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Sample records for opossum

  1. Thalamic nuclei in the opossum Monodelphis domestica.

    PubMed

    Olkowicz, Seweryn; Turlejski, Kris; Bartkowska, Katarzyna; Wielkopolska, Ewa; Djavadian, Rouzanna L

    2008-10-01

    We investigated nuclear divisions of the thalamus in the gray short-tailed opossum (Monodelphis domestica) to gain detailed information for further developmental and comparative studies. Nissl and myelin staining, histochemistry for acetylcholinesterase and immunohistochemistry for calretinin and parvalbumin were performed on parallel series of sections. Many features of the Monodelphis opossum thalamus resemble those in Didelphis and small eutherians showing no particular sensory specializations, particularly in small murid rodents. However, several features of thalamic organization in Monodelphis were distinct from those in rodents. In the opossum the anterior and midline nuclear groups are more clearly separated from adjacent structures than in eutherians. The dorsal lateral geniculate nucleus (LGNd) starts more rostrally and occupies a large part of the lateral wall of the thalamus. As in other marsupials, two cytoarchitectonically different parts, alpha and beta are discernible in the LGNd of the opossum. Each of them may be subdivided into two additional bands in acetylcholinesterase staining, while in murid rodents the LGNd consists of a homogeneous mass of cells. Therefore, differentiation of the LGNd of the Monodelphis opossum is more advanced than in murid rodents. The medial geniculate body consists of three nuclei (medial, dorsal and ventral) that are cytoarchitectonically distinct and stain differentially for parvalbumin. The relatively large size of the MG and LGNd points to specialization of the visual and auditory systems in the Monodelphis opossum. In contrast to rodents, the lateral dorsal and lateral posterior nuclei in the opossum are poorly differentiated cytoarchitectonically.

  2. Metal accumulation in wild-caught opossum.

    PubMed

    Lockhart, J Mitchell; Siddiqui, Samreen; Loughry, W J; Bielmyer-Fraser, Gretchen K

    2016-06-01

    The Virginia opossum (Didelphis virginiana) is widespread in the USA, ranging south through Latin America. The ecology of opossums is such that they are in frequent contact with soils, suggesting that they may function as a valuable bioindicator for chemical contamination in terrestrial environments. Surprisingly, there have been virtually no toxicology studies on opossums. Here, we provide the first analysis of metal contaminants in opossum liver tissues. Liver samples were obtained from 471 opossums, collected from 2003 to 2006, at four sites in North Florida and South Georgia, USA, and concentrations of copper, lead, nickel, selenium, and zinc were measured. We found little evidence of age differences in the concentration of any of the metals. However, there were at least some significant differences between years, males and females, and between sites for each metal, although the pattern of these differences was not always consistent across metals. Concentrations of metals in liver tissue were positively correlated with one another, primarily of each metal (except Pb) with zinc. Reference levels of metal contaminants are not available for opossums, but concentrations of Cu, Ni, Pb, and Zn in our samples were for the most part significantly higher than those reported from liver tissues of nine-banded armadillos (Dasypus novemcinctus) collected at the same sites and in the same years. Data from other small mammals studied elsewhere further indicate that metal concentrations in opossums were high, but at this time, it is not possible to determine if these elevated levels generated toxicity. The substantial temporal and spatial variation we found in metal concentrations suggests that determination of baseline levels for opossums may not be straightforward. Nonetheless, this is the first study quantifying metal accumulation in the livers of Didelphis virginiana and, as such, provides an important starting point for future research.

  3. The opossum MHC genomic region revisited.

    PubMed

    Krasnec, Katina V; Sharp, Alana R; Williams, Tracey L; Miller, Robert D

    2015-04-01

    The gray short-tailed opossum Monodelphis domestica is one of the few marsupial species for which a high quality whole genome sequence is available and the major histocompatibility complex (MHC) region has been annotated. Previous analyses revealed only a single locus within the opossum MHC region, designated Modo-UA1, with the features expected for encoding a functionally classical class I α-chain. Nine other class I genes found within the MHC are highly divergent and have features usually associated with non-classical roles. The original annotation, however, was based on an early version of the opossum genome assembly. More recent analyses of allelic variation in individual opossums revealed too many Modo-UA1 sequences per individual to be accounted for by a single MHC class I locus found in the genome assembly. A reanalysis of a later generation assembly, MonDom5, revealed the presence of two additional loci, now designated Modo-UA3 and UA4, in a region that was expanded and more complete than in the earlier assembly. Modo-UA1, UA3, and UA4 are all transcribed, although Modo-UA4 transcripts are rarer. Modo-UA4 is also relatively non-polymorphic. Evidence presented support the accuracy of the later assembly and the existence of three related class I genes in the opossum, making opossums more typical of mammals and most tetrapods by having multiple apparent classical MHC class I loci.

  4. Lumbosacral plexus in Brazilian Common Opossum.

    PubMed

    Senos, R; Ribeiro, M S; Benedicto, H G; Kfoury Júnior, J R

    2016-01-01

    The opossum has been suggested as an animal model for biomedical studies due to its adaptability to captivity and number of births per year. Despite many studies on morphology and experimental neurology using this opossum model, the literature does not offer details of the nerves of the lumbosacral plexus in this species. Ten lumbosacral plexus were dissected to describe the peripheral innervations of the Brazilian Common Opossum (Didelphis aurita) and compare the results with Eutheria clade species. The tensor fasciae latae muscle was absent and there was only one sartorius muscle for each limb. The distribution of the nerves were similar to other mammals, except for the caudal gluteal nerve, sartorius muscle innervations and the position of the pudendal nerve which arose from the major ischiatic foramen together with the ischiatic nerve, the cranial gluteal nerve and the caudal gluteal nerve. No anatomical variation was found. The special position of the pudendal nerve suggested that the Brazilian Common Opossum is a better model than rats or rabbits in surgical procedures with that specific nerve. In addition, the study revealed that the pelvic limb nerves are not an invariable structure of reference for muscle homology and homonym as reported previously. New investigation using other species of opossums are necessary to best comprehend the lumbosacral plexus distribution in the Methatheria clade and to confirm that other opossum species is eligible as a good model for pudendal nerve studies.

  5. Opossum alcohol dehydrogenases: Sequences, structures, phylogeny and evolution: evidence for the tandem location of ADH genes on opossum chromosome 5.

    PubMed

    Holmes, Roger S

    2009-03-16

    BLAT (BLAST-Like Alignment Tool) analyses and interrogations of the recently published opossum genome were undertaken using previously reported rat ADH amino acid sequences. Evidence is presented for six opossum ADH genes localized on chromosome 5 and organized in a comparable ADH gene cluster to that reported for human and rat ADH genes. The predicted amino acid sequences and secondary structures for the opossum ADH subunits and the intron-exon boundaries for opossum ADH genes showed a high degree of similarity with other mammalian ADHs, and four opossum ADH classes were identified, namely ADH1, ADH3, ADH6 and ADH4 (for which three genes were observed: ADH4A, ADH4B and ADH4C). Previous biochemical analyses of opossum ADHs have reported the tissue distribution and properties for these enzymes: ADH1, the major liver enzyme; ADH3, widely distributed in opossum tissues with similar kinetic properties to mammalian class 3 ADHs; and ADH4, for which several forms were localized in extrahepatic tissues, especially in the digestive system and in the eye. These ADHs are likely to perform similar functions to those reported for other mammalian ADHs in the metabolism of ingested and endogenous alcohols and aldehydes. Phylogenetic analyses examined opossum, human, rat, chicken and cod ADHs, and supported the proposed designation of opossum ADHs as class I (ADH1), class III (ADH3), class IV (ADH4A, ADH4B and ADH4C) and class VI (ADH6). Percentage substitution rates were examined for ADHs during vertebrate evolution which indicated that ADH3 is evolving at a much slower rate to that of the other ADH classes.

  6. Photic preference of the short-tailed opossum (Monodelphis domestica).

    PubMed

    Seelke, A M H; Dooley, J C; Krubitzer, L A

    2014-06-06

    The gray short-tailed opossum (Monodelphis domestica) is a nocturnal South American marsupial that has been gaining popularity as a laboratory animal. However, compared to traditional laboratory animals like rats, very little is known about its behavior, either in the wild or in a laboratory setting. Here we investigated the photic preference of the short-tailed opossum. Opossums were placed in a circular testing arena and allowed to move freely between dark (0 lux) and light (∼1.4, 40, or 400 lux) sides of the arena. In each of these conditions opossums spent significantly more time in the dark than in the illuminated side and a greater proportion of time in the dark than would be expected by chance. In the high-contrast (∼400 lux) illumination condition, the mean bout length (i.e., duration of one trip on the light or dark side) was significantly longer on the dark side than on the light side. When we examined the number of bouts greater than 30 and 60s in duration, we found a significant difference between the light and dark sides in all light contrast conditions. These data indicate that the short-tailed opossum prefers the dark to the light, and can also detect very slight differences in light intensity. We conclude that although rats and opossums share many similar characteristics, including ecological niche, their divergent evolutionary heritage results in vastly different behavioral capabilities. Only by observing the behavioral capabilities and preferences of opossums will we be able to manipulate the experimental environment to best elicit and elucidate their behavior and alterations in behavior that can arise from experimental manipulations.

  7. Besnoitia darlingi infection in a Virginia opossum (Didelphis virginiana).

    PubMed

    Shaw, Shannon; Grasperge, Britton; Nevarez, Javier; Reed, Scott; Long, Lauren; Rademacher, Nathalie; Sánchez-Migallón Guzmán, David

    2009-03-01

    This is a case report of natural infection with Besnoitia darlingi in a Virginia opossum (Didelphis virginiana) in Louisiana. Clinical pathologic data included a severe nonregenerative anemia, inflammatory leukogram, increased hepatocellular leakage enzymes, renal azotemia, hyperkalemia, hypoglycemia, hypoalbuminemia, and proteinuria. Tissue cysts containing bradyzoites were found in the majority of organs, especially the skin, mucous membranes, kidneys, adrenals, lungs, and heart. Images of the bradyzoites obtained by transmission electron microscopy were consistent with the previously described ultrastructure of Besnoitia darlingi. This opossum also suffered from an open phalangeal fracture and concurrent gastrointestinal parasites. Histopathologic findings included a glomerulonephritis and hepatic necrosis.

  8. Precocity of Gnathostoma turgidum in naturally infected four-eyed opossum Philander opossum pallidus from Temascal, Oaxaca, Mexico.

    PubMed

    Almeyda-Artigas, Roberto Javier; Mosqueda-Cabrera, Miguel Angel; Sánchez-Núñez, Edmundo

    2010-01-01

    Two female advanced third-stage larvae of Gnathostoma turgidum recovered from the liver of one naturally infected four-eyed opossum Philander opossum pallidus collected in Oaxaca, Mexico, were morphologically examined. Because of some characteristics, the larvae do not fit into the typical advanced third-stage. The body shows a size at least three times larger than expected and rows of spines only in the anterior part of the body surface. Consequently, in this research, we document for the first time the precocity in third-stage larvae of G. turgidum, and we also highlight some facts about the fourth larval stage occurring in spirurins.

  9. Experimental aerosol inoculation of Mycobacterium bovis in North American opossums (Didelphis virginiana).

    PubMed

    Fitzgerald, Scott D; Zwick, Laura S; Diegel, Kelly L; Berry, Dale E; Church, Steven V; Sikarskie, James G; Kaneene, John B; Reed, Willie M

    2003-04-01

    The goal of this study was to evaluate the susceptibility of North American opossums (Didelphis virginiana) to aerosol inoculation of Mycobacterium bovis at two dose levels in order to gain information on disease pathogenesis, fecal shedding of the organism, and the potential role that opossums play in the spread of this disease in nature. Six opossums received high dose (1 x 10(7) colony forming units (cfu) by aerosol inoculation, six opossums received low dose (1 x 10(3) cfu inoculation, and six opossums were sham-inoculated with sterile water and served as controls. Lungs were the most frequently infected tissues, with nine of 12 inoculated opossums positive for M. bovis on culture. Gross lesions consisted of multifocal pneumonia and enlarged lymph nodes. Microscopically, granulomatous pneumonia and granulomatous lymphadenitis associated with acid-fast bacilli were present in eight of 12 inoculated opossums. Fecal shedding of M. bovis was uncommon at both inoculation doses. While opossums were highly susceptible to aerosol inoculation of M. bovis, they did not become emaciated or develop widely disseminated lesions. From this study, opossums may transmit tuberculosis by aerosol infection to other opossums in close contact and serve as a source of infection to carnivores that feed upon them, however, transmission of the disease to large herbivores by fecal shedding or direct contact may be less likely.

  10. Genomic identification of chemokines and cytokines in opossum.

    PubMed

    Wong, Emily S W; Papenfuss, Anthony T; Belov, Katherine

    2011-03-01

    The cytokine repertoire of marsupials is largely unknown. The sequencing of the opossum genome has expedited the identification of many immune genes. However, many genes have not been identified using automated annotation pipelines because of high levels of sequence divergence. To fill gaps in our knowledge of the cytokine gene complement in marsupials, we searched the genome assembly of the gray short-tailed opossum for chemokine, interleukin, colony-stimulating factor, tumor necrosis factor, and transforming growth factor genes. In particular, we focused on genes that were not previously identified through Ensembl's automatic annotations. We report that the vast majority of cytokines are conserved, with direct orthologs between therian species. The major exceptions are chemokine genes, which show lineage-specific duplication/loss. Thirty-six chemokines were identified in opossum, including a lineage-specific expansion of macrophage inflammatory protein family genes. Divergent cytokines IL7, IL9, IL31, IL33, and CSF2 were identified. This is the first time IL31 and IL33 have been described outside of eutherian species. The high levels of similarities between the cytokine gene repertoires of therians suggest that the marsupial immune response is highly similar to eutherians.

  11. Visual acuity in the short-tailed opossum (Monodelphis domestica).

    PubMed

    Dooley, J C; Nguyen, H M; Seelke, A M H; Krubitzer, L

    2012-10-25

    Monodelphis domestica (short-tailed opossum) is an emerging animal model for studies of neural development due to the extremely immature state of the nervous system at birth and its subsequent rapid growth to adulthood. Yet little is known about its normal sensory discrimination abilities. In the present investigation, visual acuity was determined in this species using the optokinetic test (OPT), which relies on involuntary head tracking of a moving stimulus and can be easily elicited using a rotating visual stimulus of varying spatial frequencies. Using this methodology, we determined that the acuity of Monodelphis is 0.58 cycles per degree (cpd), which is similar to the acuity of rats using the same methodology, and higher than in mice. However, acuity in the short-tailed opossum is lower than in other marsupials. This is in part due to the methodology used to determine acuity, but may also be due to differences in diel patterns, lifestyle and phylogeny. We demonstrate that for the short-tailed opossum, the OPT is a rapid and reliable method of determining a baseline acuity and can be used to study enhanced acuities due to cortical plasticity.

  12. Ectoparasites of opossums and raccoons in southeastern Georgia.

    PubMed

    Pung, O J; Durden, L A; Banks, C W; Jones, D N

    1994-11-01

    Twelve species of ectoparasites (four fleas, three ticks, three chiggers, one macronyssid mite, and one atopomelid mite) were recovered from 42 opossums, Didelphis virginiana Kerr, live-trapped from September 1992 through April 1994 in southeastern Georgia. The fleas, Ctenocephalides felis (Bouché) (prevalence = 19%) and Polygenis gwyni (C. Fox) (36%); the ticks, Dermacentor variabilis (Say) (40%) and Ixodes scapularis Say (19%); and the macronyssid mite, Ornithonyssus wernecki (Fonseca) (21%), exhibited the highest infestation prevalences on opossums. The atopomelid mite, Didelphilichus serrifer Fain, and the chigger mite Leptotrombidium peromysci Vercammen-Grandjean & Langston, both ectoparasites of opossums, are reported from Georgia for the first time. Six species of ectoparasites (one chewing louse, four ticks, and one macronyssid mite) were collected from 58 raccoons, Procyon lotor (L.), examined between October 1992 and September 1993 in the same region. The chewing louse, Trichodectes octomaculatus Paine (prevalence = 24%); and the ticks, Amblyomma americanum (L.) (69%), D. variabilis (55%), and Ixodes texanus Banks (24%), exhibited the highest infestation prevalences on raccoons. Three species of ticks, A. americanum, D. variabilis, and I. scapularis, were the only ectoparasites recovered from both host species. Several of the ectoparasites collected are proven vectors of pathogenic agents that affect humans and animals.

  13. Helminths of three species of opossums (Mammalia, Didelphidae) from Mexico

    PubMed Central

    Acosta-Virgen, Karla; López-Caballero, Jorge; García-Prieto, Luis; Mata-López, Rosario

    2015-01-01

    Abstract From August 2011 to November 2013, 68 opossums (8 Didelphis sp., 40 Didelphis virginiana, 15 Didelphis marsupialis, and 5 Philander opossum) were collected in 18 localities from 12 Mexican states. A total of 12,188 helminths representing 21 taxa were identified (6 trematodes, 2 cestodes, 3 acanthocephalans and 10 nematodes). Sixty-six new locality records, 9 new host records, and one species, the trematode Brachylaima didelphus, is added to the composition of the helminth fauna of the opossums in Mexico. These data, in conjunction with previous records, bring the number of taxa parasitizing the Mexican terrestrial marsupials to 41. Among these species, we recognized a group of helminths typical of didelphids in other parts of the Americas. This group is constituted by the trematode Rhopalias coronatus, the acanthocephalan Oligacanthorhynchus microcephalus and the nematodes Cruzia tentaculata, Gnathostoma turgidum, and Turgida turgida. In general, the helminth fauna of each didelphid species showed a stable taxonomic composition with respect to previously sampled sites. This situation suggests that the rate of accumulation of helminth species in the inventory of these 3 species of terrestrial marsupials in the Neotropical portion of Mexico is decreasing; however, new samplings in the Nearctic portion of this country will probably increase the richness of the helminthological inventory of this group of mammals. PMID:26257556

  14. Visual acuity in the short-tailed opossum (Monodelphis domestica)

    PubMed Central

    Dooley, James C.; Nguyen, Hoang; Seelke, Adele M. H.; Krubitzer, Leah

    2013-01-01

    Monodelphis domestica (short-tailed opossum) is an emerging animal model for studies of neural development due to the extremely immature state of the nervous system at birth and its subsequent rapid growth to adulthood. Yet little is known about its normal sensory discrimination abilities. In the present investigation, visual acuity was determined in this species using the optokinetic test (OPT), which relies on involuntary head tracking of a moving stimulus and can be easily elicited using a rotating visual stimulus of varying spatial frequencies. Using this methodology, we determined that the acuity of Monodelphis is 0.58 cycles per degree (cpd), which is similar to the acuity of rats using the same methodology, and higher than in mice. However, acuity in the short-tailed opossum is lower than in other marsupials. This is in part due to the methodology used to determine acuity, but may also be due to differences in diel patterns, lifestyle and phylogeny. We demonstrate that for the short-tailed opossum, the OPT is a rapid and reliable method of determining a baseline acuity and can be used to study enhanced acuities due to cortical plasticity. PMID:22871523

  15. Opossums and Cat Fleas: New Insights in the Ecology of Murine Typhus in Galveston, Texas.

    PubMed

    Blanton, Lucas S; Idowu, Boluwatife M; Tatsch, Tyler N; Henderson, Joshua M; Bouyer, Donald H; Walker, David H

    2016-08-03

    Murine typhus is an acute undifferentiated febrile illness caused by Rickettsia typhi The classic reservoir (Rattus spp.) and flea vector (Xenopsylla cheopis) were once culprits of murine typhus in the United States. Vector and rodent control efforts have drastically decreased the prevalence of disease, except in a few endemic foci where opossums and cat fleas play a role in transmission. Since 2012, there has been a reemergence of murine typhus in Galveston, TX. We hypothesize that opossums and cat fleas are involved in the transmission of R. typhi in Galveston. To explore this, we sought to find the seroprevalence of typhus group antibodies from opossums. We also sought to find the prevalence of R. typhi in fleas parasitizing these animals. We collected blood from 12 opossums and found that eight (66.7%) had the presence of anti-R. typhi antibodies. All opossums were infested with fleas; a total of 250 Ctenocephalides felis fleas were collected from these animals. Seven opossums (53.8%) were infested with fleas that had molecular evidence of R. typhi infection, while six (46.2%) were infested with fleas that contained Candidatus Rickettsia senegalensis, an organism closely related to R. felis The minimum flea infection rate for R. typhi was 7.0%. The minimum infection rate for Candidatus R. senegalensis was 6.1%. Our study demonstrates that fleas infected with R. typhi parasitize opossums in Galveston. It is therefore likely that opossums and their fleas play a role in the city's recent reemergence of murine typhus.

  16. Postmortem scavenging by the Virginia opossum (Didelphis virginiana): Impact on taphonomic assemblages and progression.

    PubMed

    King, Kama A; Lord, Wayne D; Ketchum, Heather R; O'Brien, R Christopher

    2016-09-01

    The Virginia opossum (Didelphis virginiana) is a highly active scavenger whose behavior has significant impacts on rates of decomposition and skeletonization, which have previously not been addressed. In this study, scavenging by the opossum led to the skeletonization of carcasses in half of the accumulated degree days (ADD) of a comparable non-scavenged control carcass. Opossums used body orifices, as well as natural tears caused by the decomposition process, to access internal tissues and consume them. This activity resulted in little movement of the carcass and the retained appearance of natural undisturbed decomposition. This concealed activity has the potential to cause drastically incorrect estimates of time since deposition and post-mortem interval. Scavenging by opossums was also found to leave distinct tooth mark and other defects on bone, which have not been previously distinguished in the literature. This research suggests, beyond effects on PMI, that scavenging by opossums has been historically overlooked and misattributed to canid scavengers.

  17. Central nervous system regeneration: from leech to opossum.

    PubMed

    Mladinic, M; Muller, K J; Nicholls, J G

    2009-06-15

    A major problem of neurobiology concerns the failure of injured mammalian spinal cord to repair itself. This review summarizes work done on two preparations in which regeneration can occur: the central nervous system of an invertebrate, the leech, and the spinal cord of an immature mammal, the opossum. The aim is to understand cellular and molecular mechanisms that promote and prevent regeneration. In the leech, an individual axon regrows successfully to re-establish connections with its synaptic target, while avoiding other neurons. Functions that were lost are thereby restored. Moreover, pairs of identified neurons become re-connected with appropriate synapses in culture. It has been shown that microglial cells and nitric oxide play key roles in leech CNS regeneration. In the opossum, the neonatal brain and spinal cord are so tiny that they survive well in culture. Fibres grow across spinal cord lesions in neonatal animals and in vitro, but axon regeneration stops abruptly between postnatal days 9 and 12. A comprehensive search has been made in spinal cords that can and cannot regenerate to identify genes and establish their locations. At 9 days, growth-promoting genes, their receptors and key transcription molecules are up-regulated. By contrast at 12 days, growth-inhibitory molecules associated with myelin are prominent. The complete sequence of the opossum genome and new methods for transfecting genes offer ways to determine which molecules promote and which inhibit spinal cord regeneration. These results lead to questions about how basic research on mechanisms of regeneration could be 'translated' into effective therapies for patients with spinal cord injuries.

  18. Central nervous system regeneration: from leech to opossum

    PubMed Central

    Mladinic, M; Muller, K J; Nicholls, J G

    2009-01-01

    A major problem of neurobiology concerns the failure of injured mammalian spinal cord to repair itself. This review summarizes work done on two preparations in which regeneration can occur: the central nervous system of an invertebrate, the leech, and the spinal cord of an immature mammal, the opossum. The aim is to understand cellular and molecular mechanisms that promote and prevent regeneration. In the leech, an individual axon regrows successfully to re-establish connections with its synaptic target, while avoiding other neurons. Functions that were lost are thereby restored. Moreover, pairs of identified neurons become re-connected with appropriate synapses in culture. It has been shown that microglial cells and nitric oxide play key roles in leech CNS regeneration. In the opossum, the neonatal brain and spinal cord are so tiny that they survive well in culture. Fibres grow across spinal cord lesions in neonatal animals and in vitro, but axon regeneration stops abruptly between postnatal days 9 and 12. A comprehensive search has been made in spinal cords that can and cannot regenerate to identify genes and establish their locations. At 9 days, growth-promoting genes, their receptors and key transcription molecules are up-regulated. By contrast at 12 days, growth-inhibitory molecules associated with myelin are prominent. The complete sequence of the opossum genome and new methods for transfecting genes offer ways to determine which molecules promote and which inhibit spinal cord regeneration. These results lead to questions about how basic research on mechanisms of regeneration could be ‘translated’ into effective therapies for patients with spinal cord injuries. PMID:19525562

  19. Antiinflammatory agents protect opossum esophagus during radiotherapy. [Cobalt 60

    SciTech Connect

    Northway, M.G.; Eastwood, G.L.; Libshitz, H.I.; Feldman, M.S.; Mamel, J.J.; Szwarc, I.A.

    1982-10-01

    Eighteen opossums received 2250 rad /sup 60/Co to the entire esophagus and lower esophageal sphincter. Animals received treatment with 600 mg aspirin, 25 mg/kg hydrocortisone, or saline before irradiation and twice daily for 1 week after irradiation. At 10 days postirradiation, animals were evaluated for signs of acute esophagitis by esophagoscopy and barium esophagram. Each animal was then killed and the esophagus removed and evaluated histologically. Animals treated with either aspirin or hydrocortisone had significantly milder esophagitis than control irradiated animals.

  20. Lack of Sarcocystis neurona antibody response in Virginia opossums (Didelphis virginiana) fed Sarcocystis neurona-infected muscle tissue.

    PubMed

    Cheadle, M A; Lindsay, D S; Greiner, E C

    2006-06-01

    Serum was collected from laboratory-reared Virginia opossums (Didelphis virginiana) to determine whether experimentally infected opossums shedding Sarcocystis neurona sporocysts develop serum antibodies to S. neurona merozoite antigens. Three opossums were fed muscles from nine-banded armadillos (Dasypus novemcinctus), and 5 were fed muscles from striped skunks (Mephitis mephitis). Serum was also collected from 26 automobile-killed opossums to determine whether antibodies to S. neurona were present in these opossums. Serum was analyzed using the S. neurona direct agglutination test (SAT). The SAT was modified for use with a filter paper collection system. Antibodies to S. neurona were not detected in any of the serum samples from opossums, indicating that infection in the opossum is localized in the small intestine. Antibodies to S. neurona were detected in filter-paper-processed serum samples from 2 armadillos naturally infected with S. neurona.

  1. Platypus and opossum calcitonins exhibit strong activities, even though they belong to mammals.

    PubMed

    Yamashita, Teruhito; Udagawa, Nobuyuki; Thirukonda, Gnanasagar Janardhanan; Uehara, Shunsuke; Yamauchi, Hirose; Suzuki, Nobuo; Li, Feng; Kobayashi, Yasuhiro; Takahashi, Naoyuki

    2017-01-04

    In mammalian assay systems, calcitonin peptides of non-mammalian species exhibit stronger activity than those of mammals. Recently, comparative analyses of a wide-range of species revealed that platypus and opossum, which diverged early from other mammals, possess calcitonins that are more similar in amino acid sequence to those of non-mammals than mammals. We herein determined whether platypus and opossum calcitonins exhibit similar biological activities to those of non-mammalian calcitonins using an assay of actin ring formation in mouse osteoclasts. We also compared the dose-dependent effects of each calcitonin on cAMP production in osteoclasts. Consistent with the strong similarities in their primary amino acid sequences, platypus and opossum calcitonins disrupted actin rings with similar efficacies to that of salmon calcitonin. Human calcitonin exhibited the weakest inhibitory potency and required a 100-fold higher concentration (EC50=3×10(-11)M) than that of salmon calcitonin (EC50=2×10(-13)M). Platypus and opossum calcitonins also induced cAMP production in osteoclast cultures with the same efficacies as that of salmon calcitonin. Thus, platypus and opossum calcitonins exhibited strong biological activities, similar to those of the salmon. In addition, phylogenetic analysis revealed that platypus and opossum calcitonins clustered with the salmon-type group but not human- or porcine-type group. These results suggest that platypus and opossum calcitonins are classified into the salmon-type group, in terms of the biological activities and amino acid sequences.

  2. Cage change intervals for opossums (Monodelphis domestica) in individually ventilated cages.

    PubMed

    Allison, Sarah O; Criley, Jennifer M; Kim, Ji Young; Goodly, Lyndon J

    2011-09-01

    The opossum Monodelphis domestica is the most commonly used marsupial in biomedical research. At our institution, these opossums are housed in polycarbonate (35.6 cm × 25.4 cm × 17.8 cm) individually ventilated cages. Previous studies of the cage microenvironment of rodents housed in individually ventilated cages have demonstrated that the cage-change frequency could be extended from 7 to 14 d, without detriment to the animals' wellbeing. We sought to determine whether the cage change frequency for opossums housed in individually ventilated cages could be extended to 14 d. Opossums were placed into 3 experimental groups: singly housed males, singly housed females, and females housed with litters. The 14-d testing period was repeated twice, with temperature, relative humidity, and ammonia levels tested on days 0, 7, and 14. Acceptable ranges for the cage microenvironment were based on standards followed by our institution for housing rodents: temperature between 22 to 26 °C, relative humidity between 30% to 70%, and ammonia less than 25 ppm. Throughout both 14-d testing periods, temperature, relative humidity, and ammonia levels for singly housed male and singly housed female opossums were within acceptable ranges. However, ammonia levels exceeded the recommended 25 ppm on day 7 of both testing periods for female opossums housed with litters. In summary, the cage-change frequency for a singly housed opossum in an individually ventilated cage can be extended to 14 d.

  3. Prevalence and risk factors associated with Sarcocystis neurona infections in opossums (Didelphis virginiana) from central California.

    PubMed

    Rejmanek, Daniel; Vanwormer, Elizabeth; Miller, Melissa A; Mazet, Jonna A K; Nichelason, Amy E; Melli, Ann C; Packham, Andrea E; Jessup, David A; Conrad, Patricia A

    2009-12-03

    Sarcocystis neurona, a protozoal parasite shed by opossums (Didelphis virginiana), has been shown to cause significant morbidity and mortality in horses, sea otters, and other marine mammals. Over the course of 3 years (fall 2005-summer 2008), opossums from central California were tested for infection with S. neurona. Of 288 opossums sampled, 17 (5.9%) were infected with S. neurona based on the molecular characterization of sporocysts from intestinal scrapings or feces. Risk factors evaluated for association with S. neurona infection in opossums included: age, sex, location, season, presence of pouch young in females, concomitant infection, and sampling method (live-trapped or traffic-killed). Multivariate logistic regression analysis identified that opossums in the Central Valley were 9 times more likely to be infected than those near the coast (p=0.009). Similarly, opossum infection was 5 times more likely to be detected during the reproductive season (March-July; p=0.013). This first investigation of S. neurona infection prevalence and associated risk factors in opossums in the western United States can be used to develop management strategies aimed at reducing the incidence of S. neurona infections in susceptible hosts, including horses and threatened California sea otters (Enhydra lutris neries).

  4. The opossum genome: insights and opportunities from an alternative mammal.

    PubMed

    Samollow, Paul B

    2008-08-01

    The strategic importance of the genome sequence of the gray, short-tailed opossum, Monodelphis domestica, accrues from both the unique phylogenetic position of metatherian (marsupial) mammals and the fundamental biologic characteristics of metatherians that distinguish them from other mammalian species. Metatherian and eutherian (placental) mammals are more closely related to one another than to other vertebrate groups, and owing to this close relationship they share fundamentally similar genetic structures and molecular processes. However, during their long evolutionary separation these alternative mammals have developed distinctive anatomical, physiologic, and genetic features that hold tremendous potential for examining relationships between the molecular structures of mammalian genomes and the functional attributes of their components. Comparative analyses using the opossum genome have already provided a wealth of new evidence regarding the importance of noncoding elements in the evolution of mammalian genomes, the role of transposable elements in driving genomic innovation, and the relationships between recombination rate, nucleotide composition, and the genomic distributions of repetitive elements. The genome sequence is also beginning to enlarge our understanding of the evolution and function of the vertebrate immune system, and it provides an alternative model for investigating mechanisms of genomic imprinting. Equally important, availability of the genome sequence is fostering the development of new research tools for physical and functional genomic analyses of M. domestica that are expanding its versatility as an experimental system for a broad range of research applications in basic biology and biomedically oriented research.

  5. Opossums (Mammalia: Didelphidae) in the diets of Neotropical pitvipers (Serpentes: Crotalinae): evidence for alternative coevolutionary outcomes?

    PubMed

    Voss, Robert S

    2013-05-01

    Opossums and pitvipers are sympatric throughout most of the New World, but trophic relationships between these speciose clades have only recently attracted the attention of researchers. Although it is now known that some venom-resistant opossums prey on pitvipers, a review of the literature on diets shows that some Neotropical pitvipers prey on opossums. Interestingly, some pitviper species prey on opossums known or suspected to be venom resistant. If venom resistance and venom potency are coevolved traits, then these observations suggest that alternative outcomes may result in role-switching between victims and exploiters. Because molecular antagonists (e.g., venom toxins and toxin-neutralizing serum proteins) that could mediate such outcomes have been plausibly identified, this system is a potentially fruitful field for evolutionary research.

  6. Normal conjunctival flora in the North American opossum (Didelphis virginiana) and raccoon (Procyon lotor).

    PubMed

    Pinard, Chantale L; Brightman, Alan H; Yeary, Teresa J; Everson, Troy D; Cox, Linda K; Chengappa, M M; Davidson, Harriet J

    2002-10-01

    We documented the normal conjunctival bacterial flora from 17 opossums (Didelphis virginiana) and 10 raccoons (Procyon lotor) trapped in Manhattan, Kansas (USA) from November 1999 to January 2000. Both raccoons and opossums were free of apparent ocular disease. The inferior conjunctival sacs of each animal were swabbed for aerobic bacterial and Mycoplasma culture and polymerase chain reaction (PCR) for Mycoplasma and Chlamydia detection. All conjunctival samples were positive for one or more species of aerobic bacteria. The most common isolate from opossums was Staphylococcus spp. Other isolates included Streptococcus spp., Bacillus spp., Corynebacterium spp., and Enterococcus faecalis. The most common isolates in raccoons was Bacillus spp. Other isolates included Streptococcus spp., Staphylococcus spp., non-hemolytic Escherichia coli, and Enterococcus faecalis. Mycoplasma culture was negative in samples from opossums and raccoons. Evidence of Mycoplasma and Chlamydia presence was detected by PCR.

