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PubMed1987

Species-specific pharmacology of antiestrogens: role of metabolism.

The nonsteroidal antiestrogen tamoxifen exhibits a paradoxical species-specific pharmacology. The drug is a full estrogen in the mouse, a partial estrogen/antiestrogen in humans and the rat, and an antiestrogen in the chick oviduct. Inasmuch as tamoxifen has antiestrogenic effects in vitro, differential metabolism of tamoxifen to estrogens might occur in the species in which it has an estrogenic pharmacology. Tamoxifen or its metabolite 4-hydroxytamoxifen could lose the alkylaminoethane side chain to form the estrogenic compound metabolite E or bisphenol. Sensitive metabolic studies with [3H]tamoxifen in chicks, rats, and mice identified 4-hydroxytamoxifen as the major metabolite, but no potentially estrogenic metabolites were observed. Athymic mice with transplanted human breast tumors can be used to study the ability of tamoxifen to stimulate target tissue or tumor growth. Estradiol caused the growth of transplanted MCF-7 breast cancer cells into solid tumors and a uterotrophic response. However, tamoxifen does not support tumor growth when administered alone, although it stimulates uterine growth. Since a similar profile of metabolites is sequestered in human and mouse tissues, these studies strongly support the concept that the drug can selectively stimulate or inhibit events in the target tissues of different species without metabolic intervention.

Animals↗
PubMed1977

Species specificity of informatin.

Informatin, the protein moiety of nuclear pre-mRNA containing particles, exhibits species specific antigenic properties but shows also some interspecies cross-reactivities.

Animals↗
PubMed2003

Genus- and species-specific PCR primers for the detection and identification of bifidobacteria.

16SrDNA-targeted genus- and species-specific PCR primers have been developed and used for the identification and detection of bifidobacteria. These primers cover all of the described species that inhabit the human gut, or occur in dairy products. Identification of cultured bifidobacteria using PCR primer pairs is rapid and accurate, being based on nucleic acid sequences. Detection of bifidobacteria can be achieved using DNA extracted from human faeces as template in PCR reactions. We have found that, in adult faeces, the Bifidobacterium catenulatum group was the most commonly detected species, followed by Bifidobacterium longum, Bifidobacterium adolescentis, and Bifidobacterium bifidum. In breastfed infants, Bifidobacterium breve was the most frequently detected species, followed by Bifidobacterium infantis, B. longum and B. bifidum. It was notable that the B. catenulatum group was detected with the highest frequency in adults, although it has often been reported that B. adolescentis is the most common species. Real-time, quantitative PCR using primers targeting 16S rDNA shows promise in the enumeration of bifidobacteria in faecal samples. The approach to detect the target bacteria with quantitative PCR described in this review will contribute to future studies of the composition and dynamics of the intestinal microflora.

Adult↗
PubMed1991

Transcriptional regulation of the apolipoprotein A-I gene. Species-specific expression correlates with rates of gene transcription.

