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Several Mammalian Species (several + mammalian_species)
Selected AbstractsThe death of cardiotonic steroid-treated cells: evidence of Na+i,K+i -independent H+i -sensitive signallingACTA PHYSIOLOGICA, Issue 1-2 2006S. N. Orlov Abstract Na/K-ATPase is the only known target of cardiotonic steroids (CTS) identified in plants, amphibians and later on in several mammalian species, including human. We focus our review on recent data implicating CTS in the tissue-specific regulation of cell survival and death. In vascular smooth muscle cells, CTS inhibited cell death triggered by apoptotic stimuli via a novel Na+i -mediated, Ca2+i -independent mechanism of expression of antiapoptotic genes, including mortalin. In contrast, exposure to CTS in vascular endothelial and renal epithelial cells led to cell death, showing combined markers of apoptosis and necrosis. This mode of cell death, termed oncosis, is caused by CTS interaction with Na/K-ATPase but is independent of the inhibition of Na/K-ATPase-mediated ion fluxes and inversion of the [Na+]i/[K+]i ratio. The intermediates of intracellular signalling involved in Na+i, K+i -independent oncosis of CTS-treated cells remain unknown. Recently, we found that this mode of cell death can be protected by modest intracellular acidification via the expression of H+i -sensitive genes. The molecular origin of intracellular Na+ and H+ sensor involvement in the development of apoptosis and oncosis is currently under investigation. [source] Production of biologically active equine interleukin 12 through expression of p35, p40 and single chain IL-12 in mammalian and baculovirus expression systemsEQUINE VETERINARY JOURNAL, Issue 7 2001E. L. J. McMONAGLE Summary Interleukin-12 (IL-12) is a key cytokine in the development of cell-mediated immune responses. Bioactive IL-12 is a heterodimeric cytokine composed of disulphide linked p35 and p40 subunits. The aim of this study was to verify biologically activity of the products expressed from equine interleukin-12 (IL-12) p35 and p40 cDNAs and to establish whether equine IL-12 could be expressed as a p35/p40 fusion polypeptide, as has been reported for IL-12a of several mammalian species. We report production of equine IL-12 through expression of p35 and p40 subunits in mammalian and insect cells and of a p35:p40 fusion polypeptide in mammalian cells. Conditioned medium recovered from cultures transiently transfected with constructs encoding equine p35 and p40 subunits or single chain IL-12 enhanced IFN-, production in cells derived from equine lymph nodes. Preincubation of IFN-, inducing preparations with anti-p40 monoclonal antibody resulted in a significant decrease in IFN-, induction capacity. Medium recovered from p35 and p40-expressing baculovirus infected cultures enhanced target cell IFN-, production and proliferation. Experimental studies in mice and other animals have revealed a therapeutic benefit of IL-12 in cancer, inflammatory and infectious disease and an adjuvant effect in prophylactic regimes. Production of a bioactive species-specific IL-12 is a first step towards an investigation of its potential application in equine species. [source] Age Differences in the Responses to Adult and Juvenile Alarm Calls by Bonnet Macaques (Macaca radiata)ETHOLOGY, Issue 2 2000Uma Ramakrishnan This study examined the differential responses to alarm calls from juvenile and adult wild bonnet macaques (Macaca radiata) in two parks in southern India. Field studies of several mammalian species have reported that the alarm vocalizations of immature individuals are often treated by perceivers as less provocative than those of adults. This study documents such differences in response using field-recorded playbacks of juvenile and adult alarm vocalizations. To validate the use of playback vocalizations as proxies of natural calls, we compared the responses of bonnet macaques to playbacks of alarm vocalizations with responses engendered by natural alarm vocalizations. We found that the frequency of flight, latency to flee, and the frequency of scanning to vocalization playbacks and natural vocalizations were comparable, thus supporting the use of playbacks to compare the effects of adult and juvenile calls. Our results showed that adult alarm calls were more provocative than juvenile alarm calls, inducing greater frequencies of flight with faster reaction times. Conversely, juvenile alarm calls were more likely to engender scanning by adults, a result interpreted as reflecting the lack of reliability of juvenile calls. Finally, we found age differences in flight behavior to juvenile alarm calls