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LINE-1 repetitive DNA probes for species-specific cloning from Mus spretus and Mus domesticus genomes.

Mus domesticus and Mus spretus mice are closely related subspecies. For genetic investigations involving hybrid mice, we have developed a set of species-specific oligonucleotide probes based on the detection of LINE-1 sequence differences. LINE-1 is a repetitive DNA family whose many members are interspersed among the genes. In this study, library screening experiments were used to fully characterize the species specificity of four M. domesticus LINE-1 probes and three M. spretus LINE-1 probes. It was found that the nucleotide differences detected by the probes define large, species-specific subfamilies. We show that collaborative use of such probes can be employed to selectively detect thousands of species-specific library clones. Consequently, these probes could be exploited to monitor and access almost any given species-specific region of interest within hybrid genomes.

Animals↗

Sex preference and species specificity of rodent (Mus musculus and Microtus arvalis pheromones.

The behavioural response to the sex pheromones in the externally voided urine of field voles (Microtus arvalis) and laboratory mice (CFLP, CBA strains) although specific for species showed no strain specificity. Bladder urine (free of accessory sex-gland secretions) and the preputial glands of CFLP and CBA mice contain sex attractants. Ether extracts made of blood of male CFLP mice attracted CFLP female mice.

Animals↗

Species-specific oligonucleotides and multiplex PCR for forensic discrimination of two species of scallops, Placopecten magellanicus and Chlamys islandica.

Characterization of DNA that remains in seafood products after skin, scales, and shells are removed is widely used in forensic species identification, however, ordinary methods may be prohibitively expensive or time-consuming if large sample series need to be discriminated. Forensic discrimination of two species of bivalves commercially harvested from the North Atlantic, sea scallops (Placopecten magellanicus) and Icelandic scallops (Chlamys islandica), was made by means of species-specific oligonucleotides (SSOs) in a multiplex polymerase chain reaction (PCR). The test is a simultaneous in vitro amplification of a portion of the mitochondrial Cytochrome Oxidase I locus with a PCR anchor primer for a sequence identical in both species, and two alternative SSOs that selectively amplify either a 619-bp in Placopecten or a 459-bp DNA fragment in Chlamys. Fragment size and thus species identity are determined directly by gel electrophoresis. In the forensic application, analysis of more than 900 scallops from a series of samples seized from two fishing vessels showed significantly variable proportions of the species from the closed and open fisheries (Placopecten versus Chlamys, respectively). The multiplex SSO test provides a direct means of forensic identification of large population sample series, without the necessity of secondary DNA sequencing, RFLP mapping, or fingerprinting, and can be adapted to other loci and species.

Animals↗

Demonstration of species-specific and cross-reactive components of the adult microsomal antigens from Schistosoma mansoni and S. japonicum (MAMA and JAMA).

Analysis of human serum reactivities to the Schistosoma mansoni adult microsomal antigens (MAMA) showed that S. japonicum and S. haematobium infection sera, as a rule, did not react as well to MAMA as did the homologous S. mansoni infection sera. The degree of species specificity, although not absolute, was quite pronounced. Purification of the corresponding microsomal antigens from S. japonicum adults (JAMA) and subsequent assays with both homologous and heterologous infection sera show a distinct and reciprocating species specificity between S. mansoni and S. japonicum microsomal antigens. The specificities of these antigens were quantitated by k-ELISA. Qualitative analysis of active antigenic components for both JAMA and MAMA involved assay by the "Western blot" or enzyme-linked immunoelectrotransfer blot (EITB). The EITB patterns of both antigens, after resolution by SDS-PAGE, show species-specific reactive bands at the 16,000 to 35,000 m.w. region. S. japonicum-specific antigens are located at the 18,000 to 35,000 m.w. region whereas S. mansoni-specific antigens were associated with m.w. components of 16,000 to 29,000. High m.w. antigen components (greater than 40,000) of both JAMA and MAMA are recognized by both heterologous and homologous infection sera and are thus not species specific. The demonstration of the clear separation of species-specific antigen bands of JAMA and MAMA by physical size offers a unique opportunity to isolate and characterize the species specificities of antibody-antigen reactions in these parasitic infections.