Previous studies have shown that the abundance of apoA-I mRNA in liver and intestine correlates with a 2-3-fold species-specific difference in the plasma concentration of high density lipoprotein and apoA-I. In order to determine the role of gene transcription in regulating the tissue, steady state apoA-I mRNA abundance nuclear run-on assays were conducted using nuclei from two species of nonhuman primates. The transcriptional activity expressed as the ratio of apoA-I signal intensity to that for the constitutively expressed glyceraldehyde-3-phosphate dehydrogenase was calculated for seven individual animals in each of the two nonhuman primate species. The African green monkey showed a ratio of 4.18 +/- 0.35, and the cynomolgus monkey showed 2.03 +/- 0.13 (n = 7, p less than 0.004). To identify possible cis-acting elements that may be involved in transcriptional regulation of the apoA-I gene, a portion of the apoA-I regulatory region, corresponding to nucleotides -231 to +263 (where +1 is the start site of transcription), was isolated from both species using the polymerase chain reaction. The nucleotide sequence of this region was compared between monkey species, as well as with the same region from the apoA-I gene isolated from human genomic DNA. In this region, the African green monkey apoA-I gene showed 95% similarity, whereas the cynomolgus monkey showed 94% similarity to the human sequence. Although a high degree of sequence similarity was observed among all species, numerous sequence specific differences were noted in the first intron between the two primate species and between nonhuman and human primate sequences. Results from studies measuring relative promoter strength indicated that the African green monkey 5'-regulatory region had a consistently higher level of activity (1.4-3.0-fold) than the same region from the cynomolgus monkey. Interestingly, the African green monkey promoter also showed a significantly higher transcriptional activity than the human or rabbit promoter, suggesting the presence of a nonhuman primate specific cis-acting element(s) regulating apoA-I gene expression. These results demonstrate that a portion of the species-specific difference in apoA-I gene expression may be explained by sequence divergence in the 5'-regulatory region including exon/intron 1 of the apoA-I gene.

Animals↗
PubMed1976

Evidence for species-specific substrate-site-directed inactivation of rabbit adenylate kinase by N6-(6-iodoacetamido-n-hexyl)adenosine 5'-triphosphate.

Adenosine 5'-triphosphate (ATP) derivatives bearing iodoacetylamino-n-alkyl substituents [(CH2)nNHCOCH2I] on N6 were synthesized as potential ATP-site-directed irreversible inhibitors of adenylate kinases from rabbit, pig, and carp muscle. When n was 5 no enzyme was progressively inhibited (inactivated) by 1 mM inhibitor under the test conditions (6 h at 0 degrees); when n was 6 the rabbit enzyme was 76% inactivated by 0.79 mM inhibitor whereas the pig and carp enzymes were unaffected by 2.76 mM inhibitor; when n was 7, 1 mM inhibitor inactivated 14% of the rabbit enzyme and did not inactivate the pig and carp enzymes; when n was 8, all enzymes were inactivated 11-15% by 1 mM inhibitor. No inactivation occurred when the iodine of the hexamethylene analogue was replaced by hydrogen. The selective effect occured also in mixtures of the rabbit and pig enzymes and evidence could not be found that the hexamethylene analogue was activated by the rabbit enzyme or deactivated by the pig and carp preparations. The species-specific inactivation in concluded from various lines of evidence to be ATP-site-directed and is attributed to alkylation of an amino acid residue of the rabbit enzyme which in the pig and carp enzymes is absent, inaccessible, or less reactive. These and previous studies with several other enzymes provide evidence that substrate-site-directed agents capable of bonding covalently to an amino acid residue outside the substrate site can be designed to exert species-specific or tissue-specific irreversible inhibition of target enzymes.

Adenosine Triphosphate↗
PubMed2004

Rapid turnover and species-specificity of vomeronasal pheromone receptor genes in mice and rats.

Pheromones are used by individuals of the same species to elicit behavioral or physiological changes, and they are perceived primarily by the vomeronasal organ (VNO) in terrestrial vertebrates. VNO pheromone receptors are encoded by the V1r and V2r gene superfamilies in mammals. A comparison of the V1r and V2r repertoires between closely related species can provide significant insights into the evolutionary genetic mechanisms responsible for species-specific pheromone communications. A total of 137 putatively functional V1r genes of 12 families were previously identified from the mouse genome. We report the identification of 95 putatively functional V1r genes from the draft rat genome sequence. These genes map primarily to four blocks in two chromosomes. The rat V1r genes can be phylogenetically grouped into 10 families, which are shared with mouse, and 2 new families, which are rat-specific. Even in many shared families, gene numbers differ between the two species, apparently due to frequent gene duplication and pseudogenization after the separation of the two species. Molecular dating suggests that most of the rat V1r families emerged before or during the radiation of mammalian orders, but many duplications within families occurred as recently as in the past 10 million years (MY). Our results show that the evolution of the V1r repertoire is characterized by exceptionally fast gene turnover via gains and losses of individual genes, suggesting rapid and substantial changes in pheromone communication between species.