and to playbacks of motorcycle engine sounds, with juveniles and subadults more likely to flee than adults after hearing such sounds. These findings might reflect an increased vulnerability to predators or a lack of experience in young bonnet macaques. [source] Analysis of the NADH-dependent retinaldehyde reductase activity of amphioxus retinol dehydrogenase enzymes enhances our understanding of the evolution of the retinol dehydrogenase familyFEBS JOURNAL, Issue 14 2007Diana Dalfó In vertebrates, multiple microsomal retinol dehydrogenases are involved in reversible retinol/retinal interconversion, thereby controlling retinoid metabolism and retinoic acid availability. The physiologic functions of these enzymes are not, however, fully understood, as each vertebrate form has several, usually overlapping, biochemical roles. Within this context, amphioxus, a group of chordates that are simpler, at both the functional and genomic levels, than vertebrates, provides a suitable evolutionary model for comparative studies of retinol dehydrogenase enzymes. In a previous study, we identified two amphioxus enzymes, Branchiostoma floridae retinol dehydrogenase 1 and retinol dehydrogenase 2, both candidates to be the cephalochordate orthologs of the vertebrate retinol dehydrogenase enzymes. We have now proceeded to characterize these amphioxus enzymes. Kinetic studies have revealed that retinol dehydrogenase 1 and retinol dehydrogenase 2 are microsomal proteins that catalyze the reduction of all- trans -retinaldehyde using NADH as cofactor, a remarkable combination of substrate and cofactor preferences. Moreover, evolutionary analysis, including the amphioxus sequences, indicates that Rdh genes were extensively duplicated after cephalochordate divergence, leading to the gene cluster organization found in several mammalian species. Overall, our data provide an evolutionary reference with which to better understand the origin, activity and evolution of retinol dehydrogenase enzymes. [source] DNA methylation variation in cloned miceGENESIS: THE JOURNAL OF GENETICS AND DEVELOPMENT, Issue 2 2001Jun Ohgane Abstract Summary: Mammalian cloning has been accomplished in several mammalian species by nuclear transfer. However, the production rate of cloned animals is quite low, and many cloned offspring die or show abnormal symptoms. A possible cause of the low success rate of cloning and abnormal symptoms in many cloned animals is the incomplete reestablishment of DNA methylation after nuclear transfer. We first analyzed tissue-specific methylation patterns in the placenta, skin, and kidney of normal B6D2F1 mice. There were seven spots/CpG islands (0.5% of the total CpG islands detected) methylated differently in the three different tissues examined. In the placenta and skin of two cloned fetuses, a total of four CpG islands were aberrantly methylated or unmethylated. Interestingly, three of these four loci corresponded to the tissue-specific loci in the normal control fetuses. The extent of aberrant methylation of genomic DNA varied between the cloned animals. In cloned animals, aberrant methylation occurred mainly at tissue-specific methylated loci. Individual cloned animals have different methylation aberrations. In other words, cloned animals are by no means perfect copies of the original animals as far as the methylation status of genomic DNA is concerned. genesis 30:45,50, 2001. © 2001 Wiley-Liss, Inc. [source] Rhythmic hippocampal slow oscillation characterizes REM sleep in humansHIPPOCAMPUS, Issue 6 2001Róbert Bódizs Abstract Hippocampal rhythmic slow activity (RSA) is a well-known electrophysiological feature of exploratory behavior, spatial cognition, and rapid eye movement (REM) sleep in several mammalian species. Recently, RSA in humans during spatial navigation was reported, but systematic data regarding human REM sleep are lacking. Using mesio-temporal corticography with foramen ovale electrodes in epileptic patients, we report the presence of a 1.5,3-Hz synchronous rhythmic hippocampal oscillation seemingly specific to REM sleep. This oscillation is continuous during whole REM periods, is clearly observable by visual inspection, and appears in tonic and phasic REM sleep episodes equally. Quantitative analysis proved that this 1.5,3-Hz frequency band significantly differentiates REM sleep from waking and slow-wake sleep (SWS). No other frequency band proved to be significant or showed this high rhythmicity. Even in temporo-lateral surface recordings, although visually much less striking, the relative power of the 1.5,3-Hz frequency band differentiates REM sleep from other states with statistical significance. This