  7. Ontogeny of cells containing estrogen receptor-like immunoreactivity in the Brazilian opossum brain.

    PubMed

    Fox, C A; Ross, L R; Jacobson, C D

    1991-11-19

    In this study, we have used the Brazilian short-tailed opossum (Monodelphis domestica) as a model to study the ontogeny of estrogen receptors in the mammalian brain. Monodelphis is a small, pouchless marsupial which breeds well under laboratory conditions and whose young are born in an immature sexually undifferentiated state. The Abbott H222 monoclonal rat estrogen receptor antibody (gift of Abbott Laboratories) was utilized in an indirect immunohistochemical procedure to detect estrogen receptors in developing opossum brains. Estrogen receptors were first expressed in the dorsomedial and ventromedial hypothalamus of the opossum 10 days after birth (10PN). Most regions that contained estrogen receptor-like immunoreactivity (ER LI) in the adult opossum contained ER LI at 15 PN. These areas include the lateral septum, medial preoptic area, bed nucleus of the stria terminalis, periventricular preoptic area and hypothalamus, amygdala, dorsomedial and ventromedial hypothalamic nuclei, arcuate nucleus, ventral premammillary nucleus, and the midbrain central grey. The number of cells that contain ER LI increased through 60PN in all regions that will contain ER LI in the adult opossum. These results indicate that estrogen receptors are present in early development of the Monodelphis brain and may mark the beginning of a critical period for sexual differentiation of the opossum brain.

  8. Brief communication: Forelimb compliance in arboreal and terrestrial opossums.

    PubMed

    Schmitt, Daniel; Gruss, Laura T; Lemelin, Pierre

    2010-01-01

    Primates display high forelimb compliance (increased elbow joint yield) compared to most other mammals. Forelimb compliance, which is especially marked among arboreal primates, moderates vertical oscillations of the body and peak vertical forces and may represent a basal adaptation of primates for locomotion on thin, flexible branches. However, Larney and Larson (Am J Phys Anthropol 125 [2004] 42-50) reported that marsupials have forelimb compliance comparable to or greater than that of most primates, but did not distinguish between arboreal and terrestrial marsupials. If forelimb compliance is functionally linked to locomotion on thin branches, then elbow yield should be highest in marsupials relying on arboreal substrates more often. To test this hypothesis, we compared forelimb compliance between two didelphid marsupials, Caluromys philander (an arboreal opossum relying heavily on thin branches) and Monodelphis domestica (an opossum that spends most of its time on the ground). Animals were videorecorded while walking on a runway or a horizontal 7-mm pole. Caluromys showed higher elbow yield (greater changes in degrees of elbow flexion) on both substrates, similar to that reported for arboreal primates. Monodelphis was characterized by lower elbow yield that was intermediate between the values reported by Larney and Larson (Am J Phys Anthropol 125 [2004] 42-50) for more terrestrial primates and rodents. This finding adds evidence to a model suggesting a functional link between arboreality--particularly locomotion on thin, flexible branches--and forelimb compliance. These data add another convergent trait between arboreal primates, Caluromys, and other arboreal marsupials and support the argument that all primates evolved from a common ancestor that was a fine-branch arborealist.

  9. The role of the vomeronasal system in food preferences of the gray short-tailed opossum, Monodelphis domestica

    PubMed Central

    Halpern, Mimi; Daniels, Yasmine; Zuri, Ido

    2005-01-01

    Although feeding deficits have been reported in snakes and lizards following vomeronasal system disruption, no deficit has been previously reported in a mammal. We tested gray short-tailed opossums with items from four different food categories prior to occluding access to the vomeronasal organ. Preoperatively, opossums preferred meat to fruit or vegetables. Following occlusion of the nasopalatine canal, but not after control treatment, opossums failed to demonstrate food preferences. PMID:15725360

  10. Genetically different isolates of Trypanosoma cruzi elicit different infection dynamics in raccoons (Procyon lotor) and Virginia opossums (Didelphis virginiana).

    PubMed

    Roellig, Dawn M; Ellis, Angela E; Yabsley, Michael J

    2009-12-01

    Trypanosoma cruzi is a genetically and biologically diverse species. In the current study we determined T. cruzi infection dynamics in two common North American reservoirs, Virginia opossums (Didelphis virginiana) and raccoons (Procyon lotor). Based on previous molecular and culture data from naturally-exposed animals, we hypothesised that raccoons would have a longer patent period than opossums, and raccoons would be competent reservoirs for both genotypes T. cruzi I (TcI) and TcIIa, while opossums would only serve as hosts for TcI. Individuals (n=2 or 3) of each species were inoculated with 1x10(6) culture-derived T. cruzi trypomastigotes of TcIIa (North American (NA) - raccoon), TcI (NA - opossum), TcIIb (South American - human), or both TcI and TcIIa. Parasitemias in opossums gradually increased and declined rapidly, whereas parasitemias peaked sooner in raccoons and they maintained relatively high parasitemia for 5weeks. Raccoons became infected with all three T. cruzi strains, while opossums only became infected with TcI and TcIIb. Although opossums were susceptible to TcIIb, infection dynamics were dramatically different compared with TcI. Opossums inoculated with TcIIb seroconverted, but parasitemia duration was short and only detectable by PCR. In addition, raccoons seroconverted sooner (3-7days post inoculation) than opossums (10days post inoculation). These data suggest that infection dynamics of various T. cruzi strains can differ considerably in different wildlife hosts.

  11. Motor function of the opossum sphincter of Oddi.

    PubMed Central

    Toouli, J; Dodds, W J; Honda, R; Sarna, S; Hogan, W J; Komarowski, R A; Linehan, J H; Arndorfer, R C

    1983-01-01

    We studied the opossum sphincter of Oddi (SO) because in this species the SO is approximately 3 cm in length and its extraduodenal location permits recording of motor activity with negligible interference from duodenal motor activity. The SO segment of 120 animals was evaluated by one or more of the following: (a) intraluminal manometry; (b) electromyography; (c) common bile duct (CBD) flow monitored by a drop counter; (d) cineradiography of intraductal contrast medium; and (e) histologic examination. SO pull-throughs using an infused catheter of 0.6-mm o.d. invariably showed a high pressure zone (HPZ) of 18 +/- 3 SE mm Hg in the terminal 4-5 mm of the SO segment. This HPZ had a narrow lumen, 0.5-0.7 mm in diam, and prominent circular muscle. The HPZ in the terminal SO had both active and passive components. HPZ with minimal amplitude and a paucity of underlying smooth muscle were present inconstantly at the junction of the SO segment with the CBD and pancreatic duct, respectively. The dominant feature of the SO segment was rhythmic peristaltic contractions that originated in the proximal SO and propagated toward the duodenum. These contractions occurred spontaneously at a rate of 2-8/min, ranged up to 200 mm Hg in magnitude, had a duration of approximately 5 s and were not abolished by tetrodotoxin. Concurrent myoelectric and manometric recordings showed that each phasic contraction was immediately preceded by an electrical spike burst. Simultaneous recordings of cineradiography, CBD inflow of contrast medium, SO manometry, and SO electromyography indicated that rhythmic peristaltic contractions stripped contrast medium from the SO into the duodenum. During SO systole, CBD emptying was transiently interrupted, whereas SO filling occurred during the diastolic interval between SO peristaltic contractions. SO distention increased the frequency of SO peristalsis. We conclude that (a) the dominant feature of the opossum SO is rhythmic peristaltic contractions that

  12. Surveillance and movements of Virginia opossum (Didelphis virginiana) in the bovine tuberculosis region of Michigan.

    PubMed

    Walter, W D; Fischer, J W; Anderson, C W; Marks, D R; Deliberto, T; Robbe-Austerman, S; Vercauteren, K C

    2013-07-01

    Wildlife reservoir hosts of bovine tuberculosis (bTB) include Eurasian badgers (Meles meles) and brushtail possum (Trichosurus vulpecula) in the UK and New Zealand, respectively. Similar species warrant further investigation in the northern lower peninsula of Michigan, USA due to the continued presence of bTB on cattle farms. Most research in Michigan, USA has focused on interactions between white-tailed deer (Odocoileus virginianus) and cattle (Bos taurus) for the transmission of the infectious agent of bTB, Mycobacterium bovis, due to high deer densities and feeding practices. However, limited data are available on medium-sized mammals such as Virginia opossum (Didelphis virginiana; hereafter referred to as opossum) and their movements and home range in Michigan near cattle farms. We conducted surveillance of medium-sized mammals on previously depopulated cattle farms for presence of M. bovis infections and equipped opossum with Global Positioning System (GPS) technology to assess potential differences in home range between farms inside and outside the bTB core area that has had cattle test positive for M. bovis. On farms inside the bTB core area, prevalence in opossum was comparable [6%, 95% confidence interval (CI) 2.0-11.0] to prevalence in raccoon (Procyon lotor; 4%, 95% CI 1.0-9.0, P=0.439) whereas only a single opossum tested positive for M. bovis on farms outside the bTB core area. The prevalence in opossum occupying farms that had cattle test positive for M. bovis was higher (6.4%) than for opossum occupying farms that never had cattle test positive for M. bovis (0.9%, P=0.01). Mean size of home range for 50% and 95% estimates were similar by sex (P=0.791) both inside or outside the bTB core area (P=0.218). Although surveillance efforts and home range were not assessed on the same farms, opossum use of farms near structures was apparent as was selection for farms over surrounding forested habitats. The use of farms, stored feed, and structures by opossum

  13. Intrahepatic growth and maturation of Gnathostoma turgidum in the natural definitive opossum host, Didelphis virginiana.

    PubMed

    Díaz-Camacho, Sylvia Páz; Delgado-Vargas, Francisco; Willms, Kaethe; de la Cruz-Otero, María del Carmen; Guadalupe Rendón-Maldonado, José; Robert, Lilia; Antuna, Silvia; Nawa, Yukifumi

    2010-09-01

    Gnathostoma turgidum is a gastric nematode parasite of opossums found in the Americas. We recently found that G. turgidum juveniles appear in the liver of the opossums where they become mature adults and almost synchronously move to the stomach during certain months of the year, suggesting the importance of the liver for the growth and maturation of this species in the final hosts. In this study we attempted to detect G. turgidum larvae in the liver of opossums, Didelphis virginiana that are the natural final hosts. The results show that tiny (<3mm in length) third stage larvae (L3) appeared in the liver of opossums around November and December. Also in the liver, we found large L3 of up to about 10mm in length together with juveniles and mature adults from February to March. In spite of their length, large L3 have 4 rows of hooklets, and their gonads remained undeveloped. Morphological features of the small and large L3 of G. turgidum are described including scanning electron microscope images. The seasonal switching of the several growth stages of G. turgidum from small L3 to adult worms in the liver and eventual migration to the stomach in opossums suggests the unique feature of G. turgidum utilizing the liver as the maturation site.

  14. Experimental Aerosol Inoculation and Investigation of Potential Lateral Transmission of Mycobacterium bovis in Virginia Opossum (Didelphis virginiana).

    PubMed

    Fenton, Karla A; Fitzgerald, Scott D; Bolin, Steve; Kaneene, John; Sikarskie, James; Greenwald, Rena; Lyashchenko, Konstantin

    2012-01-01

    An endemic focus of Mycobacterium bovis (M. bovis) infection in the state of Michigan has contributed to a regional persistence in the animal population. The objective of this study was to determine if Virginia opossums (Didelphis virginiana) contribute to disease persistence by experimentally assessing intraspecies lateral transmission. One wild caught pregnant female opossum bearing 11 joeys (young opossum) and one age-matched joey were obtained for the study. Four joeys were aerosol inoculated with M. bovis (inoculated), four joeys were noninoculated (exposed), and four joeys plus the dam were controls. Four replicate groups of one inoculated and one exposed joey were housed together for 45 days commencing 7 days after experimental inoculation. At day 84 opossums were sacrificed. All four inoculated opossums had a positive test band via rapid test, culture positive, and gross/histologic lesions consistent with caseogranulomatous pneumonia. The exposed and control groups were unremarkable on gross, histology, rapid test, and culture. In conclusion, M. bovis infection within the inoculated opossums was confirmed by gross pathology, histopathology, bacterial culture, and antibody tests. However, M. bovis was not detected in the control and exposed opossums. There was no appreciable lateral transmission of M. bovis after aerosol inoculation and 45 days of cohabitation between infected and uninfected opossums.

  15. Experimental Aerosol Inoculation and Investigation of Potential Lateral Transmission of Mycobacterium bovis in Virginia Opossum (Didelphis virginiana)

    PubMed Central

    Fenton, Karla A.; Fitzgerald, Scott D.; Bolin, Steve; Kaneene, John; Sikarskie, James; Greenwald, Rena; Lyashchenko, Konstantin

    2012-01-01

    An endemic focus of Mycobacterium bovis (M. bovis) infection in the state of Michigan has contributed to a regional persistence in the animal population. The objective of this study was to determine if Virginia opossums (Didelphis virginiana) contribute to disease persistence by experimentally assessing intraspecies lateral transmission. One wild caught pregnant female opossum bearing 11 joeys (young opossum) and one age-matched joey were obtained for the study. Four joeys were aerosol inoculated with M. bovis (inoculated), four joeys were noninoculated (exposed), and four joeys plus the dam were controls. Four replicate groups of one inoculated and one exposed joey were housed together for 45 days commencing 7 days after experimental inoculation. At day 84 opossums were sacrificed. All four inoculated opossums had a positive test band via rapid test, culture positive, and gross/histologic lesions consistent with caseogranulomatous pneumonia. The exposed and control groups were unremarkable on gross, histology, rapid test, and culture. In conclusion, M. bovis infection within the inoculated opossums was confirmed by gross pathology, histopathology, bacterial culture, and antibody tests. However, M. bovis was not detected in the control and exposed opossums. There was no appreciable lateral transmission of M. bovis after aerosol inoculation and 45 days of cohabitation between infected and uninfected opossums. PMID:22701815

  16. Cystine and dibasic amino acid uptake by opossum kidney cells

    SciTech Connect

    States, B.; Segal, S. )

    1990-06-01

    The characteristics of the uptake of L-cystine by the continuous opossum kidney cell line, OK, were examined. Uptake of cystine is rapid and, in contrast to other continuous cultured cell lines, these cells retain the cystine/dibasic amino acid transport system which is found in vivo and in freshly isolated kidney tissue. Confluent monolayers of cells also fail to show the presence of the cystine/glutamate transport system present in LLC-PK1 cells, fibroblasts, and cultured hepatocytes. Uptake of cystine occurs via a high-affinity saturable process which is independent of medium sodium concentration. The predominant site of cystine transport is across the apical cell membrane. The intracellular concentration of GSH far exceeds that of cystine with a ratio greater than 100:1 for GSH:cysteine. Incubation of cells for 5 minutes with a physiological level of labelled cystine resulted in the labelling of 66% and 5% of the total intracellular cysteine and glutathione, respectively. The ability of these cells to reflect the shared cystine/dibasic amino acid transport system makes them a suitable model for investigation of the cystine carrier which is altered in human cystinuria.

  17. Characterization of protamine uptake by opossum kidney epithelial cells.

    PubMed

    Nagai, Junya; Komeda, Takuji; Katagiri, Yuki; Yumoto, Ryoko; Takano, Mikihisa

    2013-01-01

    Protamine, a mixture of polypeptides that is rich in arginine, has been used clinically as an antidote to heparin overdoses and a complexing agent in a long-acting insulin preparation. When protamine is administered intravenously, its abundant accumulation in the kidneys has been reported. However, the renal uptake mechanism for protamine is not clear. In this study, we examined the transport mechanism for protamine in opossum kidney (OK) cells, a suitable in vitro model for renal proximal tubular epithelial cells. Flow cytometric analysis revealed that the association of fluorescein isothiocyanate (FITC)-labeled protamine from salmon (FITC-protamine) by OK cells was inhibited by unlabeled protamine in a concentration-dependent manner. The association of FITC-protamine was temperature- and energy-dependent. Confocal microscopy analysis showed that the fluorescence was localized in the cytoplasm and nucleus of OK cells. In addition, FITC-protamine association was inhibited by cationic drugs such as polycationic gentamicin and polymixin B, but it was increased by a basic amino acid, arginine. Inhibitors for clathrin- and caveolin-dependent endocytosis showed inhibitory effects on FITC-protamine association. Pretreatment with heparinase III partially but significantly decreased the association of FITC-protamine. These results suggest that protamine may be taken up by OK cells via receptor-mediated endocytosis, which may result in its localization in the cytoplasm and nucleus of the cells.

  18. Basic Maintenance and Breeding of the Opossum Monodelphis domestica.

    PubMed

    Keyte, Anna L; Smith, Kathleen K

    2008-10-01

    INTRODUCTIONMonodelphis domestica, the gray, short-tailed, or laboratory opossum, is the most commonly used laboratory marsupial. In addition to the factors that make it a convenient laboratory animal (small size, ease of care, nonseasonal breeding), it is the first marsupial whose genome has been sequenced. Monodelphis has proven useful as a model organism for studies on spinal cord regeneration, ultraviolet (UV)-induced melanoma, and genetic influences on cholesterol, as well as comparative studies of the immune system. In addition, Monodelphis has been used to understand the basic functions of the olfactory system and the role of various olfactory chemicals in social and reproductive behavior. Recently, Monodelphis has been used to understand fundamental aspects of marsupial development, anatomy, evolution, and evolutionary consequences of the derived marsupial mode of development and reproduction. Monodelphis are easily maintained and bred in the lab. To do extensive embryonic work, a reasonably large breeding colony must be maintained. A colony of ~100 animals (~3:1 female:male ratio) allows for sacrifice of up to 12 pregnant females per month for experimental purposes, as well as for replenishment of the colony. However, because adults will fight and often kill one another if kept in the same cage for prolonged periods, we have developed a special breeding protocol that provides high rates of breeding success (75%-90%), with minimal injury due to fighting. Here, we outline this breeding strategy and describe how to successfully maintain a colony of Monodelphis in a laboratory setting.

  19. Anatomical study of the opossum (Didelphis albiventris) extraocular muscles.

    PubMed Central

    Matheus, S M; Soares, J C; da Silva, A M; Seullner, G

    1995-01-01

    The anatomy of the extraocular muscles was studied in 10 adult opossums (Didelphis albiventris) of both sexes. Eight extraocular muscles were identified: 4 rectus muscles, 2 oblique muscles, the levator palpebrae superioris and the retractor ocular bulbi. The rectus muscles originate very close one to another between the orbital surfaces of the presphenoid and palatine bones. These muscles diverge on the way to their insertion which occurs at about 2 mm from the limbus. The levator palpebrae superioris originates with the dorsal rectus and is positioned dorsally in relation to it. The retractor ocular bulbi forms a cone which embraces the optic nerve and is located internally in relation to the rectus muscles. The dorsal oblique originates on the presphenoid bone and after a tendinous trajectory through a trochlea on the medial wall of the orbit, inserts into the ocular bulb. The only muscle arising from the anterior orbital floor is the ventral oblique. The main nerve supply for these muscles is the oculomotor, except for the dorsal oblique which is innervated by the trochlear nerve, and the lateral rectus which is innervated by the abducens nerve. The retractor ocular bulbi receives branches from the inferior division of the oculomotor nerve and some branches from the abducens nerve. Images Fig. 1 Fig. 2 Fig. 3 PMID:7649843

  20. Chemical communication and reproduction in the gray short-tailed opossum (Monodelphis domestica).

    PubMed

    Harder, John D; Jackson, Leslie M

    2010-01-01

    The gray short-tailed opossum is one of the most widely studied of all marsupials and an important model for study of olfactory communication, particularly as it relates to pheromonal activation of reproduction. Males respond to differentially to female skin gland secretions and urine from anestrous females, while females respond only skin gland secretions, particularly that of the suprasternal gland. Divergent responses by male and female opossums to odors from these different body sources are most likely related to sex-specific production and deposition of chemical signals in this species. Female opossums do not have an estrous cycle but are stimulated to estrus by male pheromone. Females nuzzle scent marks from male suprasternal gland secretions, and thereby facilitate delivery of a nonvolatile estrus-inducing pheromone to the chemosensory epithelium of vomeronasal organ. Neuroendocrine correlates of pheromonal induction of estrus include elevated plasma estradiol and upregulation of progesterone receptors in hypothalamic regions that control reproductive behavior.

  1. The partial 5-HT1A receptor agonist buspirone enhances neurogenesis in the opossum (Monodelphis domestica).

    PubMed

    Grabiec, Marta; Turlejski, Kris; Djavadian, Rouzanna L

    2009-06-01

    We demonstrate for the first time that neurogenesis in the adult Monodelphis opossum has a typical mammalian pattern and occurs only in the dentate gyrus (DG) and subventricular zone (SVZ) of the lateral ventricles. In these two brain regions neurogenesis is present throughout the lifespan, although its rate is reduced by half in the old age. Treatment with buspirone, a partial 5-HT1A receptor agonist which is used in human clinic as an anxiolytic agent, boosts proliferation in the SVZ and DG in both adult and aged opossums. The neuronal phenotype dominates among newly generated cells in both non-treated and buspirone-treated opossums. We suggest that if functional importance of adult neurogenesis is in improving olfactory discrimination and generation of hippocampus-dependent memory, both spatial and emotional, then administration of drugs increasing the rate of neurogenesis via activation of 5-HT1A receptors may be a valuable aid in combating problems of the advanced age.

  2. Prevalence of Sarcocystis species sporocysts in Northern Virginia opossums (Didelphis virginiana).

    PubMed

    Elsheikha, Hany M; Murphy, Alice J; Mansfield, Linda S

    2004-08-01

    A total of 206 Virginia opossums ( Didelphis virginiana) collected from the mid-Michigan region, United States, during a period extending from 1996 to 2002 were sampled for the presence of Sarcocystis spp sporocysts. All isolates were phenotypically identified as Sarcocystis spp and genotyped to the species level by PCR-based techniques. The overall prevalence of Sarcocystis spp in opossums was 18% (37/206). The prevalence of Sarcocystis spp differed significantly with age ( P<0.001) and adult opossums were more commonly infected (14.6%; 30/206) than juveniles (3.4%; 7/206). No significant difference in the prevalence of Sarcocystis spp infection was observed between male and female ( P<0.15). The highest prevalence was recorded during summer (9.2%; 19/206). PCR-RFLP analyses demonstrated the majority of Sarcocystis isolates to be S. neurona, with some animals co-infected with sporocysts of S. falcatula. Out of the 37 Sarcocystis-infected opossums, 23 (62%) had sporocysts of S. neurona only, four (11%) had sporocysts of S. falcatula only, and eight (22%) had a mixture of S. neurona and S. falcatula sporocysts. These findings indicate that mixed Sarcocystis infections in opossums are common. The propensity for Sarcocystis spp to co-exist in the opossum gut enhances dissemination and environmental contamination with these coccidia. Additionally, this increases the chance for sexual recombination between Sarcocystis spp, given the proclivity of these species to reproduce sexually at high numbers in the intestinal cells of their definitive host.

  3. A new species of Pterygodermatites (Nematoda: Rictulariidae) from the Incan shrew opossum, Lestoros inca.

    PubMed

    Jiménez, F Agustín; Patterson, Bruce D

    2012-06-01

    Pterygodermatites ( Paucipectines ) hymanae n. sp. (Rictulariidae) collected from the Incan shrew opossum, Lestoros inca , from Peru is described herein. These nematodes show a subapical, slightly dorsal oral opening and a laterally compressed buccal capsule with 2 conspicuous lateral walls and a dorsal wall. Each lateroventral wall possesses 4 relatively large denticles, and the dorsal wall has 6 denticles. Females are characterized by a conspicuously large postvulvar 37th spine, which may reach 1 mm. This is the first record of endoparasites in the Incan shrew opossum and the fifth species of Pterygodermatites recorded in New World marsupials.

  4. West Nile Virus Isolated from a Virginia Opossum (Didelphis virginiana) in Northwestern Missouri, USA, 2012

    PubMed Central

    Bosco-Lauth, Angela; Harmon, Jessica R.; Lash, R. Ryan; Weiss, Sonja; Langevin, Stanley; Savage, Harry M.; Godsey, Marvin S.; Burkhalter, Kristen; Root, J. Jeffrey; Gidlewski, Thomas; Nicholson, William L.; Brault, Aaron C.; Komar, Nicholas

    2016-01-01

    We describe the isolation of West Nile virus (WNV; Flaviviridae, Flavivirus) from blood of a Virginia opossum (Didelphis virginiana) collected in northwestern Missouri, USA in August 2012. Sequencing determined that the virus was related to lineage 1a WNV02 strains. We discuss the role of wildlife in WNV disease epidemiology. PMID:25098303

  5. West Nile virus isolated from Virginia opossum (Didelphis virginiana) in Northwest Missouri 2012

    DOE PAGES

    Bosco-Lauth, Angela; Harmon, Jessica; Lash, R. Ryan; ...

    2014-12-01

    We describe the isolation of West Nile virus (WNV; Flaviviridae, flavivirus) from blood of a Virginia opossum (Didelphis virginiana) collected in northwestern Missouri, USA in August 2012. Furthermore, sequencing determined that the virus was related to lineage 1a WNV02 strains. We discuss the role of wildlife in WNV disease epidemiology.

  6. Virginia Opossums, Minimum Reproduction Age and Predators in the Penna Aging Model

    NASA Astrophysics Data System (ADS)

    Altevolmer, A. K.

    Age-specific predators are introduced into the Penna model of biological aging. It is shown that populations with a variable minimum reproduction age find a stable state with an earlier onset of reproduction, if older ages are eaten by the predators. This behavior agrees with the demographic data of the Virgina opossum.

  7. Leptospira borgpetersenii from free-living white-eared opossum (Didelphis albiventris): first isolation in Brazil.

    PubMed

    Jorge, Sérgio; Hartleben, Cláudia P; Seixas, Fabiana K; Coimbra, Marco A A; Stark, Cledir B; Larrondo, Adriana G; Amaral, Marta G; Albano, Ana Paula N; Minello, Luiz F; Dellagostin, Odir A; Brod, Claudiomar S

    2012-11-01

    Leptospirosis is a zoonotic disease that occurs all over the world, caused by bacteria of the genus Leptospira. Marsupial and didelphidae families are considered susceptible to infection caused by a wide range of Leptospira serovars for which they serve as reservoirs. Thirty-three free-living white-eared opossums (Didelphis albiventris) were captured in Southern Brazil and bodily fluids were collected. From the urine samples it was possible to obtain an isolate identified as Leptospira borgpetersenii by rpoB gene sequencing and belonging to serovar Castellonis by Multilocus Variable-Number Tandem-Repeat Analysis. This is the first report of the isolation of Leptospira spp. from the white-eared opossum in Brazil. In addition, the new strain was also virulent in the hamster model of lethal leptospirosis. The microscopic agglutination test (MAT) was used for detecting the presence of antibodies against Leptospira spp. in white-eared opossum, human, cattle and canine sera using a panel of 59 Leptospira strains that included the new isolate. The inclusion of the new strain in the MAT battery increased the MAT sensitivity for canine sera. These findings suggest that the white-eared opossum is an important reservoir of pathogenic Leptospira spp.

  8. The laboratory opossum (Monodelphis domestica) as a natural mammalian model for human cancer research.

    PubMed

    Wang, Zhiqiang; Hubbard, Gene B; Clubb, Fred J; Vandeberg, John L

    2009-01-01

    This study established that human cancer cells (A375 melanoma, HT-29 colon cancer, PC-3p prostate cancer) that were xenografted into suckling opossums could proliferate and globally metastasize as early as 11 days after injection. Light and electron microscopic examinations (HT-29 colon cancer) determined that the cellular features exhibited by the xenogeneic human tumors grown in laboratory opossums were consistent with those observed in tumors removed from humans. The tumor induction rate, patterns of tumor growth and regression, and types of host immune responses against the xenografted tumors were influenced by injection dosages, injection sites and injection ages of suckling opossums. The results highlight the value of the opossum model as a natural in vivo system for investigating human cancer growth, metastasis and apoptosis at the cellular and molecular levels; enhancing identification of tumor associated antigens or T cell epitopes through use of humoral and cellular expression cloning techniques; elucidating mechanisms utilized by tumor cells to evade host immunosurveillance; and devising diagnostic and therapeutic methods for cancer treatment.

  9. Molecular characterization of Sarcocystis neurona strains from opossums (Didelphis virginiana) and intermediate hosts from Central California.

    PubMed

    Rejmanek, Daniel; Miller, Melissa A; Grigg, Michael E; Crosbie, Paul R; Conrad, Patricia A

    2010-05-28

    Sarcocystis neurona is a significant cause of neurological disease in horses and other animals, including the threatened Southern sea otter (Enhydra lutris nereis). Opossums (Didelphis virginiana), the only known definitive hosts for S. neurona in North America, are an introduced species in California. S. neurona DNA isolated from sporocysts and/or infected tissues of 10 opossums, 6 horses, 1 cat, 23 Southern sea otters, and 1 harbor porpoise (Phocoena phocoena) with natural infections was analyzed based on 15 genetic markers, including the first internal transcribed spacer (ITS-1) region; the 25/396 marker; S. neurona surface antigen genes (snSAGs) 2, 3, and 4; and 10 different microsatellites. Based on phylogenetic analysis, most of the S. neurona strains segregated into three genetically distinct groups. Additionally, fifteen S. neurona samples from opossums and several intermediate hosts, including sea otters and horses, were found to be genetically identical across all 15 genetic markers, indicating that fatal encephalitis in Southern sea otters and equine protozoal myeloencephalitis (EPM) in horses is strongly linked to S. neurona sporocysts shed by opossums.

  10. Occurrence of gastrointestinal protozoa in Didelphis albiventris (opossum) in the central region of Rio Grande do Sul state.

    PubMed

    Zanette, Régis A; da Silva, Aleksandro S; Lunardi, Fabiane; Santurio, Janio M; Monteiro, Silvia G

    2008-06-01

    The aim of this study was to evaluate the parasitism by gastrointestinal protozoa in Didelphis albiventris (opossum) in the central region of Rio Grande do Sul state. Fecal samples from six free living opossums were collected for research of parasites. Samples were analyzed by the centrifugal-flotation method with zinc sulfate and parasites were identified microscopically based on (oo)cyst size and morphology. Cysts of Giardia sp. and oocysts of Cryptosporidium sp. and Eimeria sp. were observed in four of the six opossums. All four infected marsupials showed mild infection by protozoa. This is the first report of Giardia sp. in D. albiventris.

  11. INFECTION BY Rickettsia felis IN OPOSSUMS (Didelphis sp.) FROM YUCATAN, MEXICO.

    PubMed

    Peniche-Lara, Gaspar; Ruiz-Piña, Hugo A; Reyes-Novelo, Enrique; Dzul-Rosado, Karla; Zavala-Castro, Jorge

    2016-01-01

    Rickettsia felis is an emergent pathogen and the causative agent of a typhus-like rickettsiosis in the Americas. Its transmission cycle involves fleas as biological vectors (mainly Ctenocephalides felis) and multiple domestic and synanthropic mammal hosts. Nonetheless, the role of mammals in the cycle of R. felis is not well understood and many efforts are ongoing in different countries of America to clarify it. The present study describes for the first time in Mexico the infection of two species of opossum (Didelphis virginiana and D. marsupialis) by R. felis. A diagnosis was carried out from blood samples by molecular methods through the gltA and 17 kDa genes and sequence determination. Eighty-seven opossum samples were analyzed and 28 were found to be infected (32.1%) from five out of the six studied localities of Yucatan. These findings enable recognition of the potential epidemiological implications for public health of the presence of infected synanthropic Didelphis in households.

  12. Receptors and cGMP signalling mechanism for E. coli enterotoxin in opossum kidney

    SciTech Connect

    Forte, L.R.; Krause, W.J.; Freeman, R.H. Harry S. Truman Memorial Veterans Medical Center, Columbia, MO )

    1988-11-01

    Receptors for the heat-stable enterotoxin produced by Escherichia coli were found in the kidney and intestine of the North American opossum and in cultured renal cell lines. The enterotoxin markedly increased guanosine 3{prime},5{prime}-cyclic monophosphate (cGMP) production in slices of kidney cortex and medulla, in suspensions of intestinal mucosa, and in the opossum kidney (OK) and rat kangaroo kidney (PtK-2) cell lines. In contrast, atrial natriuretic factor elicited much smaller increases in cGMP levels of kidney, intestine, or cultured kidney cell lines. The enterotoxin receptors in OK cells had a molecular mass of approximately 120 kDa when measured by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of receptors crosslinked with {sup 125}I-enterotoxin. The occurrence of receptors for the E. coli peptide in OK implies that these receptors may be involved in the regulation of renal tubular function in the opossum. E. coli enterotoxin caused a much larger increase in urine cGMP excretion than did atrial natriuretic factor when these peptides were injected intravenously into opossums. However, atrial natriuretic factor elicited a marked diuresis, natriuresis, and increased urinary excretion of calcium, phosphate, potassium, and magnesium. In contrast, the enterotoxin did not acutely influence OK fluid and electrolyte excretion. Thus the substantial increase in cGMP synthesis produced by the bacterial peptide in OK cortex and medulla in vitro and the increased renal excretion of cGMP in vivo were not associated with changes in electrolyte or water excretion. Whether cGMP represents a second messenger molecule in the kidney is an interesting question that was raised but not answered in this series of experiments.

  13. Steatohepatitis in laboratory opossums exhibiting a high lipemic response to dietary cholesterol and fat.

    PubMed

    Chan, Jeannie; Sharkey, Francis E; Kushwaha, Rampratap S; VandeBerg, Jane F; VandeBerg, John L

    2012-07-01

    Plasma VLDL and LDL cholesterol were markedly elevated (>40-fold) in high-responding opossums, but moderately elevated (6-fold) in low-responding opossums after they had consumed a high-cholesterol and high-fat diet for 24 wk. In both high- and low-responding opossums, plasma triglycerides were slightly elevated, threefold and twofold, respectively. Dietary challenge also induced fatty livers in high responders, but not in low responders. We studied the lipid composition, histopathological features, and gene expression patterns of the fatty livers. Free cholesterol (2-fold), esterified cholesterol (11-fold), and triglycerides (2-fold) were higher in the livers of high responders than those in low responders, whereas free fatty acid levels were similar. The fatty livers of high responders showed extensive lobular disarray by histology. Inflammatory cells and ballooned hepatocytes were also present, as were perisinusoidal fibrosis and ductular proliferation. In contrast, liver histology was normal in low responders. Hepatic gene expression revealed differences associated with the development of steatohepatitis in high responders. The accumulation of hepatic cholesterol was concomitant with upregulation of the HMGCR gene and downregulation of the CYP27A1, ABCG8, and ABCB4 genes. Genes involved in inflammation (TNF, NFKB1, and COX2) and in oxidative stress (CYBA and NCF1) were upregulated. Upregulation of the growth factor genes (PDGF and TGFB1) and collagen genes (Col1A1, Col3A1, and Col4A1) was consistent with fibrosis. Some of the histological characteristics of the fatty livers of high-responding opossums imitate those in the livers of humans with nonalcoholic steatohepatitis.