Animals↗
PubMed2004

Biochemical and kinetic characterization of BACE1: investigation into the putative species-specificity for beta- and beta'-cleavage sites by human and murine BACE1.

Beta-amyloid peptides (Abeta) are produced by a sequential cleavage of amyloid precursor protein (APP) by beta- and gamma-secretases. The lack of Abeta production in beta-APP cleaving enzyme (BACE1)(-/-) mice suggests that BACE1 is the principal beta-secretase in mammalian neurons. Transfection of human APP and BACE1 into neurons derived from wild-type and BACE1(-/-) mice supports cleavage of APP at the canonical beta-secretase site. However, these studies also revealed an alternative BACE1 cleavage site in APP, designated as beta', resulting in Abeta peptides starting at Glu11. The apparent inability of human BACE1 to make this beta'-cleavage in murine APP, and vice versa, led to the hypothesis that this alternative cleavage was species-specific. In contrast, the results from human BACE1 transgenic mice demonstrated that the human BACE1 is able to cleave the endogenous murine APP at the beta'-cleavage site. To address this discrepancy, we designed fluorescent resonance energy transfer peptide substrates containing the beta- and beta'-cleavage sites within human and murine APP to compare: (i) the enzymatic efficiency; (ii) binding kinetics of a BACE1 active site inhibitor LY2039911; and (iii) the pharmacological profiles for human and murine recombinant BACE1. Both BACE1 orthologs were able to cleave APP at the beta- and beta'-sites, although with different efficiencies. Moreover, the inhibitory potency of LY2039911 toward recombinant human and native BACE1 from mouse or guinea pig was indistinguishable. In summary, we have demonstrated, for the first time, that recombinant BACE1 can recognize and cleave APP peptide substrates at the postulated beta'-cleavage site. It does not appear to be a significant species specificity to this cleavage.

Amino Acid Sequence↗
PubMed2004

Bacterial species specificity in proU osmoinducibility and nptII and lacZ expression.

Reporter gene-based transcriptional fusions are increasingly being used to address questions in microbial ecology, with constitutively expressed fusions enabling microbe tracking and inducible fusions reporting the presence of environmental signals. To more readily apply this technology to a variety of bacterial species, we examined species specificity in the expression of three promoters of interest. A comparison of two potentially constitutive promoters, each fused to the reporter gene gfp, showed that the nptII promoter (P(nptII)) was expressed in a broader range of species (100% of 11 tested) than the lacZ promoter (P(lacZ)) (75% of 11 tested), and thus has broader applicability for marking bacteria than P(lacZ). For the species that expressed P(lacZ), however,P(lacZ) was expressed 3-fold more than P(nptII), on average. The Escherichia coli proU promoter, which is induced by low water potential in E. coli, Salmonella typhimurium, Pantoea agglomerans, and Pseudomonas syringae, was shown to be similarly responsive to water potential in strains of Clavibacter michiganensis, Enterobacter aerogenes, Pseudomonas fluorescens, Pseudomonas putida, and Sinorhizobium meliloti, as well as mildly osmoresponsive in Agrobacterium tumefaciens, supporting its broad use as a reporter of water potential. Surprisingly, this promoter was not regulated by water potential in strains of Staphylococcus aureus and Erwinia amylovora, illustrating heretofore unrecognized species specificity in proU inducibility, as well as potential limitations in the species that can serve as bioreporters of water potential.

Amino Acid Transport Systems↗
PubMed2006

Species-specific cell-matrix interactions are essential for differentiation of alveoli like structures and milk gene expression in primary mammary cells of the Cape fur seal (Arctocephalus pusillus pusillus).