could mean that the 1.5,3-Hz hippocampal RSA spreads over other cortical areas in humans as in other mammals. We suggest that this oscillation is the counterpart of the hippocampal theta of mammalian REM sleep, and that the 1.5,3-Hz delta EEG activity is a basic neurophysiological feature of human REM sleep. Hippocampus 2001;11:747,753. © 2001 Wiley-Liss, Inc. [source] The distribution, metabolism and function of creatine in the male mammalian reproductive tract: a reviewINTERNATIONAL JOURNAL OF ANDROLOGY, Issue 1 2000N. P. Moore Creatine is widely distributed throughout the male reproductive system in several mammalian species, and proteins involved in its metabolism and transport have been reported in a number of cell and tissue types. Creatine is synthesized within some organs, incorporating nitrogen from amino acid metabolism. Although creatine metabolism is obligatory for the motility of sea urchin spermatozoa, this does not appear to be the case for mammals. The possible functions of creatine within the reproductive tract are discussed. [source] Androgen dynamics in the context of children's peer relations: an examination of the links between testosterone and peer victimizationAGGRESSIVE BEHAVIOR, Issue 1 2009Tracy Vaillancourt Abstract Testosterone levels have been shown to decrease in the face of social defeat in several mammalian species. Among humans, the loss of social status has been studied primarily in the context of athletic competition, with winners having higher testosterone levels than losers. This study examined testosterone levels in relation to peer victimization (bullying) in a sample of 151 boys and girls aged 12,13. Statistically controlling for age and pubertal status, results indicated that on average verbally bullied girls produced less testosterone and verbally bullied boys produced more testosterone than their nonbullied counterparts. Similar trends were evident comparing social and physical bullying with testosterone. Sex differences are discussed in terms of empirically validated differences in coping styles, as girls tend to internalize, whereas boys tend to externalize, their abuse. Aggr. Behav. 35:103,113, 2009. © 2008 Wiley-Liss, Inc. [source] Lipopolysaccharide-Induced Oestrogen Receptor Regulation in the Paraventricular Hypothalamic Nucleus of Lewis and Fischer RatsJOURNAL OF NEUROENDOCRINOLOGY, Issue 11 2002L. Tonelli Abstract Oestrogen receptor (ER) regulation of gene transcription in neurosecretory and pituitary cells has been proposed as an important mechanism for increased hypothalamic-pituitary-adrenal (HPA) axis responses in females of several mammalian species, including humans. Inbred female Fischer (F344/N) and Lewis (LEW/N) rats have similar oestrogen levels, although Fischer rats exhibit hyper- and Lewis rats hypo-HPA axis responses. The blunted HPA axis response of Lewis rats has been associated with their blunted hypothalamic corticotropin releasing hormone (CRH) expression. To determine if the female CRH expression deficiency in Lewis rats is associated with defective ER expression and regulation, hypothalamic paraventricular nucleus (PVN) transcript levels of CRH and ER were determined under basal conditions and after immune challenge. Microdissected PVN were obtained from control and lipopolysaccharide (LPS) treated Lewis and Fischer rats and CRH, ER, and , mRNA levels were determined by semiquantitative reverse-transcriptase-polymerase chain reaction. In addition, ER, and , protein levels were determined by semiquantitative Western blots. ER, and , mRNA and protein levels in the PVN of control Fischer rats were significantly higher than in control Lewis rats. ER, and , mRNA and protein levels in Fischer rats were reduced by LPS administration at the time of maximal CRH mRNA levels but did not change in Lewis rats, an effect independent of oestrogen levels. These data indicate that defective neuroendocrine HPA axis responses are associated with defective ER expression and regulation in Lewis PVN despite oestrogen concentrations. [source] Molecular Evidence for Persistence of Anaplasma phagocytophilum in the Absence of Clinical Abnormalities in Horses after Recovery from Acute Experimental InfectionJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 3 2009P. Franzén Background: Anaplasma phagocytophilum infects several mammalian species, and can persist in sheep, dogs, and calves. However, whether this organism persists in horses or induces long-term clinical abnormalities is not known. Objectives: To evaluate whether A. phagocytophilum can persist in horses and to document clinical findings for 3 months after complete recovery from acute