  14. Metabolic, ventilatory, and hygric physiology of the gracile mouse opossum (Gracilinanus agilis).

    PubMed

    Cooper, C E; Withers, P C; Cruz-Neto, A P

    2009-01-01

    We present the first complete study of basic laboratory-measured physiological variables (metabolism, thermoregulation, evaporative water loss, and ventilation) for a South American marsupial, the gracile mouse opossum (Gracilinanus agilis). Body temperature (T(b)) was thermolabile below thermoneutrality (T(b) = 33.5 degrees C), but a substantial gradient between T(b) and ambient temperature (T(a)) was sustained even at T(a) = 12 degrees C (T(b) = 30.6 degrees C). Basal metabolic rate of 1.00 mL O2 g(-1) h(-1) at T(a) = 30 degrees C conformed to the general allometric relationship for marsupials, as did wet thermal conductance (5.7 mL O2 g(-1) h(-1) degrees C(-1)). Respiratory rate, tidal volume, and minute volume at thermoneutrality matched metabolic demand such that O2 extraction was 12.4%, and ventilation increased in proportion to metabolic rate at low T(a). Ventilatory accommodation of increased metabolic rate at low T(a) was by an increase in respiratory rate rather than by tidal volume or O2 extraction. Evaporative water loss at the lower limit of thermoneutrality conformed to that of other marsupials. Relative water economy was negative at thermoneutrality but positive below T(a) = 12 degrees C. Interestingly, the Neotropical gracile mouse opossums have a more positive water economy at low T(a) than an Australian arid-zone marsupial, perhaps reflecting seasonal variation in water availability for the mouse opossum. Torpor occurred at low T(a), with spontaneous arousal when T(b) > 20 degrees C. Torpor resulted in absolute energy and water savings but lower relative water economy. We found no evidence that gracile mouse opossums differ physiologically from other marsupials, despite their Neotropical distribution, sympatry with placental mammals, and long period of separation from Australian marsupials.

  15. Cephalic sensory influence on forelimb movement in newborn opossums, Monodelphis domestica.

    PubMed

    Adadja, T; Cabana, T; Pflieger, J-F

    2013-01-03

    Like other marsupials, the opossum Monodelphis domestica is born very immature and crawls, unaided by the mother, from the urogenital opening to a nipple where it attaches and pursues its development. If the alternate, rhythmic movements of the forelimbs which allow this locomotion are generated by the developing spinal motor networks, sensory information is nonetheless needed to guide the newborn to a nipple. Behavioral, anatomical and physiological studies suggest that the auditory and the visual systems are insufficiently developed in newborn opossums to influence spinal motor centers, while the vestibular, trigeminal, and olfactory systems are likelier candidates. The trigeminal, vestibular and olfactory regions of the brain were electrically stimulated to test their relative effectiveness at eliciting forelimb movement in newborn opossums, using in vitro preparations of brain-spinal cord with the limbs attached. The minimal stimulation of the cervical spinal cord needed to induce forelimb movement was considered as threshold (T). Stimulations of the trigeminal ganglion (5G) at ∼2T and of the vestibular complex at ∼20T could induce the same movement, and were not statistically different, in contrast to the ∼600T necessary for the olfactory bulb (OB). Neurofilament-200 immunohistochemistry and retrograde tracing with Texas-Red conjugated Dextran Amines were used to study trigeminal innervation of the facial skin and pathways by which trigeminal inputs may be relayed to the spinal cord. Numerous nerve fibers were observed in the snout dermis, especially in the maxillary region, but also elsewhere in the head skin. Some 5G cells project to the upper spinal cord, but more project to the caudal medulla where they could contact secondary trigeminal neurons or reticular cells projecting to the spinal cord. These results support a significant influence of the trigeminal and the vestibular systems, but not of olfaction, on forelimb movement of neonatal opossums.

  16. Torpor in the Patagonian opossum ( Lestodelphys halli): implications for the evolution of daily torpor and hibernation

    NASA Astrophysics Data System (ADS)

    Geiser, Fritz; Martin, Gabriel M.

    2013-10-01

    Hibernation and daily torpor are two distinct forms of torpor, and although they are related, it is not known how and in which sequence they evolved. As the pattern of torpor expressed by the oldest marsupial order the opossums (Didelphimorphia) may provide insights into the evolution of torpor, we aimed to provide the first quantitative data on the thermal biology and torpor expression of the rare Patagonian opossum ( Lestodelphys halli). It is the opossum with the southernmost distribution, has a propensity of autumnal fattening, and therefore, is likely to hibernate. We captured two male Lestodelphys, which while in captivity displayed strong daily fluctuations of body temperatures (Tb) measured with implanted miniature data loggers even when they remained normothermic. In autumn and early winter, torpor was expressed occasionally when food was available, but cold exposure and food withdrawal increased torpor use. The mean Tb throughout the study was 32.2 ± 1.4 °C, the minimum Tb measured in torpid Lestodelphys was 7.7 °C, average torpor bout duration was 10.3 h, and the maximum torpor bout duration was 42.5 h. Thus, the pattern of torpor expressed by Lestodelphys was intermediate between that of daily heterotherms and hibernators suggesting that it may represent an ancestral opportunistic torpor pattern from which the derived patterns of daily torpor and seasonal hibernation diverged.

  17. Computational analyses of mammalian lactate dehydrogenases: human, mouse, opossum and platypus LDHs.

    PubMed

    Holmes, Roger S; Goldberg, Erwin

    2009-10-01

    Computational methods were used to predict the amino acid sequences and gene locations for mammalian lactate dehydrogenase (LDH) genes and proteins using genome sequence databanks. Human LDHA, LDHC and LDH6A genes were located in tandem on chromosome 11, while LDH6B and LDH6C genes were on chromosomes 15 and 12, respectively. Opossum LDHC and LDH6B genes were located in tandem with the opossum LDHA gene on chromosome 5 and contained 7 (LDHA and LDHC) or 8 (LDH6B) exons. An amino acid sequence prediction for the opossum LDH6B subunit gave an extended N-terminal sequence, similar to the human and mouse LDH6B sequences, which may support the export of this enzyme into mitochondria. The platypus genome contained at least 3 LDH genes encoding LDHA, LDHB and LDH6B subunits. Phylogenetic studies and sequence analyses indicated that LDHA, LDHB and LDH6B genes are present in all mammalian genomes examined, including a monotreme species (platypus), whereas the LDHC gene may have arisen more recently in marsupial mammals.

  18. Geographic Association of Rickettsia felis-Infected Opossums with Human Murine Typhus, Texas

    PubMed Central

    Boostrom, Ardys; Beier, Magda S.; Macaluso, Jackie A.; Macaluso, Kevin R.; Sprenger, Daniel; Hayes, Jack; Radulovic, Suzan

    2002-01-01

    Application of molecular diagnostic technology in the past 10 years has resulted in the discovery of several new species of pathogenic rickettsiae, including Rickettsia felis. As more sequence information for rickettsial genes has become available, the data have been used to reclassify rickettsial species and to develop new diagnostic tools for analysis of mixed rickettsial pathogens. R. felis has been associated with opossums and their fleas in Texas and California. Because R. felis can cause human illness, we investigated the distribution dynamics in the murine typhus–endemic areas of these two states. The geographic distribution of R. felis-infected opossum populations in two well-established endemic foci overlaps with that of the reported human cases of murine typhus. Descriptive epidemiologic analysis of 1998 human cases in Corpus Christi, Texas, identified disease patterns consistent with studies done in the 1980s. A close geographic association of seropositive opossums (22% R. felis; 8% R. typhi) with human murine typhus cases was also observed. PMID:12023908

  19. Geographic association of Rickettsia felis-infected opossums with human murine typhus, Texas.

    PubMed

    Boostrom, Ardys; Beier, Magda S; Macaluso, Jacqueline A; Macaluso, Kevin R; Sprenger, Daniel; Hayes, Jack; Radulovic, Suzana; Azad, Abdu F

    2002-06-01

    Application of molecular diagnostic technology in the past 10 years has resulted in the discovery of several new species of pathogenic rickettsiae, including Rickettsia felis. As more sequence information for rickettsial genes has become available, the data have been used to reclassify rickettsial species and to develop new diagnostic tools for analysis of mixed rickettsial pathogens. R. felis has been associated with opossums and their fleas in Texas and California. Because R. felis can cause human illness, we investigated the distribution dynamics in the murine typhus-endemic areas of these two states. The geographic distribution of R. felis-infected opossum populations in two well-established endemic foci overlaps with that of the reported human cases of murine typhus. Descriptive epidemiologic analysis of 1998 human cases in Corpus Christi, Texas, identified disease patterns consistent with studies done in the 1980s. A close geographic association of seropositive opossums (22% R. felis; 8% R. typhi) with human murine typhus cases was also observed.

  20. Scanning Electron Microscopic Structure of the Lingual Papillae of the Common Opossum (Didelphis marsupialis)

    NASA Astrophysics Data System (ADS)

    Okada, Shigenori; Schraufnagel, Dean E.

    2005-08-01

    The mammalian tongue has evolved for specialized functions in different species. The structure of its papillae tells about the animal's diet, habit, and taxonomy. The opossum has four kinds of lingual papillae (filiform, conical, fungiform, vallate). Scanning electron microscopy of the external features, connective tissue cores, and corrosion casts of the microvasculature show the filiform papillae have a spearhead-like main process and spiny accessory processes around the apical part of the main process. The shape and number of both processes depend on their position on the tongue. On the apex, the main processes have shovel-like capillary networks and the accessory processes have small conical networks. On the lingual radix, the processes have small capillary loops. In the patch region, conical papillae have capillaries arranged as a full sail curving posteriorly. The fungiform papillae are scattered among the filiform papillae and have capillary baskets beneath each taste bud. Giant fungiform papillae on the tongue tip are three to four times larger than the ones on the lingual body. Capillaries of giant papillae form a fan-shaped network. The opossum has three vallate papillae arranged in a triangle. Their tops have secondary capillary loops but not their lateral surfaces. Mucosal folds on the posterolateral border have irregular, fingerlike projections with cylindrical capillary networks. These findings and the structure of the rest of the masticatory apparatus suggest the lingual papillae of opossum have kept their ancestral carnivorous features but also developed the herbivore characteristics of other marsupials.

  1. First evidence of gregarious denning in opossums (Didelphimorphia, Didelphidae), with notes on their social behaviour.

    PubMed

    Astúa, Diego; Carvalho, Rafael A; Maia, Paula F; Magalhães, Arthur R; Loretto, Diogo

    2015-06-01

    The Didelphidae are considered solitary opossums with few social interactions, usually limited to mating-related or mother-pouch young interactions. Anecdotal reports suggest that additional interactions occur, including den sharing by a few individuals, usually siblings. Here, we report novel observations that indicate opossums are more social than previously thought. These include nest sharing by males and females of Marmosa paraguayana, Gracilinanus microtarsus and Marmosops incanus prior to the onset of the breeding season and without signs of sexual activity; this is taken to indicate early pair-bonding matching and cooperative nest building. We also recorded den sharing among recently weaned siblings of Didelphis aurita and Caluromys philander. In addition, we observed 13 individuals of Didelphis albiventris representing three age classes resting without agonistic interactions in a communal den. These are the first reports of gregarious behaviour involving so many individuals, which are either unrelated or represent siblings from at least two litters, already weaned, sharing the same den with three adults. Sociality in opossums is probably more complex than previously established, and field experimental designs combining the use of artificial nests with camera traps or telemetry may help to gauge the frequency and extent of these phenomena.

  2. Adaptive evolution of the venom-targeted vWF protein in opossums that eat pitvipers.

    PubMed

    Jansa, Sharon A; Voss, Robert S

    2011-01-01

    The rapid evolution of venom toxin genes is often explained as the result of a biochemical arms race between venomous animals and their prey. However, it is not clear that an arms race analogy is appropriate in this context because there is no published evidence for rapid evolution in genes that might confer toxin resistance among routinely envenomed species. Here we report such evidence from an unusual predator-prey relationship between opossums (Marsupialia: Didelphidae) and pitvipers (Serpentes: Crotalinae). In particular, we found high ratios of replacement to silent substitutions in the gene encoding von Willebrand Factor (vWF), a venom-targeted hemostatic blood protein, in a clade of opossums known to eat pitvipers and to be resistant to their hemorrhagic venom. Observed amino-acid substitutions in venom-resistant opossums include changes in net charge and hydrophobicity that are hypothesized to weaken the bond between vWF and one of its toxic snake-venom ligands, the C-type lectin-like protein botrocetin. Our results provide the first example of rapid adaptive evolution in any venom-targeted molecule, and they support the notion that an evolutionary arms race might be driving the rapid evolution of snake venoms. However, in the arms race implied by our results, venomous snakes are prey, and their venom has a correspondingly defensive function in addition to its usual trophic role.

  3. CUTANEOUS EPITHELIOTROPIC T-CELL LYMPHOMA WITH METASTASES IN A VIRGINIA OPOSSUM (DIDELPHIS VIRGINIANA).

    PubMed

    Higbie, Christine T; Carpenter, James W; Choudhary, Shambhunath; DeBey, Brad; Bagladi-Swanson, Mary; Eshar, David

    2015-06-01

    A 2-yr-old, captive, intact female Virginia opossum ( Didelphis virginiana ) with a 7-mo history of ulcerative dermatitis and weight loss was euthanatized for progressive worsening of clinical signs. Initially the opossum was treated with several courses of antibiotics, both topically and systemically; systemic nonsteroidal anti-inflammatory medication; and, later, systemic glucocorticoids, with no improvement in clinical signs. Histopathologic samples of skin lesions taken 3 mo into the course of disease revealed no evidence of neoplasia; however, cytologic samples of a skin lesion taken 5 mo into the course of disease revealed mature lymphocytes, and were suggestive of cutaneous lymphoma. Postmortem histopathology revealed neoplastic cells consistent with lymphoma; these were found in the haired skin of the forearm, axilla, hind limb, face, and lateral body wall, as well as the liver, kidney, axillary lymph node, heart, and spleen. Multifocal neutrophilic and eosinophilic ulcerative and necrotizing dermatitis and folliculitis of the haired skin were also present. To the authors' knowledge, this is the first documented case of cutaneous lymphoma in a Virginia opossum and the first documented case with visceral metastases in a marsupial.

  4. Observations on besnoitiosis in Virginia opossum (Didelphis virginiana) from Michigan, USA.

    PubMed

    El Sheikha, Hany M; Hussein, Hussein S; Monib, Mohammad el-Salahy M; Mansfield, Linda S

    2007-04-01

    Besnoitia tissue cysts were found in five naturally-infected adult opossums (Didelphis virginiana) from Michigan. Details of the microscopy, histopathology, ultra-structure, and genetic features of the cysts were studied to identify their species-specific traits. The materials were differentiated phenotypically from cysts of other Besnoitia spp. by difference in size, pattern of tissue distribution, morphology of pellicle and nucleus, number of micronemes and rhoptries, amount of lipids and amylopectin, and presence of enigmatic bodies. Morphometric variations identified the tissue cysts and the pathologic changes in opossums host to be due to B. darlingi. The data were proved by phylogenetic analysis based on DNA sequences of the first internal transcribed spacer of nuclear rDNA. Cluster analysis showed that B. darlingi was distinct from all other Besnoitia spp. as two distinct phylogenetic clades: I- included Besnoitia spp. described from opossum (B. darlingi), sheep (B. jellisoni), rodent (B. akadoni) and rabbit (B. oryctofelisi) and clade II- encompassed parasites described from cattle (B. besnoiti), equids (B. bennetti) and reindeer (B. tarandi). The genetic attributed particular to the genus Besnoitia complemented the morphologica features and lead to accurate delimitation of Besnoitia species.

  5. Torpor in the Patagonian opossum (Lestodelphys halli): implications for the evolution of daily torpor and hibernation.

    PubMed

    Geiser, Fritz; Martin, Gabriel M

    2013-10-01

    Hibernation and daily torpor are two distinct forms of torpor, and although they are related, it is not known how and in which sequence they evolved. As the pattern of torpor expressed by the oldest marsupial order the opossums (Didelphimorphia) may provide insights into the evolution of torpor, we aimed to provide the first quantitative data on the thermal biology and torpor expression of the rare Patagonian opossum (Lestodelphys halli). It is the opossum with the southernmost distribution, has a propensity of autumnal fattening, and therefore, is likely to hibernate. We captured two male Lestodelphys, which while in captivity displayed strong daily fluctuations of body temperatures (Tb) measured with implanted miniature data loggers even when they remained normothermic. In autumn and early winter, torpor was expressed occasionally when food was available, but cold exposure and food withdrawal increased torpor use. The mean Tb throughout the study was 32.2 ± 1.4 °C, the minimum Tb measured in torpid Lestodelphys was 7.7 °C, average torpor bout duration was 10.3 h, and the maximum torpor bout duration was 42.5 h. Thus, the pattern of torpor expressed by Lestodelphys was intermediate between that of daily heterotherms and hibernators suggesting that it may represent an ancestral opportunistic torpor pattern from which the derived patterns of daily torpor and seasonal hibernation diverged.

  6. ABCB4 mediates diet-induced hypercholesterolemia in laboratory opossums[S

    PubMed Central

    Chan, Jeannie; Mahaney, Michael C.; Kushwaha, Rampratap S.; VandeBerg, Jane F.; VandeBerg, John L.

    2010-01-01

    High-responding opossums are susceptible to developing hypercholesterolemia on a high-cholesterol diet, but low-responding opossums are resistant. The observation of low biliary cholesterol and low biliary phospholipids in high responders suggested that the ABCB4 gene affects response to dietary cholesterol. Two missense mutations (Arg29Gly and Ile235Leu) were found in the ABCB4 gene of high responders. High responders (ATHH strain) were bred with low responders (ATHE or ATHL strain) to produce F1 and F2 progeny in two different genetic crosses (KUSH6 and JCX) to determine the effect of ABCB4 allelic variants on plasma cholesterol concentrations after a dietary challenge. Pedigree-based genetic association analyses consistently implicated a variant in ABCB4 or a closely linked locus as a major, but not the sole, genetic contributor to variation in the plasma cholesterol response to dietary cholesterol. High responders, but not low responders, developed liver injury as indicated by elevated plasma biomarkers of liver function, probably reflecting damage to the canalicular membrane by bile salts because of impaired phospholipid secretion. Our results implicate ABCB4 as a major determinant of diet-induced hypercholesterolemia in high-responding opossums and suggest that other genes interact with ABCB4 to regulate lipemic response to dietary cholesterol. PMID:20488799

  7. Transcriptomic Changes Associated with Pregnancy in a Marsupial, the Gray Short-Tailed Opossum Monodelphis domestica

    PubMed Central

    Hansen, Victoria Leigh; Schilkey, Faye Dorothy; Miller, Robert David

    2016-01-01

    Live birth has emerged as a reproductive strategy many times across vertebrate evolution; however, mammals account for the majority of viviparous vertebrates. Marsupials are a mammalian lineage that last shared a common ancestor with eutherians (placental mammals) over 148 million years ago. Marsupials are noted for giving birth to highly altricial young after a short gestation, and represent humans’ most distant viviparous mammalian relatives. Here we ask what insight can be gained into the evolution of viviparity in mammals specifically and vertebrates in general by analyzing the global uterine transcriptome in a marsupial. Transcriptome analyses were performed using NextGen sequencing of uterine RNA samples from the gray short-tailed opossum, Monodelphis domestica. Samples were collected from late stage pregnant, virgin, and non-pregnant experienced breeders. Three different algorithms were used to determine differential expression, and results were confirmed by quantitative PCR. Over 900 opossum gene transcripts were found to be significantly more abundant in the pregnant uterus than non-pregnant, and over 1400 less so. Most with increased abundance were genes related to metabolism, immune systems processes, and transport. This is the first study to characterize the transcriptomic differences between pregnant, non-pregnant breeders, and virgin marsupial uteruses and helps to establish a set of pregnancy-associated genes in the opossum. These observations allowed for comparative analyses of the differentially transcribed genes with other mammalian and non-mammalian viviparous species, revealing similarities in pregnancy related gene expression over 300 million years of amniote evolution. PMID:27598793

  8. An architectonic study of the neocortex of the short-tailed opossum (Monodelphis domestica).

    PubMed

    Wong, Peiyan; Kaas, Jon H

    2009-01-01

    Short-tailed opossums (Monodelphis domestica) belong to the branch of marsupial mammals that diverged from eutherian mammals approximately 180 million years ago. They are small in size, lack a marsupial pouch, and may have retained more morphological characteristics of early marsupial neocortex than most other marsupials. In the present study, we used several different histochemical and immunochemical procedures to reveal the architectonic characteristics of cortical areas in short-tailed opossums. Subdivisions of cortex were identified in brain sections cut in the coronal, sagittal, horizontal or tangential planes and processed for a calcium-binding protein, parvalbumin (PV), neurofilament protein epitopes recognized by SMI-32, the vesicle glutamate transporter 2 (VGluT2), myelin, cytochrome oxidase (CO), and Nissl substance. These different procedures revealed similar boundaries among areas, suggesting that functionally relevant borders were detected. The results allowed a fuller description and more precise demarcation of previously identified sensory areas, and the delineation of additional subdivisions of cortex. Area 17 (V1) was especially prominent, with a densely populated layer 4, high myelination levels, and dark staining of PV and VGluT2 immunopositive terminations. These architectonic features were present, albeit less pronounced, in somatosensory and auditory cortex. The major findings support the conclusion that short-tailed opossums have fewer cortical areas and their neocortex is less distinctly laminated than most other mammals.

  9. Cellular basis of differential limb growth in postnatal gray short-tailed opossums (Monodelphis domestica).

    PubMed

    Beiriger, Anastasia; Sears, Karen E

    2014-06-01

    While growth has been studied extensively in invertebrates, the mechanisms by which it is controlled in vertebrates, particularly in mammals, remain poorly understood. In this study, we investigate the cellular basis of differential limb growth in postnatal Monodelphis domestica, the gray short-tailed opossum, to gain insights into the mechanisms regulating mammalian growth. Opossums are an ideal model for the study of growth because they are born with relatively large, well-developed forelimbs and small hind limbs that must "catch up" to the forelimb before the animal reaches adulthood. Postnatal Days 1-17 were identified as a key period of growth for the hind limbs, during which they undergo accelerated development and nearly quadruple in length. Histology performed on fore- and hind limbs from this period indicates a higher rate of cellular differentiation in the long bones of the hind limbs. Immunohistochemical assays indicate that cellular proliferation is also occurring at a significantly greater rate in the long bones of the hind limb at 6 days after birth. Taken together, these results suggest that a faster rate of cellular proliferation and differentiation in the long bones of the hind limb relative to those of the forelimb generates a period of accelerated growth through which the adult limb phenotype of M. domestica is achieved. Assays for gene expression suggest that the molecular basis of this differential growth differs from that previously identified for differential pre-natal growth in opossum fore- and hind limbs.

  10. Transcriptomic Changes Associated with Pregnancy in a Marsupial, the Gray Short-Tailed Opossum Monodelphis domestica.

    PubMed

    Hansen, Victoria Leigh; Schilkey, Faye Dorothy; Miller, Robert David

    2016-01-01

    Live birth has emerged as a reproductive strategy many times across vertebrate evolution; however, mammals account for the majority of viviparous vertebrates. Marsupials are a mammalian lineage that last shared a common ancestor with eutherians (placental mammals) over 148 million years ago. Marsupials are noted for giving birth to highly altricial young after a short gestation, and represent humans' most distant viviparous mammalian relatives. Here we ask what insight can be gained into the evolution of viviparity in mammals specifically and vertebrates in general by analyzing the global uterine transcriptome in a marsupial. Transcriptome analyses were performed using NextGen sequencing of uterine RNA samples from the gray short-tailed opossum, Monodelphis domestica. Samples were collected from late stage pregnant, virgin, and non-pregnant experienced breeders. Three different algorithms were used to determine differential expression, and results were confirmed by quantitative PCR. Over 900 opossum gene transcripts were found to be significantly more abundant in the pregnant uterus than non-pregnant, and over 1400 less so. Most with increased abundance were genes related to metabolism, immune systems processes, and transport. This is the first study to characterize the transcriptomic differences between pregnant, non-pregnant breeders, and virgin marsupial uteruses and helps to establish a set of pregnancy-associated genes in the opossum. These observations allowed for comparative analyses of the differentially transcribed genes with other mammalian and non-mammalian viviparous species, revealing similarities in pregnancy related gene expression over 300 million years of amniote evolution.

  11. Microscopic anatomy of the lower respiratory tract of the grey short-tailed opossum (Monodelphis domestica).

    PubMed

    Cope, L A; Henry, R W; Reed, R B

    2012-04-01

    The respiratory tracts of seven grey short-tailed opossums were histologically examined. Six opossums were prepared by perfusion with buffered formalin. Opossum seven was perfused with gluteraldehyde. Samples taken from the respiratory passages and lungs of specimens 1-6 were stained with haematoxylin and eosin. A mixture of methylene and azure blue was used for specimen 7. The trachea and right and left principal bronchi are lined with a pseudostratified ciliated columnar epithelium with occasional goblet cells. The secondary and tertiary bronchi and the primary and secondary bronchioles are lined by a simple ciliated columnar epithelium. The terminal bronchioles and a portion of the respiratory bronchioles are lined by a simple ciliated cuboidal epithelium. The terminal portion of the respiratory bronchioles and the alveolar ducts are lined with simple squamous epithelium. Alveoli are lined by type I and II pneumocytes. Tracheal glands are present in the tela submucosa. The fibromusculocartilaginous tunic of the trachea consists of c-shaped cartilage rings and the trachealis muscle. A lamina muscularis mucosa begins in the intrapulmonary portion of the principal bronchus and continues into the respiratory bronchioles. Bronchial glands are present in the propria submucosa and tela submucosa of the principal bronchi. The musculocartilaginous tunic is localized to the extrapulmonary portion of the principal bronchus. The bronchial cartilages are irregular shaped plates and limited to the extrapulmonary portion of the principal bronchus. The visceral pleura is a simple squamous mesothelium covering the outer surface of the lung.

  12. Cell birth and death in the developing retina of the Brazilian opossum, Monodelphis domestica.

    PubMed

    Sakaguchi, Donald S; Hoffelen, Samantha Van; Greenlee, M Heather W; Harper, Matthew M; Au, Daniel T

    2008-02-21

    The purpose of this study was to characterize cytogenesis and apoptosis in the developing retina of the Brazilian opossum, Monodelphis domestica. Monodelphis is a small pouchless marsupial whose young undergo a protracted period of postnatal development. Moreover, the Monodelphis retina represents a unique in vivo compartment for investigating cellular interactions that occur during early neural development and is an important system to study plasticity of neural stem cells following transplantation. Using bromodeoxyuridine (BrdU) labeling of newly generated cells, double-labeling immunohistochemistry and TUNEL labeling of apoptotic cells we have performed a detailed analysis of cell birth and death in the Monodelphis retina from fetal development through early postnatal life. Pregnant opossums or pups received a single injection of BrdU between gestational day 12 and postnatal day 35 (35PN), eyes were collected two hours after injection or on day 15, 30, or 60 of postnatal life. BrdU-labeled cells were visualized immunohistochemically. Cells were classified according to their morphology, location and immunoreactivity for cell-type specific antibodies. Cell genesis in the opossum retina begins at E13 and was near completion by 25PN. Apoptotic retinal cells were identified using the TUNEL technique for labeling of fragmented DNA. Apoptosis covered a relatively broad period of postnatal development, beginning around 10PN, peaking at 30PN, and concluding before 60PN. These results demonstrate that the retina of Monodelphis, a polyprotodont marsupial, is generated in a similar pattern to the wallaby, a diprotodont marsupial, and to eutherian species.

  13. First evidence of gregarious denning in opossums (Didelphimorphia, Didelphidae), with notes on their social behaviour

    PubMed Central

    Astúa, Diego; Carvalho, Rafael A.; Maia, Paula F.; Magalhães, Arthur R.; Loretto, Diogo

    2015-01-01

    The Didelphidae are considered solitary opossums with few social interactions, usually limited to mating-related or mother–pouch young interactions. Anecdotal reports suggest that additional interactions occur, including den sharing by a few individuals, usually siblings. Here, we report novel observations that indicate opossums are more social than previously thought. These include nest sharing by males and females of Marmosa paraguayana, Gracilinanus microtarsus and Marmosops incanus prior to the onset of the breeding season and without signs of sexual activity; this is taken to indicate early pair-bonding matching and cooperative nest building. We also recorded den sharing among recently weaned siblings of Didelphis aurita and Caluromys philander. In addition, we observed 13 individuals of Didelphis albiventris representing three age classes resting without agonistic interactions in a communal den. These are the first reports of gregarious behaviour involving so many individuals, which are either unrelated or represent siblings from at least two litters, already weaned, sharing the same den with three adults. Sociality in opossums is probably more complex than previously established, and field experimental designs combining the use of artificial nests with camera traps or telemetry may help to gauge the frequency and extent of these phenomena. PMID:26085500

  14. An Architectonic Study of the Neocortex of the Short-Tailed Opossum (Monodelphis domestica)

    PubMed Central

    Wong, Peiyan; Kaas, Jon H.

    2013-01-01

    Short-tailed opossums (Monodelphis domestica) belong to the branch of marsupial mammals that diverged from eutherian mammals approximately 180 million years ago. They are small in size, lack a marsupial pouch, and may have retained more morphological characteristics of early marsupial neocortex than most other marsupials. In the present study, we used several different histochemical and immunochemical procedures to reveal the architectonic characteristics of cortical areas in short-tailed opossums. Subdivisions of cortex were identified in brain sections cut in the coronal, sagittal, horizontal or tangential planes and processed for a calcium-binding protein, parvalbumin (PV), neurofilament protein epitopes recognized by SMI-32, the vesicle glutamate transporter 2 (VGluT2), myelin, cytochrome oxidase (CO), and Nissl substance. These different procedures revealed similar boundaries among areas, suggesting that functionally relevant borders were detected. The results allowed a fuller description and more precise demarcation of previously identified sensory areas, and the delineation of additional subdivisions of cortex. Area 17 (V1) was especially prominent, with a densely populated layer 4, high myelination levels, and dark staining of PV and VGluT2 immunopositive terminations. These architectonic features were present, albeit less pronounced, in somatosensory and auditory cortex. The major findings support the conclusion that short-tailed opossums have fewer cortical areas and their neocortex is less distinctly laminated than most other mammals. PMID:19546531

  15. Effect of light-dark changes on the locomotor activity in open field in adult rats and opossums.

    PubMed

    Klejbor, I; Ludkiewicz, B; Turlejski, K

    2013-11-01

    There have been no reports on how the light-dark changes determine the locomotor activity of animals in the group of high reactivity (HR) and low reactivity (LR). In the present study we have compared selected parameters of the locomotor activity of the HR and the LR groups of the laboratory opossums and Wistar rats during consecutive, light and dark phases in the open field test. Sixty male Wistar adult rats, at an average weight of 350 g each, and 24 adult Monodelphis opossums of both sexes at an average weight of 120 g each were used. The animals' activity for 2 h daily between the hours of 17:30 and 19:30, in line with the natural light-dark cycle were recorded and then analysed using VideoTrack ver.2.0 (Vievpoint France). According to our results, we noted that a change of the experimental conditions from light to dark involves an increase in the locomotor activity in rats and opossums of the HR group, while there is no effect on the activity of the rats and opossums in the LR group. Locomotor activity in the HR rats, both in the light and dark conditions is characterised by a consistent pattern of change - higher activity in the first stage of the recording and a slowdown (habituation) in the second phase of the observation. The locomotor activity of the opossum, during both light and dark conditions, was observed to be at a consistently high level compared to the rats.

  16. Response to novelty in the laboratory Wistar rat, wild-captive WWCPS rat, and the gray short-tailed opossum (Monodelphis domestica).

    PubMed

    Pisula, Wojciech; Turlejski, Krzysztof; Stryjek, Rafał; Nałęcz-Tolak, Aleksandra; Grabiec, Marta; Djavadian, Rouzanna L

    2012-10-01

    Behavior of the laboratory gray short-tailed opossums (Monodelphis domestica), Warsaw Wild Captive Pisula Stryjek rats (WWCPS) and laboratory rats (Wistar) has been registered in the period of familiarization with a new environment and consecutive confrontation with a novel, innocuous object placed in that familiarized environment. In the new environment the sequence of anxiety, investigation, and habituation was shortest in the opossum, longer in the laboratory rat and longest in the WWCPS rat. When placed in it, gray short-tailed opossums investigated the new environment with the shortest delay and most intensity. In reaction to novel objects, opossums and laboratory rats prolonged the time spent in the proximity of the new object, while the WWCPS rat did not show that reaction. Both opossums and laboratory rats increased the number of contacts with the new object, whereas WWCPS rats reduced those contacts. Behavior of all three species and lines grouped in different clusters. Some other quantitative and qualitative differences in behavior of the investigated animals are also described, showing a higher level of anxiety in both lines of rats than in the opossum. Behavioral differences between species and lines of animals used in this study may be attributed to different ecological adaptations of rats and opossums and to the effect of domestication in the laboratory rats. These behavioral differences make comparisons of opossums vs rat, and wild rat vs laboratory rat interesting models for studying the brain mechanisms of anxiety and neotic motivations.

  17. Growth inhibition and chromosomal instability of cultured marsupial (opossum) cells after treatment with DNA polymerase α inhibitor.

    PubMed

    Takemura, Masaharu; Kazama, Tomoko; Sakuma, Kurumi; Mizushina, Yoshiyuki; Oshima, Teruyoshi

    2011-01-01

    The DNA replication mechanism has been well established for eutherian mammals (placental mammals such as humans, mice, and cattle), but not, to date, for metatherian mammals (marsupials such as kangaroos, koalas, and opossums). In this study, we found that dehydroaltenusin, a selective inhibitor of mammalian (eutherian) DNA polymerase α, clearly suppressed the growth of metatherian (opossum and rat kangaroo) cultured cells. In cultured opossum (OK) cells, dehydroaltenusin also suppressed the progression of DNA replication. These results suggest that dehydroaltenusin inhibits metatherian as well as eutherian DNA replication. Dehydroaltenusin treatment of OK cells engendered fluctuations in the numbers of chromosomes in the OK cells as well as inhibition of cell growth and DNA replication. This suggests that partial inhibition of DNA replication by dehydroaltenusin causes chromosomal instability in cultured cells.

  18. Making the most of RNA-seq: Pre-processing sequencing data with Opossum for reliable SNP variant detection

    PubMed Central

    2017-01-01

    Identifying variants from RNA-seq (transcriptome sequencing) data is a cost-effective and versatile alternative to whole-genome sequencing. However, current variant callers do not generally behave well with RNA-seq data due to reads encompassing intronic regions. We have developed a software programme called Opossum to address this problem. Opossum pre-processes RNA-seq reads prior to variant calling, and although it has been designed to work specifically with Platypus, it can be used equally well with other variant callers such as GATK HaplotypeCaller. In this work, we show that using Opossum in conjunction with either Platypus or GATK HaplotypeCaller maintains precision and improves the sensitivity for SNP detection compared to the GATK Best Practices pipeline. In addition, using it in combination with Platypus offers a substantial reduction in run times compared to the GATK pipeline so it is ideal when there are only limited time or computational resources available. PMID:28239666

  19. Reduction of the number of new cells reaching olfactory bulbs impairs olfactory perception in the adult opossum.

    PubMed

    Grabiec, Marta; Turlejski, Kris; Djavadian, Rouzanna

    2009-01-01

    In adult mammals cells generated in the subventricular zone (SVZ) migrate to olfactory bulbs (OB). Functional significance of this continuous neurogenesis is not clear. We injected opossums (Monodelphis domestica) for seven consecutive days with a 5HT(1A) agonist (8-OH-DPAT or buspirone) or its antagonist WAY100635. One hour after each of these injections bromodeoxyuridine (BrdU) a marker of dividing cells was also injected. Two months later, when newly generated neurons settled in the OB and matured the ability of these opossums to detect hidden food by olfactory cues was tested. Afterwards, numbers of BrdU-labeled cell nuclei in their OB were counted and a phenotype of labeled cells established. In all groups investigated the majority of new cells differentiated into neurons (55-76%) and a lower proportion into astroglia (6-12%). Numbers of BrdU-labeled cells differed depending on the applied treatment: both agonists of the 5HT(1A) receptor increased these numbers, while its antagonist decreased them. The increased number of new OB interneurons did not change the time required for finding all three food items and therefore did not improve the opossums' performance in this test of the olfactory perception. However, opossums that had the reduced number of new generated OB cells searched longer for each food item and in consequence took three times longer to find all three crickets, than did opossums from other groups. In conclusion, lower numbers of new neurons in the opossums OB correlated with their worse behavioral performance in a test based on olfactory perception.

