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PubMed2001

Differential representation of species-specific primate vocalizations in the auditory cortices of marmoset and cat.

A number of studies in various species have demonstrated that natural vocalizations generally produce stronger neural responses than do their time-reversed versions. The majority of neurons in the primary auditory cortex (A1) of marmoset monkeys responds more strongly to natural marmoset vocalizations than to the time-reversed vocalizations. However, it was unclear whether such differences in neural responses were simply due to the difference between the acoustic structures of natural and time-reversed vocalizations or whether they also resulted from the difference in behavioral relevance of both types of the stimuli. To address this issue, we have compared neural responses to natural and time-reversed marmoset twitter calls in A1 of cats with those obtained from A1 of marmosets using identical stimuli. It was found that the preference for natural marmoset twitter calls demonstrated in marmoset A1 was absent in cat A1. While both cortices responded approximately equally to time-reversed twitter calls, marmoset A1 responded much more strongly to natural twitter calls than did cat A1. This differential representation of marmoset vocalizations in two cortices suggests that experience-dependent and possibly species-specific mechanisms are involved in cortical processing of communication sounds.

Animals↗
PubMed2006

Murine encephalitis caused by HCoV-OC43, a human coronavirus with broad species specificity, is partly immune-mediated.

The human coronavirus HCoV-OC43 causes a significant fraction of upper respiratory tract infections. Most coronaviruses show a strong species specificity, although the SARS-Coronavirus crossed species from palm civet cats to infect humans. Similarly, HCoV-OC43, likely a member of the same coronavirus group as SARS-CoV, readily crossed the species barrier as evidenced by its rapid adaptation to the murine brain [McIntosh, K., Becker, W.B., Chanock, R.M., 1967. Growth in suckling-mouse brain of "IBV-like" viruses from patients with upper respiratory tract disease. Proc Natl Acad Sci U.S.A. 58, 2268-73]. Herein, we investigated two consequences of this plasticity in species tropism. First, we showed that HCoV-OC43 was able to infect cells from a large number of mammalian species. Second, we showed that virus that was passed exclusively in suckling mouse brains was highly virulent and caused a uniformly fatal encephalitis in adult mice. The surface glycoprotein is a major virulence factor in most coronavirus infections. We identified three changes in the HCoV-OC43 surface glycoprotein that correlated with enhanced neurovirulence in mice; these were located in the domain of the protein responsible for binding to host cells. These data suggest that some coronaviruses, including HCoV-OC43 and SARS-CoV, readily adapt to growth in cells from heterologous species. This adaptability has facilitated the isolation of HCoV-OC43 viral variants with markedly differing abilities to infect animals and tissue culture cells.

Animals↗
PubMed1996

Species-specificity of rRNA gene transcription in plants manifested as a switch in RNA polymerase specificity.

Rapid evolution of ribosomal RNA (rRNA) gene promoters often prevents their recognition in a foreign species. Unlike animal systems, we show that foreign plant rRNA gene promoters are recognized in an alien species, but tend to program transcription by a different polymerase. In plants, RNA polymerase I transcripts initiate at a TATATA element (+1 is underlined) important for promoter strength and start-site selection. However, transcripts initiate from +32 following transfection of a tomato promoter into Arabidopsis. The rRNA gene promoter of a more closely related species, Brassica oleracea, programs both +1 and +29 transcription. A point mutation at +2 improving the identity between the Brassica and Arabidopsis promoters increases +1 transcription, indicating a role for the initiator element in species-specificity. Brassica +29 transcripts can be translated to express a luciferase reporter gene, implicating RNA polymerase II. TATA mutations that disrupt TATA-binding protein (TBP) interactions inhibit +29 transcription and luciferase expression. Co-expressed TBP proteins bearing compensatory mutations restore +29 transcription and luciferase activity, suggesting a direct TBP-TATA interaction. Importantly, +1 transcription is unaffected by the TATA mutations, suggesting that in the context of pol I recognition, the TATA-containing initiator element serves a function other than TBP binding.

