of the different Chlamydia spp., the 0.8-kb fragment was shown to react specifically with C. pneumoniae. Subcloning of this fragment into the pGEX-1 lambda T expression vector resulted in the expression of a 62-kDa fusion protein. This fusion protein as well as the cleaved C. pneumoniae peptide were recognized by anti-C. pneumoniae rabbit immune serum, while the glutathione S-transferase moiety was not recognized. The fusion protein was used to produce monospecific rabbit antiserum. This antiserum was shown to react with a 76-kDa protein in all C. pneumoniae isolates tested, specifically recognize C. pneumoniae inclusions in tissue culture, and neutralize infectivity of C. pneumoniae in cell culture. No reactivity was observed with Chlamydia trachomatis or Chlamydia psittaci. To isolate the entire coding sequence of the 76-kDa protein, two partially overlapping fragments of C. pneumoniae DNA, a 3.2-kb HindIII fragment and a 1.2-kb PvuII fragment, were isolated, cloned, and sequenced. No significant sequence similarity was found with any previously reported nucleotide or amino acid sequence of the other Chlamydia species. This C. pneumoniae protein containing a species-specific epitope could play a role in pathogenesis and may be useful as a diagnostic tool.

Amino Acid Sequence↗
PubMed1992

Selective species specificity of tumor necrosis factor for toxicity in the mouse.

The selective cytotoxic activity of tumor necrosis factor (TNF) on many transformed human or murine cell lines is (almost) not species-specific. There are, however, a limited number of biological assay systems such as gene induction in murine thymoma cells and the murine thymocyte proliferation assay, in which recombinant murine (rm) TNF, but not recombinant human (rh) TNF is active. We have now investigated the possible species specificity of the lethality-inducing properties of TNF in the mouse. When administered alone, only rmTNF, but not rhTNF caused lethality. This difference was not due to a different endotoxin contamination or to a different pharmacokinetic behavior. When a sensitizing agent, galactosamine, was added, the species specificity was abolished. We have shown previously that similar conclusions could be drawn for at least some of the antitumor mechanisms of TNF. We conclude that to mimic the two major phenomena caused by endotoxin administration, viz. lethality and antitumor effect, two distinct signals are needed. In mice, rmTNF can provide both, while rhTNF needs another agent (a sensitizer) to cause systemic toxicity. The results are discussed with respect to recent findings showing that, in the mouse, rhTNF can only bind to the TNF-R55 receptor type, while rmTNF can bind both to the TNF-R55 and TNF-R75 receptor types.

Animals↗
PubMed1989

Contextual conditioning and the control of copulatory behavior by species-specific sign stimuli in male Japanese quail.

Three experiments were conducted to identify species-specific sign stimuli sufficient to elicit copulatory behavior in male Japanese quail and to determine how learning is involved in the control of behavior by these sign stimuli. In Experiment 1, sexually experienced subjects were tested for copulatory behavior with a live female quail and with a model consisting of a female quail's head and neck mounted in front of a foam pad. Comparable levels of copulatory behavior were observed in the two tests, indicating that static visual cues provided by a female quail's head and neck are sufficient to elicit copulatory behavior in this species. Experiment 2 showed that male birds that previously received numerous opportunities to copulate with a live female quail in the test situation were significantly more likely to copulate with the head + neck model than were sexually inexperienced subjects. Experiment 3 showed that prior sexual experience with live quail facilitated responding to the head + neck model only if the sexual experience was provided in the same place where subjects were later tested with the model. This last finding suggests that sexual experience facilitates control of copulatory behavior by species-specific sign stimuli through contextual conditioning. Contextual conditioning may lower the threshold for sexual behavior with the result that a stimulus as impoverished as an immobile model containing only the head and neck of a female quail becomes sufficient to elicit normal levels of copulatory behavior. The results are also discussed as an example of conditioned stimulus facilitation of responding to an unconditioned stimulus.

Animals↗
PubMed1996

Diagnosis of cutaneous tuberculosis by polymerase chain reaction using a species-specific gene.

BACKGROUND: Diagnosis of tuberculosis (TB), especially cutaneous TBC, by conventional microbiologic methods is still a very laborious process and the results are usually inconclusive. Our purpose was to identify M. tuberculosis bacilli in uncultured clinical samples from skin lesions by means of the rapid, specific, and sensitive polymerase chain reaction (PCR). METHODS: The PCR, using a set of species-specific primers, was performed on biopsies and fluid secretions from lesions. RESULTS: A positive amplification reaction was observed in three of the four samples studied. For one of the samples, the result was confirmed by a positive culture in Löwenstein-Jensen medium and for the other two, by molecular hybridization and the clinical course of the patients after treatment. Samples obtained from a patient with panniculitis of Christian-Weber and a normal skin biopsy were included as negative controls. CONCLUSIONS: We propose the PCR method as a tool for the diagnosis of cutaneous TBC. The presence of the M. tuberculosis in an erythema induratum of Bazin suggests a revision of the concept of this disease as a tuberculide reaction.