Animals↗

Species-specific association of the cell-aggregation molecule mediates recognition in marine sponges.

Reaggregation of dissociated cells of marine sponges, resulting in reformation of functional sponges, is a calcium-dependent process mediated by large, proteoglycan-like molecules termed aggregation factors (AF). During aggregation, species-specific sorting of cells is often observed. We purified and characterized AFs from three different sponge species and investigated their role in species-specific aggregation using novel approaches. The calcium-dependent association between purified AFs is species-specific in most combinations, as was shown in overlay assays and bead-sorting assays with AFs immobilized onto colored beads. Species-specific interactions of living cells and AF-beads resulted in incorporation of only homospecific AF-beads into reforming cell aggregates. Sequences from peptides obtained from the AF core proteins could all be aligned to the sequence of one species, the Microciona prolifera AFp3 core protein. In contrast to this similarity, major species-specific differences were seen in carbohydrate composition and in the response of AFs to specific carbohydrate-recognizing antibodies. In summary, our data point to a prominent role for the calcium-dependent association of AFs in recognition processes during aggregation. As this association of AFs occurs via carbohydrate-carbohydrate interactions, we speculate that the specificity of those interactions may be fundamental to recognition mechanisms required for regeneration of individuals from dissociated cells and for rejection of foreign material by sponge individuals.

Animals↗

Sequence divergence within the sperm-specific polypeptide TCTE1 is correlated with species-specific differences in sperm binding to zona-intact eggs.

The T-complex-associated testes-expressed (TCTE1) gene encodes a novel sperm cell-specific polypeptide (TCTE1) that is conserved across vertebrate species. TCTE1 is absolutely required for fertilization and is expressed in earlier stages of spermatogenesis. When the amino acid sequence of the TCTE1 gene product is compared among various mammalian species, a large, highly conserved domain is observed, along with a divergent domain encoding the 56-58 residues at the N terminus. In this study, the N-terminal regions of the TCTE1 polypeptide from three rodent species--mouse, gerbil, and rat--were compared. The results show that while the gerbil and mouse species are most distant in evolutionary terms, their TCTE1 homologs have not undergone significant divergence. In contrast, the N-terminal region of the rat TCTE1 homolog has evolved rapidly, a finding that indicates positive Darwinian selection. We have tested the correlation between TCTE1 divergence and heterospecific sperm-egg binding ability in the three species under study. Gerbil sperm bind to mouse eggs, while no significant binding is observed between rat sperm and mouse eggs. The results obtained support the hypothesis that the sperm-specific polypeptide TCTE1 may facilitate species-specific divergence of sperm function.

Amino Acid Sequence↗

Application of species-specific polymerase chain reaction in the forensic identification of tiger species.

Globally, tigers are considered to be endangered, and are listed on Appendix I of CITES. A simple test, using a species-specific primer pair, was developed to identify tiger meat, faeces and dried skin, and provide forensic evidence of illegal wildlife trade. The specific fragment of mitochondrial cytochrome b gene was also successfully amplified from raw DNA products extracted from single tiger hairs. This PCR-based approach opens a new avenue to forensic identification of less-than-optimal samples.

Animals↗

Genus- and species-specific DNA probes to identify mycobacteria using the polymerase chain reaction.

Differential diagnosis of Mycobacterium tuberculosis, M. avium, and other mycobacteria remains a lengthy process. Recently, the use of DNA probes has been proposed as a new approach for a more specific and rapid diagnosis. Here, we report the cloning and sequencing of a genus-specific probe for Mycobacterium and a species-specific M. avium probe. The genus-specific probe hybridizes with DNA from nine ATCC type strains and 13 isolates of mycobacteria but not to non-mycobacterial DNA. In addition, the cloned fragment could also be amplified by polymerase chain reaction (PCR) in DNa of ten different mycobacterial type strains. The M. avium specific probe hybridizes strongly to sequences amplified in M. avium but not other mycobacterial or non-mycobacterial DNA. Amplification of the target sequence by PCR allowed the detection of 1 fg of all mycobacterial DNA tested for the genus-specific probe and 1 fg of M. avium DNA for the species-specific probe.