Arabidopsis↗
PubMed1984

Species-specific detection of Mycoplasma hyorhinis using DNA probes.

Two specific DNA fragments from a genomic library of Mycoplasma hyorhinis demonstrated species-specific Southern and dot hybridization using a panel of different mycoplasmas. These probes selectively recognized M. hyorhinis sequences in purified DNA, broth-grown organisms, and infected cell cultures, providing a direct method for differential detection of this mycoplasma species without prior purification of the organism.

Cloning, Molecular↗
PubMed1996

Sequence divergence associated with species-specific splicing of the nonmuscle beta-tropomyosin alternative exon.

Alternative splicing of vertebrate beta-tropomyosin transcripts ensures mutually exclusive expression of internal exons 6A and 6B in nonmuscle and skeletal muscle cells, respectively. Recently, we reported that this splicing regulation requires species-specific elements, since the splicing profile for the chicken, rat, and Xenopus beta-tropomyosin alternative exons is not reproduced in transfection experiments when heterologous myogenic cells are used. By analyzing the splicing pattern of hybrid chicken/rat beta-TM constructions transfected into both quail and mouse cell lines, we demonstrate that chicken beta-tropomyosin exon 6A is flanked by stronger splicing signals than rat exon 6A, thus leading to the misregulation of splicing in heterologous cells. We have characterized three splicing signals that contribute to this difference: 1) nonconsensus nucleotide differences at positions +4 and +6 in the donor site downstream of exon 6A, 2) differences in the pyrimidine composition between the branch site and acceptor site upstream of exon 6A, and 3) a pyrimidine-rich intronic exon 6A splicing enhancer present upstream of exon 6A only in the chicken beta-TM gene. The functional divergence between splicing signals in two homologous vertebrate genes reveals species-specific strategies for proper modulation of splicing of alternative exons.

Alternative Splicing↗
PubMed2004

Simultaneous speciation of mercury and butyltin compounds in natural waters and snow by propylation and species-specific isotope dilution mass spectrometry analysis.

A robust method has been developed for simultaneous determination of mercury and butyltin compounds in aqueous samples. This method is capable of providing accurate results for analyte concentrations in the picogram per liter to nanogram per liter range. The simultaneous determination of the mercury and tin compounds is achieved by species-specific isotope dilution, derivatization, and gas chromatography-inductively coupled plasma mass spectrometer (GC-ICP-MS). In derivatization by ethylation and propylation, reaction conditions such as pH and the effect of chloride were carefully studied. Ethylation was found to be more sensitive to matrix effects, especially for mercury compounds. Propylation was thus the preferred derivatization method for simultaneous determination of organomercury and organotin compounds in environmental samples. The analytical method is highly accurate and precise, with RSD values of 1 and 3% for analyte concentrations in the picogram per liter to nanogram per liter range. By use of cleaning procedures and SIDMS blank measurements, detection limits in the range 10-60 pg L(-1) were achieved; these are suitable for determination of background levels of these contaminants in environmental samples. This was demonstrated by using the method for analysis of real snow and seawater samples. This work illustrates the great advantage of species-specific isotope dilution for the validation of an analytical speciation method-the possibility of overcoming species transformations and non-quantitative recovery. Analysis time is saved by use of the simultaneous method, because of the use of a single sample-preparation procedure and one analysis.

Hydrogen-Ion Concentration↗
PubMed1995

Representation of a species-specific vocalization in the primary auditory cortex of the common marmoset: temporal and spectral characteristics.