Adult↗
PubMed1996

Isolation and characterization of a species-specific DNA probe for the detection of Candida krusei.

In an attempt to design species-specific primers for the detection of Candida krusei by polymerase chain reaction, a partial genomic DNA library from Candida krusei was screened for hybridization with radiolabeled genomic probes from a broad variety of fungal and bacterial species and from human. Species-specific candidate DNA inserts were then tested for hybridization with dot blots of DNA from various organisms. One 570-basepair insert from Candida krusei DNA that hybridized under stringent conditions only with DNA from Candida krusei and human was sequenced. It revealed considerable homology with the gene for the mitochondrial inner membrane protease I of Saccharomyces cerevisiae, and the 147 amino acid residues deduced from an open reading frame showed considerable homology with the N-terminal portion of the enzyme from Saccharomyces cerevisiae. From the sequence of the Candida krusei DNA fragment, a pair of 21-base oligonucleotide primers enclosing a 501-basepair sequence was designed for polymerase chain reaction. When these primers were tested with a broad range of genomic DNAs, the expected amplification was obtained only with Candida krusei DNA and not with DNA from any other source, including human. Experiments with DNA from mixed cultures of Candida krusei and other yeasts and bacteria showed that the polymerase chain reaction was specific for Candida krusei and that as few as ten cells could be detected.

Amino Acid Sequence↗
PubMed2005

Identification of Actinobacillus actinomycetemcomitans using species-specific 16S rDNA primers.

The purpose of this study was to develop species-specific PCR primers for use in the identification and detection of Actinobacillus actinomycetemcomitans. These primers target variable regions of the 16S ribosomal RNA coding gene (rDNA). We assessed the specificity of the primers against 9 A. actinomycetemcomitans strains and 11 strains (3 species) of the Haemophilus genus. Primer sensitivity was determined by testing serial dilutions of the purified genomic DNAs of A. actinomycetemcomitans ATCC 33384T. Our obtained data revealed that we had obtained species-specific amplicons for all of the tested A. actinomycetemcomitans strains, and that none of these amplicons occurred in any of the other species. Our PCR protocol proved able to detect as little as 4 fg of A. actinomycetemcomitans chromosomal DNA. Our findings suggest that these PCR primers are incredibly sensitive, and should prove suitable for application in epidemiological studies, as well as the diagnosis and monitoring of periodontal pathogens after treatment for periodontitis.

Aggregatibacter actinomycetemcomitans↗
PubMed1995

Species-specific identification of Mycobacterium bovis by PCR.

The Random Amplified Polymorphic DNA (RAPD) technique was used in the identification of a species-specific fragment of Mycobacterium bovis. A fragment of approximately 500 bp was amplified from the genome of 15 different M. bovis strains, including M. bovis BCG Pasteur, but was shown to be absent in 26 different mycobacteria and 20 different clinical isolates of Mycobacterium tuberculosis. When the fragment was used as a probe in a Southern blot analysis, several radioactive bands common to M. tuberculosis and M. bovis were observed. However, this fragment hybridized specifically to a 2900 bp EcoRI fragment in the M. bovis genome, but failed to hybridize in either M. tuberculosis or M. avium chromosomal DNA. Based on a partial nucleotide sequence of the 500 bp fragment, two oligonucleotide primers were designed and a PCR assay was developed. Using purified mycobacterial DNA samples, only M. bovis and M. bovis BCG rendered a unique amplification band. This PCR assay is able to detect down to 10 fg purified M. bovis DNA, which corresponds roughly to two bacilli. The assay is also useful for identifying the bacilli directly from uncultured biological samples, such as milk.

Bacterial Typing Techniques↗
PubMed1993

The negative effect of human immunodeficiency virus type 1 Nef on cell surface CD4 expression is not species specific and requires the cytoplasmic domain of CD4.