Animals↗

A theoretical model for the Gla-TSR-EGF-1 region of the anticoagulant cofactor protein S: from biostructural pathology to species-specific cofactor activity.

Protein S (PS), which functions as a species-specific anticoagulant cofactor to activated protein C (APC), is a mosaic protein that interacts with the phospholipid membrane via its gamma-carboxyglutamate-rich (Gla) module. This module is followed by the thrombin-sensitive region (TSR), sensitive to thrombin cleavage, four epidermal growth factor (EGF)-like modules and a last region referred to as the sex hormone binding globulin (SHBG) domain. Of these, the TSR and the first EGF-like regions have been shown to be important for the species-specific interaction with APC. Difficulties in crystallising PS have so far hindered its study at the atomic level. Here, we report theoretical models for the Gla and EGF-1 modules of human PS constructed using prothrombin and factor X experimental structures. The TSR was built interactively. Analysis of the model linked with the large body of biochemical literature on PS and related proteins leads to suggestions that (i) the TSR stabilises the calcium-loaded Gla module through hydrophobic and ionic interactions and its conformation depends on the presence of the Gla module; (ii) the TSR does not form a calcium binding site but is protected from thrombin cleavage in the calcium-loaded form owing to short secondary structure elements and close contact with the Gla module; (iii) the PS missense mutations in this region are consistent with the structural data, except in one case which needs further investigation; and (iv) the two PS 'faces' involving regions of residues Arg49-Gln52-Lys97 (TSR-EGF-1) and Thr103-Pro106 (EGF-1) may be involved in species-specific interactions with APC as they are richer in nonconservative substitution when comparing human and bovine protein S. This preliminary model helps to plan future experiments and the resulting data will be used to further validate and optimise the present structure.

1-Carboxyglutamic Acid↗

[Evolution mechanism of species-specific lifespan].

Numerous empiric data prove incontestably that species-specific lifespan is under control of genetic program. At the same time the modern evolution theories of aging deny an opportunity of existence of specific genes predetermining longevity. Basic premise for non-acceptance of the aging gene concept is convincing: animals in habitat do not live long enough for aging to exert any effect on their survival. Therefore, the natural selection can not differentiate them by the longevity attribute. To solve the collision the population approach was used in this work. As known from ecological laws the innate population growth rate (r(in)), lifetime of one generation (T), and inborn fertility (R(0)) are interconnected by the next dependence: r(in) = In R(0)/T. The examining of mathematical model of population showed that r(in) value is stabilized by inter-population natural selection on the level which corresponds to environment press in the species ecological niche. Therefore, species-specific longevity and fecundity are under control of this natural selection.

Animals↗

Brugia malayi and Brugia pahangi: synthetic biotin labeling of oligonucleotide probes for use in species-specific detection assays.

We have developed a novel, high-yield synthetic approach for the incorporation of multiple biotin residues into a series of species-specific oligonucleotide probes for the detection of filarial parasites. The probes are designed to detect species-specific regions of a highly repeated DNA sequence (HhaI repeat) found in all species of Brugia. The synthetic method described in this paper was used to construct oligomer probes tailed on the 5' end with 1 to 46 biotinylated uridine residues. Probes with 46 biotins were found to be more sensitive than probes with 30 or fewer biotins. We also found that alternating the biotinylated uridine residues with nonbiotinylated thymidine residues improved the sensitivity of the probes. Melting temperature studies indicated that the long tails (up to 91 nucleotides) had only a minimal effect on the Tm of the probes. Conditions were found that optimized the sensitivity of the probes while maintaining their species specificity. Using these conditions, the probes were shown to be sensitive enough to detect single parasites in blood using a chemiluminescent detection system. This method of nonradioactively labeling oligonucleotides for the detection of infectious agents will enable the use of such probes in endemic regions in developing countries.

Animals↗

Rapid identification of Candida species with species-specific DNA probes.