1. The temporal and spectral characteristics of neural representations of a behaviorally important species-specific vocalization were studied in neuronal populations of the primary auditory cortex (A1) of barbiturate-anesthetized adult common marmosets (Callithrix jacchus), using both natural and synthetic vocalizations. The natural vocalizations used in electrophysiological experiments were recorded from the animals under study or from their conspecifics. These calls were frequently produced in vocal exchanges between members of our marmoset colony and are part of the well-defined and highly stereotyped vocal repertoire of this species. 2. The spectrotemporal discharge pattern of spatially distributed neuron populations in cortical field A1 was found to be correlated with the spectrotemporal acoustic pattern of a complex natural vocalization. However, the A1 discharge pattern was not a faithful replication of the acoustic parameters of a vocalization stimulus, but had been transformed into a more abstract representation than that in the auditory periphery. 3. Subpopulations of A1 neurons were found to respond selectively to natural vocalizations as compared with synthetic variations that had the same spectral but different temporal characteristics. A subpopulation responding selectively to a given monkey's call shared some but not all of its neuronal memberships with other individual-call-specific neuronal subpopulations. 4. In the time domain, responses of individual A1 units were phase-locked to the envelope of a portion of a complex vocalization, which was centered around a unit's characteristic frequency (CF). As a whole, discharges of A1 neuronal populations were phase-locked to discrete stimulus events but not to their rapidly changing spectral contents. The consequence was a reduction in temporal complexity and an increase in cross-population response synchronization. 5. In the frequency domain, major features of the stimulus spectrum were reflected in rate-CF profiles. The spectral features of a natural call were equally or more strongly represented by a subpopulation of A1 neurons that responded selectively to that call as compared with the entire responding A1 population. 6. Neuronal responses to a complex call were distributed very widely across cortical field A1. At the same time, the responses evoked by a vocalization scattered in discrete cortical patches were strongly synchronized to stimulus events and to each other. As a result, at any given time during the course of a vocalization, a coherent representation of the integrated spectrotemporal characteristics of a particular vocalization was present in a specific neuronal population. 7. These results suggest that the representation of behaviorally important and spectrotemporally complex species-specific vocalizations in A1 is 1) temporally integrated and 2) spectrally distributed in nature, and that the representation is carried by spatially dispersed and synchronized cortical cell assemblies that correspond to each individual's vocalizations in a specific and abstracted way.

Acoustic Stimulation↗
PubMed2006

Molecular discrimination of Perna (Mollusca: Bivalvia) species using the polymerase chain reaction and species-specific mitochondrial primers.

This work was prompted by the need to be able to identify the invasive mussel species, Perna viridis, in tropical Australian seas using techniques that do not rely solely on morphology. DNA-based molecular methods utilizing a polymerase chain reaction (PCR) approach were developed to distinguish unambiguously between the three species in the genus Perna. Target regions were portions of two mitochondrial genes, cox1 and nad4, and the intergenic spacer between these that occurs in at least two Perna species. Based on interspecific sequence comparisons of the nad4 gene, a conserved primer has been designed that can act as a forward primer in PCRs for any Perna species. Four reverse primers have also been designed, based on nad4 and intergenic spacer sequences, which yield species-specific products of different lengths when paired with the conserved forward primer. A further pair of primers has been designed that will amplify part of the cox1 gene of any Perna species, and possibly other molluscs, as a positive control to demonstrate that the PCR is working.

Animals↗
PubMed1999

The evolution of neuronal circuits underlying species-specific behavior.

The nervous system is evolutionarily conservative compared to the peripheral appendages that it controls. However, species-specific behaviors may have arisen from very small changes in neuronal circuits. In particular, changes in neuromodulatory systems may allow multifunctional circuits to produce different sets of behaviors in closely related species. Recently, it was demonstrated that even species differences in complex social behavior may be attributed to a change in the promoter region of a single gene regulating a neuromodulatory action.

Animals↗
PubMedDate not supplied

[Relation between the dynamics of a species-specific motor reaction and the duration of diencephalic stimulation].