The nef gene product of human immunodeficiency virus type 1 has been shown to induce CD4 downregulation from the surface of human cells. To determine if this effect is species specific, we used a retroviral vector to transduce the human immunodeficiency virus type 1 nef gene into murine cells expressing human, chimpanzee, or murine CD4. Our results indicate that Nef induces cell surface downregulation of all three molecules. We also determined that Nef is functional in murine T cells and induces downregulation of both murine CD4 and CD8 (Ly-2) from the cell surface. In contrast, Nef does not downregulate cell surface expression of human CD8 in either murine or human cells. By using a mutant of human CD4 lacking its cytoplasmic domain and a human CD4/CD8 chimera, we determined that the cytoplasmic domain of CD4 is required for its downregulation by Nef. Transduction with a control vector had no effect on CD4 cell surface levels, indicating that retroviral transduction by itself has no significant effect on the cell surface levels of CD4. These results show that the observed downregulation of CD4 by Nef is independent of human-specific factors, is not species specific, and requires the cytoplasmic domain of CD4.

Acquired Immunodeficiency Syndrome↗
PubMed1999

Species-specific primers of chitin synthase 1 gene for the differentiation of the Trichophyton mentagrophytes complex.

Species-specific primers were designed from nucleotide sequences of the chitin synthase 1 gene (CHS1) of Arthroderma benhamiae, A. simii and A. vanbreuseghemii. The A. benhamiae-specific primer amplified a 560-bp fragment from A. benhamiae but not from A. simii and A. vanbreuseghemii. The A. simii-specific primers amplified a 470-bp fragment from A. simii but not from A. benhamiae and A. vanbreuseghemii. The A. vanbreuseghemii-specific primers amplified a 360-bp fragment from A. vanbreuseghemii but not from A. benhamiae and A. simii. With these species-specific primers of CHS1 genes, 10 clinical isolates from humans and animals were examined by polymerase chain reaction analyses. These isolates proved to be identical to A. vanbreuseghemii.

Animals↗
PubMed2001

Molecular microbial analysis of Bifidobacterium isolates from different environments by the species-specific amplified ribosomal DNA restriction analysis (ARDRA).

One hundred and six isolates of the genus Bifidobacterium, isolated from different environments (mainly gastrointestinal), were identified and classified taxonomically to species level by amplified ribosomal DNA restriction analysis. Two restriction endonucleases (Sau3AI and BamHI) were chosen for aligning the 16S rRNA sequences of 16 bifidobacterial species retrieved from various databases, to obtain species-specific restriction patterns. A rapid and accurate identification scheme was obtained by comparing the resulting 16S rDNA digestion profiles of 16 Bifidobacterium type-strains and 90 strains of various origins. All of the investigated strains were previously confirmed at the species level as belonging to the genus Bifidobacterium by fluorescence in-situ hybridisation and by polymerase chain reaction amplification with genus- and species-specific primers. The present work demonstrates that species-specific detection of Bifidobacterium adolescentis, Bifidobacterium animalis, Bifidobacterium bifidum, Bifidobacterium breve, Bifidobacterium catenulatum, Bifidobacterium coryneforme, Bifidobacterium cuniculi, Bifidobacterium dentium, Bifidobacterium infantis, Bifidobacterium lactis, Bifidobacterium longum, Bifidobacterium suis, Bifidobacterium magnum, Bifidobacterium pseudolongum, Bifidobacterium pseudocatenulatum and Bifidobacterium pullorum present in different micro-ecological environments (e.g. gastrointestinal tract) can be accomplished in a reliable, rapid and accurate manner, circumventing the recognised deficiencies of traditional identification techniques.

Journal Article↗
PubMedDate not supplied

[The effect of different types of species-specific acoustic signals on the rate of mammalian cardiac contractions].

Experiments with rodents and even-toed ungulates show that significant changes in the heart rate (HR) in response to administration of species-specific sound stimuli occur only under conditions of deficiency of useful information. Cardiac response depends mainly upon the type of the signal, ecology and physiology of the animal-recipient. In mammals living in colonies and herds in the open (ground squirrels, reindeer) HR changes become conspicuous only under conditions excluding acquirement of visual information. Active escape conditioning by one of the species-specific signals in Arctic ground squirrels at the stage of habituation leads to selective decrease of intensity and probability of cardiac response to conditioned stimulus and any other type of alarm signal (whistling). Experiments with HR recording in albino rats show that biological dominant of maternal breeding as compared to other species-specific signals selectively influences degree of emotional discomfort in pups.

Acoustic Stimulation↗
PubMed1986

Recombinant tumor necrosis factor: species specificity for a variety of human and murine transformed cell lines.