Few models are in place for analysis of extreme lactation patterns such as that of the fur seals which are capable of extended down regulation of milk production in the absence of involution. During a 10-12 month lactation period, female fur seals suckle pups on shore for 2-3 days, and then undertake long foraging trips at sea for up to 28 days, resulting in the longest intersuckling bouts recorded. During this time the mammary gland down regulates milk production. We have induced Cape fur seal (Arctocephalus pusillus pusillus) mammary cells in vitro to form mammospheres up to 900 microm in diameter, larger than any of their mammalian counterparts. Mammosphere lumens were shown to form via apoptosis and cells comprising the cellular boundary stained vimentin positive. The Cape fur seal GAPDH gene was cloned and used in RT-PCR as a normalization tool to examine comparative expression of milk protein genes (alphaS2-casein, beta-lactoglobulin and lysozyme C) which were prolactin responsive. Cape fur seal mammary cells were found to be unique; they did not require Matrigel for rapid mammosphere formation and instead deposited their own matrix within 2 days of culture. When grown on Matrigel, cells exhibited branching/stellate morphogenesis highlighting the species-specific nature of cell-matrix interactions during morphological differentiation. Matrix produced in vitro by cells did not support formation of human breast cancer cell line, PMC42 mammospheres. This novel model system will help define the molecular pathways controlling the regulation of milk protein expression and species specific requirements of the extracellular matrix in the cape fur seal.

Animals↗
PubMed2002

Species specific identification of nine human Bifidobacterium spp. in feces.

Based on the 16S rDNA sequences, species specific primers were designed for the rapid identification by DNA amplification of nine human Bifidobacterium spp., namely B. adolescentis, B. angulatum, B. bifidum, B. breve, B. catenulatum, B. dentium, B. infantis, B. longum, B. pseudocatenulatum. B. lactis currently included in dairy products was added to the series. The primers were designed to target different positions of the 16S rDNA, allowing the simultaneous identification of these ten species of Bifidobacterium using two mixtures of primers. The identification procedure described in this paper was validated by establishing a correlation with an AluI restriction pattern of the different full length amplified 16S rDNA. This multiple primer DNA amplification technique was applied for the identification of pure colonies of Bifidobacterium spp. or directly from total bacteria recovered from human fecal samples. The technique was shown to be useful to detect dominant species and, when primers were used in separate reactions, underrepresented species could be identified as well.

Adult↗
PubMed1989

Structural determinant of the species-specific transcription of the mouse rRNA gene promoter.

Mammalian ribosomal DNA (rDNA) transcription has a certain species specificity such that, both in vivo and in vitro, human rDNA cannot be transcribed by mouse machinery and vice versa. This is due to a species-dependent transcription factor, TFID (Y. Mishima, I. Financsek, R. Kominami, and M. Muramatsu, Nucleic Acids Res. 10:6659-6670, 1982). On the basis of the information obtained from 5' and 3' substitution mutants, we prepared a chimeric gene in which the mouse sequence from positions -32 to -14 was inserted into the corresponding location of the human rDNA promoter. The chimeric gene could be transcribed by mouse extracts nearly as efficiently as the wild-type mouse promoter. The chimeric gene could also sequester transcription factor TFID at an efficiency similar to that for the mouse promoter. Partially purified mouse TFID that could not protect the human rDNA promoter against DNase I produced a clear footprint on this chimeric gene that was similar to that on mouse rDNA promoter. The basic structure of the mouse rDNA core promoter is discussed in relation to the interaction with TFID.

Animals↗
PubMed2005

Probucol enhances the expression of human hepatic scavenger receptor class B type I, possibly through a species-specific mechanism.