Species-specific reaction of thumping behaviour with the hind limbs in response to electrical stimulation of the ventromedial, dorsomedial and caudal parts of the hypothalamus was studied in chronic experiments on rabbits. Reaction of avoidance dominated during current action of various durations (1-20 s). The specific reaction under study appeared after the termination of stimulation and lasted for 30-120 s. The number of kicks in response to single stimulation depended on its duration (T). With T rising from 1 to 10 s, the number of kicks increased; with T being equal to 20 s, it decreased. The latency of the first kick after the termination of stimulation regularily increased with increase of its duration, and reaction intensity maxima shifted to the right along the axis of time. Possible mechanisms of limb kicking behaviour are discussed based on a transition of avoidance reaction during stimulus action to emotional reaction in post-stimulus period.

Animals↗
PubMed1990

Species-specific sequences of abalone lysin, the sperm protein that creates a hole in the egg envelope.

Abalone eggs are contained within a rigid, elevated vitelline envelope through which the sperm must pass before reaching the egg cell membrane. Abalone spermatozoa possess an acrosomal protein called lysin that creates a hole in the egg vitelline envelope by a nonenzymatic mechanism. Lysins from two species of abalone, termed pink and red, which share the same habitat, exhibit species specificity in the dissolution of isolated egg envelopes. Cloning and sequencing the cDNAs for pink and red abalone lysins reveal transcript lengths of approximately 660 nucleotides. The open reading frames of 465 (pink) and 462 (red) nucleotides show a 13% difference. The 3' untranslated regions before the poly(A) tails are 170 (pink) and 165 (red) nucleotides long and differ from each other by about 7%. The protein sequences show nearly identical signal sequences of 18 amino acids for both lysins. The mature protein is 137 amino acids in the pink abalone and 136 in the red abalone; the two mature lysins differ in 29 of 137 amino acids (21%). The most variable region, which may account for lysin's species specificity, is at the NH2 terminus, where 11 of the 15 amino acids differ between the two species. Predictions of secondary structure indicate that both lysins contain four homologous amphiphilic alpha-helices.

Amino Acid Sequence↗
PubMed1991

Comparison of the bindin proteins of Strongylocentrotus franciscanus, S. purpuratus, and Lytechinus variegatus: sequences involved in the species specificity of fertilization.

Bindin is the sea urchin sperm acrosomal protein that is responsible for the species-specific adhesion of the sperm to the egg. Two new bindin cDNA sequences that contain the entire open reading frame for the binding precursor are reported: one for Strongylocentrotus franciscanus and one for Lytechinus variegatus. Both contain inverted repetitive sequences in their 3' untranslated regions, and the S. franciscanus cDNA contains an inverted repetitive sequence match between the 5' untranslated region and the coding region. The middle third of the mature bindin sequence is highly conserved in all three species, and the flanking sequences share short repeated sequences that vary in number between the species. Cross-fertilization data are reported for the species S. purpuratus, S. franciscanus, L. variegatus, and L. pictus. A barrier to cross-fertilization exists between the sympatric Strongylocentrotus species, but there is no barrier between the allopatric Lytechinus species.

Amino Acid Sequence↗
PubMed1992

Species-specific recognition patterns of monoclonal antibodies directed against vimentin.

Two commercially available monoclonal antibodies raised against the intermediate filament protein vimentin were characterized concerning their species-specific reaction pattern on vertebrate cells. The antibody V9 exhibited extensive reactivity with vimentin of all mammalian species tested, but specifically did not detect vimentin in mouse cells and chicken fibroblasts. The antibody VIM 3B4 recognized vimentin in cells of chicken and most mammalian species, except for rodent species. Characterization of the binding site of VIM 3B4 on human vimentin by limited proteolysis and immunoblotting as well as by sequence comparison strongly suggested that the epitope is located in the coil 2 part of the vimentin rod domain. Site-directed mutagenesis of a mouse vimentin cDNA clone followed by in vivo expression showed that VIM 3B4 could detect rodent vimentin containing a single amino acid substitution (valine for leucine) at position 353 of the mouse vimentin sequence. Practical application for this finding was demonstrated by the unequivocal identification of a modified murine vimentin protein, distinct from the endogenous vimentin, in a cytoplasmic intermediate filament network in mouse skin fibroblasts transfected with a recombinant plasmid expression vector.