Tumor necrosis factor (TNF) exhibits cytotoxic or cytostatic activity on a wide range of animal and human transformed cell lines. Using pure, recombinant human and mouse TNF, we examined the degree of species specificity of the in vitro TNF activity on a variety of human and murine transformed cell lines. This species specificity was studied for the TNF activity alone or in synergism with IFN-gamma. Recombinant human and mouse TNF behave remarkably similarly regarding the in vitro cytolytic/cytostatic activity. However, a certain degree of species-specific preference could be revealed as human cell lines needed a higher concentration of recombinant mouse TNF than of recombinant human TNF to attain a similar effect, while on mouse cells the reverse was true. Also, synergism with IFN-gamma seemed more effective when the target cell was treated with homologous TNF.

Animals↗
PubMed1995

Species-specific polymorphism in the promoter of the apolipoprotein A-I gene: restoration of human transcriptional efficiency by substitution at positions -189, -144 and -48 bp.

Previous studies indicate that species-specific differences in apolipoprotein A-I (apo A-I) expression could be largely explained by cis-acting factors located within or near the 5' flanking region (-231 to +223 bp, where +1 is the start site of transcription). In the present studies, we have localized 7 sites within the (-231 to -15 bp) region of the African green monkey apo A-I gene that differ from the human apo A-I gene 5' flanking region. To identify which of the 7 polymorphic sites were essential for the species-specific differences in apo A-I gene expression, mutated promoter constructs were transfected into HepG2 cells and reporter gene expression was measured. Each of the 7 sites within a defined 5' flanking region of the human gene was individually mutated to the African green nucleotide sequence found at that position. Three of the sites (-189, -144 and -48) were found to raise the human apo A-I promoter activity to approx. 60-65% of the African green promoter. While double mutations (-144/-48 bp and -189/-144 bp), restored the human apo A-I promoter activity to 100% of that found with the African green monkey promoter. Additional studies revealed similar DNA: protein interactions with DNA probes from either human or African green monkey and HepG2 cell nuclear extract. In conclusion, these studies demonstrate that double and triple nucleotide substitutions within the human apo A-I promoter are sufficient to restore gene expression in HepG2 cells to levels seen with the African green monkey promoter. These data suggest that sites -189, -144 and -48 bp are involved in significantly altering the binding affinity of a nuclear factor determining the species-specific level of apo A-I gene transcription.

Animals↗
PubMed1977

The requirement of viable thymocytes for species-specific attachment to and release from macrophages.

The role of the thymocyte in its species-specific binding to macrophages has been explored. Although formalin treatment of macrophages resulted in loss of binding to thymocytes, formalin treatment of thymocytes did not have this effect. However, two differences between living and formalin-treated thymocytes were noted. Formalin-treated thymocytes bound to macrophages of any species whereas the binding of living thymocytes was species specific. Living thymocytes attained maximum binding in approximately 1 hr and then the fraction bound gradually diminished. Formalin-treated thymocytes remained bound to the macrophage and appeared to be phagocytized. Released thymocytes did not bind to fresh macrophages, but released macrophages bound to fresh thymocytes. The results suggest that the binding of thymocytes to macrophages results in maturation of thymocytes.

Animals↗
PubMed2006

The development of species-specific immunodiagnostics for Stachybotrys chartarum: the role of cross-reactivity.

Mold contamination and exposure to fungi in indoor environments has been associated with various adverse health effects but little is known about the significance of individual fungal species in the initiation or exacerbation of such effects. Using Stachybotrys chartarum as a model fungus we sought to demonstrate that monoclonal antibodies (mAbs) can provide species-specific diagnostic reagents and also be used to investigate immunological cross-reactivity patterns among fungi. Mice were immunized with S. chartarum spore walls and monoclonal antibodies were screened against 60 fungal species and 24 different isolates of S. chartarum using an indirect ELISA. One species-specific mAb (IgG(1)) reacted only with spore preparations but not mycelium of S. chartarum or propagules of any other fungus. Five cross-reactive mAbs (IgM) documented extensive cross-reactivity among nine related Stachybotrys species and several non-related genera including several species of Cladosporium, Memnoniella, Myrothecium and Trichoderma. We also found that the ELISA reactivity for cross-reactive antigens and different isolates of S. chartarum differed considerably for normalized total amounts of mycelial antigen. We demonstrate that mAbs and immunoassays have the potential to detect S. chartarum species-specifically. The observed reactivity patterns with cross-reactive mAbs suggest that several fungi may share common antigens and that the majority of antigens are expressed by spores and mycelia. The observed cross-reactivity patterns need to be considered for accurate interpretations of environmental and serological analyses.

Animals↗