Rapid identification of Candida species has become more important because of an increase in infections caused by species other than Candida albicans, including species innately resistant to azole antifungal drugs. We previously developed a PCR assay with an enzyme immunoassay (EIA) format to detect amplicons from the five most common Candida species by using universal fungal primers and species-specific probes directed to the ITS2 region of the gene for rRNA. We designed probes to detect seven additional Candida species (C. guilliermondii, C. kefyr, C. lambica, C. lusitaniae, C. pelliculosa, C. rugosa, and C. zeylanoides) included in the API 20C sugar assimilation panel, five probes for species not identified by API 20C (C. haemulonii, C. norvegica, C. norvegensis, C. utilis, and C. viswanathii), and a probe for the newly described species C. dubliniensis, creating a panel of 18 Candida species probes. The PCR-EIA correctly identified multiple strains of each species tested, including five identified as C. albicans by the currently available API 20C database but determined to be C. dubliniensis by genotypic and nonroutine phenotypic characteristics. Species identification time was reduced from a mean of 3.5 days by conventional identification methods to 7 h by the PCR-EIA. This method is simple, rapid, and feasible for identifying Candida species in clinical laboratories that utilize molecular identification techniques and provides a novel method to differentiate the new species, C. dubliniensis, from C. albicans.

Base Sequence↗

A species-specific frequency filter through specific inhibition, not specific excitation.

Many bushcrickets produce specific song spectra for acoustic communication. Song detection and/ or recognition may make use of such specificity. Where in the nervous system are the filters for song frequency situated? A peripheral tuning for song frequency typically does not exist. Auditory receptor cells of bushcrickets connect to local and ascending neurons in the prothoracic ganglion. One of the ascending neurons (1) may function as a frequency filter in a group of four related bushcrickets (genera Ancistrura, Barbitistes). The frequency response of ascending neuron 1 is species-specific roughly corresponding to the frequency of the conspecific male song. The species-specific tuning of the neuron is not brought about by specific excitation, but by specific inhibition. By eliminating this frequency-dependent and species-specific inhibition the former filter neuron is transformed into an unspecific broad-band neuron in all four species. Its tuning then does not differ from omega neuron 1, a local neuron which is rather unspecific for frequency. Also, the supra-threshold responses of ascending neuron 1, which are different in intact animals, are similar to each other and similar to omega neuron 1 following elimination of inhibition. Only ascending neuron 1 of Ancistrura retains some species-specific features at low frequencies. In conclusion, evolution changed inhibition, not excitation of a species-specific neuron.

Action Potentials↗

Development of Species-Specific Markers of the Tropical Oyster (Crassostrea belcheri) in Thailand.

Randomly amplified polymorphic DNA (RAPD) analysis was used to identify species-specific markers of 5 oyster species in Thailand: Crassostrea belcheri, Crassostrea iredalei, Saccostrea cucullata, Saccostrea forskali, and Striostrea (Parastriostrea) mytiloides. Species-specific markers were found in C. belcheri, C. iredalei, and S. cucullata but not in S. forskali and S. mytiloides. Three C. belcheri-specific RAPD fragments were cloned and sequenced. A primer set was designed from each of the recombinant clones (pPACB1, pPACB2, and pPACB3). The polymerase chain reaction products showed expected sizes of 536, 600, and 500 bp, respectively, with the sensitivity of detection approximately 30 pg of C. belcheri total DNA template. The specificity of pPACB1 was examined against 135 individuals of indigenous oyster species in Thailand and against outgroup references S. commercialis (N = 12) and Perna viridis (N = 12). Results indicated the species-specific nature of primers developed from pPACB1. This primer set can be used for broodstock selection and determination of C. belcheri larvae to assist the selective breeding program for this commercially important species.

Journal Article↗

Identification and differentiation of Staphylococcus carnosus and Staphylococcus simulans by species-specific PCR assays of sodA genes.