Animals↗
PubMed1990

[Isolation of antibodies against species-specific M. bovis antigens].

Tuberculin PPD antibodies were isolated from hyperimmune rabbit serum by affinity chromatography. They were crossover depleted for elimination of antibodies specific to common (with atypical mycobacteria) antigens. Antibodies to M. bovis species-specific antigens may be used for preparing an immunosorbent and affinity chromatographically isolating the antigens from tuberculin PPD.

Animals↗
PubMed1986

A comparison between fructose 1,6-diphosphate, glucose, or normal saline infusions and species-specific blood exchange transfusions in the treatment of bowel ischemia.

Infusion of fructose 1,6-diphosphate, (FDP), the rate-limiting substrate in anaerobic metabolism, decreases infarction in the ischemic heart. This study evaluates the effect of FDP (5% in H2O), glucose (D5W), or normal saline (N/S) infusions and species-specific blood (SSB) exchange transfusions on mortality rates and bowel infarction in rats with intestinal ischemia. One hundred twenty Sprague-Dawley male rats (50 to 75 gm) were divided into six experimental groups. Group I controls (n = 20) underwent sham laparotomy. Group II (n = 20) underwent superior mesenteric artery (SMA) occlusion for 90 minutes. Group III rats (n = 20) were infused with FDP with SMA occlusion (90 minutes). Group IV rats (n = 20) were infused with D5W with SMA occlusion (90 minutes). Group V rats (n = 20) were infused with N/S with SMA occlusion (90 minutes). Group VI rats (n = 20) received species-specific exchange transfusion after SMA occlusion (90 minutes). A typical rat given 1 ml of D5W/75 gm had a serum glucose of 478 ng/dl with an osmolality of 293 mosm/L. After being given 1 ml of NS/75 gm, rats had a serum glucose level of 170 mg/dl with an osmolality of 291 mos/ml. Control rats had a serum glucose level of 139 mg/dl with an osmolality of 295 mosm/L. Survival at 48 hours without bowel infarction was 20 of 20 (100%) in group I, three of 20 (15%) in group II, 12 of 20 (60%) in group III, 12 of 20 (60%) in group IV, five of 20 (25%) in group V, and six of 20 (30%) in group VI (p less than 0.05 groups III and IV versus group II). FDP and D5W infusions increased survival after bowel ischemia in the rat. The mechanism of action may involve provision of a substrate for anaerobic metabolism to ischemic bowel via collateral pathways, hemodilution, and/or volume expansion.

Animals↗
PubMed1976

[Species specificity of morphogenetic factors of Acetabularia, localized in the cytoplasmic zone adjacent to the cell membrane].

The species specificity of the factors controlling the cap development was established in the experiments with the transplantation of both the intact and centrifuged in the basal direction apical regions of Acetabularia meditteranea on nuclear basal regions of A. crenulata. These factors are found at the stage of 72 hrs of regeneration primarily in the cytoplasmic zone adjacent to the cell membrane which is not displaced during centrifugation. Using direct measurements and radiochemical method, we have shown that the accumulation of proteins proceeded in this zone due, mainly, to their transition from the cytoplasmic zone displaced during centrifugation.

Acetabularia↗
PubMed1993

[Concentration of species alien (bovine) IgG in the blood serum of foals after the intake of non-species specific colostrum preparation].

Sixteen vital foals with free access to maternal colostrum received a additional non-species-specific commercial colostrum additive within the first 18 hours of their life. The additive had been prepared from bovine colostrum. At birth no bovine IgG was detectable. The concentration of bovine IgG reached its maximum 18 hours post natum with XG = 74.6 mg/dl. 96 hours after birth IgG levels had dropped to XG = 20.9 mg/dl. The correlation of bovine IgG with GGT-activity was highly significant. Formation of antibodies against bovine IgG could not be demonstrated. It is not possible to increase igG in the circulation of newborn foals to satisfactory levels with IgG of bovine origin in the used commercial colostrum additive.

Animals↗