  20. Expression, purification and characterization of the recombinant chimeric IgE Fc-fragment opossum-human-opossum (OSO), an active immunotherapeutic vaccine component.

    PubMed

    Xu, Bingze; Lundgren, Mats; Magnusson, Ann-Christine; Fuentes, Alexis

    2010-11-01

    The active vaccine component recombinant chimeric IgE Fc-fragment opossum-human-opossum (OSO) has been expressed in CHO-K1 cells. It contains two identical polypeptide chains with 338 amino acid residues in each chain connected by two disulfide bridges. The cell lines were adapted to suspension culture in a serum-free medium. An expression level of 60 mg/L was obtained after 8 days in a shaking flask at a temperature of 31.5 degrees C. The OSO protein has been purified to homogeneity by a combination of three chromatographic steps. Virus inactivation and reduction by solvent detergent treatment and nano-filtration were included in the process. The residual host cell protein content was less than 50 ng/mg OSO as analyzed by ELISA. Purity was analyzed by SDS-PAGE under reducing and non-reducing conditions and was estimated by densitometry to be above 99.0%. The dimer content was less than 0.1% as estimated by analytical size exclusion chromatography. The molecular mass, as estimated by SDS-PAGE, is 90 kDa. A value of around 74 kDa was calculated from its amino acid composition. This indicates that the protein is heavily glycosylated containing around 18% carbohydrate. Isoelectric focusing in polyacrylamide gel disclosed a ladder type band pattern with pI values in the pH-range 7.0-8.3, indicating a variation in the sialic acid content. The OSO protein is not stable at temperatures above 40 degrees C and at pH values below 4 indicating that virus inactivation by incubating the protein solution at higher temperature or at lower pH is not possible.

  1. Facial Mechanosensory Influence on Forelimb Movement in Newborn Opossums, Monodelphis domestica.

    PubMed

    Desmarais, Marie-Josée; Beauregard, France; Cabana, Thérèse; Pflieger, Jean-François

    2016-01-01

    The opossum, Monodelphis domestica, is born very immature but crawls, unaided, with its forelimbs (FL) from the mother's birth canal to a nipple where it attaches to pursue its development. What sensory cues guide the newborn to the nipple and trigger its attachment to it? Previous experiments showed that low intensity electrical stimulation of the trigeminal ganglion induces FL movement in in vitro preparations and that trigeminal innervation of the facial skin is well developed in the newborn. The skin does not contain Vater-Pacini or Meissner touch corpuscles at this age, but it contains cells which appear to be Merkel cells (MC). We sought to determine if touch perceived by MC could exert an influence on FL movements. Application of the fluorescent dye AM1-43, which labels sensory cells such as MC, revealed the presence of a large number of labeled cells in the facial epidermis, especially in the snout skin, in newborn opossums. Moreover, calibrated pressure applied to the snout induced bilateral and simultaneous electromyographic responses of the triceps muscle in in vitro preparations of the neuraxis and FL from newborn. These responses increase with stimulation intensity and tend to decrease over time. Removing the facial skin nearly abolished these responses. Metabotropic glutamate 1 receptors being involved in MC neurotransmission, an antagonist of these receptors was applied to the bath, which decreased the EMG responses in a reversible manner. Likewise, bath application of the purinergic type 2 receptors, used by AM1-43 to penetrate sensory cells, also decreased the triceps EMG responses. The combined results support a strong influence of facial mechanosensation on FL movement in newborn opossums, and suggest that this influence could be exerted via MC.

  2. Male influence on oestrous cycles in female woolly opossum (Caluromys philander).

    PubMed

    Perret, M; Ben M'Barek, S

    1991-03-01

    Plasma progesterone concentrations and the occurrence of oestrous cycles were studied in isolated woolly opossums subsequently subjected to male influences during a 40-day period. Pairing (N = 48) or exposure to male urine (N = 15) resulted in all females exhibiting oestrous during the stimulation phase, providing evidence that the activation of ovarian activity in the woolly opossum involves pheromonal cues from males. The latency of occurrence of oestrous in stimulated females depended upon their sexual state before male stimulation. In anoestrous females, the mean latency was 20.7 +/- 0.9 days (N = 35), a value which agrees with the duration of the follicular phase. In females which first entered oestrous before male stimulation, the latency of induced oestrous was inversely correlated to the date of occurrence of the previous oestrous. The inter-oestrous interval was normal (38.1 +/- 1 days, N = 5) when females were in oestrous at the beginning of male stimulation. In contrast, the inter-oestrous interval was significantly shortened (28.7 +/- 2 days, N = 7) or lengthened (51.1 +/- 1.7 days, N = 16) depending on whether females were in the luteal or follicular phases at the beginning of male stimulation. During pairing several females became pregnant and gave birth 24 +/- 0.9 days (N = 13) after copulation. In the woolly opossum, the response to male influences involves mechanisms similar to those observed in eutherians and results in enhancement and synchronization of oestrous cycles in females. Pheromonal interactions could play an important role in synchronizing oestrous cycles in wild females during the dry season, a period when animals regroup to feed on spatially localized food resources.

  3. Male pheromone stimulates ovarian follicular development and body growth in juvenile female opossums (Monodelphis domestica).

    PubMed

    Harder, John D; Jackson, Leslie M

    2003-02-11

    Female opossums are induced into estrus by direct exposure to a non-volatile pheromone in male scentmarks. Juvenile females develop this responsiveness by 150 days of age (days), and earlier (130 days) if exposed to male pheromone beginning at 90 days. The goal of this study was to examine the effect of male pheromone on body growth and ovarian follicular development in young opossums. Females (n = 28) were weaned at 56 days and caged individually with ad libitum food and water from 84 days. Body mass was recorded 2-3 times weekly and the onset of estrus was monitored by urogenital sinus cytology. Exposed females were given continuous access to adult male scentmarks from 90 days and randomly selected for necropsy at 105 and 130 days. Unexposed females were isolated from direct contact with males and their scentmarks and randomly selected for necropsy at 90, 105, 130, and 150 days. Exposed females were larger (63.5 +/- 1.1 g) than unexposed females (56.6 +/- 1.1 g) at 130 days, and 4 of 5 had expressed estrus or proestrus. Uterine mass at 130 days was higher (P < 0.05) in exposed (129.8 +/- 28.8 mg) than in unexposed (25.4 +/- 6.7 mg) females, none of which expressed estrus by 150 days. The mean number of developing, antral follicles per female increased from 1.5 +/- 1.5 at 90 days to 17.8 +/- 5.2 at 130 days. Mean diameter of developing antral follicles at 130 days was larger in exposed (534 +/- 54 microm) than in unexposed females (393 +/- 4 microm). The results of this study demonstrate that pheromonal induction of first estrus in juvenile opossums is associated with an increased rate of body growth and follicular development.

  4. Facial Mechanosensory Influence on Forelimb Movement in Newborn Opossums, Monodelphis domestica

    PubMed Central

    Desmarais, Marie-Josée; Beauregard, France; Cabana, Thérèse; Pflieger, Jean-François

    2016-01-01

    The opossum, Monodelphis domestica, is born very immature but crawls, unaided, with its forelimbs (FL) from the mother's birth canal to a nipple where it attaches to pursue its development. What sensory cues guide the newborn to the nipple and trigger its attachment to it? Previous experiments showed that low intensity electrical stimulation of the trigeminal ganglion induces FL movement in in vitro preparations and that trigeminal innervation of the facial skin is well developed in the newborn. The skin does not contain Vater-Pacini or Meissner touch corpuscles at this age, but it contains cells which appear to be Merkel cells (MC). We sought to determine if touch perceived by MC could exert an influence on FL movements. Application of the fluorescent dye AM1-43, which labels sensory cells such as MC, revealed the presence of a large number of labeled cells in the facial epidermis, especially in the snout skin, in newborn opossums. Moreover, calibrated pressure applied to the snout induced bilateral and simultaneous electromyographic responses of the triceps muscle in in vitro preparations of the neuraxis and FL from newborn. These responses increase with stimulation intensity and tend to decrease over time. Removing the facial skin nearly abolished these responses. Metabotropic glutamate 1 receptors being involved in MC neurotransmission, an antagonist of these receptors was applied to the bath, which decreased the EMG responses in a reversible manner. Likewise, bath application of the purinergic type 2 receptors, used by AM1-43 to penetrate sensory cells, also decreased the triceps EMG responses. The combined results support a strong influence of facial mechanosensation on FL movement in newborn opossums, and suggest that this influence could be exerted via MC. PMID:26848758

  5. Physical mapping of the IGF2 locus in the South American opossum Monodelphis domestica.

    PubMed

    Lawton, B R; Obergfell, C; O'Neill, R J; O'Neill, M J

    2007-01-01

    The South American opossum Monodelphis domestica has been a model organism for marsupials for many years and has recently been the subject of a large-scale genome sequencing effort that will provide the foundation for comparative studies of gene function and regulation. Genomic imprinting is one mechanism of gene regulation that has received increasing attention due to the impact of imprinting defects on development and disease. We have mapped the imprinted insulin-like growth factor II (IGF2) gene of M. domestica as a first step in understanding the regulatory mechanisms involved in genomic imprinting in this marsupial.

  6. Nest-building in gray short-tailed opossums: temperature effects and sex differences.

    PubMed

    Fadem, B H; Kraus, D B; Sheffet, R H

    1986-01-01

    The effects of ambient temperature and of sex on nest-building behavior were studied in a laboratory colony of gray short-tailed opossums, small, Brazilian marsupials. At 24 degrees C, both males and females used more nesting material and built larger nests of better quality than at 27 degrees C. Although both males and females built nests using the mouth, forelegs, hindlegs and tail, females built nests more reliably at the higher temperature and used more nesting material than males at both temperatures. These findings are discussed with respect to the thermoregulatory and reproductive characteristics of marsupials.

  7. Different strategies of exploration and phenotypic variability of the locomotor behavior in new environment: Comparative study of the laboratory opossum (Monodelphis domestica) and Wistar rat (Rattus norvegicus).

    PubMed

    Klejbor, Ilona; Turlejski, Krzysztof

    2012-01-01

    Spontaneous locomotor activity of opossums and Wistar rats during a two-hour session in the open field has been recorded, assessed and behavior of individuals of the two species compared. Afterwards, groups of highly active (HA) and low active (LA) opossums and rats were selected on the basis of the distance traveled in the test. Differences between the selected groups were evaluated. Opossums were generally more active, moving faster and covering longer distance. They spent more time in the central part of the open field and traveled across the center more times than rats, therefore they showed also a lower level of anxiety. These data confirm our previous results indicating that opossums preferentially use the risky exploration strategy while rats mainly rely on the defensive behavior. Opossums showed a higher variability of the volume of locomotor activity than rats. Comparison of the HA and LA groups of opossums and rats showed that in each species they differed on another principle: the level of anxiety in Wistar rats and level of locomotor activity in opossums. Therefore results of the open field test might measure different parameters in different species.

  8. Mapping the prion protein distribution in marsupials: insights from comparing opossum with mouse CNS.

    PubMed

    Poggiolini, Ilaria; Legname, Giuseppe

    2012-01-01

    The cellular form of the prion protein (PrP(C)) is a sialoglycoprotein widely expressed in the central nervous system (CNS) of mammalian species during neurodevelopment and in adulthood. The location of the protein in the CNS may play a role in the susceptibility of a species to fatal prion diseases, which are also known as the transmissible spongiform encephalopathies (TSEs). To date, little is known about PrP(C) distribution in marsupial mammals, for which no naturally occurring prion diseases have been reported. To extend our understanding of varying PrP(C) expression profiles in different mammals we carried out a detailed expression analysis of PrP(C) distribution along the neurodevelopment of the metatherian South American short-tailed opossum (Monodelphis domestica). We detected lower levels of PrP(C) in white matter fiber bundles of opossum CNS compared to mouse CNS. This result is consistent with a possible role for PrP(C) in the distinct neurodevelopment and neurocircuitry found in marsupials compared to other mammalian species.

  9. Nitric oxide: Mediator of nonadrenergic noncholinergic hyperpolarization of opossum esophageal circular smooth muscle

    SciTech Connect

    Du, C.; Murray, J.; Conklin, J.L.; Bates, J.N. )

    1991-03-15

    The electromyogram recorded from circular smooth muscle (SM) of opossum esophagus, either during peristalsis or when the intrinsic esophageal nerves are stimulated by an electrical field (EFS), consists of a hyperpolarization followed by a depolarization. This membrane response results from the interaction of a nonadrenergic-noncholinergic (NANC) neurotransmitter with its receptors on SM membrane. N{sup G}-nitro-L-arginine (L-NNA), an inhibitor of nitric oxide synthase, and nitric oxide (NO) were used to test the hypothesis that NO is a mediator of this NANC nerve-induced response. The transmembrane potential difference of circular SM cells of opossum esophagus was recorded with glass microelectrode. The nerve-mediated membrane response was evoked by EFS. L-NNA (50uM) abolished the initial hyperpolarization and reduced the amplitude of and the time to maximal depolarization. L-arginine (1mM), the substrate for NO synthase, antagonized the effect of L-NNA. Neither L-NNA nor L-arginine altered the resting membrane potential. Exogenous NO produced hyperpolarization of SM membrane potential and attenuated the amplitude of EFS-induced hyperpolarization and depolarization. Nitrosocysteine, a NO-containing compound, also hyperpolarized the membrane potential. Effect of NO was neither blocked by L-NNA nor by TTX. The data support the hypothesis that NO or an NO-containing compound mediates NANC nerve-induced responses of the esophageal SM membrane.

  10. Development and plasticity of the retina in the opossum Monodelphis domestica.

    PubMed

    Djavadian, Rouzanna; Bisti, Silvia; Maccarone, Rita; Bartkowska, Katarzyna; Turlejski, Krzysztof

    2006-01-01

    We investigated the rate of cell proliferation and death in the retina of the Monodelphis opossum during its postnatal development and the influence of early monocular enucleation on these processes. Our results show that in the opossum, as in other marsupials, the peak of the retinal cells divisions occurs postnatally and that generation of retinal cells continues till the time of eye opening (P34), except of the marginal rim, where it continued till P60. Ganglion and amacrine cells are generated between postnatal days (P) P4 and P9, while bipolar cells and photoreceptors are generated simultaneously between P14 and P25. The peak of ganglion cell death as detected by the TUNEL method occurs around P14-19 in the center of retina. The second peak of apoptosis appears in the inner nuclear layer (INL) at P19-25. Gliogenesis takes place between P25 and P34. We also found that monocular enucleation performed during the early period of retinal development (P0-P7) did not influence proliferation, developmental apoptosis or other developmental processes in the retina of the remaining eye.

  11. On the genomics of immunoglobulins in the gray, short-tailed opossum Monodelphis domestica.

    PubMed

    Wang, Xinxin; Olp, Jonathan J; Miller, Robert D

    2009-08-01

    Annotated maps of the IGH, IGK, and IGL loci in the gray, short-tailed opossum Monodelphis domestica were generated from analyses of the available whole genome sequence for this species. Analyses of their content and organization confirmed a number of previous conclusions based on characterization of complementary DNAs encoding opossum immunoglobulin heavy and light chains and limited genomic analysis, including (a) the predominance of a single immunoglobulin heavy chain variable region (IGHV) subgroup and clan, (b) the presence of a single immunoglobulin (Ig)G subclass, (c) the apparent absence of an IgD, and (d) the general organization and V gene complexity of the IGK and IGL light chain loci. In addition, several unexpected discoveries were made including the presence of a partial V to D, germline-joined IGHV segment, the first germline-joined Ig V gene to be found in a mammal. In addition was the presence of a larger number of IGKV subgroups than had been previously identified. With this report, annotated maps of the major histocompatibility complex, T-cell receptor, and immunoglobulin loci have been completed for M. domestica, the only non-eutherian mammalian species for which this has been accomplished, strengthening the utility of this species as a model organism.

  12. Arrested development of the dorsal column following neonatal spinal cord injury in the opossum, Monodelphis domestica.

    PubMed

    Wheaton, Benjamin J; Noor, Natassya M; Dziegielewska, Katarzyna M; Whish, Sophie; Saunders, Norman R

    2015-03-01

    Developmental studies of spinal cord injury in which regrowth of axons occurs across the site of transection rarely distinguish between the recovery of motor-controlling pathways and that of ascending axons carrying sensory information. We describe the morphological changes that occur in the dorsal column (DC) of the grey short-tailed opossum, Monodelphis domestica, following spinal cord injury at two early developmental ages. The spinal cords of opossums that had had their mid-thoracic spinal cords completely transected at postnatal day 7 (P7) or P28 were analysed. Profiles of neurofilament immunoreactivity in transected cords showing DC development were differentially affected by the injury compared with the rest of the cord and cytoarchitecture was modified in an age- and site-dependent manner. The ability of DC neurites to grow across the site of transection was confirmed by injection of fluorescent tracer below the injury. P7 transected cords showed labelling in the DC above the site of original transection indicating that neurites of this sensory tract were able to span the injury. No growth of any neuronal processes was seen after P28 transection. Thus, DC is affected by spinal injury in a differential manner depending on the age at which the transection occurs. This age-differential response, together with other facets of remodelling that occur after neonatal spinal injury, might explain the locomotor adaptations and recovery observed in these animals.

  13. Ultrastructural analysis between fetal and adult wound healing process of marsupial opossum skin.

    PubMed

    Matsuno, Kei; Ihara, Setsunosuke

    2015-01-01

    The opossum delivers a newborn baby equivalent to tremature fetus state by postpregnancy. The peculiarity is advantageous for studies of fetus, because operations to take out fetus from the uterus of a mother are not necessary. When mammalian skin is wounded by full-thickness excision, fetal and adult wound healing processes differ. Fetal-type wound healing does not leave a scar. However, studies of how the fetal wound healing process differs in detail from the adult type are not advanced. We first observed the normal skin development of the gray short-tailed opossum (Monodelphis domestica) using an electron microscope. As for normal skin, an epidermis became multi-layered, and thickened from birth through to 7 days after birth. The quantity of extracellular matrix of the dermis increased thereafter, and several types of cells were found in the dermis. To examine the wound healing, we used material from a 1 day-old newborn baby, and from another 15 days after birth, and compared the wound healing style morphologically. Differences in the constitution of cells and fine structures of the skin were observed, it was obviously suggested that change in the wound healing style from fetal-type to adult-type occurred between 1 to 15 days after birth.

  14. On the prenatal initiation of T cell development in the opossum Monodelphis domestica.

    PubMed

    Hansen, Victoria L; Miller, Robert D

    2017-04-01

    Thymus-dependent lymphocytes (T cells) are a critical cell lineage in the adaptive immune system of all jawed vertebrates. In eutherian mammals the initiation of T cell development takes place prenatally and the offspring of many species are born relatively immuno-competent. Marsupials, in contrast, are born in a comparatively altricial state and with a less well developed immune system. As such, marsupials are valuable models for studying the peri- and postnatal initiation of immune system development in mammals. Previous results supported a lack of prenatal T cell development in a variety of marsupial species. In the gray short-tailed opossum, Monodelphis domestica, however, there was evidence that αβT cells were present on postnatal day 1 and likely initiated development prenatally. Demonstrated here is the presence of CD3ε(+) lymphocytes in late-stage embryos at a site in the upper thoracic cavity, the site of an early developing thymus. CD3ε(+) cells were evident as early as 48 h prior to parturition. In day 14 embryos, where there is clear organogenesis, CD3ε(+) cells were only found at the site of the early thymus, consistent with no extra-thymic sites of T cell development in the opossum. These observations are the first evidence of prenatal T cell lineage commitment in any marsupial.

  15. INFECTION BY Rickettsia felis IN OPOSSUMS (Didelphis sp.) FROM YUCATAN, MEXICO

    PubMed Central

    PENICHE-LARA, Gaspar; RUIZ-PIÑA, Hugo A.; REYES-NOVELO, Enrique; DZUL-ROSADO, Karla; ZAVALA-CASTRO, Jorge

    2016-01-01

    Rickettsia felis is an emergent pathogen and the causative agent of a typhus-like rickettsiosis in the Americas. Its transmission cycle involves fleas as biological vectors (mainly Ctenocephalides felis) and multiple domestic and synanthropic mammal hosts. Nonetheless, the role of mammals in the cycle of R. felis is not well understood and many efforts are ongoing in different countries of America to clarify it. The present study describes for the first time in Mexico the infection of two species of opossum (Didelphis virginiana and D. marsupialis) by R. felis. A diagnosis was carried out from blood samples by molecular methods through the gltAand 17 kDa genes and sequence determination. Eighty-seven opossum samples were analyzed and 28 were found to be infected (32.1%) from five out of the six studied localities of Yucatan. These findings enable recognition of the potential epidemiological implications for public health of the presence of infected synanthropic Didelphis in households. PMID:27074326

  16. Cone pigments in a North American marsupial, the opossum (Didelphis virginiana).

    PubMed

    Jacobs, Gerald H; Williams, Gary A

    2010-05-01

    Only two of the four cone opsin gene families found in vertebrates are represented in contemporary eutherian and marsupial species. Recent genetic studies of two species of South American marsupial detected the presence of representatives from two of the classes of cone opsin genes and the structures of these genes predicted cone pigments with respective peaks in the ultraviolet and long-wavelength portions of the spectrum. The Virginia opossum (Didelphis virginiana), a profoundly nocturnal animal, is the only marsupial species found in North America. The prospects for cone-based vision in this species were examined through recordings of the electroretinogram (ERG), a commonly examined retinal response to photic stimulation. Recorded under flickering-light conditions that elicit signals from cone photoreceptors, the spectral sensitivity of the opossum eye is well accounted for by contributions from the presence of a single cone pigment having peak absorption at 561-562 nm. A series of additional experiments that employed various chromatic adaptation paradigms were conducted in a search for possible contributions from a second (short-wavelength sensitive) cone pigment. We found no evidence that such a mechanism contributes to the ERG in this marsupial.

  17. West Nile virus isolated from Virginia opossum (Didelphis virginiana) in Northwest Missouri 2012

    SciTech Connect

    Bosco-Lauth, Angela; Harmon, Jessica; Lash, R. Ryan; Weiss, Sonja; Langevin, Stanley; Savage, Harry; Marvin S. Godsey, Jr.; Burkhalter, Kristen; Root, J. Jeffrey; Gidlewski, Thomas; Nicholson, William; Brault, Aaron C.; Komar, Nicholas

    2014-12-01

    We describe the isolation of West Nile virus (WNV; Flaviviridae, flavivirus) from blood of a Virginia opossum (Didelphis virginiana) collected in northwestern Missouri, USA in August 2012. Furthermore, sequencing determined that the virus was related to lineage 1a WNV02 strains. We discuss the role of wildlife in WNV disease epidemiology.

  18. Dogs and Opossums Positive for Vaccinia Virus during Outbreak Affecting Cattle and Humans, São Paulo State, Brazil.

    PubMed

    Peres, Marina G; Barros, Claudenice B; Appolinário, Camila M; Antunes, João M A P; Mioni, Mateus S R; Bacchiega, Thais S; Allendorf, Susan D; Vicente, Acácia F; Fonseca, Clóvis R; Megid, Jane

    2016-02-01

    During a vaccinia virus (VACV) outbreak in São Paulo State, Brazil, blood samples were collected from cows, humans, other domestic animals, and wild mammals. Samples from 3 dogs and 3 opossums were positive for VACV by PCR. Results of gene sequencing yielded major questions regarding other mammalian species acting as reservoirs of VACV.

  19. Localization of genes for V+LDL plasma cholesterol levels on two diets in the opossum Monodelphis domestica[S

    PubMed Central

    Kammerer, Candace M.; Rainwater, David L.; Gouin, Nicolas; Jasti, Madhuri; Douglas, Kory C.; Dressen, Amy S.; Ganta, Prasanth; VandeBerg, John L.; Samollow, Paul B.

    2010-01-01

    Plasma cholesterol levels among individuals vary considerably in response to diet. However, the genes that influence this response are largely unknown. Non-HDL (V+LDL) cholesterol levels vary dramatically among gray, short-tailed opossums fed an atherogenic diet, and we previously reported that two quantitative trait loci (QTLs) influenced V+LDL cholesterol on two diets. We used hypothesis-free, genome-wide linkage analyses on data from 325 pedigreed opossums and located one QTL for V+LDL cholesterol on the basal diet on opossum chromosome 1q [logarithm of the odds (LOD) = 3.11, genomic P = 0.019] and another QTL for V+LDL on the atherogenic diet (i.e., high levels of cholesterol and fat) on chromosome 8 (LOD = 9.88, genomic P = 5 × 10−9). We then employed a novel strategy involving combined analyses of genomic resources, expression analysis, sequencing, and genotyping to identify candidate genes for the chromosome 8 QTL. A polymorphism in ABCB4 was strongly associated (P = 9 × 10−14) with the plasma V+LDL cholesterol concentrations on the high-cholesterol, high-fat diet. The results of this study indicate that genetic variation in ABCB4, or closely linked genes, is responsible for the dramatic differences among opossums in their V+LDL cholesterol response to an atherogenic diet. PMID:20650928

  20. Localization of genes for V+LDL plasma cholesterol levels on two diets in the opossum Monodelphis domestica.

    PubMed

    Kammerer, Candace M; Rainwater, David L; Gouin, Nicolas; Jasti, Madhuri; Douglas, Kory C; Dressen, Amy S; Ganta, Prasanth; Vandeberg, John L; Samollow, Paul B

    2010-10-01

    Plasma cholesterol levels among individuals vary considerably in response to diet. However, the genes that influence this response are largely unknown. Non-HDL (V+LDL) cholesterol levels vary dramatically among gray, short-tailed opossums fed an atherogenic diet, and we previously reported that two quantitative trait loci (QTLs) influenced V+LDL cholesterol on two diets. We used hypothesis-free, genome-wide linkage analyses on data from 325 pedigreed opossums and located one QTL for V+LDL cholesterol on the basal diet on opossum chromosome 1q [logarithm of the odds (LOD) = 3.11, genomic P = 0.019] and another QTL for V+LDL on the atherogenic diet (i.e., high levels of cholesterol and fat) on chromosome 8 (LOD = 9.88, genomic P = 5 x 10(-9)). We then employed a novel strategy involving combined analyses of genomic resources, expression analysis, sequencing, and genotyping to identify candidate genes for the chromosome 8 QTL. A polymorphism in ABCB4 was strongly associated (P = 9 x 10(-14)) with the plasma V+LDL cholesterol concentrations on the high-cholesterol, high-fat diet. The results of this study indicate that genetic variation in ABCB4, or closely linked genes, is responsible for the dramatic differences among opossums in their V+LDL cholesterol response to an atherogenic diet.

  1. Developmental expression of spontaneous activity in the spinal cord of postnatal opossums, Monodelphis domestica: an anatomical study.

    PubMed

    Lavallée, Annie; Pflieger, Jean-François

    2009-07-28

    Using Sulforhodamine-101 (SR101) labeling and calcium imaging on in vitro preparations, we investigated the development of spontaneous activity in the spinal enlargements of a marsupial born more immature than eutherian mammals, the opossum Monodelphis domestica. Following the retrograde transport of Calcium Green dye from the limb nerves, we observed the occurrence of spontaneous calcium waves activating the motor columns of the cervical enlargement of opossums aged from P3 to P15 (day of birth: P0) and of the lumbar enlargement from at least P6 to P12. In other preparations, SR101 was added to the bath to identify the active cells. In P1 opossums, only a few SR101-labeled cells were observed in the cervical enlargement and none in the lumbar enlargement. At P5, their number increased cervically and they appeared in the lumbar enlargement. Motoneurons were the major cell type labeled by SR101 but dye leakage made their quantification inaccurate. SR101-labeled cells also occurred elsewhere in the ventral and dorsal grey. Their number increased until P12-14 in both enlargements and then decreased to disappear by P21, the last age examined. Thus in contrast to eutherian mammals, in which spontaneous activity is mostly prenatal, spontaneous activity occurs predominantly postnatally in opossums. It increases at the time when connections from the brain begin to impinge on spinal neurons and when the limbs, especially the hindlimbs, start moving and then decreases as the systems mature.

  2. Prevalence of agglutinating antibodies to Sarcocystis neurona in skunks (Mephitis Mephitis), raccoons (Procyon lotor), and opossums (Didelphis Virginiana) from Connecticut.

    PubMed

    Mitchell, Sheila M; Richardson, Dennis J; Cheadle, M Andy; Zajac, Anne M; Lindsay, David S

    2002-10-01

    Equine protozoal myeloencephalitis is the most important protozoan disease of horses in North America and is usually caused by Sarcocystis neurona. Natural cases of encephalitis caused by S. neurona have been reported in skunks (Mephitis mephitis) and raccoons (Procyon lotor). Opossums (Didelphis spp.) are the only known definitive host. Sera from 24 striped skunks, 12 raccoons, and 7 opossums (D. virginiana) from Connecticut were examined for agglutinating antibodies to S. neurona using the S. neurona agglutination test (SAT) employing formalin-fixed merozoites as antigen. The SAT was validated for skunk sera using pre- and postinfection serum samples from 2 experimentally infected skunks. Of the 24 (46%) skunks 11 were positive, and all 12 raccoons were positive for S. neurona antibodies. None of the 7 opossums was positive for antibodies to S. neurona. These results suggest that exposure to sporocysts of S. neurona by intermediate hosts is high in Connecticut. The absence of antibodies in opossums collected from the same areas is most likely because of the absence of systemic infection in the definitive host.

  3. Morphologic characterization and distribution of endocrine cells in the large intestine of the opossum Didelphis aurita (Wied-Neuwied, 1826).

    PubMed

    Dos Santos, Daiane Cristina Marques; Cupertino, Marli do Carmo; Novaes, Rômulo Dias; Soares, Ítalo Augusto da Costa; Fonseca, Cláudio César; da Matta, Sérgio Luis Pinto; Sartori, Sirlene Souza Rodrigues

    2013-10-01

    This study was designed to investigate the morphology and distribution of argyrophil, argentaffins, and insulin-immunoreactive endocrine cells in the large intestine of the opossum Didelphis aurita. Fragments of the large intestine of 10 male specimens of the opossum D. aurita were collected, processed, and submitted for histochemistry, immunohistochemistry, and scanning electron microscopy. The tunics of the large intestine of D. aurita presented morphological characteristics that have already been described for eutherian mammals. The morphometric data showed that the inner circular layer of all portions and regions analyzed is thicker relative to the longitudinal layer, and these layers in the rectum are thicker compared to the cecum and ascending colon. The majority of mucus-secreting cells have acid and neutral mucins, suggesting that the production of mucus is mixed. The number of these cells increases in the region of the cecum toward the rectum. Important findings include the occurrence of argyrophil, argentaffins, and insulin-immunoreactive endocrine cells in all segments of the large intestine of the opossum (D. aurita). To the best of our knowledge, this is the first report about the presence of insulin-immunoreactive endocrine cells in the large intestine of the opossum (D. aurita).

  4. Dogs and Opossums Positive for Vaccinia Virus during Outbreak Affecting Cattle and Humans, São Paulo State, Brazil

    PubMed Central

    Peres, Marina G.; Barros, Claudenice B.; Appolinário, Camila M.; Antunes, João M.A.P.; Mioni, Mateus S.R.; Bacchiega, Thais S.; Allendorf, Susan D.; Vicente, Acácia F.; Fonseca, Clóvis R.

    2016-01-01

    During a vaccinia virus (VACV) outbreak in São Paulo State, Brazil, blood samples were collected from cows, humans, other domestic animals, and wild mammals. Samples from 3 dogs and 3 opossums were positive for VACV by PCR. Results of gene sequencing yielded major questions regarding other mammalian species acting as reservoirs of VACV. PMID:26812352

  5. Behavioural observations of singly-housed grey short-tailed opossums (Monodelphis domestica) in standard and enriched environments.

    PubMed

    Wilkinson, M; Stirton, C; McConnachie, A

    2010-10-01

    The grey short-tailed opossum (Monodelphis domestica) has been used in biomedical research for over three decades. It is normally housed in standard rat cages and appears to have adapted well to captivity. Owing to their aggressive behaviour towards each other, adult males are normally housed singly and may spend considerable periods of time in social isolation. We wanted to carry out a preliminary study on the behaviour of singly-housed male short-tailed opossums in two different settings: a standard rat cage and an enriched floor pen. Five male opossums aged between 10 and 12 weeks were housed for seven days at a time in the two settings and their behaviour was filmed during the dark phase. Recordings were carried out on the first and the last night of housing, from 19:00 to 07:00 h, and all behaviours quantified according to an ethogram. All five males in this study showed stereotypic behaviours while housed in standard rat cages, but no such behaviours were seen when the animals were in the floor pen. In both cases, but very especially in the pen, animals spent less time active as the week came to an end. Some activities such as sniffing the air, manipulating the nest and, especially, interacting with the floor tube occupied the animals' time in the cage considerably more than in the pen. Conversely, the opossums spent considerably more time walking when inside the floor pen than when they were in the cage. The general trend with other activities such as eating, drinking or grooming was one of more time being devoted to them inside the cage than inside the floor pen, but the differences did not approach statistical significance. These findings suggest that single housing of short-tailed opossums in standard rat caging is detrimental to their welfare.

  6. The evolution of active vibrissal sensing in mammals: evidence from vibrissal musculature and function in the marsupial opossum Monodelphis domestica.

    PubMed

    Grant, Robyn A; Haidarliu, Sebastian; Kennerley, Natalie J; Prescott, Tony J

    2013-09-15

    Facial vibrissae, or whiskers, are found in nearly all extant mammal species and are likely to have been present in early mammalian ancestors. A sub-set of modern mammals, including many rodents, move their long mystacial whiskers back and forth at high speed whilst exploring in a behaviour known as 'whisking'. It is not known whether the vibrissae of early mammals moved in this way. The grey short-tailed opossum, Monodelphis domestica, is considered a useful species from the perspective of tracing the evolution of modern mammals. Interestingly, these marsupials engage in whisking bouts similar to those seen in rodents. To better assess the likelihood that active vibrissal sensing was present in ancestral mammals, we examined the vibrissal musculature of the opossum using digital miscroscopy to see whether this resembles that of rodents. Although opossums have fewer whiskers than rats, our investigation found that they have a similar vibrissal musculature. In particular, in both rats and opossums, the musculature includes both intrinsic and extrinsic muscles with the intrinsic muscles positioned as slings linking pairs of large vibrissae within rows. We identified some differences in the extrinsic musculature which, interestingly, matched with behavioural data obtained through high-speed video recording, and indicated additional degrees of freedom for positioning the vibrissae in rats. These data show that the whisker movements of opossum and rat exploit similar underlying mechanisms. Paired with earlier results suggesting similar patterns of vibrissal movement, this strongly implies that early therian (marsupial and placental) mammals were whisking animals that actively controlled their vibrissae.