disease. Animals: Five clinically normal adult horses that had recovered spontaneously from experimentally induced acute disease caused by a Swedish equine isolate of A. phagocytophilum. Methods: Horses were monitored for up to 129 days post inoculation (PI) by daily clinical examination and at least alternate day blood sampling for evidence of A. phagocytophilum on polymerase chain reaction (PCR) and blood smears. All horses were euthanized and underwent postmortem examination. Results: All horses were periodically PCR positive after recovery from acute infection. Before day 66 PI 2 horses were persistently PCR negative whereas 3 horses were intermittently PCR positive. Subsequently, 4 of 5 horses were intermittently PCR positive, particularly after stress mimicking interventions. One animal was positive immediately before postmortem examination. Clinical abnormalities related to persistence of anaplasma were not observed. No specific changes were found at postmortem examination, and all sampled tissues from all horses were negative on PCR for A. phagocytophilum. Conclusions and Clinical Importance: Infection with A. phagocytophilum can persist in the horse for at least 129 days. However, the continued presence of the organism is not associated with detectable clinical or pathological abnormalities. [source] Configurations of germinal vesicle (GV) chromatin in the goat differ from those of other speciesMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 2 2005Hong-Shu Sui Abstract Configuration of germinal vesicle (GV) chromatin has been studied and found correlated with the developmental competence of oocytes in several mammalian species. A common feature in the configuration of GV chromatin in the species studied so far is that the diffuse chromatin (the so called "NSN" pattern) condenses into a perinucleolar ring (the so called "SN" configuration) with follicular growth. However, no study has been published on the configuration of GV chromatin in the goat. Nor is it known whether the perinucleolar ring of condensed chromatin (CC) in an oocyte represents a step toward final maturation or atresia. Changes in configurations of GV chromatin and RNA synthesis during goat oocyte growth, atresia and maturation in vivo and in vitro were investigated in this study. Based on both the size of nucleoli and the degree of chromatin condensation, the GV chromatin of goat oocytes was classified into GV1 characterized by large nucleoli and diffuse chromatin, GV2 with medium-sized nucleoli and condensed net-like (GV2n) or clumped (GV2c) chromatin, GV3 with small nucleoli and net-like (GV3n) or clumped (GV3c) chromatin, and GV4 with no nucleolus but clumped chromatin. The results showed that (i) the configurations of GV chromatin in the goat differ from those of other species in that the chromatin did not condense into a perinucleolar ring; (ii) most of the goat oocytes are synchronized at the GV3n configuration before GVBD; (iii) the GVn pattern might represent a healthy state, but the GVc an atretic state; (iv) in both goats and mice, the GC-specific (Chromomycin A3, CMA3) and the AT-specific (Hoechst 33342) fluorochromes followed the same pattern of distribution in GV chromatin; (v) the nucleolar size decreased significantly with oocyte growth and maturation in vivo and in vitro; and (vi) goat oocytes began GVBD at 8 hr and had completed it by 20 hr after onset of estrus. The peculiar configuration of GV chromatin of goat oocytes can be a useful model for studies of morphological and functional changes of different nuclear compartments during the cell cycle and cell differentiation, and the functional differentiation between GV3n and GV3c might be used for reference to the question whether the "SN" configuration in other species inclines toward ovulation or atresia. Mol. Reprod. Dev. 71: 227,236, 2005. © 2005 Wiley-Liss, Inc. [source] Chromatin Configurations in the Ferret Germinal Vesicle that Reflect Developmental Competence for In Vitro MaturationREPRODUCTION IN DOMESTIC ANIMALS, Issue 2 2009X Sun Contents In several mammalian species, the configuration of germinal vesicle (GV) chromatin correlates with the developmental competence of oocytes. Yet, no study has been published on the configuration of GV chromatin in ferret, nor is it known whether a specific configuration predicts meiotic competence in this species, in spite of the potential importance of ferret cloning to the study of human disease and to species conservation efforts. Here, we report on an analysis of the chromatin configuration in ferret GV oocytes and on how they correlate with meiotic development. Three distinct configurations were identified