OBJECTIVE: Scavenger receptor class B type I (SR-BI) is a major receptor for high-density lipoproteins (HDL) in the liver, which is the terminus of reverse cholesterol transport. Overexpression of SR-BI attenuated experimental atherosclerosis in murine models, concomitant with a reduction in plasma HDL-cholesterol levels. Probucol is known to be a potent hypolipidemic drug to regress xanthoma formation and carotid atherosclerosis in conjunction with a marked reduction in HDL-cholesterol levels. The aim of the present study was to know the effect of probucol on the expression of SR-BI and the underlying mechanism. METHODS AND RESULTS: We found that probucol increased the expression of SR-BI proteins in in vitro human liver cells and an in vivo rabbit model, but not in wild-type C57Bl6 mice. The decay curve of SR-BI protein was markedly retarded in probucol-treated HepG2 cells in the presence of cycloheximide, indicating that probucol may stabilize human SR-BI protein. To determine the underlying mechanism for the observed species-specific effect, we conducted the following host-swap experiments, in which SR-BI was transfected or expressed in heterologous cells or hosts. Probucol did not increase human SR-BI protein in the liver of transgenic mice carrying the entire human SR-BI genome. Although probucol could stabilize even murine SR-BI, when transfected into a human cell line, HepG2, human SR-BI was not stabilized in a mouse hepatoma cell line, Hepa 1-6, treated with probucol. CONCLUSIONS: Probucol enhances hepatic SR-BI protein expression, possibly through species-specific stabilization of the protein.

Adult↗
PubMed1991

Isolation, characterization, and molecular cloning of a specific Mycobacterium tuberculosis antigen gene: identification of a species-specific sequence.

A rabbit polyclonal antiserum exhibiting a specific recognition pattern for Mycobacterium tuberculosis proteins was used to screen an M. tuberculosis genomic library constructed in the expression vector lambda gt11. One clone, denominated C1:10, expressed M. tuberculosis-specific determinants as part of a large fusion protein with beta-galactosidase. The gene for this protein has been sequenced, and it encodes a protein of 134 amino acids (13.8 kDa) which did not display significant homology with any of the previously reported proteins in the data bases. Hybridization studies with restriction fragments of the cloned sequence revealed that it was not present in the genomes of related mycobacteria, namely, M. bovis, M. bovis BCG, M. flavescens, M. fortuitum, M. phlei, and M. vaccae. These findings suggest that we have detected a gene, or a fragment therefrom, unique for M. tuberculosis whose nucleotide and amino acid sequences could be useful tools in the design of an improved vaccine or a diagnostic method of greater accuracy for tuberculosis.

Amino Acid Sequence↗
PubMed1980

[Effect of azathioprine and prednisolone on recipients of xenografts presensitized with donor species-specific antigen (author's transl)].

Presensitization induced by pretreatment of the recipients with donor species-specific spleen antigen cannot be completely reversed by immunosuppressive drugs. However, there is a suppressive influence of the combined administration of azathioprine and prednisolone on hemagglutinating antibody production after transplantation as well as an effect on function and survival time of renal xenografts.

Animals↗
PubMed1998

Restriction fragment length polymorphism species-specific patterns in the identification of white truffles.

A molecular method for the identification of ectomycorrhizae belonging to five species of white truffle is described. The polymerase chain reaction (PCR) and universal primers were used to amplify internal transcribed spacers and 5.8S rDNA, target sequences present in a high number of copies. The amplified products were digested with restriction enzymes in order to detect interspecific polymorphisms. Species-specific restriction fragment length polymorphism patterns were determined for all five species. The use of PCR in conjunction with restriction enzymes provides a sensitive and efficient tool for use in distinguishing ectomycorrhizal species and monitoring inoculated seedlings or field mycorrhizal populations.

Ascomycota↗
PubMed2001

[The species-specific feeding of rabbits in pet husbandry].