  7. Prevalence of antibodies to Trypanosoma cruzi, Toxoplasma gondii, Encephalitozonn cuniculi, Sarcocystis neurona, Besnoitia darlingi, and Neospora caninum in North American opossum, Didelphis virginiana, from Southern Louisian

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We examined the prevalence of antibodies to zoonotic protozoan parasites (Trypanosoma cruzi, Toxoplasma gondii, and Encephalitozoon cuniculi) and protozoan’s of veterinary importance (Neospora caninum, Sarcocystis neurona and Besnoitia darlingi) in a population of North American opossums (Didelphis...

  8. Radiation esophagitis in the opossum: radioprotection with indomethacin. [/sup 60/Co

    SciTech Connect

    Northway, M.G.; Libshitz, H.I.; Osborne, B.M.; Feldman, M.S.; Mamel, J.J.; West, J.H.; Szwarc, I.A.

    1980-05-01

    Twenty-five opossums were evaluated before irradiation by fiberoptic endoscopy and air-contrast barium esophagram examination. All animals received 2250 rad /sup 60/Co-irradiated in a single exposure to the entire esophagus and lower exophageal sphincter. Animals received treatment with indomethacin. Acute esophagitis occurred 7 to 10 days postirradiation in control animals and was characterized by erythema, ulceration, and sloughing of esophageal mucosa as determined by air-contrast barium esophagram, endoscopy, and histology. Prostaglandin-treated animals showed more severe evidence of esophagitis than control animals. Indomethacin-treated animals showed no signs or only mild esophagitis posttreatment. It is concluded that indomethacin treatment may significantly reduce the severity of radiation esophagitis perhaps by blockade of prostaglandin synthesis.

  9. Dietary effects on hematologic and serum chemical values in gray short-tailed opossums (Monodelphis domestica).

    PubMed

    VandeBerg, J L; Cothran, E G; Kelly, C A

    1986-02-01

    At the time of weaning (8 weeks), 57 gray short-tailed opossums (Monodelphis domestica) were placed in four dietary groups. One group was fed a horsemeat-based diet that had been used for 2.5 years in our colony, and three groups were fed three different commercial fox food diets. After the animals had reached sexual maturity (6 months), blood samples were collected and subjected to standard hematologic and serum chemical assays. Significant differences were observed among the dietary groups and between sexes in several values, but all animals appeared to be healthy and robust. The ranges, means, and standard deviations for the values presented here can be used as reference values for healthy young adult animals being fed these particular diets.

  10. Odors as cues for orientation to mothers by weanling Virginia opossums

    SciTech Connect

    Holmes, D.J. )

    1992-12-01

    Three experiments were conducted to investigate whether whole-body and pouch odors facilitate social cohesion between young Virginia opossums and their mothers just prior to weaning. In experiment 1, young oriented toward plastic buckets containing their mothers, directing significantly higher levels of investigative behavior and more distress vocalizations toward them than toward buckets containing unrelated lactating females. In experiment 2, young oriented toward and investigated empty buckets containing whole-body odors of their mothers more than empty buckets containing odors of other females. Similarly, more investigative behavior was directed toward plastic bucket lids containing pouch odors from subjects mothers than toward pouch odors from unrelated females in experiment 3. These results suggest that social odors help young didelphid marsupials maintain contact with their mothers, as in other mammals, and that whole-body and pouch gland odors are important chemical signals in this nongregarious species.

  11. First molecular evidence of Toxoplasma gondii in opossums (Didelphis virginiana) from Yucatan, Mexico

    PubMed Central

    Torres-Castro, M.; Noh-Pech, H.; Puerto-Hernández, R.; Reyes-Hernández, B.; Panti-May, A.; Hernández-Betancourt, S.; Yeh-Gorocica, A.; González-Herrera, L.; Zavala-Castro, J.; Puerto, F.I.

    2016-01-01

    Toxoplasma gondii is an obligate intracellular parasite recognized as a causal agent of toxoplasmosis; zoonotic disease endemic in many countries worldwide, including Mexico. Different species of animals participate in the wild cycle infection, including opossums of the species Didelphis virginiana. Thirteen D. virginiana were captured in Yucatan, Mexico. Detection of T. gondii was achieved by Polymerase Chain Reaction, which determined an infection of 76.9% (10/13) in brains. Positive amplicons were sequenced for analysis, this produced results similar to T. gondii with identity and coverage values of 98% and 96-100%, respectively. This study presents the first molecular evidence of the circulation of T. gondii in D. virginiana from Mexico. PMID:27200271

  12. Particle size selection in cadmium uptake by the opossum shrimp, Mysis relicta

    SciTech Connect

    Bigelow, L.K.; Lasenby, D.C. )

    1991-11-01

    Fecal pellets of plankton play a key role in the recycling of trace contaminants within the aquatic environment. This is especially true for those plankton that undergo vertical migration in the water column. The opossum shrimp Mysis relicta is generally thought of as an omnivorous zooplankter occupying the pelagic zone of lakes, making itself available as a food source to a wide variety of fish. Several mechanisms have been suggested to explain the increase in concentration of metals from food source to fecal pellet. This study examines the feeding behavior of M. relicta to test the hypothesis that particle size selection can account for increased metal concentrations found in the fecal pellets of invertebrates.

  13. First molecular evidence of Toxoplasma gondii in opossums (Didelphis virginiana) from Yucatan, Mexico.

    PubMed

    Torres-Castro, M; Noh-Pech, H; Puerto-Hernández, R; Reyes-Hernández, B; Panti-May, A; Hernández-Betancourt, S; Yeh-Gorocica, A; González-Herrera, L; Zavala-Castro, J; Puerto, F I

    2016-01-01

    Toxoplasma gondii is an obligate intracellular parasite recognized as a causal agent of toxoplasmosis; zoonotic disease endemic in many countries worldwide, including Mexico. Different species of animals participate in the wild cycle infection, including opossums of the species Didelphis virginiana. Thirteen D. virginiana were captured in Yucatan, Mexico. Detection of T. gondii was achieved by Polymerase Chain Reaction, which determined an infection of 76.9% (10/13) in brains. Positive amplicons were sequenced for analysis, this produced results similar to T. gondii with identity and coverage values of 98% and 96-100%, respectively. This study presents the first molecular evidence of the circulation of T. gondii in D. virginiana from Mexico.

  14. Evolutionary dynamics of transposable elements in the short-tailed opossum Monodelphis domestica.

    PubMed

    Gentles, Andrew J; Wakefield, Matthew J; Kohany, Oleksiy; Gu, Wanjun; Batzer, Mark A; Pollock, David D; Jurka, Jerzy

    2007-07-01

    The genome of the gray short-tailed opossum Monodelphis domestica is notable for its large size ( approximately 3.6 Gb). We characterized nearly 500 families of interspersed repeats from the Monodelphis. They cover approximately 52% of the genome, higher than in any other amniotic lineage studied to date, and may account for the unusually large genome size. In comparison to other mammals, Monodelphis is significantly rich in non-LTR retrotransposons from the LINE-1, CR1, and RTE families, with >29% of the genome sequence comprised of copies of these elements. Monodelphis has at least four families of RTE, and we report support for horizontal transfer of this non-LTR retrotransposon. In addition to short interspersed elements (SINEs) mobilized by L1, we found several families of SINEs that appear to use RTE elements for mobilization. In contrast to L1-mobilized SINEs, the RTE-mobilized SINEs in Monodelphis appear to shift from G+C-rich to G+C-low regions with time. Endogenous retroviruses have colonized approximately 10% of the opossum genome. We found that their density is enhanced in centromeric and/or telomeric regions of most Monodelphis chromosomes. We identified 83 new families of ancient repeats that are highly conserved across amniotic lineages, including 14 LINE-derived repeats; and a novel SINE element, MER131, that may have been exapted as a highly conserved functional noncoding RNA, and whose emergence dates back to approximately 300 million years ago. Many of these conserved repeats are also present in human, and are highly over-represented in predicted cis-regulatory modules. Seventy-six of the 83 families are present in chicken in addition to mammals.

  15. Postnatal development of limb motor innervation in the opossum Monodelphis domestica: immunohistochemical localization of acetylcholine.

    PubMed

    Barthélemy, Dorothy; Cabana, Thérèse

    2005-03-31

    The development of limb motor innervation was studied in the opossum Monodelphis domestica, a marsupial born with immature mobile forelimbs and immobile hindlimbs. Choline acetyltransferase (ChAT), the synthesis enzyme of acetylcholine, was evidenced on sections of the spinal enlargements, and the protein that transports acetylcholine (VAChT) on limb sections. In newborn, ChAT immunolabeling occurred in small, undifferentiated neurons of the ventral horn, presumably motoneurons, and intermediate and dorsal gray matter, and in the presumptive white matter, all less abundant at lumbosacral than brachial levels. Scant immunolabeling for VAChT marked small terminal-looking profiles, presumably growth cones or immature neuromuscular junctions, decreasing proximodistally in each limb and being less abundant in hindlimbs than forelimbs; it was absent distally in the foot where no muscle tissue was formed. ChAT labeling disappeared from the white matter within 1 week while cholinergic neurons increased in number and size. Motoneurons segregated in a medial and lateral group by 4-5 weeks. VAChT-labeled profiles increased in number and size and they flattened along a proximodistal gradient within each limb, but later in the hindlimbs than in the forelimbs. Labeling appeared in distal foot muscle at 1 week. The density, size, and shape of terminals became comparable in all segments of a given limb by 3-4 weeks. Their number and size increased, and by 8 weeks, they clustered in 3 or 4 along muscle fibers. Thus, limb motor innervation develops largely postnatally in the opossum, along rostrocaudal and proximodistal gradients. Its timecourse is compared to the development of motor behaviors.

  16. Experimental infection of the opossum Didelphis aurita by Rickettsia felis, Rickettsia bellii, and Rickettsia parkeri and evaluation of the transmission of the infection to ticks Amblyomma cajennense and Amblyomma dubitatum.

    PubMed

    Horta, Maurício C; Sabatini, Guilherme S; Moraes-Filho, Jonas; Ogrzewalska, Maria; Canal, Raoní B; Pacheco, Richard C; Martins, Thiago F; Matushima, Eliana R; Labruna, Marcelo B

    2010-12-01

    This work evaluated the infection of opossums (Didelphis aurita) by Rickettsia felis, Rickettsia bellii, and Rickettsia parkeri and their role as amplifier hosts for horizontal transmission to Amblyomma cajennense and/or Amblyomma dubitatum ticks. Infection in D. aurita was induced by intraperitoneal inoculation with R. felis (n = 4 opossums), R. bellii (n = 4), and R. parkeri (n = 2). Another group of six opossums were inoculated intraperitoneally with Leibovitz-15 sterile culture medium, representing the uninfected groups (n = 2 opossums simultaneously to each infected group). Opossum blood samples collected during the study were used for DNA extraction, followed by real-time polymerase chain reaction targeting the rickettsial gene gltA, hematology, and detection of Rickettsia spp.-reactive antibodies by indirect immunofluorescence assay. Opossums were infested with uninfected A. cajennense and/or A. dubitatum for 30 days postinoculation (DPI). Flat ticks molted from ticks fed on opossums were allowed to feed on uninfected rabbits, which were tested for seroconversion by immunofluorescence assay. Samples of flat ticks were also tested by real-time polymerase chain reaction. Inoculated opossums showed no clinical abnormalities. Antibodies to Rickettsia spp. were first detected at the second to fourth DPI, with detectable titers until the 150th DPI. Rickettsemia was detected only in one opossum inoculated with R. parkeri, at the eighth DPI. Only one A. cajennense tick (2.0%) previously fed on a R. parkeri-inoculated opossum became infected. None of the rabbits infested with opossum-derived ticks seroconverted. The study demonstrated that R. felis, R. bellii, and R. parkeri were capable to produce antibody response in opossums, however, with undetectable rickettsemia for R. felis and R. bellii, and very low rickettsemia for R. parkeri. Further studies must be done with different strains of these rickettsiae, most importantly the strains that have

  17. Distribution and function of TrkB receptors in the developing brain of the opossum Monodelphis domestica.

    PubMed

    Bartkowska, Katarzyna; Aniszewska, Agata; Turlejski, Kris; Djavadian, Ruzanna L

    2014-07-01

    The expression, development pattern, spatiotemporal distribution, and function of TrkB receptors were investigated during the postnatal brain development of the opossum. Full-length TrkB receptor expression was detectable in the newborn opossum, whereas three different short forms that are expressed in the adult brain were almost undetectable in the newborn opossum brain. The highest level of full-length TrkB receptor expression was observed at P35, which corresponds to the time of eye opening. We found that in different brain structures, TrkB receptors were localized in various compartments of cells. The hypothalamus was distinguished by the presence of TrkB receptors not only in cell bodies but also in the neuropil. Double immunofluroscent staining for TrkB and a marker for the identification of the cell phenotype in several brain regions such as the olfactory bulb, hippocampus, thalamus, and cerebellum showed that unlike in eutherians, in the opossum, TrkB receptors were predominantly expressed in neurons. A lack of TrkB receptors in glial cells, particularly astrocytes and oligodendrocytes, provides evidence that TrkB receptors can play a functionally different role in marsupials than in eutherians. The effects of TrkB signaling on the development of cortical progenitor cells were examined in vitro using shRNAs. Blockade of the endogenous TrkB receptor expression induced a decrease in the number of progenitor cells proliferation, whereas the number of apoptotic progenitor cells increased. These changes were statistically significant but relatively small. In contrast, TrkB signaling was strongly involved in regulation of the cortical progenitor cell differentiation process.

  18. Exceptionally preserved North American Paleogene metatherians: adaptations and discovery of a major gap in the opossum fossil record.

    PubMed

    Sánchez-Villagra, Marcelo; Ladevèze, Sandrine; Horovitz, Inés; Argot, Christine; Hooker, Jeremy J; Macrini, Thomas E; Martin, Thomas; Moore-Fay, Scott; de Muizon, Christian; Schmelzle, Thomas; Asher, Robert J

    2007-06-22

    A major gap in our knowledge of the evolution of marsupial mammals concerns the Paleogene of the northern continents, a critical time and place to link the early history of metatherians in Asia and North America with the more recent diversification in South America and Australia. We studied new exceptionally well-preserved partial skeletons of the Early Oligocene fossil Herpetotherium from the White River Formation in Wyoming, which allowed us to test the relationships of this taxon and examine its adaptations. Herpetotheriidae, with a fossil record extending from the Cretaceous to the Miocene, has traditionally been allied with opossums (Didelphidae) based on fragmentary material, mainly dentitions. Analysis of the new material reveals that several aspects of the cranial and postcranial anatomy, some of which suggests a terrestrial lifestyle, distinguish Herpetotherium from opossums. We found that Herpetotherium is the sister group to the crown group Marsupialia and is not a stem didelphid. Combination of the new palaeontological data with molecular divergence estimates, suggests the presence of a long undocumented gap in the fossil record of opossums extending some 45Myr from the Early Miocene to the Cretaceous.

  19. A VpreB3 homologue in a marsupial, the gray short-tailed opossum, Monodelphis domestica.

    PubMed

    Wang, Xinxin; Parra, Zuly E; Miller, Robert D

    2012-08-01

    A VpreB surrogate light (SL) chain was identified for the first time in a marsupial, the opossum Monodelphis domestica. Comparing the opossum VpreB to homologues from eutherian (placental mammals) and avian species supported the marsupial gene being VpreB3. VpreB3 is a protein that is not known to traffic to the cell surface as part of the pre-B cell receptor. Rather, VpreB3 associates with nascent immunoglobulin chains in the endoplasmic reticulum. Homologues of other known SL chains VpreB1, VpreB2, and λ5, which are found in eutherian mammals, were not found in the opossum genome, nor have they been identified in the genomes of nonmammals. VpreB3 likely evolved from earlier gene duplication, independent of that which generated VpreB1 and VpreB2 in eutherians. The apparent absence of VpreB1, VpreB2, and λ5 in marsupials suggests that an extracellular pre-B cell receptor containing SL chains, as it has been defined in humans and mice, may be unique to eutherian mammals. In contrast, the conservation of VpreB3 in marsupials and its presence in nonmammals is consistent with previous hypotheses that it is playing a more primordial role in B cell development.

  20. Experimental infection of opossums Didelphis aurita by Rickettsia rickettsii and evaluation of the transmission of the infection to ticks Amblyomma cajennense.

    PubMed

    Horta, Maurício C; Moraes-Filho, Jonas; Casagrande, Renata A; Saito, Tais B; Rosa, Simone C; Ogrzewalska, Maria; Matushima, Eliana R; Labruna, Marcelo B

    2009-02-01

    The present study evaluated the infection of opossums (Didelphis aurita) by Rickettsia rickettsii and their role as amplifier hosts for horizontal transmission of R. rickettsii to Amblyomma cajennense ticks. Three groups of opossums were evaluated: on day 0, group 1 (G1) was inoculated intraperitoneally with R. rickettsii; group 2 (G2) was infested by R. rickettsii-infected ticks; and group 3 (G3) was the uninfected control group. Opossum rectal temperature was measured daily. Blood samples were collected every 2 to 4 days during 30 days, and used to (1) inoculate guinea pigs intraperitoneally; (2) extract DNA followed by real-time polymerase chain reaction (PCR) targeting the rickettsial gene gltA; (3) study hematology; (4) detect R. rickettsii-reactive antibodies by indirect immunofluorescence assay (IFA). Blood was also collected every 10 days from days 30 to 180, to be tested by serology. Opossums were infested by uninfected A. cajennense larvae and nymphs from days 3 to 15. Engorged ticks were collected and allowed to molt in an incubator. Thereafter, the subsequent flat ticks were allowed to feed on uninfected rabbits, which were tested for seroconversion by IFA. Samples of flat ticks were also tested by real-time PCR. All G1 and G2 opossums became infected by R. rickettsii, as demonstrated by realtime PCR or/and guinea pig inoculation, but they showed no clinical abnormality. Rickettsemia was first detected at days 2 to 8, lasting intermittently till days 1 to 30. Approximately 18% and 5% of the flat ticks previously fed on G1 and G2 opossums, respectively, became infected by R. rickettsii, but only the rabbits infested with G1-derived ticks seroconverted. The study demonstrated that R. rickettsii was capable of infecting opossums without causing illness and developing rickettsemia capable of causing infection in guinea pigs and ticks, although the infection rate in ticks was low.

  1. Biochemical genetics of opossum aldehyde dehydrogenase 3: evidence for three ALDH3A-like genes and an ALDH3B-like gene.

    PubMed

    Holmes, Roger S

    2010-04-01

    Mammalian ALDH3 isozymes participate in peroxidic and fatty aldehyde metabolism, and in anterior eye tissue UV-filtration. BLAT analyses were undertaken of the opossum genome using rat ALDH3A1, ALDH3A2, ALDH3B1, and ALDH3B2 amino acid sequences. Two predicted opossum ALDH3A1-like genes and an ALDH3A2-like gene were observed on chromosome 2, as well as an ALDH3B-like gene, which showed similar intron-exon boundaries with other mammalian ALDH3-like genes. Opossum ALDH3 subunit sequences and structures were highly conserved, including residues previously shown to be involved in catalysis and coenzyme binding for rat ALDH3A1. Eleven glycine residues were conserved for all of the opossum ALDH3-like sequences examined, including two glycine residues previously located within the stem of the rat ALDH3A1 active site funnel. Phylogeny studies of human, rat, opossum, and chicken ALDH3-like sequences indicated that the common ancestor for ALDH3A- and ALDH3B-like genes predates the appearance of birds during vertebrate evolution.

  2. Serological evidence of exposure to tick-borne agents in opossums (Didelphis spp.) in the state of São Paulo, Brazil.

    PubMed

    Melo, Andréia Lima Tomé; Aguiar, Daniel Moura de; Spolidorio, Mariana Granziera; Yoshinari, Natalino Hajime; Matushima, Eliana Reiko; Labruna, Marcelo Bahia; Horta, Mauricio Claudio

    2016-06-07

    This work involved a serological investigation of tick-borne pathogens in opossums in eight municipalities of the state of São Paulo, Brazil. Serum samples from 109 opossums (91 Didelphis aurita and 18 Didelphis albiventris) were tested to detect antibodies to Rickettsia rickettsii (Taiaçu strain, 1:64 cut-off) and Ehrlichia canis (São Paulo strain, 1:40 cut-off), by indirect immunofluorescence assay (IFA); and against Borrelia burgdorferi (strain G39/40) by enzyme-linked immunosorbent assay (ELISA). The presence of antibodies to anti-R. rickettsii, anti-E. canis and anti-B. burgdorferi was detected in 32 (29.35%), 16 (14.67%) and 30 (27.52%) opossums, respectively. Opossum endpoint titers ranged from 64 to 1,024 for R. rickettsii, from 40 to 160 for E. canis, and from 400 to >51,200 for B. burgdorferi. These serological results suggest that opossums have been exposed to Rickettsia spp., Ehrlichia spp., and B. burgdorferi-related agents in the state of São Paulo. Our study underscores the need for further research about these agents in this study area, in view of the occurrence of Spotted Fever and Baggio-Yoshinari Syndrome disease in humans in the state of São Paulo, Brazil.

  3. Nitric oxide: Mediator of nonadrenergic noncholinergic nerve-induced responses of opossum esophageal muscle

    SciTech Connect

    Murray, J.; Du, C.; Conklin, J.L.; Ledlow, A.; Bates, J.N. )

    1991-03-15

    Nonadrenergic noncholinergic (NANC) nerves of the opossum esophagus mediate relaxation of circular muscle from the lower esophageal sphincter (LES) and the off contraction of circular esophageal muscle. The latencies between the end of the stimulus and the off contraction describe a gradient such that the latency is longest in muscle from the caudad esophagus. N{sup G}-nitro-L-arginine (L-NNA), an inhibitor of nitric oxide synthase, and nitric oxide were used to test the hypothesis that NO is a mediator of these nerve-induced responses. Both electrical field stimulation (EFS) of intrinsic esophageal nerves and exogenous NO relaxed LES muscle. Only EFS-induced relaxation was inhibited by L-NNA. L-arginine, the substrate for NO synthase, antagonized the inhibitory effect of L-NNA. Exogenous NO neither relaxed nor contracted circular esophageal muscle. Both the amplitude and the latency of the off contraction were diminished by L-NNA. L-arginine antagonized the action of L-NNA. N{sup G}-nitro-L-arginine also attenuated the gradient in the latency of the off response by shortening latencies in muscle form the caudad esophagus. It had no effect on cholinergic nerve-induced contraction of longitudinal esophageal muscle. These data support the hypothesis that NO or an NO-containing compound mediates NANC nerve-induced responses of the esophagus and LES.

  4. Biogeographic determinants of genetic diversification in the mouse opossum Gracilinanus agilis (Didelphimorphia: Didelphidae).

    PubMed

    Faria, Michel Barros; Nascimento, Fabrícia F; Oliveira, João Alves de; Bonvicino, Cibele Rodrigues

    2013-01-01

    The genetic variation of Brazilian populations of the mouse opossum Gracilinanus agilis was analyzed on the basis of the mitochondrial Cytochrome b gene (mt-Cytb) and the exon 28 of the nuclear Von Willenbrand factor (e28-vWF). The radiation of Gracilinanus was dated at 4.80 Ma, with the appearance of G. agilis around 1.93 Ma. Gracilinanus aceramarcae appeared as the first offshoot of the genus, followed by Gracilinanus emiliae and Gracilinanus microtarsus, which composed a sister clade of G. agilis. Phylogeographic analyses and genetic distance estimates indicate G. agilis as a single species, with haplotypes grouping in three well-supported clades, one from midwestern Brazil, a second one from northeastern Brazil, and a third one from eastern Brazil. Phylogeographic patterns in G. agilis were interpreted in search for congruence between genetic breaks and historic geomorphologic events documented for the region stretching northeastern to central-western of the Brazilian shield. The Rio São Francisco and the Serra Geral de Goiás were found to represent relevant geographic barriers to gene flow for G. agilis populations as well as for populations of several other widespread taxa.

  5. Highly conserved d-loop sequences in woolly mouse opossums Marmosa (Micoureus).

    PubMed

    Rocha, Rita Gomes; Leite, Yuri Luiz Reis; Ferreira, Eduardo; Justino, Juliana; Costa, Leonora Pires

    2012-04-01

    This study reports the occurrence of highly conserved d-loop sequences in the mitochondrial genome of the woolly mouse opossum genus Marmosa subgenus Micoureus (Mammalia, Didelphimorphia, Didelphidae). Sixty-six sequences of Marmosa (Micoureus) demerarae, Marmosa (Micoureus) constantiae, and Marmosa (Micoureus) paraguayanus were amplified using universal d-loop primers and virtually no genetic differences were detected within and among species. These sequences matched the control region of the mitochondrial marsupial genome. Analyses of qualitative aspects of these sequences revealed that their structural composition is very similar to the d-loop region of other didelphid species. However, the total lack of variability has not been reported from other closely related species. The data analyzed here support the occurrence of highly conserved d-loop sequences, and we found no support for the hypothesis that these sequences are d-loop-like nuclear pseudogenes. Furthermore, the control and flanking regions obtained with different primers corroborate the lack of variability of the d-loop sequences in the mitochondrial genome of Marmosa (Micoureus).

  6. Early postnatal B cell ontogeny and antibody repertoire maturation in the opossum, Monodelphis domestica.

    PubMed

    Wang, Xinxin; Sharp, Alana R; Miller, Robert D

    2012-01-01

    Marsupials are a lineage of mammals noted for giving birth to highly altricial young, which complete much of their "fetal" development externally attached to a teat. Postnatal B cell ontogeny and diversity was investigated in a model marsupial species, the gray short-tailed opossum, Monodelphis domestica. The results support the initiation of B cell development late in gestation and progressing into the first two weeks of postnatal life. Transcription of CD79a and CD79b was detected in embryonic tissue prior to birth, while immunoglobulin heavy chain locus transcription was not detected until the first postnatal 24 hours. Transcription of the Ig light chains was not detected until postnatal day 7 at the earliest. The predicted timing of the earliest appearance of mature B cells and completion of gene rearrangements is consistent with previous analyses on the timing of endogenous antibody responses in newborn marsupials. The diversity of early B cell IgH chains is limited, as has been seen in fetal humans and mice, but lacks bias in the gene segments used to encode the variable domains. Newborn light chain diversity is, from the start, comparable to that of the adult, consistent with an earlier hypothesis that light chains contribute extensively to antibody diversity in this species.

  7. Integrated cytogenetic BAC map of the genome of the gray, short-tailed opossum, Monodelphis domestica.

    PubMed

    Duke, S E; Samollow, P B; Mauceli, E; Lindblad-Toh, K; Breen, M

    2007-01-01

    The generation of high-quality genome assemblies for numerous species is advancing at a rapid pace. As the number of genome assemblies increases, so does our ability to investigate genome relationships and their contributions to unraveling complex biological, evolutionary, and biomedical processes. A key process in the generation of a genome assembly is to determine and verify the precise physical location and order of the large sequence blocks (scaffolds) that result from the assembly. For organisms of relatively recent common ancestry this process may be achieved largely through comparative sequence alignment. However, as the evolutionary distance between species lengthens, the use of comparative sequence alignment becomes increasingly less reliable. Simultaneous cytogenetic mapping, using multicolor fluorescence in-situ hybridization (FISH) analysis, offers an alternative means to define the cytogenetic location and relative order of DNA sequences, thereby anchoring the genome sequence to the karyotype. In this article we report the molecular cytogenetic locations of 415 bacterial artificial chromosome (BAC) clones that served to anchor sequence scaffolds of the gray, short-tailed opossum (Monodelphis domestica) to its karyotype, which enabled accurate integration of these regions into the genome assembly.

  8. Estrogen in peripheral plasma during postnatal development in gray short-tailed opossums.

    PubMed

    Fadem, B H; Harder, J D

    1992-09-01

    Plasma samples obtained from gray short-tailed opossums (Monodelphis domestica) at selected ages through adulthood were assayed for estrogen (E). Levels of E in one mixed-sex plasma pool of animals aged postnatal day (pd) 4 and one of two mixed-sex plasma pools of animals aged pd 8 were over 300 pg/ml. On pd 16, E levels in males and females averaged 30 and 47 pg/ml, respectively. While no significant sex differences in E levels were seen on pd 30 or pd 60, mean E levels for animals on pd 30 were significantly higher (275 pg/ml in males and 181 pg/ml in females) than on pd 60 (78 pg/ml in males and 85 pg/ml in females) or pd 145 (adults). In adult animals, estrogen levels in females averaged 54 pg/ml; all adult male E levels were below the limit of sensitivity of the assay. Maternal E levels, which did not vary significantly by age of litter, averaged 10 pg/ml overall. These findings are discussed with respect to possible significance of high E levels in developing marsupials for sexual differentiation and general brain development.

  9. Plasma concentrations of progesterone and testosterone in captive woolly opossums (Caluromys philander).

    PubMed

    Perret, M; Atramentowicz, M

    1989-01-01

    Plasma testosterone and progesterone concentrations were measured in captive woolly opossums, a didelphid marsupial originating from neotropical forests in French Guyana. Although not exposed to cyclic environmental conditions as in the field, both sexes exhibited spontaneous circannual changes in sexual hormones. Males showed synchronous variations in plasma testosterone characterized by significant elevated concentrations during April and September (8.6 +/- 1 ng/ml, N = 5) and lower levels from May to July (3.6 +/- 0.4 ng/ml). In females, synchronous periods of 2-3 successive oestrous cycles occurred. Between these periods, females remained acyclic. The oestrous cycle, determined by urogenital smears, lasted 28-45 days (n = 14) and included a 20-day spontaneous luteal phase in which progesterone concentrations reached 30-40 ng/ml plasma. Even though testosterone concentrations in paired males increased significantly in response to oestrous periods of the paired females, spontaneous circannual rhythms of sexual activity were not well synchronized between the sexes in captivity. When compared to field data, sexual activity of captive animals followed a pattern similar to that in wild animals, without any changes in males but with a delay of 3 months in females.

  10. Postnatal development of Leydig cells in the opossum (Monodelphis domestica): an immunocytochemical and endocrinological study.

    PubMed

    Xie, Q; Mackay, S; Ullmann, S L; Gilmore, D P; Payne, A P; Gray, C

    1998-03-01

    This study involved characterization of Leydig cells of the opossum Monodelphis domestica, functionally by immunocytochemical identification of the enzyme 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) and by measurement of testosterone levels using RIA. Immunostaining for 3 beta-HSD was first detected in a few Leydig cells on Day 16, was increased by Day 24, reached a peak at 4 mo, and was present even in senescent (3 yr) animals. Plasma testosterone was first measurable (0.35 nM) at prepuberty (3.5 mo). Prior to that, plasma testosterone concentrations were uniformly below the level of detection (< 0.3 nM) in both sexes from Day 5 to 2.5 mo. By 4 mo (puberty), plasma testosterone levels in males had risen significantly to 1.53 +/- 0.35 nM, continuing to increase to 1.79 +/- 0.4 nM at 6 mo and peaking at 2.71 +/- 0.29 nM in the adult (1-2 yr). Ovarian testosterone concentrations were consistently lower than those in the testis, as were those of adrenals of both sexes. Thus the testis would appear to be the major source of androgen production throughout life in this species. Our immunocytochemical study suggests that in Monodelphis, puberty is reached at 4 mo, and this was further supported by a rise in circulating testosterone levels at this time.

  11. Membrane potential and mechanical responses of the opossum esophagus to vagal stimulation and swallowing.

    PubMed

    Rattan, S; Gidda, J S; Goyal, R K

    1983-10-01

    Studies were performed in anesthetized opossums. The electrical changes, recorded using a suction electrode applied to the outside of the esophagus, and mechanical activity, recorded by an intraluminal catheter, were monitored from 5 cm above the lower esophageal sphincter. Swallowing was associated with membrane hyperpolarization followed by depolarization and spike burst. Electrical stimulation of the decentralized vagus also caused a prompt hyperpolarization followed by an overshoot depolarization. Single pulses of stimulation caused primarily hyperpolarization. The amplitude and duration of hyperpolarization increased with increasing frequencies of vagal stimulation. Spike burst occurred as the membrane potential was recovering from the peak hyperpolarization and moving toward peak depolarization. The latency of onset of spike burst decreased with increasing frequency of vagal stimulation. The muscle contraction occurred after a latency. The latency of contractions, like the latency of spike burst, decreased with increased frequency of vagal stimulation. These studies show that (a) membrane hyperpolarization is present during the latent period of contraction associated with swallowing, suggesting that swallow-induced esophageal response may be mediated by vagal inhibitory pathway to the esophagus and (b) spike bursts can be temporally dissociated from depolarization by changing the vagal stimulation frequency, suggesting that spike burst and depolarization may be mediated by different excitatory mechanisms.

  12. Fish and opossum shrimp entrainment in the Mt. Elbert Pumped-Storage Power Plant

    SciTech Connect

    Maiolie, M.A.

    1987-01-01

    Impacts of operating the Mt. Elbert Pumped-Storage Power Plant on fish and opossum shrimp (mysis relicta) were investigated from 1981 to 1985 at Twin Lakes, Colorado to determine any negative effects on the Twin Lakes fishery. Daytime generation cycles entrained shrimp at densities averaging 0.05 to 0.23 shrimp/m/sup 3/ of discharge. Eight hour daytime generation cycles would entrain 50,000 to 300,000 shrimp at these rates. Generation cycles which occurred after dark entrained many times more shrimp with densities as high as 1.21 shrimp/m/sup 3/ of discharge. Entrainment density during nighttime pump-back cycles was much greater; averaging 2 to 17 shrimp/m/sup 3/ discharged. Six to 44 million shrimp were entrained during typical 8 h pump-back cycles. Differences between daytime and nighttime entrainment rates appeared to be caused by migration of shrimp into the water column at night making them more vulnerable to entrainment. Losses were estimated to have reduced Lower Twin Lake shrimp abundance by 39% in 1985.

  13. Seasonal population characteristics of the opossum shrimp, Mysis relicta, in southeastern Lake Michigan, 1970-71

    USGS Publications Warehouse

    Reynolds, James B.; DeGraeve, G.M.

    1972-01-01

    This study of depth distribution, abundance, growth, reproduction and standing crop of the opossum shrimp, Mysis relicta, in southeastern Lake Michigan was based on monthly samples collected from August 1970 through July 1971 (except February and March). Population density was usually low at 10-20 fathoms, moderate at 25-30 fathoms and relatively high at 35 fathoms and deeper. Abundance was highest in midsummer and lowest in December. Free-living mysids were 3-25 mm long. Average growth rate was 1 mm per month. At maximum lengths, females were longer than males. Weight increased as approximately the cube of the length. The population consisted mostly of juveniles during summer and autumn and subadults and adults in winter and spring. Sizable numbers of adults apparently moved to relatively shallow water (10-35 fathoms) in winter, where they bred and released their young. In deeper water (40 fathoms or more), some reproduction occurred throughout the year. Most recruitment was in April and May. Standing crop ranged as high as 50 kg per hectare. Mysis apparently has a one-year life cycle in southeastern Lake Michigan.