The aim of this study was to design species-specific PCR assays for rapid and reliable identification and differentiation of Staphylococcus (S.) carnosus and S. simulans strains. Two different sets of primers, targeting the manganese-dependent superoxide dismutase (sodA) gene of S. carnosus and S. simulans, respectively, were designed. Species-specificity of both sets of primers was evaluated by using 93 strains, representing 26 different species of the genus Staphylococcus, 3 species of the genus Kocuria (K.), 1 species of the genus Micrococcus (Mic.) and 1 species of the genus Macrococcus (Mac.) as reference. By using primers simF and simR the expected PCR fragment was obtained only when purified DNA from S. simulans strains was used. Amplification performed by using primers carF and carR produced a PCR fragment of the expected length, when DNA from strains of S. carnosus and S. condimenti were used as template. Nevertheless, DraI digestion of the carF/carR PCR fragment allowed a clear differentiation of strains of these two species. Species-specific PCR assays designed during this study, overcoming many of the limitations of the traditional identification procedures, can be considered a valid strategy for detection and identification of S. carnosus and S. simulans strains. The rapidity (about 4h from DNA isolation to results), the reliability and low cost of the PCR procedures established suggests that the methods may be profitably applied for specific detection and identification of S. carnosus, S. condimenti and S. simulans strains in starter cultures and meat products.

Bacterial Proteins↗

IgE antibodies are more species-specific than IgG antibodies in human onchocerciasis and lymphatic filariasis.

To explore the relative species specificities of the IgE and IgG antibody responses to helminth infections in man, we studied four pools of sera from patients infected with Wuchereria bancrofti, Brugia malayi, Onchocerca volvulus or Ascaris lumbricoides and ten individual sera from patients with onchocerciasis. IgE antibodies were detected by radioallergosorbent test (RAST) analysis and IgG antibodies by a Staphylococcus protein A radioimmunoassay (Staph A-RIA). Analysis of the binding curves with four different immunosorbents (prepared from antigens of B. malayi, O. volvulus, Dipetalonema viteae and A. lumbricoides) in the RAST and the binding curves with these same four antigens in the Staph A-RIA confirmed the relative species specificities for both the IgE and IgG antibody responses. Then determination of these antibody levels after specific absorption of the sera with both homologous and heterologous antigens showed that in all instances there was significantly less cross-reactivity with heterologous parasite antigens (i.e. higher species specificity) in the IgE antibody response to filarial infection than in the corresponding IgG antibody response. Such findings imply that efforts toward developing techniques for specific immunodiagnosis of filarial infections are likely to be particularly successful if focused on the IgE antibody response of exposed individuals.

Antigens↗

Spectral determination of responses to species-specific calls in the dorsal nucleus of the lateral lemniscus.

This study evaluated how neurons in the dorsal nucleus of the lateral lemniscus (DNLL) in Mexican free-tailed bats respond to both tone bursts and species-specific calls. Up to 20 calls were presented to each neuron, of which 18 were social communication and 2 were echolocation calls. We also measured excitatory response regions (ERRs): the range of tone burst frequencies that evoked discharges at a fixed intensity. Neurons were unselective for one or another call in that each neuron responded to any call so long as the call had energy that encroached on its ERR. Additionally, responses were evoked by the same set of calls, and with similar spike counts, when they were presented normally or reversed. By convolving activity in the ERRs with the spectrogram of each call, we showed that responses to tones accurately predicted discharge patterns evoked by species-specific calls. DNLL cells are remarkably homogeneous in that neurons having similar BFs responded to each of the species-specific calls with similar response profiles. The homogeneity was further illustrated by the ability to accurately predict the response profiles of a particular DNLL cell to species-specific calls from the ERR of another similarly tuned DNLL cell. Thus DNLL neurons tuned to the same or similar frequencies responded to species-specific calls with latencies and temporal discharge patterns that were so similar as to be virtually interchangeable. What this suggests is that DNLL responses evoked by complex sounds can be largely explained by a simple summation of the excitation in each neuron's ERR. Finally, superimposing the spectrograms of each call on the responses evoked by that call revealed that the DNLL population response re-creates both the spectral and the temporal features of each signal.

Acoustic Stimulation↗

Alternative splicing of conserved exons is frequently species-specific in human and mouse.

In this article, we provide evidence that a frequent source of diversity between mammalian transcripts occurs as a consequence of species-specific alternative splicing (AS) of conserved exons. Using a highly predictive computational method, we estimate that >11% of human and mouse cassette alternative exons undergo skipping in one species but constitutively splicing in the other. These species-specific AS events are predicted to modify conserved domains in proteins more frequently than other classes of AS events. The results thus provide evidence that species-specific AS of conserved exons constitutes an additional potential source of complexity and species-specific differences between mammals.

Alternative Splicing↗