To meet nutrient demands as well as the species specific requirements of an animal it is absolutely necessary to know its nutrition physiology (KAMPHUES et al. 1999). Characteristics of the nutrition physiology of rabbits include the anatomy of the intestinal tract (i.e. the teeth, the size of gut as well as the small intestine and colon), the special ingesting behaviour (selection, intensity of gnawing and chewing) and digestive processes within the intestinal tract (digestion by own as well as by microbial enzymes, processes of separation (producing soft faeces) and the excretion of digested or undigested nutrients (excretion via faeces or kidneys, quality of faeces). In feeding pet rabbits it has to be recommended, that these species do not need concentrates, but ingredients with higher crude fiber contents due to their origin and their intestinal tract. Therefore these herbivorous species should be fed with hay, straw or vegetables and not with concentrates exclusively. If these components are not offered (an usual feeding practice in rabbits kept as companion animals), other products rich in crude fibre have to be fed. The offer of a pressed diet in cube form with long fibrous ingredients would be a possibility to upgrade a ration poor in crude fibre. To meet the gnawing requirement of the rabbits this cubes should be pressed intensively. Furthermore it is advisable to exchange ingredients of the mixed feed with a high energy content (i.e. sunflower seeds, nuts) for ingredients of lower energy density (i.e. oat hulls, pelleted ground hay). Finally calcium oversupply has to be avoided because higher calcium intake may result in urolithiasis (calcium stones/concrements).

Animal Feed↗
PubMed2005

A novel species-specific PCR assay for identifying Lactobacillus fermentum.

Lactobacillus fermentum is a Gram-positive bacterium that is associated with active caries lesions. Methods for identifying Lactobacillus species traditionally have been based upon culture methods coupled with biochemical tests, which are generally unreliable. The aim of this study was to develop a species-specific PCR assay for the direct detection of L. fermentum in oral clinical samples. PCR primers specific for L. fermentum were identified by alignment of bacterial 16S rRNA genes and selection of sequences specific for L. fermentum at their 3' ends. PCR positivity for L. fermentum DNA was indicated by amplification of a 337 bp product. The primers were shown to be specific for L. fermentum DNA, since no PCR product was obtained when genomic DNA from a wide range of other oral bacteria, including closely related Lactobacillus species, were used as test species. The PCR assay was then used in an attempt to identify L. fermentum DNA in supragingival plaque samples and in pus aspirates from subjects with acute dento-alveolar abscesses. Four out of 70 (5.7 %) supragingival plaque samples analysed were positive for the presence of L. fermentum DNA while none of the 19 pus samples analysed was positive for L. fermentum DNA. This PCR assay provides a more rapid, specific and sensitive alternative to conventional culture methods for the identification of L. fermentum in clinical specimens.

DNA, Bacterial↗
PubMed2006

Species-specific population structure in rock-specialized sympatric cichlid species in Lake Tanganyika, East Africa.

Species richness and geographical phenotypic variation in East African lacustrine cichlids are often correlated with ecological specializations and limited dispersal. This study compares mitochondrial and microsatellite genetic diversity and structure among three sympatric rock-dwelling cichlids of Lake Tanganyika, Eretmodus cyanostictus, Tropheus moorii, and Ophthalmotilapia ventralis. The species represent three endemic, phylogenetically distinct tribes (Eretmodini, Tropheini, and Ectodini), and display divergent ecomorphological and behavioral specialization. Sample locations span both continuous, rocky shoreline and a potential dispersal barrier in the form of a muddy bay. High genetic diversity and population differentiation were detected in T. moorii and E. cyanostictus, whereas much lower variation and structure were found in O. ventralis. In particular, while a 7-km-wide muddy bay curtails dispersal in all three species to a similar extent, gene flow along mostly continuous habitat appeared to be controlled by distance in E. cyanostictus, further restricted by site philopatry and/or minor habitat discontinuities in T. moorii, and unrestrained in O. ventralis. In contrast to the general pattern of high gene flow along continuous shorelines in rock-dwelling cichlids of Lake Malawi, our study identifies differences in population structure among stenotopic Lake Tanganyika species. The amount of genetic differentiation among populations was not related to the degree of geographical variation of body color, especially since more phenotypic variation is observed in O. ventralis than in the genetically highly structured E. cyanostictus.

Animals↗