  14. Increase of annexin 1 immunoreactivity in spinal cord of newborn opossum (Monodelphis domestica) at the time when regeneration after injury stops being possible.

    PubMed

    Mladinic, M; Del Bel, E; Nicholls, J

    2007-11-01

    Annexins constitute a family of proteins that associate reversibly with cell membranes in a calcium dependent manner. We have studied the distribution of annexin 1, which is known to mediate anti-inflammatory actions of glucocorticoids, and which is upregulated after spinal cord injury, in newborn and adult South American opossum (Monodelphis domestica) spinal cord. We show the increase in the annexin 1 immunoreactivity in spinal cords of neonatal opossums over the critical period when regeneration after injury ceases to be possible. We further show the restricted and specific sites at which it is detected in adult opossum cerebellum and hippocampus. Since the procedures used in immunochemistry of annexin in CNS have in the past yielded conflicting results, different procedures were tested and shown to be reliable. As a control, annexin 1 distribution was surveyed in kidney.

  15. Leishmania chagasi in Opossums (Didelphis albiventris) in an Urban Area Endemic for Visceral Leishmaniasis, Campo Grande, Mato Grosso do Sul, Brazil

    PubMed Central

    Humberg, Roberta M. P.; Oshiro, Elisa T.; Cruz, Maria do Socorro Pires e; Ribolla, Paulo E. M.; Alonso, Diego P.; Ferreira, Alda M. T.; Bonamigo, Raquel A.; Tasso, Norton; de Oliveira, Alessandra Gutierrez

    2012-01-01

    We investigated the occurrence of Leishmania infantum chagasi in Didelphis albiventris opossums at a wild animal rehabilitation center in the city of Campo Grande, Brazil. A total of 54 opossums were tested for L. i. chagasi infection in peripheral blood and bone marrow samples. The samples were analyzed by direct examination, culturing in a specific medium, and polymerase chain reaction–restriction fragment length polymorphism. Leishmania i. chagasi DNA was detected by polymerase chain reaction–restriction fragment length polymorphism in 11 (20.37%) animals. A total of 81.81% of positive opossums were captured in areas of known visceral leishmaniasis transmission. These results suggest a role for D. albiventris in the urban transmission of visceral leishmaniasis. PMID:22802435

  16. Prevalence of and risk factors associated with the presence of Sarcocystis neurona sporocysts in opossum (Didelphis virginiana) from Michigan: a retrospective study.

    PubMed

    Elsheikha, Hany M; Murphy, Alice J; Mansfield, Linda S

    2004-11-10

    From April 1996 to December 2002 the prevalence of Sarcocystis neurona sporocysts in North American opossum (Didelphis virginiana) in Southern Michigan was estimated. Sporocysts of S. neurona were found in intestinal scrapings from 31 (15%) of 206 examined opossum. The frequency of infection was higher in adult animals (26/206; 12.6%) and females (19/206; 9.2%) than in juveniles (5/206; 2.4%) and males (12/206; 5.8%). Also, prevalence of S. neurona sporocysts in opossums in relation to factors such as age, sex, season, body condition, presence of concomitant infection, and presence of young in the pouch of females was studied in detail over the course of the year, 2002. Univariate analyses identified the following factors as being associated with the presence of S. neurona sporocysts in opossums: (i) for age, adult (odd ratio [OR] = 2.074, P = 0.0005); (ii) for sex, female (OR = 7.016, P = 0.0119); (iii) for season, summer (OR = 7.917, P = 0.0032) and spring (OR = 4.071, P = 0.1063); (iv) for body condition, poor (OR = 3.50, P = 0.1200) and good (OR = 1.167, P = 0.8637); (v) for the presence of concomitant infection (OR = 23.056, P = 0001), and (vi) for the presence of young in the pouch of females (OR = 40.083, P = 0.0001). Multivariate logistic-regression analyses selected the following factors as being significantly associated with presence of S. neurona sporocysts in opossums: (i) for the presence of concomitant infection (OR = 8.722, P = 0.0160) and (ii) for the presence of young in the pouch of females (OR = 31.915, P = 0.0065). The prevalence of S. neurona sporocysts in D. virginiana suggests that this opossum may constitute an ample reservoir of infection to other animals in the northern United States.

  17. Angiotensin type 1 receptor resistance to blockade in the opossum proximal tubule cell due to variations in the binding pocket.

    PubMed

    Nistala, Ravi; Andresen, Bradley T; Pulakat, Lakshmi; Meuth, Alex; Sinak, Catherine; Mandavia, Chirag; Thekkumkara, Thomas; Speth, Robert C; Whaley-Connell, Adam; Sowers, James R

    2013-04-15

    Blockade of the angiotensin (ANG) II receptor type 1 (AT(1)R) with angiotensin receptor blockers (ARBs) is widely used in the treatment of hypertension. However, ARBs are variably effective in reducing blood pressure, likely due, in part, to polymorphisms in the ARB binding pocket of the AT(1)R. Therefore, we need a better understanding of variations/polymorphisms that alter binding of ARBs in heterogeneous patient populations. The opossum proximal tubule cell (OKP) line is commonly used in research to evaluate renal sodium handling and therefore blood pressure. Investigating this issue, we found natural sequence variations in the opossum AT(1)R paralleling those observed in the human AT(1)R. Therefore, we posited that these sequence variations may explain ARB resistance. We demonstrate that OKP cells express AT(1)R mRNA, bind (125)I-labeled ANG II, and exhibit ANG II-induced phosphorylation of Jak2. However, Jak2 phosphorylation is not inhibited by five different ARBs commonly used to treat hypertension. Additionally, nonradioactive ANG II competes (125)I-ANG II efficiently, whereas a 10-fold molar excess of olmesartan and the ANG II receptor type 2 blocker PD-123319 is unable to block (125)I-ANG II binding. In contrast, ANG II binding to OKP cells stably expressing rat AT(1A)Rs, which have a conserved AT(1)R-binding pocket with human AT(1)R, is efficiently inhibited by olmesartan. A novel observation was that resistance to ARB binding to opossum AT(1)Rs correlates with variations from the human receptor at positions 108, 163, 192, and 198 within the ARB-binding pocket. These observations highlight the potential utility of evaluating AT(1)R polymorphisms within the ARB-binding pocket in various hypertensive populations.

  18. The development of a testosterone stimulation test in the Virginia opossum (Didelphis virginiana) and its use in evaluating deslorelin contraception.

    PubMed

    Johnston, S D; Camacho, F C; Carrillo, L; Guy, N; Govea, J; Martinez, O; Parãs, A; Lisle, A T; D'Occhio, M

    2008-01-01

    The aims of the present study were to examine the variability of testosterone secretion in the Virginia Opossum over a 24 h period and to develop a testosterone stimulation test that would provide an index of the prevailing testosterone biosynthetic capacity of the testes; the latter was used to clinically evaluate the efficacy of a gonadotrophin-releasing hormone agonist contraceptive. Sexually-mature captive opossums (n = 12) located in Africam Safari (Mexico) sampled every 12 h over 24 h consistently showed basal (<0.21 ng mL(-1)) blood testosterone concentrations. Intra-muscular injection of buserelin (2 microg mL(-1)) and human chorionic gonadotrophin (hCG; 1000 IU) resulted in an increase (P < 0.05) of plasma testosterone concentrations with maximal concentrations (3.9 ng mL(-1) and 5.8 ng mL(-1) respectively) occurring 120 min after injection. Plasma testosterone declined relatively rapidly to basal concentrations after 240 min with hCG but remained elevated after the same period of time with buserelin. Male opossums treated with (n = 6) and without (n = 6) a controlled-release deslorelin implant (Suprelorin; 4.7 mg deslorelin) were evaluated over a 10-week period for changes in testosterone secretion (hCG stimulation test) and sperm production (spermatorrhea). At the end of this period, the animals were hemi-castrated and their relative testicular quantitative histology compared. Testosterone concentration decreased over the course of the study in both treated and control animals (P < 0.0001) but there was no apparent effect of deslorelin on testosterone secretion, testicular histology (relative proportions of testicular cell types and seminiferous tubule diameter), or sperm production (presence of sperm in the cauda epididymis or urine).

  19. Demography and population dynamics of the mouse opossum (Thylamys elegans) in semi-arid Chile: seasonality, feedback structure and climate.

    PubMed Central

    Lima, M.; Stenseth, N. C.; Yoccoz, N. G.; Jaksic, F. M.

    2001-01-01

    Here we present, to the authors' knowledge for the very first time for a small marsupial, a thorough analysis of the demography and population dynamics of the mouse opossum (Thylamys elegans) in western South America. We test the relative importance of feedback structure and climatic factors (rainfall and the Southern Oscillation Index) in explaining the temporal variation in the demography of the mouse opossum. The demographic information was incorporated into a stage-structured population dynamics model and the model's predictions were compared with observed patterns. The mouse opossum's capture rates showed seasonal (within-year) and between-year variability, with individuals having higher capture rates during late summer and autumn and lower capture rates during winter and spring. There was also a strong between-year effect on capture probabilities. The reproductive (the fraction of reproductively active individuals) and recruitment rates showed a clear seasonal and a between-year pattern of variation with the peak of reproductive activity occuring during winter and early spring. In addition, the fraction of reproductive individuals was positively related to annual rainfall, while population density and annual rainfall positively influenced the recruitment rate. The survival rates were negatively related to annual rainfall. The average finite population growth rate during the study period was estimated to be 1.011 +/- 0.0019 from capture-recapture estimates. While the annual growth rate estimated from the seasonal linear matrix models was 1.026, the subadult and adult survival and maturation rates represent between 54% (winter) and 81% (summer) of the impact on the annual growth rate. PMID:11571053

  20. Immunolocalization of cation-chloride cotransporters in the developing and mature spinal cord of opossums, Monodelphis domestica.

    PubMed

    Phan, Ha-Loan; Pflieger, Jean-François

    2013-01-01

    Spinal inhibition is required to generate coordinated outputs between antagonistic muscles during locomotion. It relies on low neuronal chloride concentration set by two cation-chloride cotransporters, NKCC1 and KCC2 which, respectively, pumps Cl(-) in or out of neurons. It is generally accepted that NKCC1 is gradually inactivated during development, while KCC2 is upregulated and activated, resulting in low intracellular [Cl(-)]. Newborn opossums are very immature but perform rhythmic and alternate movements of the forelimbs to crawl on the mother's belly and attach to a teat. Their hindlimbs are immobile. The alternation of the forelimbs suggests that mechanisms allowing spinal inhibition are present at birth. We studied the anatomical basis of inhibition in the spinal enlargements of postnatal opossums by immunolocalizing NKCC1 and KCC2. In some specimens, motoneurons and sensory afferents were labeled with TRDA prior to immunolabeling. At birth, both NKCC1 and KCC2 are detected in the presumptive gray and white matter of the ventral and the intermediolateral cord of both enlargements, but are sparse in the dorsal horn, where KCC2 is mostly seen on a small bundle of dendrites along primary afferents. KCC2 labeling is bright and has a mesh-like appearance in the gray matter and a radial appearance in the white matter, whereas NKCC1 is pale and diffuse. The subsequent expression of the cotransporters follows general ventrodorsal and mediolateral gradients, with the lumbar segments slightly lagging the cervical segments, until the mature pattern is observed around the 5th week. At all ages studied, KCC2 labeling is strong in the periphery of neurons. NKCC1 labeling decreases and becomes more uniformly distributed in the cells with age. Despite the significant anatomical and motor differences between the forelimbs and the hindlimbs of neonatal opossums, the maturation of KCC2 and NKCC1 is quite similar in both enlargements.

  1. Correlation between dopaminergic phenotype and expression of calretinin in the midbrain nuclei of the opossum (Monodelphis domestica): an immunohistological study.

    PubMed

    Klejbor, Ilona; Ludkiewicz, Beata; Wojcik, Sławomir; Turlejski, Krzysztof

    2013-01-01

    We investigated distribution and morphology of neurons of the midbrain nuclei: the ventral tegmental area (VTA), substantia nigra (SN) and periaqueductal gray (PAG) of the adult grey short-tailed opossums that were double immunolabeled for the presence of calretinin (CR) and/or tyrosine hydroxylase (TH). The majority of TH-immunopositive neurons and fibers were located in the VTA, SN, and only scarce population of small neurons expressing TH was present in the PAG. In the SN 80 percent of TH-expressing neurons had large cell bodies, and only a small fraction had small perikarya. In the PAG populations of large and medium sized neurons were equal and 20 percent of neurons had small perikarya. Much scarcer population of TH-immunoreactive neurons in the PAG consisted of large or small neurons in its dorsal part (PAGd) and almost exclusively small neurons in the ventral part (PAGv). Distribution of neurons expressing TH and their types in the opossum are similar to those in rodents. The majority of CR-immunolabeled neurons were found in the VTA. In its subdivision, the parabrachal pigmented nucleus (PBP) cells expressing CR were approximately 28 percent more numerous than cells expressing TH. In spite of that, only 42 percent of TH-expressing neurons coexpressed CR. The high degree of colocalization TH and CR was observed in the SN. We propose that a higher percentage of TH/CR colocalization, which is observed in the opossums SN, may give them the ability to adapt to changes in their motor functions.

  2. Myosin isoform expression in the prehensile tails of didelphid marsupials: functional differences between arboreal and terrestrial opossums.

    PubMed

    Rupert, J E; Schmidt, E Cordero; Moreira-Soto, A; Herrera, B Rodríguez; Vandeberg, J L; Butcher, M T

    2014-08-01

    Prehensile tails are defined as having the ability to grasp objects and are commonly used as a fifth appendage during arboreal locomotion. Despite the independent evolution of tail prehensility in numerous mammalian genera, data relating muscle structure, physiology, and function of prehensile tails are largely incomplete. Didelphid marsupials make an excellent model to relate myosin heavy chain (MHC) isoform fiber type with structure/function of caudal muscles, as all opossums have a prehensile tail and tail use varies between arboreal and terrestrial forms. Expanding on our previous work in the Virginia opossum, this study tests the hypothesis that arboreal and terrestrial opossums differentially express faster versus slower MHC isoforms, respectively. MHC isoform expression and percent fiber type distribution were determined in the flexor caudae longus (FCL) muscle of Caluromys derbianus (arboreal) and Monodelphis domestica (terrestrial), using a combination of gel electrophoresis and immunohistochemistry analyses. C. derbianus expresses three MHC isoforms (1, 2A, 2X) that are distributed (mean percentage) as 8.2% MHC-1, 2.6% 1/2A, and 89.2% 2A/X hybrid fibers. M. domestica also expresses MHC-1, 2A, and 2X, in addition to the 2B isoform, distributed as 17.0% MHC-1, 1.3% 1/2A, 9.0% 2A, 75.2% 2A/X, and 0.3% 2X/B hybrid fibers. The distribution of similar isoform fiber types differed significantly between species (P < 0.001). Although not statistically significant, C. derbianus was observed to have larger cross-sectional area (CSA) for each corresponding fiber type along with a greater amount of extra-cellular matrix. An overall faster fiber type composition (and larger fibers) in the tail of an arboreal specialist supports our hypothesis, and correlates with higher muscle force required for tail hanging and arboreal maneuvering on terminal substrates. Conversely, a broader distribution of highly oxidative fibers in the caudal musculature is well suited for

  3. Progesterone receptor in the forebrain of female gray short-tailed opossums: effects of exposure to male stimuli.

    PubMed

    Vitazka, Maria E; Cárdenas, Horacio; Cruz, Yolanda; Fadem, Barbara H; Norfolk, Jennifer R; Harder, John D

    2009-01-01

    Progesterone receptor immunoreactivity (PRir) in brain areas involved in reproductive behavior in eutherian species was examined for the first time in a female marsupial, the gray short-tailed opossum (Monodelphis domestica, hereinafter, opossum). PRir in nuclei of neurons, measured as area covered by stained nuclei, was seen in the arcuate nucleus (Arc); anteroventral periventricular nucleus (AVPv); bed nucleus of the stria terminalis (BST); medial preoptic area (MPOA), and ventromedial hypothalamus (VMH), but not in control areas adjacent to the hypothalamus or cortex. Female opossums are induced into cytological, urogenital sinus (UGS), estrus by male pheromones and into behavioral estrus, i.e., receptivity, by pairing with a male, and both estradiol (E) and progesterone (P) are involved in induction of receptivity in intact and ovariectomized females. PRir in the AVPv, MPOA, and VMH was very low in females that had never been exposed to males or their scent marks, i.e., naïve anestrous (NVA) females, and either previous or current exposure to males or their scent marks was associated with elevated PRir. PRir was significantly higher in the AVPv and MPOA of anestrous females with previous but no current exposure to males and their scent marks, i.e., experienced anestrous (EXPA) females, than in NVA females, but PRir was significantly lower in the MPOA and VMH of EXPA females than in females that were behaviorally receptive and had recently copulated, i.e., behavioral receptive estrous (BRE) females. PRir was higher in the VMH of both UGS estrous (UGSE) and BRE females compared to that in EXPA animals, but PRir did not differ between UGSE and BRE females in any of the 3 brain areas examined, including the MPOA These results provide evidence that pheromonal induction of estrus and sexual receptivity in opossums is associated with elevation of PRir in the VMH and MPOA and that prior exposure to males or their pheromones, even in the absence of current male stimuli

  4. Amelotin Gene Structure and Expression during Enamel Formation in the Opossum Monodelphis domestica

    PubMed Central

    Gasse, Barbara; Liu, Xi; Corre, Erwan; Sire, Jean-Yves

    2015-01-01

    Amelotin (AMTN) is an ameloblast-secreted protein that belongs to the secretory calcium-binding phosphoprotein family, which also includes the enamel matrix proteins amelogenin, ameloblastin and enamelin. Although AMTN is supposed to play an important role in enamel formation, data were long limited to the rodents, in which it is expressed during the maturation stage. Recent comparative studies in sauropsids and amphibians revealed that (i) AMTN was expressed earlier, i.e. as soon as ameloblasts are depositing the enamel matrix, and (ii) AMTN structure was different, a change which mostly resulted from an intraexonic splicing in the large exon 8 of an ancestral mammal. The present study was performed to know whether the differences in AMTN structure and expression in rodents compared to non-mammalian tetrapods dated back to an early ancestral mammal or were acquired later in mammalian evolution. We sequenced, assembled and screened the jaw transcriptome of a neonate opossum Monodelphis domestica, a marsupial. We found two AMTN transcripts. Variant 1, representing 70.8% of AMTN transcripts, displayed the structure known in rodents, whereas variant 2 (29.2%) exhibited the nonmammalian tetrapod structure. Then, we studied AMTN expression during amelogenesis in a neonate specimen. We obtained similar data as those reported in rodents. These findings indicate that more than 180 million years ago, before the divergence of marsupials and placentals, changes occurred in AMTN function and structure. The spatiotemporal expression was delayed to the maturation stage of amelogenesis and the intraexonic splicing gave rise to isoform 1, encoded by variant 1 and lacking the RGD motif. The ancestral isoform 2, housing the RGD, was initially conserved, as demonstrated here in a marsupial, then secondarily lost in the placental lineages. These findings bring new elements towards our understanding of the non-prismatic to prismatic enamel transition that occurred at the onset of

  5. Long-term regulation of Na+,K+-ATPase in opossum kidney cells by ouabain.

    PubMed

    Silva, E; Soares-da-Silva, P

    2011-09-01

    Na(+),K(+)-ATPase, a basolateral transporter responsible for tubular reabsorption of Na(+) and for providing the driving force for vectorial transport of various solutes and ions, can also act as a signal transducer in response to the interaction with steroid hormones. At nanomolar concentrations ouabain binding to Na(+),K(+)-ATPase activates a signaling cascade that ultimately regulates several membrane transporters including Na(+),K(+)-ATPase. The present study evaluated the long-term effect of ouabain on Na(+),K(+)-ATPase activity (Na(+) transepithelial flux) and expression in opossum kidney (OK) cells with low (40) and high (80) number of passages in culture, which are known to overexpress Na(+),K(+)-ATPase (Silva et al., 2006, J Membr Biol 212, 163-175). Activation of a signal cascade was evaluated by quantification of ERK1/2 phosphorylation by Western blot. Na(+),K(+)-ATPase activity was determined by electrophysiological techniques and expression by Western blot. Incubation of cells with ouabain induced activation of ERK1/2. Long-term incubation with ouabain induced an increase in Na(+) transepithelial flux and Na(+),K(+)-ATPase expression only in OK cells with 80 passages in culture. This increase was prevented by incubation with inhibitors of MEK1/2 and PI-3K. In conclusion, ouabain-activated signaling cascade mediated by both MEK1/2 and PI-3K is responsible for long-term regulation of Na(+) transepithelial flux in epithelial renal cells. OK cell line with high number of passages is suggested to constitute a particular useful model for the understanding of ouabain-mediated regulation of Na(+) transport.

  6. Protein cytoskeleton and overexpression of Na(+),K(+)-ATPase in opossum kidney cells.

    PubMed

    Silva, Elisabete; Soares-da-Silva, Patrício

    2009-11-01

    Previous studies have shown that over time in culture opossum kidney (OK) cells are endowed with increased Na(+),K(+)-ATPase activity and expression (Silva et al., 2006, J Membr Biol 212:163-175; Silva and Soares-da-Silva, 2007, Am J Physiol Regul Integr Comp Physiol 293:R1764-R1770). The present work evaluated the cytoskeleton reorganization in OK cells at passages 40 and 80 in culture and its possible relationship with membrane transport proteins and cell morphology. It is shown that OK cells with 80 passages in culture have increased size, internal complexity, and total protein expression. In OK cells with 80 passages in culture the use of in-cell western showed that ezrin/radixin/moesin complex was increased by 20%. The most abundant ankyrin-G isoform in OK cells with 40 passages was the approximately 200/220 kDa isoform, whereas in OK cells with 80 passages the most abundant isoform was the approximately 170 kDa isoform. The spectrin-betaII approximately 240 kDa isoform, the predominant isoform in OK cells with 40 passages, was marginally detected in OK cells with 80 passages. Besides Na(+),K(+)-ATPase, GLUT2, and NHE3 expression was also significantly increased in OK cells with 80 passages. It is concluded that the prolonged cell passaging of OK cells results in an interesting and valuable experimental model to analyze the reorganization of the renal cell cytoskeleton proteins and its relationship with transporter and signaling membrane proteins.

  7. Amelotin Gene Structure and Expression during Enamel Formation in the Opossum Monodelphis domestica.

    PubMed

    Gasse, Barbara; Liu, Xi; Corre, Erwan; Sire, Jean-Yves

    2015-01-01

    Amelotin (AMTN) is an ameloblast-secreted protein that belongs to the secretory calcium-binding phosphoprotein family, which also includes the enamel matrix proteins amelogenin, ameloblastin and enamelin. Although AMTN is supposed to play an important role in enamel formation, data were long limited to the rodents, in which it is expressed during the maturation stage. Recent comparative studies in sauropsids and amphibians revealed that (i) AMTN was expressed earlier, i.e. as soon as ameloblasts are depositing the enamel matrix, and (ii) AMTN structure was different, a change which mostly resulted from an intraexonic splicing in the large exon 8 of an ancestral mammal. The present study was performed to know whether the differences in AMTN structure and expression in rodents compared to non-mammalian tetrapods dated back to an early ancestral mammal or were acquired later in mammalian evolution. We sequenced, assembled and screened the jaw transcriptome of a neonate opossum Monodelphis domestica, a marsupial. We found two AMTN transcripts. Variant 1, representing 70.8% of AMTN transcripts, displayed the structure known in rodents, whereas variant 2 (29.2%) exhibited the nonmammalian tetrapod structure. Then, we studied AMTN expression during amelogenesis in a neonate specimen. We obtained similar data as those reported in rodents. These findings indicate that more than 180 million years ago, before the divergence of marsupials and placentals, changes occurred in AMTN function and structure. The spatiotemporal expression was delayed to the maturation stage of amelogenesis and the intraexonic splicing gave rise to isoform 1, encoded by variant 1 and lacking the RGD motif. The ancestral isoform 2, housing the RGD, was initially conserved, as demonstrated here in a marsupial, then secondarily lost in the placental lineages. These findings bring new elements towards our understanding of the non-prismatic to prismatic enamel transition that occurred at the onset of

  8. Mitochondrial phenotype of marsupial torpor: Fuel metabolic switch in the Chilean mouse-opossum Thylamys elegans.

    PubMed

    Cortés, Pablo Andres; Bacigalupe, Leonardo Daniel; Mondaca, Fredy; Desrosiers, Véronique; Blier, Pierre U

    2016-01-01

    Torpor is a phenotype characterized by a controlled decline of metabolic rate and body temperature. During arousal from torpor, organs undergo rapid metabolic reactivation and rewarming to near normal levels. As torpor progress, animals show a preference for fatty acids over glucose as primary source of energy. Here, we analyzed for first time the changes in the maximal activity of key enzymes related to fatty acid (Carnitine palmitoyltransferase and β-Hydroxyacyl CoA dehydrogenase) and carbohydrate (Pyruvate kinase, Phosphofructokinase and Lactate dehydrogenase) catabolism, as well as mitochondrial oxidative capacity (Citrate synthase), in six organs of torpid, arousing and euthermic Chilean mouse-opossums (Thylamys elegans). Our results showed that activity of enzymes related to fatty acid and carbohydrate catabolism were different among torpor phases and the pattern of variation differs among tissues. In terms of lipid utilization, maximal enzymatic activities differ in tissues with high oxidative capacity such as heart, kidney, and liver. In terms of carbohydrate use, lower enzymatic activities were observed during torpor in brain and liver. Interestingly, citrate synthase activity did not differ thought torpor-arousal cycle in any tissues analyzed, suggesting no modulation of mitochondrial content in T. elegans. Overall results provide an indication that modulation of enzymes associated with carbohydrate and fatty-acid pathways is mainly oriented to limit energy expensive processes and sustain energy metabolism during transition from torpor to euthermy. Future studies are required to elucidate if physiological events observed for T. elegans are unique from other marsupials, or represents a general response in marsupials. J. Exp. Zool. 325A:41-51, 2016. © 2015 Wiley Periodicals, Inc.

  9. The COOH terminus of megalin regulates gene expression in opossum kidney proximal tubule cells

    PubMed Central

    Li, Yuanli; Cong, Rong; Biemesderfer, Daniel

    2008-01-01

    We recently reported that megalin is subjected to regulated intramembrane proteolysis (RIP) and includes 1) protein kinase C (PKC)-regulated, metalloprotease-mediated ectodomain shedding producing a membrane-bound megalin COOH-terminal fragment (MCTF) and 2) γ-secretase-mediated cleavage of the MCTF producing a soluble megalin intracellular domain (MICD). Based on studies of RIP of other receptors, the MICD is predicted to target to the nucleus and regulate gene expression. To determine whether RIP of megalin regulates proximal tubule gene expression, we stably expressed the transfected MCTF (tMCTF) or transfected MICD (tMICD) in opossum kidney proximal tubule (OKP) cells and examined the resulting phenotype. Immunoblotting and immunocytochemical analysis of tMCTF cells showed the tMCTF was expressed and constitutively processed by γ-secretase. Analysis of specific protein expression in tMCTF- and tMICD-transfected cells using Western blot showed endogenous megalin and Na+/H+ exchanger 3 (NHE3) protein expression to be dramatically lower than that of control cells. Expression of other proteins including myosin VI, β-adaptin, and the Na-K-ATPase appeared unchanged. Analysis of specific mRNA expression using quantitative real-time PCR showed megalin and NHE3 mRNA levels were significantly lower in tMCTF- and tMICD-transfected cells compared with controls. Inhibition of γ-secretase activity in tMCTF cells resulted in an 8- to 10-fold recovery of megalin mRNA within 4 h. These data show that the COOH-terminal domain of megalin regulates expression of specific proteins in OKP cells and provides the first evidence that RIP of megalin may be part of a signaling pathway linking protein absorption and gene expression in proximal tubule. PMID:18495814

  10. Phylogenetic evaluation of taxonomic definition of didelphid mouse opossum of the genus Thylamys from valleys of Coquimbo region, Chile.

    PubMed

    Boric-Bargetto, Dusan; Zúñiga-Reinoso, Álvaro; Cancino, Ricardo A; González-Acuña, Daniel; Rodríguez-Serrano, Enrique; Palma, R Eduardo; Hernández, Cristián E

    2016-04-21

    Only two species of Didelphidae are currently recognized in Chile, the sister species Thylamys elegans, endemic of Mediterranean ecorregion and Thylamys pallidior, the inhabitant of the Puna and desert canyons. Three subspecies have been described for T. elegans: T. e. elegans, T. e. coquimbensis and T. e. soricinus. However, a recent study based on morphological analyses, synonymized T. elegans coquimbensis from the Coquimbo valleys (30-31° S) with T. pallidior and proposed that T. elegans and T. pallidior could be in sympatry at Coquimbo valleys between Fray Jorge (30°40'S) and Paiguano (30°02' S). We assess the current definition of T. e. coquimbensis and T. e. elegans, as well as this taxonomical conflict among the mouse opossums from the Coquimbo valleys through phylogenetic analyses of cytochrome b mitochondrial gene sequences. In this study, for the first time, we used specimens from the type localities of T. e. coquimbensis and T. e. elegans. In addition, we analyzed diagnostic cranial structures for this taxonomic revision. The results supported two allopatric clades, allowing us to keep the taxonomic definition of T. e. elegans and T. e. coquimbensis as phylogenetic reciprocal monophyletic clades and polyphyletic with T. pallidior. This result corroborates previous morphological analyses, which support that mouse opossums from the Coquimbo valleys are T. e. coquimbensis, thus extending its geographic distribution to the coast of Coquimbo and Atacama regions. We don´t have evidence for sympatric distribution between T. elegans and T. pallidior in the Coquimbo region.

  11. Relationship between sodium-dependent phosphate transporter (NaPi-IIc) function and cellular vacuole formation in opossum kidney cells.

    PubMed

    Shiozaki, Yuji; Segawa, Hiroko; Ohnishi, Saori; Ohi, Akiko; Ito, Mikiko; Kaneko, Ichiro; Kido, Shinsuke; Tatsumi, Sawako; Miyamoto, Ken-ichi

    2015-01-01

    NaPi-IIc/SLC34A3 is a sodium-dependent inorganic phosphate (Pi) transporter in the renal proximal tubules and its mutations cause hereditary hypophosphatemic rickets with hypercalciuria (HHRH). In the present study, we created a specific antibody for opossum SLC34A3, NaPi-IIc (oNaPi-IIc), and analyzed its localization and regulation in opossum kidney cells (a tissue culture model of proximal tubular cells). Immunoreactive oNaPi-IIc protein levels increased during the proliferative phase and decreased during differentiation. Moreover, stimulating cell growth upregulated oNaPi-IIc protein levels, whereas suppressing cell proliferation downregulated oNaPi-IIc protein levels. Immunocytochemistry revealed that endogenous and exogenous oNaPi-IIc proteins localized at the protrusion of the plasma membrane, which is a phosphatidylinositol 4,5-bisphosphate (PIP2) rich-membrane, and at the intracellular vacuolar membrane. Exogenous NaPi-IIc also induced cellular vacuoles and localized in the plasma membrane. The ability to form vacuoles is specific to electroneutral NaPi-IIc, and not electrogenic NaPi-IIa or NaPi-IIb. In addition, mutations of NaPi-IIc (S138F and R468W) in HHRH did not cause cellular PIP2-rich vacuoles. In conclusion, our data anticipate that NaPi-IIc may regulate PIP2 production at the plasma membrane and cellular vesicle formation.

  12. Are opossums a relevant factor associated with asymptomatic Leishmania infection in the outskirts of the largest Brazilian cities?

    PubMed

    Carranza-Tamayo, César Omar; Werneck, Guilherme Loureiro; Romero, Gustavo Adolfo Sierra

    2016-01-01

    A population survey was conducted to explore the prevalence and factors associated with Leishmania infection in the Fercal region of the Federal District. The Fercal region is a group of neighborhoods in Brasília in which the first cases of visceral leishmaniasis were described. Leishmania infection was established by a positive leishmanin test. Although other tests were performed in the study (an immunochromatographic assay (Kalazar detect(®)) and a molecular assay), only the leishmanin skin test provided sufficient results for the measurement of the disease prevalence. Data on the epidemiological, clinical and environmental characteristics of individuals were collected along with the diagnostic tests. After sampling and enrollment, seven hundred people from 2 to 14 years of age were included in the study. The prevalence of Leishmania infection was 33.28% (95% CI 29.87-36.84). The factors associated with Leishmania infection according to the multivariate analysis were age of more than seven years and the presence of opossums near the home. Age is a known factor associated with Leishmania infection; however, the presence of wild animals, as described, is an understudied factor. The presence of opossums, which are known reservoirs of Leishmania, in peri-urban areas could be the link between the rural and urban occurrence of visceral leishmaniasis in the outskirts of largest Brazilian cities, as suggested by previous studies.

  13. Immunohistological study of the endometrial stromal fibroblasts in the opossum, Monodelphis domestica: evidence for homology with eutherian stromal fibroblasts.

    PubMed

    Kin, Koryu; Maziarz, Jamie; Wagner, Günter P

    2014-05-01

    Molecular phylogenetic studies suggest that the hemochorial placentation and decidualization are ancestral traits of eutherian mammals. While the origin of the placental tissue is well understood, the origin of the decidual cells is unclear. Here we address the origin of decidual cells by examining the expression patterns of six transcription factors (TFs) as well as four structural proteins in the endometrium of a marsupial, Monodelphis domestica, and compared them with the patterns known from eutherian species. We found a mesenchymal cell population in the subepithelial compartment of the opossum endometrium. These cells express a set of TFs, such as homeobox A11 (HOXA11), CCAAT/enhancer-binding protein beta (CEBPB), and progesterone receptor (PGR), that are important for eutherian endometrial stromal cells. On the other hand, we did not find the expression of a decidual cell marker desmin (DES) or of TFs that are important for decidual cell differentiation, such as forkhead box O1 (FOXO1), in those cells. Based on these results, we propose that opossum has cells homologous to eutherian endometrial fibroblasts but no decidual cells. In addition, we describe cellular changes associated with the progression of pregnancy: nuclear localization of CEBPB in luminal epithelial cells as early as 8 days postcoitum, expansion of endometrial glands, nuclear localization of FOXO1 in glandular epithelial cells, and expression of smooth muscle actin in luminal epithelial cells. These data show that the luminal and glandular epithelium react to the presence of the preplacentation conceptus and suggest a limited form of pregnancy recognition.

  14. A genetic analysis of the Virginia opossum mating system: evidence of multiple paternity in a highly fragmented landscape.