based on the degree of chromatin condensation: (1) fibrillar chromatin (FC), featuring strands of intertwined chromatin occupying most of the visible GV region; (2) intermediate condensed chromatin (ICC), characterized by dense, irregular chromatin masses throughout the GV; and (3) condensed chromatin (CC), which is highly compact and centered around the nucleolus. We also found that chromatin configuration was related to the extent of association with cumulus cells in cumulus,oocyte complexes; CC-configured oocytes were most often surrounded by a compact cumulus layer and also a compact corona but FC-configured oocytes were associated with neither. In addition, increasing chromatin condensation corresponded to an increase in oocyte diameter. Finally, following in vitro culture, significantly more CC-configured oocytes underwent maturation to meiotic metaphase II than did FC- or ICC-configured oocytes. We conclude that, in ferret, chromatin condensation is related to the sequential achievement of meiotic competencies during oocyte growth and differentiation, and thus can be used as a predictor of competence. [source] Mapping of the bovine genes of the de novo AMP synthesis pathway,ANIMAL GENETICS, Issue 6 2004T. Bønsdorff Summary The purine nucleotides adenosine monophosphate (AMP) and guanosine monophosphate (GMP) are critical for energy metabolism, cell signalling and cell reproduction. Despite their essential function, little is known about the regulation and in vivo expression pattern of the genes involved in the de novo purine synthesis pathway. The complete coding region of the bovine phosphoribosylaminoimidazole carboxylase gene (PAICS), which catalyses steps 6 and 7 of the de novo purine biosynthesis pathway, as well as bovine genomic sequences of the six other genes in the pathway producing inosine monophosphate (IMP) and AMP [phosphoribosyl pyrophosphate amidotransferase (PPAT), phosphoribosylglycinamide formyltransferase (GART), phosphoribosylformylglycinamidine synthase (PFAS), adenylosuccinate lyase (ADSL), 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/IMP cyclohydrolase (ATIC) and adenylosuccinate synthase (ADSS)], were identified. The genes were mapped to segments of six different bovine chromosomes using a radiation hybrid (RH) cell panel. The gene PPAT, coding for the presumed rate-limiting enzyme of the purine de novo pathway was closely linked to PAICS on BTA6. These, and the other bovine locations i.e. GART at BTA1, PFAS at BTA19, ADSL at BTA5, ATIC at BTA2 and ADSS at BTA16, are in agreement with published comparative maps of cattle and man. PAICS and PPAT genes are known to be closely linked in human, rat and chicken. Previously, an expressed sequence fragment of PAICS (Bos taurus corpus luteum, BTCL9) was mapped to BTA13. By isolation and characterization of a BAC clone, we have now identified a PAICS processed pseudogene sequence (,PAICS) on BTA13. Processed pseudogene sequences of PAICS and other genes of the purine biosynthesis pathway were identified in several mammalian species, indicating that the genes of this pathway have been susceptible to retrotransposition. The seven bovine genes are expressed at a higher level in testicular and ovary tissues compared with skeletal muscle. [source] A case of intersexuality in pigs associated with a de novo paracentric inversion 9 (p1.2; p2.2)ANIMAL GENETICS, Issue 1 2002A. Pinton In several mammalian species, genetic defects can be responsible for the interruption of and/or the deviation from the sequential steps of normal gonadal differentiation, leading to a sex-reversal syndrome. In pigs, female-to-male sex-reversal conditions are particularly frequent, but their aetiologies remain unclear. Chromosomal abnormalities that co-occur with sex-reversal disorders can be useful in the identification of loci containing responsible or susceptibility genes. This report describes a female-to-male SRY -negative intersex pig with a de novo paracentric inversion of the short arm of one chromosome 9 (p1.2; p2.2). We have fine mapped the proximal chromosomal breakpoint of this rearrangement because it corresponded to a region potentially involved in the pig intersexuality. Fluorescent in situ hybridization (FISH) experiments carried out with Bacterial Artificial Chromosome (BAC) clones located within the critical region defined by genetic linkage analysis and ordered on the porcine RH map allowed us to locate the proximal breakpoint between markers SW2571 and SW539. Further investigations are currently in progress to find new markers inside this interval, in order to determine the BAC in which the break occurred. [source] | |||||||||||||