    PubMed

    Beasley, James C; Beatty, William S; Olson, Zachary H; Rhodes, Olin E

    2010-01-01

    Using molecular techniques, we examined patterns of paternity in Virginia opossums occupying a highly fragmented agricultural landscape in northern Indiana. During 2008, we collected tissue from 64 females and their pouch young in 34 forest patches distributed over a 1100-km(2) region. Using genotypes from 10 microsatellite loci, we determined the minimum number of fathers contributing to each litter using GERUD 1.0. Genotyped offspring with known mothers were then analyzed using CERVUS 3.0, incorporating genotypes from 317 males sampled from 2007-2008 to identify potential fathers. Our analyses revealed that promiscuity was common among females, with 26 (41%) litters having > or = 2 sires. Despite the fact that we intensively sampled forest patches for potential fathers, we only were able to identify 13 fathers contributing to 14 litters, with an average Euclidean distance of 18.7 km between father-offspring pairs found in disparate patches (N = 6). Our inability to identify most (85%) fathers of sampled litters, coupled with the extensive distances observed between putative father-offspring pairs, suggests that opossums may not maintain explicit home ranges in highly fragmented landscapes.

  15. Endogenous Life Cycle of Eimeria marmosopos (Apicomplexa: Eimeriidae) from the Opossum, Didelphis marsupialis (Didelphimorphia: Didelphidae) in Costa Rica.

    PubMed

    Chinchilla, Misael; Valerio, Idalia; Duszynski, Donald

    2015-08-01

    The endogenous life cycle of Eimeria marmosopos was studied in experimentally infected young opossums, Didelphis marsupialis . All the endogenous stages were located in the epithelial cells of villi in the small intestine. Giemsa-stained mucosal scrapings and histological sections were studied for the diagnosis of all the life cycle stages. Eimeria marmosopos has 3 generations of meronts (M) that differ by size, shape, and number of merozoites (m), which also differ in their size, shape, and location of their nuclei within the cytoplasm of the meronts. The 3 meront types, M(1)-M(3), respectively, had 8-15 (m(1)), 4-9 (m(2)), and 22-30 (m(3)) merozoites. Macrogametocytes and microgametocytes, as well as macrogametes and microgametes, completed the sexual cycle, finishing with the formation of unsporulated oocysts. This parasite's endogenous development produced severe intestinal lesions in experimentally infected opossums. There are 56 Eimeria species known from all marsupials worldwide, but this is the first complete life cycle in which both the asexual and sexual stages have been documented.

  16. Prevalence of antibodies to Trypanosoma cruzi, Toxoplasma gondii, Encephalitozoon cuniculi, Sarcocystis neurona, Besnoitia darlingi, and Neospora caninum in North American opossums, Didelphis virginiana, from southern Louisiana.

    PubMed

    Houk, Alice E; Goodwin, David G; Zajac, Anne M; Barr, Stephen C; Dubey, J P; Lindsay, David S

    2010-12-01

    We examined the prevalence of antibodies to zoonotic protozoan parasites ( Trypanosoma cruzi, Toxoplasma gondii, and Encephalitozoon cuniculi) and protozoans of veterinary importance ( Neospora caninum, Sarcocystis neurona, and Besnoitia darlingi) in a population of North American opossums ( Didelphis virginiana) from Louisiana. Samples from 30 opossums were collected as part of a survey for T. cruzi in Louisiana. Frozen sera from these 30 opossums were examined using an indirect immunofluorescent antibody test (IFAT) against in vitro-produced antigenic stages of these protozoans. Additionally, 24 of the 30 samples were examined using hemoculture, and all 30 were examined in the modified direct agglutination test (MAT) for antibodies to To. gondii. The prevalences of reactive IFAT samples were as follows: 60% for T. cruzi, 27% for To. gondii, 23% for E. cuniculi, 17% for S. neurona, 47% for B. darlingi, and 0% for N. caninum. Hemoculture revealed that 16 (67%) of 24 samples were positive for T. cruzi, compared to 18 of 30 (60%) by IFAT. The sensitivity and specificity for the IFAT compared to hemoculture was 100% for each. The modified direct agglutination test revealed that 9 (30%) of the 30 samples from opossums had antibodies to To. gondii , compared to 8 (27%) using the IFAT. The sensitivity and specificity of the IFAT compared to the MAT was 100% and 72%, respectively.

  17. Sarcocystis neurona infections in raccoons (Procyon lotor): evidence for natural infection with sarcocysts, transmission of infection to opossums (Didelphis virginiana), and experimental induction of neurologic disease in raccoons.

    PubMed

    Dubey, J P; Saville, W J; Stanek, J F; Lindsay, D S; Rosenthal, B M; Oglesbee, M J; Rosypal, A C; Njoku, C J; Stich, R W; Kwok, O C; Shen, S K; Hamir, A N; Reed, S M

    2001-10-24

    Equine protozoal myeloencephalitis (EPM) is a serious neurologic disease of horses in the Americas and Sarcocystis neurona is the most common etiologic agent. The distribution of S. neurona infections follows the geographical distributions of its definitive hosts, opossums (Didelphis virginiana, Didelphis albiventris). Recently, cats and skunks were reported as experimental and armadillos as natural intermediate hosts of S. neurona. In the present report, raccoons (Procyon lotor) were identified as a natural intermediate host of S. neurona. Two laboratory-raised opossums were found to shed S. neurona-like sporocysts after ingesting tongues of naturally-infected raccoons. Interferon-gamma gene knockout (KO) mice fed raccoon-opossum-derived sporocysts developed neurologic signs. S. neurona was identified immunohistochemically in tissues of KO mice fed sporocysts and the parasite was isolated in cell cultures inoculated with infected KO mouse tissues. The DNA obtained from the tongue of a naturally-infected raccoon, brains of KO mice that had neurological signs, and from the organisms recovered in cell cultures inoculated with brains of neurologic KO mice, corresponded to that of S. neurona. Two raccoons fed mature S. neurona sarcocysts did not shed sporocysts in their feces, indicating raccoons are not likely to be its definitive host. Two raccoons fed sporocysts from opossum feces developed clinical illness and S. neurona-associated encephalomyelitis was found in raccoons killed 14 and 22 days after feeding sporocysts; schizonts and merozoites were seen in encephalitic lesions.

  18. Albumin transfer across the choroid plexus of South American opossum (Monodelphis domestica).

    PubMed Central

    Knott, G W; Dziegielewska, K M; Habgood, M D; Li, Z S; Saunders, N R

    1997-01-01

    1. Blood-cerebrospinal fluid (CSF) transfer of various exogenous albumins has been investigated in developing Monodelphis domestica (South American grey short-tailed opossum) and compared with the steady-state CSF: plasma ratios for endogenous (Monodelphis) albumin. Ratios for Monodelphis albumin and human albumin were similar and were the highest at postnatal day 5 (P5) (48.2 +/- 4.4 and 40.6 +/- 4.5%, respectively). The ratio for bovine albumin was similar to the steady-state ratio for Monodelphis albumin at P7-8 but became consistently lower than the Monodelphis albumin ratio at all other ages until P32-36 when all albumins tested attained a similar low ratio. The CSF:plasma ratio of chemically modified (succinylated) bovine albumin was always significantly lower than that of other albumins, except at the oldest age examined (P32-36). 2. Immunocytochemistry showed that within the brain, albumin was confined to the lumen and endothelial cells of blood vessels. In the choroid plexus only a small proportion (0.2-1.7% of the total cell number) of epithelial cells was positive for albumin, both endogenous and exogenous, at all ages studied (except the 3rd ventricle where cells were only positive from P8). The CSF was strongly positive for all albumins. The peak proportion of positive cells and of albumin concentrations in CSF occurred at P8. These findings suggest that the primary route for penetration of albumin into CSF is directly across the choroid plexus rather than via the brain. 3. Double-labelling immunocytochemistry revealed that the same epithelial cells contained both endogenous (Monodelphis) and exogenous (human) albumin. In contrast, for succinylated albumin, at P7 only about 35% (lateral ventricle) and 50% (4th ventricle) of Monodelphis albumin-positive cells were also positive for succinylated albumin, but by P30 this proportion increased to 90% at both sites. 4. Thus the developing choroid plexus distinguishes between different albumins. Chemical

  19. Effect of ezetimibe on plasma cholesterol levels, cholesterol absorption, and secretion of biliary cholesterol in laboratory opossums with high and low responses to dietary cholesterol.

    PubMed

    Chan, Jeannie; Kushwaha, Rampratap S; Vandeberg, Jane F; Vandeberg, John L

    2008-12-01

    Partially inbred lines of laboratory opossums differ in plasma low-density lipoprotein cholesterol concentration and cholesterol absorption on a high-cholesterol diet. The aim of the present studies was to determine whether ezetimibe inhibits cholesterol absorption and eliminates the differences in plasma cholesterol and hepatic cholesterol metabolism between high and low responders on a high-cholesterol diet. Initially, we determined that the optimum dose of ezetimibe was 5 mg/(kg d) and treated 6 high- and 6 low-responding opossums with this dose (with equal numbers of controls) for 3 weeks while the opossums consumed a high-cholesterol and low-fat diet. Plasma and low-density lipoprotein cholesterol concentrations decreased significantly (P < .05) in treated but not in untreated high-responding opossums. Plasma cholesterol concentrations increased slightly (P < .05) in untreated low responders but not in treated low responders. The percentage of cholesterol absorption was significantly higher in untreated high responders than in other groups. Livers from high responders with or without treatment were significantly (P < .01) heavier than livers from low responders with or without treatment. Hepatic cholesterol concentrations in untreated high responders were significantly (P < .05) higher than those in low responders with or without treatment (P < .001). The gall bladder bile cholesterol concentrations in untreated high responders were significantly (P < .05) lower than those in other groups. A decrease in biliary cholesterol in low responders treated with ezetimibe was associated with a decrease in hepatic expression of ABCG5 and ABCG8. These studies suggest that ezetimibe decreases plasma cholesterol levels in high responders mainly by decreasing cholesterol absorption and increasing biliary cholesterol concentrations. Because ezetimibe's target is NPC1L1 and NPC1L1 is expressed in the intestine of opossums, its effect on cholesterol absorption may be mediated

  20. Phylogenetic relationships of Sarcocystis neurona of horses and opossums to other cyst-forming coccidia deduced from SSU rRNA gene sequences.

    PubMed

    Elsheikha, Hany M; Lacher, David W; Mansfield, Linda S

    2005-11-01

    Phylogenetic analyses based on sequences of the nuclear-encoded small subunit rRNA (ssurRNA) gene were performed to examine the origin, phylogeny, and biogeographic relationships of Sarcocystis neurona isolates from opossums and horses from the State of Michigan, USA, in relation to other cyst-forming coccidia. A total of 31 taxa representing all recognized subfamilies and genera of Sarcocystidae were included in the analyses with clonal isolates of two opossum and two horse S. neurona. Phylogenies obtained by the four tree-building methods were consistent with the classical taxonomy based on morphological criteria. The "isosporid" coccidia Neospora, Toxoplasma, Besnoitia, Isospora lacking stieda bodies, and Hyaloklossia formed a sister group to the Sarcocystis spp. Sarcocystis species were divided into three main lineages; S. neurona isolates were located in the second lineage and clustered with S. mucosa, S. dispersa, S. lacertae, S. rodentifelis, S. muris, and Frenkelia spp. Alignment of S. neurona SSU rRNA gene sequences of Michigan opossum isolates (MIOP5, MIOP20) and a S. neurona Michigan horse isolate (MIH8) showed 100% identity. These Michigan isolates differed in 2/1085 bp (0.2%) from a Kentucky S. neurona horse isolate (SN5). Additionally, S. neurona isolates from horses and opossums were identical based on the ultrastructural features and PCR-RFLP analyses thus forming a phylogenetically indistinct group in these regions. These findings revealed the concordance between the morphological and molecular data and confirmed that S. neurona from opossums and horses originated from the same phylogenetic origin.

  1. Elevated calcium acutely regulates dynamic interactions of NHERF2 and NHE3 proteins in opossum kidney (OK) cell microvilli.

    PubMed

    Zhu, Xinjun; Cha, Boyoung; Zachos, Nicholas C; Sarker, Rafiquel; Chakraborty, Molee; Chen, Tian-E; Kovbasnjuk, Olga; Donowitz, Mark

    2011-10-07

    The brush border (BB) Na(+)/H(+) exchanger NHE3 is rapidly activated or inhibited by changes in trafficking, which mimics renal and intestinal physiology. However, there is a paradox in that NHE3 has limited mobility in the BB due to its binding to the multi-PDZ domain containing the NHERF family. To allow increased endocytosis, as occurs with elevated intracellular Ca(2+), we hypothesized that NHE3 had to be, at least transiently, released from the BB cytoskeleton. Because NHERF1 and -2 are localized at the BB, where they bind NHE3 as well as the cytoskeleton, we tested whether either or both might dynamically interact with NHE3 as part of Ca(2+) signaling. We employed FRET to study close association of NHE3 and these NHERFs and fluorescence recovery after photobleaching to monitor NHE3 mobility in the apical domain in polarized opossum kidney cells. Under basal conditions, NHERF2 and NHE3 exhibited robust FRET signaling. Within 1 min of A23187 (0.5 μm) exposure, the NHERF2-NHE3 FRET signal was abolished, and BB NHE3 mobility was transiently increased. The dynamics in FRET signal and NHE3 mobility correlated well with a change in co-precipitation of NHE3 and NHERF2 but not NHERF1. We conclude the following. 1) Under basal conditions, NHE3 closely associates with NHERF2 in opossum kidney cell microvilli. 2) Within 1 min of elevated Ca(2+), the close association of NHE3-NHERF2 is abolished but is re-established in ∼60 min. 3) The change in NHE3-NHERF2 association is accompanied by an increased BB mobile fraction of NHE3, which contributes to inhibition of NHE3 transport activity via increased endocytosis.

  2. Weight-bearing locomotion in the developing opossum, Monodelphis domestica following spinal transection: remodeling of neuronal circuits caudal to lesion.

    PubMed

    Wheaton, Benjamin J; Noor, Natassya M; Whish, Sophie C; Truettner, Jessie S; Dietrich, W Dalton; Zhang, Moses; Crack, Peter J; Dziegielewska, Katarzyna M; Saunders, Norman R

    2013-01-01

    Complete spinal transection in the mature nervous system is typically followed by minimal axonal repair, extensive motor paralysis and loss of sensory functions caudal to the injury. In contrast, the immature nervous system has greater capacity for repair, a phenomenon sometimes called the infant lesion effect. This study investigates spinal injuries early in development using the marsupial opossum Monodelphis domestica whose young are born very immature, allowing access to developmental stages only accessible in utero in eutherian mammals. Spinal cords of Monodelphis pups were completely transected in the lower thoracic region, T10, on postnatal-day (P)7 or P28 and the animals grew to adulthood. In P7-injured animals regrown supraspinal and propriospinal axons through the injury site were demonstrated using retrograde axonal labelling. These animals recovered near-normal coordinated overground locomotion, but with altered gait characteristics including foot placement phase lags. In P28-injured animals no axonal regrowth through the injury site could be demonstrated yet they were able to perform weight-supporting hindlimb stepping overground and on the treadmill. When placed in an environment of reduced sensory feedback (swimming) P7-injured animals swam using their hindlimbs, suggesting that the axons that grew across the lesion made functional connections; P28-injured animals swam using their forelimbs only, suggesting that their overground hindlimb movements were reflex-dependent and thus likely to be generated locally in the lumbar spinal cord. Modifications to propriospinal circuitry in P7- and P28-injured opossums were demonstrated by changes in the number of fluorescently labelled neurons detected in the lumbar cord following tracer studies and changes in the balance of excitatory, inhibitory and neuromodulatory neurotransmitter receptors' gene expression shown by qRT-PCR. These results are discussed in the context of studies indicating that although

  3. Locomotor kinetics and kinematics on inclines and declines in the gray short-tailed opossum Monodelphis domestica.

    PubMed

    Lammers, Andrew R; Earls, Kathleen D; Biknevicius, Audrone R

    2006-10-01

    Small terrestrial animals continually encounter sloped substrates when moving about their habitat; therefore, it is important to understand the mechanics and kinematics of locomotion on non-horizontal substrates as well as on level terrain. To this end, we trained gray short-tailed opossums (Monodelphis domestica) to move along level, 30 degrees inclined, and 30 degrees declined trackways instrumented with a force platform. Vertical, craniocaudal and mediolateral impulses, peak vertical forces, and required coefficient of friction (mu(req)) of individual limbs were calculated. Two high speed video cameras were used to simultaneously capture whole limb craniocaudal and mediolateral angles at limb touchdown, midstance and lift-off. Patterns on the level terrain were typical for non-primate quadrupeds: the forelimbs supported the majority of the body weight, forelimbs were net braking and hindlimbs net propulsive, and both limb pairs exerted small laterally directed impulses. M. domestica moved more slowly on sloped substrates in comparison to level locomotion, and exhibited a greater mu(req). On inclines, both limb pairs were more protracted at touchdown and more retracted at lift-off, fore- and hindlimbs had equal roles in body weight support, forelimbs exerted greater propulsive impulse than hindlimbs, and mu(req) was greater in the forelimbs than in hindlimbs. On declines, only the forelimbs were more protracted at touchdown; forelimbs supported the great majority of body weight while they generated nearly all of the braking impulse and, despite the disparity in fore- vs hindlimb function on the decline, mu(req) was not significantly different between limbs. These differences on the inclined and declined surfaces most likely result from (1) the location of the opossums' center of mass, which is closer to the forelimbs than to the hindlimbs, and (2) the greater functional range of the forelimbs versus the hindlimbs.

  4. Weight-Bearing Locomotion in the Developing Opossum, Monodelphis domestica following Spinal Transection: Remodeling of Neuronal Circuits Caudal to Lesion

    PubMed Central

    Wheaton, Benjamin J.; Noor, Natassya M.; Whish, Sophie C.; Truettner, Jessie S.; Dietrich, W. Dalton; Zhang, Moses; Crack, Peter J.; Dziegielewska, Katarzyna M.; Saunders, Norman R.

    2013-01-01

    Complete spinal transection in the mature nervous system is typically followed by minimal axonal repair, extensive motor paralysis and loss of sensory functions caudal to the injury. In contrast, the immature nervous system has greater capacity for repair, a phenomenon sometimes called the infant lesion effect. This study investigates spinal injuries early in development using the marsupial opossum Monodelphis domestica whose young are born very immature, allowing access to developmental stages only accessible in utero in eutherian mammals. Spinal cords of Monodelphis pups were completely transected in the lower thoracic region, T10, on postnatal-day (P)7 or P28 and the animals grew to adulthood. In P7-injured animals regrown supraspinal and propriospinal axons through the injury site were demonstrated using retrograde axonal labelling. These animals recovered near-normal coordinated overground locomotion, but with altered gait characteristics including foot placement phase lags. In P28-injured animals no axonal regrowth through the injury site could be demonstrated yet they were able to perform weight-supporting hindlimb stepping overground and on the treadmill. When placed in an environment of reduced sensory feedback (swimming) P7-injured animals swam using their hindlimbs, suggesting that the axons that grew across the lesion made functional connections; P28-injured animals swam using their forelimbs only, suggesting that their overground hindlimb movements were reflex-dependent and thus likely to be generated locally in the lumbar spinal cord. Modifications to propriospinal circuitry in P7- and P28-injured opossums were demonstrated by changes in the number of fluorescently labelled neurons detected in the lumbar cord following tracer studies and changes in the balance of excitatory, inhibitory and neuromodulatory neurotransmitter receptors’ gene expression shown by qRT-PCR. These results are discussed in the context of studies indicating that although

  5. A Sarcocystid misidentified as Hepatozoon didelphydis: molecular data from a parasitic infection in the blood of the Southern mouse opossum (Thylamys elegans) from Chile.

    PubMed

    Merino, Santiago; Vásquez, Rodrigo A; Martínez, Javier; Celis-Diez, Juan L; Martínez-de la Puente, Josué; Marín-Vial, Paula; Sánchez-Monsalvez, Inocencia; Peirce, Michael A

    2008-01-01

    The blood of 21 adult South American mouse opossums (Thylamys elegans) captured from April through August of 2005 in central Chile was examined for parasites. Light microscopic analysis of blood smears initially suggested that a highly pleomorphic Hepatozoon species typical of American opossums was infecting erythrocytes. Unexpectedly, amplification by PCR and sequencing of a DNA fragment of the small subunit rDNA combined with phylogenetic analyses indicated that the parasite is not a member of the suborder Adeleorina, which includes the Haemogregarina and Hepatozoon species, but that it is a clearly distinct member of the suborder Eimeriorina, which includes the cyst-forming family Sarcocystidae. Therefore, a reclassification of this unusual intraerythrocytic apicomplexan will require additional life cycle, microscopic, and molecular analyses.

  6. Coccidial dispersion across New World marsupials: Klossiella tejerai Scorza, Torrealba & Dagert, 1957 (Apicomplexa: Adeleorina) from the Brazilian common opossum Didelphis aurita (Wied-Neuwied) (Mammalia: Didelphimorphia).

    PubMed

    Dos Santos, Caroline Spitz; Berto, Bruno Pereira; do Bomfim Lopes, Bruno; Cordeiro, Matheus Dias; da Fonseca, Adivaldo Henrique; Filho, Walter Leira Teixeira; Lopes, Carlos Wilson Gomes

    2014-09-01

    Klossiella tejerai Scorza, Torrealba & Dagert, 1957 is a primitive coccidian parasite reported from the New World marsupials Didelphis marsupialis (Linnaeus) and Marmosa demerarae (Thomas). The current work describes K. tejerai from the Brazilian common opossum Didelphis aurita (Wied-Neuwied) in Southeastern Brazil, evidencing the coccidial dispersion across opossums of the same family. The sporocysts recovered from urine samples were ellipsoidal, 20.4 × 12.7 µm, with sporocyst residuum composed of scattered spherules and c.13 sporozoites per sporocyst, with refractile bodies and nucleus. Macrogametes, microgametes, sporonts, sporoblasts/sporocysts were identified within parasitophorous vacuoles of epithelial cells located near the renal corticomedullary junction. Didelphis marsupialis should not have transmitted K. tejerai to D. aurita because they are not sympatric; however M. demerarae is sympatric with D. marsupialis and D. aurita. Therefore, D. aurita becomes the third host species for K. tejerai in South America.

  7. Evidence for high levels of androgen in peripheral plasma during postnatal development in a marsupial: the gray short-tailed opossum (Monodelphis domestica).

    PubMed

    Fadem, B H; Harder, J D

    1992-01-01

    Plasma samples were assayed for androgen in gray short-tailed opossums (Monodelphis domestica) on the day of birth and at selected ages through adulthood. Levels of androgen in mixed-sex plasma pools of animals 4 and 8 days of age were higher than in either sex at all other ages examined. At postnatal Days 16, 30, and 60 (weaning), levels of androgen were equivalent in males and females and as high as in adult males. In both sexes, androgen levels were lower at postnatal Day 84 (juveniles) than at younger ages; after puberty, levels were significantly higher in males than in females. These findings are discussed with respect to similarities and differences between marsupials and eutherians in hormonal environment during the perinatal period and with respect to the possible role of androgens in sexual differentiation of the gray opossum brain.

  8. The relationships of marsupial-dwelling Viannaiidae and description of Travassostrongylus scheibelorum sp. n. (Trichostrongylina: Heligmosomoidea) from mouse opossums (Didelphidae) from French Guiana.

    PubMed

    Scheibel, R Philip; Catzeflis, François; Jiméñez, F Agustín

    2014-06-01

    The trichostrongylid nematode Travassostrongylus scheibelorum sp. n. from the Linnaeus' mouse opossum, Marmosa murina (Linnaeus) (type host), and the woolly mouse opossum, Marmosa demerarae (Thomas), from French Guiana is described. The nematodes have a synlophe with ridges frontally oriented from right to left, six dorsal and six ventral, at midbody; seven dorsal and seven ventral posterior to the vulva, and two cuticular thickenings within the lateral spaces; a long dorsal ray and a pointed cuticular flap covering the vulva. This is the 12th species of Travassostrongylus Orloff, 1933, which includes species featuring ridges around the synlophe and a didelphic condition. These traits contrast with those in other genera in the Viannaiidae Neveu-Lemaire, 1934, which feature ventral ridges on the synlophe of adults and a monodelphic condition. Members of the family are chiefly Neotropical and are diagnosed based on the presence of a bursa of the type 2-2-1, 2-1-2 or irregular, and cuticle without ridges on the dorsal side (at least during one stage of their development). Herein, we present a reconstruction of the ancestral states of the didelphic/monodelphic condition and the cuticular ridges that form the synlophe in opossum-dwelling trichostrongyles, namely Travassostrongylus and Viannaia Travassos, 1914. Our investigations suggest they are not reciprocal sister taxa and that the change from didelphy to monodelphy and the loss of dorsal ridges, occurred in the common ancestor of species of Viannaia. These results suggest a synlophe with three ventral ridges is not plesiomorphic in the opossum dwelling trichostrongylids.

  9. Firing properties of accessory olfactory bulb mitral/tufted cells in response to urine delivered to the vomeronasal organ of gray short-tailed opossums.

    PubMed

    Zhang, Jing-Ji; Huang, Guang-Zhe; Halpern, Mimi

    2007-05-01

    In comparison with many mammals, there is limited knowledge of the role of pheromones in conspecific communication in the gray short-tailed opossum. Here we report that mitral/tufted (M/T) cells of the accessory olfactory bulb (AOB) of male opossums responded to female urine but not to male urine with two distinct patterns: excitation followed by inhibition or inhibition. Either pattern could be mimicked by application of guanosine 5'-O-3-thiotriphosphate and blocked by guanosine 5'-O-2-thiodiphosphate, indicating that the response of neurons in this pathway is through a G-protein-coupled receptor mechanism. In addition, the inhibitor of phospholipase C (PLC), U73122, significantly blocked urine-induced responses. Male and female urine were ineffective as stimuli for M/T cells in the AOB of female opossums. These results indicate that urine of diestrous females contains a pheromone that directly stimulates vomeronasal neurons through activation of PLC by G-protein-coupled receptor mechanisms and that the response to urine is sexually dimorphic.

  10. Chromosome-wide profiling of X-chromosome inactivation and epigenetic states in fetal brain and placenta of the opossum, Monodelphis domestica.

    PubMed

    Wang, Xu; Douglas, Kory C; Vandeberg, John L; Clark, Andrew G; Samollow, Paul B

    2014-01-01

    Evidence from a few genes in diverse species suggests that X-chromosome inactivation (XCI) in marsupials is characterized by exclusive, but leaky inactivation of the paternally derived X chromosome. To study the phenomenon of marsupial XCI more comprehensively, we profiled parent-of-origin allele-specific expression, DNA methylation, and histone modifications in fetal brain and extra-embryonic membranes in the gray, short-tailed opossum (Monodelphis domestica). The majority of X-linked genes (152 of 176 genes with trackable SNP variants) exhibited paternally imprinted expression, with nearly 100% of transcripts derived from the maternal allele; whereas 24 loci (14%) escaped inactivation, showing varying levels of biallelic expression. In addition to recently reported evidence of marsupial XCI regulation by the noncoding Rsx transcript, strong depletion of H3K27me3 at escaper gene loci in the present study suggests that histone state modifications also correlate strongly with opossum XCI. In contrast to mouse, the opossum did not show an association between X-linked gene expression and promoter DNA methylation, with one notable exception. Unlike all other X-linked genes examined, Rsx was differentially methylated on the maternal and paternal X chromosomes, and expression was exclusively from the inactive (paternal) X chromosome. Our study provides the first comprehensive catalog of parent-of-origin expression status for X-linked genes in a marsupial and sheds light on the regulation and evolution of imprinted XCI in mammals.

  11. Normal organ weights, serum chemistry, hematology, and cecal and nasopharyngeal bacterial cultures in the gray short-tailed opossum (Monodelphis domestica).

    PubMed

    Evans, Kristin D; Hewett, Terry A; Clayton, Cindy J; Krubitzer, Leah A; Griffey, Stephen M

    2010-07-01

    Gray short-tailed opossums (Monodelphis domestica) currently are used in genetic, developmental, oncology, and neurologic research. Little is known about their natural flora or potential for pathogenic infectious disease. The present study aims to improve existing comparative normal blood and organ weight values available to researchers and to describe flora of clinically normal M. domestica to obtain an understanding of potential pathogenic flora in clinically abnormal animals. For evaluation of serum hematology and serum chemistry, clinically normal animals were assigned to 1 of 6 groups stratified by age (younger than 1 y, 1 to 2 y, and 2 to 3 y) and sex. Hemoglobin and phosphorus levels were higher in male than female opossums, whereas monocyte and eosinophil counts were greater in females than males. Hemoglobin concentration decreased with increasing age. The youngest group had significantly higher levels of serum alkaline phosphatase and lower serum protein levels compared with older age groups. Liver and kidney weights of adult animals (1 to 3 y) were greater in female than male opossums. The predominant nasopharyngeal flora in 20 clinically normal animals from the 2- to 3-y-old group were Streptococcus viridans, Escherichia coli, and coagulase-negative Staphylococcus spp.; predominant cecal organisms were Escherichia coli and Citrobacter spp. The availability of reference hematologic values and flora for Monodelphis domestica will aid researchers in comparisons and analysis of experimental data and in diagnosis and evaluation of potential pathogens in clinically ill animals.

  12. Molecular characterisation and expression of CD4 in two distantly related marsupials: the gray short-tailed opossum (Monodelphis domestica) and tammar wallaby (Macropus eugenii).

    PubMed

    Duncan, Louise G; Nair, Sham V; Deane, Elizabeth M

    2007-07-01

    The gene and corresponding cDNA for CD4 in the gray short-tailed opossum, Monodelphis domestica, and the cDNA sequence for CD4 in the tammar wallaby, Macropus eugenii, have been characterised. The opossum CD4 homolog reveals conserved synteny, preserved genomic organisation and analogous structural arrangement to human and mouse CD4. Opossum and tammar CD4 exhibit typical eutherian CD4 features including the highly conserved p56(lck) binding motif in the cytoplasmic region and the invariant cysteine residues in extracellular domains 1 and 4. Interestingly, the marsupial CD4 sequences substitute a tryptophan for the first cysteine in domain 2 negating the formation of a disulphide bond as seen in other eutherian CD4 sequences except human and mouse. Overall the marsupial CD4 sequences share amino acid identity of 59% to each other and 37-41% with eutherian mammals. However, in contrast to eutherian homologs, the marsupial CD4 sequences were found to be truncated at the terminal end of the cytoplasmic tail. This is the first report confirming the presence of CD4 in a marsupial and describing its key features.

  13. Distribution of the neuronal gap junction protein Connexin36 in the spinal cord enlargements of developing and adult opossums, Monodelphis domestica.

    PubMed

    Lemieux, Maxime; Cabana, Thérèse; Pflieger, Jean-François

    2010-01-01

    We use opossums Monodelphis domestica to study the development of mammalian motor systems. The immature forelimbs of the newborn perform rhythmic and alternating movements that are likely under spinal control. The hindlimbs start moving in the second week. Chemical synapses are scant in the spinal enlargements of neonatal opossums and the presence of electrochemical synapses has not been evaluated in this species or in other marsupials. As a first step aiming at evaluating the existence of such synapses in the neonatal spinal cord, we have investigated the presence of the exclusively neuronal gap junction protein connexin36 (Cx36) by immunohistochemistry in light microscopy. At birth, Cx36 immunoreactivity is moderate in the presumptive gray matter in both enlargements. Thereafter, it decreases gradually, except in the superficial dorsal horn where it increases to a plateau between P10 and P20. Cx36 labeling is detected in the presumptive white matter at birth, but then decreases except in the dorsal part of the lateral funiculus, where it is dense between P10 and P20. Cx36 has become virtually undetectable by P52. The presence of Cx36 in the spinal enlargements of postnatal opossums suggests that neurons might be linked by gap junctions at a time when chemical synapses are only beginning to form. The greater abundance of Cx36 observed transiently in the superficial dorsal horn suggests a stronger involvement of this protein in spinal sensory systems than in direct motor control of the limbs.

  14. The effects of substrate texture on the mechanics of quadrupedal arboreal locomotion in the gray short-tailed opossum (Monodelphis domestica).

    PubMed

    Lammers, Andrew R

    2009-12-01

    Among small mammals, the ability to move on tree trunks, branches, and twigs is nearly ubiquitous. Performance and locomotor mechanics on arboreal substrates may be influenced by variation in the coefficient of friction between the hands/feet of the animal and the surface of the arboreal substrate. To test this, I examined speed, substrate reaction forces, and torque around the long axis of two cylindrical trackways with rough and smooth surfaces in gray short-tailed opossums (Monodelphis domestica). Speed was determined with videography, and forces and torques were measured by an instrumented section of the trackway. The opossums traveled more slowly on the smooth arboreal trackway. There was also significant interaction between limb (forelimbs, hindlimbs) and substrate texture (rough, smooth) in braking, propulsive, and laterally directed impulses. Running on the smooth trackway had the effect of reducing some between-limb (forelimb vs. hindlimb) differences. Stability on the rough trackway was probably maintained by relatively high momentum, but on the smooth trackway, the opossums used static methods (many limbs contacting the substrate, greater muscular effort, lower momentum) to remain stable and avoid toppling. Clearly, momentum and dynamics are often important biomechanical considerations for this generalized mammal. Highly arboreal animals can remain dynamically stable on a wider variety of substrate textures.

  15. Chromosome-wide profiling of X-chromosome inactivation and epigenetic states in fetal brain and placenta of the opossum, Monodelphis domestica

    PubMed Central

    Wang, Xu; Douglas, Kory C.; VandeBerg, John L.; Clark, Andrew G.; Samollow, Paul B.

    2014-01-01

    Evidence from a few genes in diverse species suggests that X-chromosome inactivation (XCI) in marsupials is characterized by exclusive, but leaky inactivation of the paternally derived X chromosome. To study the phenomenon of marsupial XCI more comprehensively, we profiled parent-of-origin allele-specific expression, DNA methylation, and histone modifications in fetal brain and extra-embryonic membranes in the gray, short-tailed opossum (Monodelphis domestica). The majority of X-linked genes (152 of 176 genes with trackable SNP variants) exhibited paternally imprinted expression, with nearly 100% of transcripts derived from the maternal allele; whereas 24 loci (14%) escaped inactivation, showing varying levels of biallelic expression. In addition to recently reported evidence of marsupial XCI regulation by the noncoding Rsx transcript, strong depletion of H3K27me3 at escaper gene loci in the present study suggests that histone state modifications also correlate strongly with opossum XCI. In contrast to mouse, the opossum did not show an association between X-linked gene expression and promoter DNA methylation, with one notable exception. Unlike all other X-linked genes examined, Rsx was differentially methylated on the maternal and paternal X chromosomes, and expression was exclusively from the inactive (paternal) X chromosome. Our study provides the first comprehensive catalog of parent-of-origin expression status for X-linked genes in a marsupial and sheds light on the regulation and evolution of imprinted XCI in mammals. PMID:24065774

  16. In vivo strains in the femur of the Virginia opossum (Didelphis virginiana) during terrestrial locomotion: testing hypotheses of evolutionary shifts in mammalian bone loading and design.

    PubMed

    Butcher, Michael T; White, Bartholomew J; Hudzik, Nathan B; Gosnell, W Casey; Parrish, John H A; Blob, Richard W

    2011-08-01

    Terrestrial locomotion can impose substantial loads on vertebrate limbs. Previous studies have shown that limb bones from cursorial species of eutherian mammals experience high bending loads with minimal torsion, whereas the limb bones of non-avian reptiles (and amphibians) exhibit considerable torsion in addition to bending. It has been hypothesized that these differences in loading regime are related to the difference in limb posture between upright mammals and sprawling reptiles, and that the loading patterns observed in non-avian reptiles may be ancestral for tetrapod vertebrates. To evaluate whether non-cursorial mammals show loading patterns more similar to those of sprawling lineages, we measured in vivo strains in the femur during terrestrial locomotion of the Virginia opossum (Didelphis virginiana), a marsupial that uses more crouched limb posture than most mammals from which bone strains have been recorded, and which belongs to a clade phylogenetically between reptiles and the eutherian mammals studied previously. The presence of substantial torsion in the femur of opossums, similar to non-avian reptiles, would suggest that this loading regime likely reflects an ancestral condition for tetrapod limb bone design. Strain recordings indicate the presence of both bending and appreciable torsion (shear strain: 419.1 ± 212.8 με) in the opossum femur, with planar strain analyses showing neutral axis orientations that placed the lateral aspect of the femur in tension at the time of peak strains. Such mediolateral bending was unexpected for a mammal running with near-parasagittal limb kinematics. Shear strains were similar in magnitude to peak compressive axial strains, with opossum femora experiencing similar bending loads but higher levels of torsion compared with most previously studied mammals. Analyses of peak femoral strains led to estimated safety factor ranges of 5.1-7.2 in bending and 5.5-7.3 in torsion, somewhat higher than typical mammalian values

  17. α2C-Adrenoceptors modulate L-DOPA uptake in opossum kidney cells and in the mouse kidney.

    PubMed

    Moura, Eduardo; Silva, Elisabete; Serrão, Maria Paula; Afonso, Joana; Kozmus, Carina Esteves Pinto; Vieira-Coelho, Maria Augusta

    2012-10-01

    Targeted deletion or selective pharmacological inhibition of α(2C)-adrenoceptors in mice results in increased brain tissue levels of dopamine and its precursor l-3,4-dihydroxyphenylalanine (l-DOPA), without significant changes in l-DOPA synthesis. l-DOPA uptake is considered the rate-limiting step in dopamine synthesis in the kidney. Since α(2C)-adrenoceptors may influence the transport of l-DOPA, we investigated the effect of α(2C)-adrenoceptor activation on l-DOPA uptake in a kidney cell line (opossum kidney cells). l-DOPA and dopamine kidney tissue levels in α(2C)-adrenoceptor knockout (α(2C)KO) mice and in mice treated with the selective α(2C)-adrenoceptor antagonist JP-1302 were also evaluated. The α(2)-adrenoceptor agonist medetomidine (0.1-1,000 nM) produced a concentration-dependent decrease in l-DOPA uptake in opossum kidney cells (IC(50): 2.5 ± 0.5 nM and maximal effect: 28 ± 5% of inhibition). This effect was abolished by a preincubation with JP-1302 (300 nM). Furthermore, the effect of medetomidine (100 nM) was abolished by a preincubation with U-0126 (10 μM), a MEK1/2 inhibitor. Kidney tissue levels of l-DOPA were significantly higher in α(2C)KO mice compared with wild-type mice (wild-type mice: 58 ± 2 pmol/g tissue and α(2C)KO mice: 81 ± 15 pmol/g tissue, P < 0.05) and in mice treated with JP-1302 (3 μmol/kg body wt) compared with control mice (control mice: 62 ± 2 pmol/g tissue and JP-1302-treated mice: 75 ± 1 pmol/g tissue, P < 0.05), both without significant changes in dopamine kidney tissue levels. However, mice treated with JP-1302 on a high-salt diet presented significantly higher dopamine levels in the kidney and urine compared with control animals on a high-salt diet. In conclusion, in a kidney cell line, α(2C)-adrenoceptor activation inhibits l-DOPA uptake, and in mice, deletion or blockade of α(2C)-adrenoceptors increases l-DOPA kidney tissue levels.

  18. The development and migration of large multipolar neurons into the cochlear nucleus of the North American opossum.

    PubMed

    Willard, F H; Martin, G F

    1986-06-01

    We have studied the maturation of the inferior colliculus and cochlear nuclei of the North American opossum with particular emphasis on the large multipolar neurons of the cochlear nucleus. These neurons include the principal and giant cells of the dorsal cochlear nucleus (DCN) and the large neurons of the ventral cochlear nucleus (VCN), all of which can be labelled by horseradish peroxidase (HRP) injections into the contralateral inferior colliculus (IC). The size of these neurons, their characteristic Nissl patterns, and their labelling density after injections into the IC render them distinguishable from other neurons in this nuclei, even in young animals. In Nissl-stained sections of newborn opossums, a band of horizontally oriented neurons can be identified dorsomedial to the vestibular nerve root. This band extends from an apparent cytogenetic zone close to the sulcus limitans, to, but not within, the presumptive cochlear nucleus. Between birth and estimated postnatal day 22 (EPND 22) the band shifts laterally, eventually becoming incorporated into the cochlear nucleus. Many neurons in this band have perinuclear caps of Nissl substance similar to those present in the principal cells of the adult DCN. Injections of HRP into the IC as early as EPND 5 (17 days after conception) labelled neurons in the band referred to above but not in the presumptive cochlear nucleus. By EPND 15, labelled cells were clustered mainly within the nucleus proper. Most of these cells were located in the DCN, but a few were scattered in the dorsocentral VCN. Consistent labelling of small neurons in VCN was not obtained until sometime later. From EPND 15 to EPND 20 most of the labelled cells in DCN reoriented in the vertical plane, aligned in layer II, and differentiated into principal neurons. Some, however, remained deep to layer II and differentiated into giant neurons. The heavily labelled cells in VCN differentiated into large neurons. Our results suggest that the large multipolar

  19. Alpha-2 adrenergic and serotonin-1B receptors in the OK cell, an opossum kidney cell line

    SciTech Connect

    Murphy, T.J.

    1988-01-01

    Alpha-2 adrenergic and serotonin-1B (5HT{sub 1B}) receptors, both negatively-coupled to adenylyl cyclase, were characterized in the OK cell line, a renal proximal tubule epithelial cell line derived from the kidney of a North American opossum. In membrane saturation radioligand binding experiments, ({sup 3}H)yohimbine and ({sup 3}H)rauwolscine labeled an equivalent number of binding sites. Detailed pharmacological analysis of OK cell alpha-2 adrenergic receptors in competition binding assays indicate this receptor is neither an alpha-2A nor an alpha-2B adrenergic receptor subtype, although the alpha-2B receptor subtype-selective drugs prazosin, ARC-239 and chlorpromazine have affinities for OK cell alpha-2 adrenergic receptors similar to those at the alpha-2B receptor subtype. Determinations of agonist potency for inhibition of PTH-stimulated cyclic AMP production and radioligand binding analysis using ({sup 125}I)({minus})-cyanopindolol indicate that a 5HT{sub 1B} receptor is expressed in the OK cell line. A biochemical effector system coupled to this receptor subtype has not been previously described. Several compounds appear to be potent agonists at the 5TH{sub 1B} receptor including the beta adrenergic antagonists cyanopindolol, pindolol, propranolol and alprenolol.

  20. Genetic diversity of laboratory gray short-tailed opossums (Monodelphis domestica): effect of newly introduced wild-caught animals.

    PubMed

    van Oorschot, R A; Williams-Blangero, S; VandeBerg, J L

    1992-06-01

    The colony of gray, short-tailed opossums (Monodelphis domestica) at the Southwest Foundation for Biomedical Research, the primary supplier of this species for research purposes, was founded with nine animals trapped in 1978 in the state of Pernambuco, Brazil. Since 1984, 14 newly acquired founders from the state of Paraiba, Brazil have contributed to the gene pool of the colony. The animals from Paraiba and their descendants are significantly larger than the founders from Pernambuco and their descendants. The two groups also differ significantly in several measurements of morphologic traits. The changes in proportional contribution of each founder to the colony, and changes in inbreeding coefficients during the colony's history, are evaluated. Using previously established markers and three newly identified markers (ACP2, APRT, and DIA1), we show that the Paraiba-derived animals differ significantly from the original founders in allele frequencies and heterozygosity. The genetic diversity of the colony has been substantially increased by acquisition of the new founders from Paraiba. The colony is highly polymorphic, with 22.2% of loci surveyed by protein electrophoresis being variable. We conclude that the genetic differences between populations and among projects within the colony should be considered in future colony management procedures and in selection of experimental subjects.

  1. X-linked gene expression in the Virginia opossum: differences between the paternally derived Gpd and Pgk-A loci

    SciTech Connect

    Samollow, P.B.; Ford, A.L.; VandeBerg, J.L.

    1987-01-01

    Expression of X-linked glucose-6-phosphate dehydrogenase (G6PD) and phosphoglycerate kinase-A (PGK-A) in the Virginia opossum (Didelphis virginiana) was studied electrophoretically in animals from natural populations and those produced through controlled laboratory crosses. Blood from most of the wild animals exhibited a common single-banded phenotype for both enzymes. Rare variant animals, regardless of sex, exhibited single-banded phenotypes different in mobility from the common mobility class of the respective enzyme. The laboratory crosses confirmed the allelic basis for the common and rare phenotypes. Transmission of PGK-A phenotypes followed the pattern of determinate (nonrandom) inactivation of the paternally derived Pgk-A allele, and transmission of G6PD also was consistent with this pattern. A survey of tissue-specific expression of G6PD phenotypes of heterozygous females revealed, in almost all tissues, three-banded patterns skewed in favor of the allele that was expressed in blood cells. Three-banded patterns were never observed in males or in putatively homozygous females. These patterns suggest simultaneous, but unequal, expression of the maternally and paternally derived Gpd alleles within individual cells. The absence of such partial expression was noted in a parallel survey of females heterozygous at the Pgd-A locus. Thus, it appears that Gpd and Pgk-A are X-linked in D. virginiana and subject to preferential paternal allele inactivation, but that dosage compensation may not be complete for all paternally derived X-linked genes.

  2. A microsatellite-based, physically anchored linkage map for the gray, short-tailed opossum (Monodelphis domestica).

    PubMed

    Samollow, Paul B; Gouin, Nicolas; Miethke, Pat; Mahaney, Susan M; Kenney, Margaret; VandeBerg, John L; Graves, Jennifer A Marshall; Kammerer, Candace M

    2007-01-01

    The genome of the gray, short-tailed opossum, Monodelphis domestica, will be the first of any marsupial to be fully sequenced. The utility of this sequence will be greatly enhanced by construction and integration of detailed genetic and physical maps. Therefore, it is important to verify the unusual recombinational characteristics that were suggested by the 'first-generation' M. domestica linkage map; specifically, very low levels of recombination and severely reduced female recombination, both of which are contrary to patterns in other vertebrates. We constructed a new linkage map based on a different genetic cross, using a new and much larger set of map markers, and physically anchored and oriented the linkage groups onto chromosomes via fluorescence in-situ hybridization mapping. This map includes 150 loci in eight autosomal linkage groups corresponding to the eight autosome pairs, and spans 86-89% of the autosomal genome. The sex-averaged autosomal map covers 715 cM, with a full-length estimate of 866 cM; the shortest full-length linkage map reported for any vertebrate. The sex-specific maps confirmed severely reduced female recombination in all linkage groups, and an overall F/M map ratio = 0.54. These results greatly extend earlier findings, and provide an improved microsatellite-based linkage map for this species.

  3. Torpor at high ambient temperature in a neotropical didelphid, the grey short-tailed opossum (Monodelphis domestica).

    PubMed

    Busse, Sebastian; Lutter, Dominik; Heldmaier, Gerhard; Jastroch, Martin; Meyer, Carola W

    2014-11-01

    The grey short-tailed opossum, Monodelphis domestica, has been an established research animal for more than five decades, but relatively, little is known about its thermophysiology. Here we studied core body temperature (T b) and metabolic rate (MR) of female adult M. domestica housed in the laboratory at an ambient temperature (T a) of 26 °C. In expanding previous reports, the average recorded core T b of M. domestica was 34.3 °C. The T b of an individual M. domestica can drop below 30 °C (minimal T b: 28.6 °C) accompanied by a reduction in MR of up to 52 % even while having ad libitum access to food. These findings demonstrate for the first time the presence of spontaneous torpor in M. domestica. Metabolic suppression at relatively high T a and T b furthermore broadens our perspective on the use of torpor as a metabolic strategy not just restricted to cold climates.

  4. Torpor at high ambient temperature in a neotropical didelphid, the grey short-tailed opossum ( Monodelphis domestica)

    NASA Astrophysics Data System (ADS)

    Busse, Sebastian; Lutter, Dominik; Heldmaier, Gerhard; Jastroch, Martin; Meyer, Carola W.

    2014-11-01

    The grey short-tailed opossum, Monodelphis domestica, has been an established research animal for more than five decades, but relatively, little is known about its thermophysiology. Here we studied core body temperature ( T b) and metabolic rate (MR) of female adult M. domestica housed in the laboratory at an ambient temperature ( T a) of 26 °C. In expanding previous reports, the average recorded core T b of M. domestica was 34.3 °C. The T b of an individual M. domestica can drop below 30 °C (minimal T b: 28.6 °C) accompanied by a reduction in MR of up to 52 % even while having ad libitum access to food. These findings demonstrate for the first time the presence of spontaneous torpor in M. domestica. Metabolic suppression at relatively high T a and T b furthermore broadens our perspective on the use of torpor as a metabolic strategy not just restricted to cold climates.

  5. Role of dietary fatty acids on energetics and torpor in the Chilean mouse-opossum Thylamys elegans.

    PubMed

    Bozinovic, F; Méndez, M A

    1997-02-01

    We hypothetized that the Chilean mouse-opossum Thylamys elegans needs micronutrients that are in fruits and seeds, and the unsaturated fatty acids are such micronutrients that may allow individuals of this species to experience longer torpor bouts, lower body temperatures during torpor and higher energy savings during wintertime. To test this hypothesis, we studied: 1) wintertime preferences by artificial diets rich in saturated fatty acids, unsaturated fatty acids and control diets, and 2) the effect of acclimation to dietary fatty acids on the energetics and torpor patterns in this species. When individuals where allowed to choose between the experimental diets they always selected the unsaturated fatty acid diet. After 4 weeks of dietary acclimation, the average daily metabolic rate was not significantly different among treatments, neither was minimum metabolic rate during torpor significantly different, in spite of a tendency to lower values that was detected under unsaturated fatty acid treatment. A similar pattern was observed when body temperature during torpor was compared among treatments. Two explanations are proposed: 1) Acclimation time was not sufficient to obtain statistical significance, but physiological differences and 2) metabolic rate during torpor are not affected by dietary lipids in this species.

  6. Diversity of Sarcocystis spp shed by opossums in Brazil inferred with phylogenetic analysis of DNA coding ITS1, cytochrome B, and surface antigens.

    PubMed

    Valadas, Samantha Y O B; da Silva, Juliana I G; Lopes, Estela Gallucci; Keid, Lara B; Zwarg, Ticiana; de Oliveira, Alice S; Sanches, Thaís C; Joppert, Adriana M; Pena, Hilda F J; Oliveira, Tricia M F S; Ferreira, Helena L; Soares, Rodrigo M

    2016-05-01

    Although few species of Sarcocystis are known to use marsupials of the genus Didelphis as definitive host, an extensive diversity of alleles of surface antigen genes (sag2, sag3, and sag4) has been described in samples of didelphid opossums in Brazil. In this work, we studied 25 samples of Sarcocystis derived from gastrointestinal tract of opossums of the genus Didelphis by accessing the variability of sag2, sag3, sag4, gene encoding cytochrome b (cytB) and first internal transcribed spacer (ITS1). Reference samples of Sarcocystis neurona (SN138) and Sarcocystis falcatula (SF1) maintained in cell culture were also analyzed. We found four allele variants of cytB, seven allele variants of ITS1, 10 allele variants of sag2, 13 allele variants of sag3, and 6 allele variants of sag4. None of the sporocyst-derived sequences obtained from Brazilian opossums revealed 100% identity to SN138 at cytB gene, nor to SN138 or SF1 at ITS1 locus. In addition, none of the sag alleles were found identical to either SF1 or SN138 homologous sequences, and a high number of new sag allele types were found other than those previously described in Brazil. Out of ten sag2 alleles, four are novel, while eight out of 13 sag3 alleles are novel and one out of six sag4 alleles is novel. Further studies are needed to clarify if such a vast repertoire of allele variants of Sarcocystis is the consequence of re-assortments driven by sexual exchange, in order to form individuals with highly diverse characteristics, such as pathogenicity, host spectrum, among others or if it only represents allele variants of different species with different biological traits.

  7. Sandflies (Diptera: Psychodidae) associated with opossum nests at urban sites in southeastern Brazil: a risk factor for urban and periurban zoonotic Leishmania transmission?

    PubMed

    Cutolo, Andre Antonio; Teodoro, Anna Karollina Menezes; Ovallos, Fredy Galvis; Allegretti, Silmara Marques; Galati, Eunice Aparecida Bianchi

    2014-06-01

    Sandflies associated with opossum nests are reported for the first time in the yards of residences located in the urban area of the municipality of Monte Mor, situated in the metropolitan region of Campinas, state of São Paulo, Brazil. Eleven specimens of Evandromyia cortelezzii and one of Evandromyia lenti were captured in two Didelphis albiventris nests. Ev. cortelezzii is considered a secondary vector species for the transmission of Leishmania (Viannia) braziliensis and Leishmania (Leishmania) infantum in the Neotropics. This association may contribute to the introduction, establishment and maintenance of urban and periurban zoonotic transmission outbreaks of Leishmania and should therefore be investigated further.

  8. Skeletal fiber types and spindle distribution in limb and jaw muscles of the adult and neonatal opossum, Monodelphis domestica.

    PubMed

    Sciote, J J; Rowlerson, A

    1998-08-01

    The South American opossum, Monodelphis domestica, is very immature at birth, and we wished to assess its potential for studies of jaw muscle development. Given the lack of prior information about any Monodelphis fiber types or spindles, our study aimed to identify for the first time fiber types in both adult and neonatal muscles and the location of spindles in the jaw muscles. Fiber types were identified in frozen sections of adult and 6-day-old jaw and limb muscles by using myosin ATPase and metabolic enzyme histochemistry and by immunostaining for myosin isoforms. The distribution of fiber types and muscle spindles throughout the jaw-closer muscles was identified by immunostaining of sections of methacarnoy-fixed, wax-embedded heads. Most muscles contained one slow (type I) and two fast fiber types (equivalent to types IIA and IIX), which were similar to those in eutherian muscle, and an additional (non-IIB) fast type. In jaw-closer muscles, the main extrafusal fiber type was IIM (characteristic of these muscles in some eutherians), and almost all spindles were concentrated in four restricted areas: one in masseter and three in temporalis. Six-day neonatal muscles were very immature, but future spindle-rich areas were revealed by immunostaining and corresponded in position to the adult areas. Extrafusal and spindle fiber types in Monodelphis share many similarities with eutherian mammalian muscle. This finding, along with the immaturity of myosin isoform expression observed 6 days postnatally, indicates that Monodelphis could provide a valuable model for studying early developmental events in the jaw-closer muscles and their spindles.

  9. Copper complex species within a fragment of the N-terminal repeat region in opossum PrP protein.

    PubMed

    Vagliasindi, Laura I; Arena, Giuseppe; Bonomo, Raffaele P; Pappalardo, Giuseppe; Tabbì, Giovanni

    2011-03-21

    A spectroscopic (UV-Vis, CD and EPR), thermodynamic and voltammetric study of the copper(ii) complexes with the Ac-PHPGGSNWGQ-NH(2) polypeptide (L), a fragment of the opossum PrP protein N-terminal four-repeat region, was carried out in aqueous solution. It suggests the formation of a highly distorted [Cu(L)H(-2)] complex species in the neutral region, the stereochemistry of which is ascribable to a square base pyramid and a CuN(3)O(2) chromophore, resulting from the coordination of a histidine imidazole and two peptide nitrogen atoms and probably oxygen atoms from water molecules. At basic pH values a [Cu(L)H(-3)](-) species with a pseudo-octahedral geometry was also obtained, with four nitrogen donor atoms in its equatorial plane, coming from the histidine residue and from peptidic nitrogen atoms. Interestingly, at pH values relatively higher than the neutrality, the coordination sphere of the copper complex in the [Cu(L)H(-2)] species changes its stereochemistry towards a pseudo-octahedron, as suggested by the change in the parallel copper hyperfine coupling constant of the EPR spectra at low temperature. A slight difference in the redox potentials between this two-faced [Cu(L)H(-2)] complex species seems to confirm this behaviour. Both potentiometric and spectroscopic data were compared with the analogous species obtained with the Ac-PHGGGWGQ-NH(2) peptide, belonging to the octarepeat domain of the human prion protein (hPrP) N-terminal region. The [Cu(L)H(-2)] species formed by the Ac-PHPGGSNWGQ-NH(2) decapeptide, having a slightly lower stability, turned out to be less abundant and to exist within a narrow pH range.

  10. The impact of Quaternary climate oscillations on divergence times and historical population sizes in Thylamys opossums from the Andes.

    PubMed

    Giarla, Thomas C; Jansa, Sharon A

    2015-05-01

    Climate oscillations during the Quaternary altered the distributions of terrestrial animals at a global scale. In mountainous regions, temperature fluctuations may have led to shifts in range size and population size as species tracked their shifting habitats upslope or downslope. This creates the potential for both allopatric speciation and population size fluctuations, as species are either constrained to smaller patches of habitat at higher elevations or able to expand into broader areas at higher latitudes. We considered the impact of climate oscillations on three pairs of marsupial species from the Andes (Thylamys opossums) by inferring divergence times and demographic changes. We compare four different divergence dating approaches, using anywhere from one to 26 loci. Each pair comprises a northern (tropical) lineage and a southern (subtropical to temperate) lineage. We predicted that divergences would have occurred during the last interglacial (LIG) period approximately 125 000 years ago and that population sizes for northern and southern lineages would either contract or expand, respectively. Our results suggest that all three north-south pairs diverged in the late Pleistocene during or slightly after the LIG. The three northern lineages showed no signs of population expansion, whereas two southern lineages exhibited dramatic, recent expansions. We attribute the difference in responses between tropical and subtropical lineages to the availability of 'montane-like' habitats at lower elevations in regions at higher latitudes. We conclude that climate oscillations of the late Quaternary had a powerful impact on the evolutionary history of some of these species, both promoting speciation and leading to significant population size shifts.

  11. Age-dependent changes in the proteome following complete spinal cord transection in a postnatal South American opossum (Monodelphis domestica).

    PubMed

    Noor, Natassya M; Steer, David L; Wheaton, Benjamin J; Ek, C Joakim; Truettner, Jessie S; Dietrich, W Dalton; Dziegielewska, Katarzyna M; Richardson, Samantha J; Smith, A Ian; VandeBerg, John L; Saunders, Norman R

    2011-01-01

    Recovery from severe spinal injury in adults is limited, compared to immature animals who demonstrate some capacity for repair. Using laboratory opossums (Monodelphis domestica), the aim was to compare proteomic responses to injury at two ages: one when there is axonal growth across the lesion and substantial behavioural recovery and one when no axonal growth occurs. Anaesthetized pups at postnatal day (P) 7 or P28 were subjected to complete transection of the spinal cord at thoracic level T10. Cords were collected 1 or 7 days after injury and from age-matched controls. Proteins were separated based on isoelectric point and subunit molecular weight; those whose expression levels changed following injury were identified by densitometry and analysed by mass spectrometry. Fifty-six unique proteins were identified as differentially regulated in response to spinal transection at both ages combined. More than 50% were cytoplasmic and 70% belonged to families of proteins with characteristic binding properties. Proteins were assigned to groups by biological function including regulation (40%), metabolism (26%), inflammation (19%) and structure (15%). More changes were detected at one than seven days after injury at both ages. Seven identified proteins: 14-3-3 epsilon, 14-3-3 gamma, cofilin, alpha enolase, heart fatty acid binding protein (FABP3), brain fatty acid binding protein (FABP7) and ubiquitin demonstrated age-related differential expression and were analysed by qRT-PCR. Changes in mRNA levels for FABP3 at P7+1day and ubiquitin at P28+1day were statistically significant. Immunocytochemical staining showed differences in ubiquitin localization in younger compared to older cords and an increase in oligodendrocyte and neuroglia immunostaining following injury at P28. Western blot analysis supported proteomic results for ubiquitin and 14-3-3 proteins. Data obtained at the two ages demonstrated changes in response to injury, compared to controls, that were different for

  12. Spontaneous development of full weight-supported stepping after complete spinal cord transection in the neonatal opossum, Monodelphis domestica.

    PubMed

    Wheaton, Benjamin J; Callaway, Jennifer K; Ek, C Joakim; Dziegielewska, Katarzyna M; Saunders, Norman R

    2011-01-01

    Spinal cord trauma in the adult nervous system usually results in permanent loss of function below the injury level. The immature spinal cord has greater capacity for repair and can develop considerable functionality by adulthood. This study used the marsupial laboratory opossum Monodelphis domestica, which is born at a very early stage of neural development. Complete spinal cord transection was made in the lower-thoracic region of pups at postnatal-day 7 (P7) or P28, and the animals grew to adulthood. Injury at P7 resulted in a dense neuronal tissue bridge that connected the two ends of the cord; retrograde neuronal labelling indicated that supraspinal and propriospinal innervation spanned the injury site. This repair was associated with pronounced behavioural recovery, coordinated gait and an ability to use hindlimbs when swimming. Injury at P28 resulted in a cyst-like cavity encased in scar tissue forming at the injury site. Using retrograde labelling, no labelled brainstem or propriospinal neurons were found above the lesion, indicating that detectable neuronal connectivity had not spanned the injury site. However, these animals could use their hindlimbs to take weight-supporting steps but could not use their hindlimbs when swimming. White matter, demonstrated by Luxol Fast Blue staining, was present in the injury site of P7- but not P28-injured animals. Overall, these studies demonstrated that provided spinal injury occurs early in development, regrowth of supraspinal innervation is possible. This repair appears to lead to improved functional outcomes. At older ages, even without detectable axonal growth spanning the injury site, substantial development of locomotion was still possible. This outcome is discussed in conjunction with preliminary findings of differences in the local propriospinal circuits following spinal cord injury (demonstrated with fluororuby labelling), which may underlie the weight bearing locomotion observed in the apparent absence of

  13. Asp-ase Activity of the Opossum Granzyme B Supports the Role of Granzyme B as Part of Anti-Viral Immunity Already during Early Mammalian Evolution

    PubMed Central

    Fu, Zhirong; Thorpe, Michael; Akula, Srinivas; Hellman, Lars

    2016-01-01

    Granzyme B is one of the key effector molecules in our defense against viruses and intracellular bacteria. This serine protease together with the pore forming protein perforin, induces caspase or Bid-dependent apoptosis in target cells. Here we present the first characterization of a granzyme B homolog, the grathepsodenase, in a non-placental mammal, the American opossum (Monodelphis domestica). The recombinant enzyme was produced in a human cell line and used to study its primary and extended cleavage specificity using a panel of chromogenic substrates and recombinant protein substrates. The opossum granzyme B was found to have a specificity similar to human granzyme B, although slightly less restrictive in its extended specificity. The identification of a granzyme B homolog with asp-ase (cleaving after aspartic acid) specificity in a non-placental mammal provides strong indications that caspase or Bid-dependent apoptosis by a serine protease with a conserved primary specificity has been part of anti-viral immunity since early mammalian evolution. This finding also indicates that an asp-ase together with a chymase were the first two serine protease genes to appear in the mammalian chymase locus. PMID:27152961

  14. Evolution of mammalian CD1: marsupial CD1 is not orthologous to the eutherian isoforms and is a pseudogene in the opossum Monodelphis domestica.

    PubMed

    Baker, Michelle L; Miller, Robert D

    2007-05-01

    CD1 is a member of the major histocompatibility complex (MHC) class I family of proteins that present lipid antigens to T cells and natural killer (NK) T cells; it is found in both eutherian mammals and birds. In eutherians, duplication of the CD1 gene has resulted in multiple isoforms. A marsupial CD1 homologue was identified in a set of expressed sequence tags from the thymus of the bandicoot Isoodon macrourus. Southern blot and genomic sequence analyses revealed that CD1 is a single copy gene in both I. macrourus and a distantly related marsupial, the opossum Monodelphis domestica, which is currently the only marsupial species for which a whole genome sequence is available. We found that the opossum CD1 is located in a genomic region with a high degree of conserved synteny to the chromosomal regions containing human and mouse CD1. A phylogenetic analysis of mammalian CD1 revealed that marsupial CD1 is not orthologous to the eutherian CD1 isoforms, consistent with the latter having emerged by duplication after the separation of marsupials and eutherians 170-180 million years ago. The I. macrourus CD1 gene is actively transcribed and appears to encode a functional protein. In contrast, transcription of the M. domestica CD1 was not detected in any tissue and the predicted CD1 gene sequence contains a number of deletions that appear to render the locus a pseudogene.

  15. The biodynamics of arboreal locomotion: the effects of substrate diameter on locomotor kinetics in the gray short-tailed opossum (Monodelphis domestica).

    PubMed

    Lammers, Andrew R; Biknevicius, Audrone R

    2004-11-01

    Effects of substrate diameter on locomotor biodynamics were studied in the gray short-tailed opossum (Monodelphis domestica). Two horizontal substrates were used: a flat 'terrestrial' trackway with a force platform integrated into the surface and a cylindrical 'arboreal' trackway (20.3 mm diameter) with a force-transducer instrumented region. On both terrestrial and arboreal substrates, fore limbs exhibited higher vertical impulse and peak vertical force than hind limbs. Although vertical limb impulses were lower on the terrestrial substrate than on the arboreal support, this was probably due to speed effects because the opossums refused to move as quickly on the arboreal trackway. Vertical impulse decreased significantly faster with speed on the arboreal substrate because most of these trials were relatively slow, and stance duration decreased with speed more rapidly at these lower speeds. While braking and propulsive roles were more segregated between limbs on the terrestrial trackway, fore limbs were dominant both in braking and in propulsion on the arboreal trackway. Both fore and hind limbs exerted equivalently strong, medially directed limb forces on the arboreal trackway and laterally directed limb forces on the terrestrial trackway. We propose that the modifications in substrate reaction force on the arboreal trackway are due to the differential placement of the limbs about the dorsolateral aspect of the branch. Specifically, the pes typically made contact with the branch lower and more laterally than the manus, which may explain the significantly lower required coefficient of friction in the fore limbs relative to the hind limbs.

  16. Inhibition of the hemorrhagic and proteolytic activities of Lansberg's hognose pit viper (Porthidium lansbergii hutmanni) venom by opossum (Didelphis marsupialis) serum: isolation of Didelphis marsupialis 0.15Dm fraction on DEAE-cellulose chromatography.

    PubMed

    Pineda, María E; Girón, María E; Estrella, Amalid; Sánchez, Elda E; Aguilar, Irma; Fernandez, Irma; Vargas, Alba M; Scannone, Héctor; Rodríguez-Acosta, Alexis

    2008-01-01

    Earlier studies have revealed the ability of sera from several mammals to neutralize the toxic effects of snake venom. The Venezuelan opossum (Didelphis marsupialis) is one that has been found to inhibit hemorrhagic and proteolytic activities of venoms from many species of snakes. In this article it is shown that the opossum sera and its 0.15DM fraction were able to completely neutralize both hemorrhagic and hydrolysis (proteolysis) of casein effects induced by venom of the Lansberg's hognose pit viper (Porthidium lansbergii hutmanni). We have used DEAE-cellulose ion exchange chromatography to collect protein fractions from D. marsupialis sera which were able to defend mice from the lethal effects of P.l. hutmanni venom. The fractions separated were homogeneous by conventional electrophoresis using SDS-PAGE. The protein bands obtained contained molecular weights of approximately 6 to 220 kDa. These results revealed the presence of proteases inhibitors in the opossum sera fractions and the inhibition of venom activity by opossum sera suggesting a reciprocal adaptation at the molecular level.

  17. Primary sensory afferent innervation of the developing superficial dorsal horn in the South American opossum Monodelphis domestica.

    PubMed

    Kitchener, Peter D; Hutton, Elspeth J; Knott, Graham W

    2006-03-01

    The development of the primary sensory innervation of the superficial dorsal horn (SDH) was studied in postnatal opossums Monodelphis domestica by using DiI labelling of primary afferents and with GSA-IB(4) lectin binding and calcitonin gene-related peptide (CGRP) immunoreactivity to label primary afferent subpopulations. We also compared the timing of SDH innervation in the cervical and lumbar regions of the spinal cord. The first primary afferent projections to SDH emerge from the most lateral part of the dorsal root entry zone at postnatal day 5 and project around the lateral edge of the SDH toward lamina V. Innervation of the SDH occurs slowly over the second and third postnatal weeks, with the most dorsal aspect becoming populated by mediolaterally oriented varicose fibers before the rest of the dorsoventral thickness of the SDH becomes innervated by fine branching varicose fibers. Labelling with GSA-IB(4) lectin also labelled fibers at the lateral edge of the dorsal horn and SDH at P5, indicating that the GSA-IB(4) is expressed on SDH/lamina V primary afferents at the time when they are making their projections into the spinal cord. In contrast, CGRP-immunoreactive afferents were not evident until postnatal day 7, when a few short projections into the lateral dorsal horn were observed. These afferents then followed a pattern similar to the development of GSA-IB(4) projects but with a latency of several days. The adult pattern of labelling by GSA-IB(4) is achieved by about postnatal day 20, whereas the adult pattern of CGRP labelling was not seen until postnatal day 30. Electron microscopy revealed a few immature synapses in the region of the developing SDH at postnatal day 10, and processes considered to be precursors of glomerular synapses (and thus of primary afferent origin) were first seen at postnatal day 16 and adopted their definitive appearance between postnatal days 28 and 55. Although structural and functional development of forelimbs of neonatal

  18. Distribution of the parvalbumin, calbindin-D28K and calretinin immunoreactivity in globus pallidus of the Brazilian short-tailed opossum (Monodelphis domestica).

    PubMed

    Domaradzka-Pytel, Beata; Majak, Katarzyna; Spodnik, Jan; Olkowicz, Seweryn; Turlejski, Krzysztof; Djavadian, Ruzanna L; Moryś, Janusz

    2007-01-01

    This study describes the topography, borders and divisions of the globus pallidus in the Brazilian short-tailed opossum (Monodelphis domestica) and distribution of the three calcium binding proteins, parvalbumin (PV), calbindin D-28k (CB) and calretinin (CR) in that nucleus. The globus pallidus of the opossum consists of medial and lateral parts that are visible with Nissl or Timm's staining and also in PV and CR immunostained sections. Neurons of the globus pallidus expressing these proteins were classified into three types on the basis of size and shape of their soma and dendritic tree. Type 1 neurons had medium-sized fusiform soma with dendrites sprouting from the opposite poles. Neurons of the type 2 had medium-to-large, multipolar soma with scarce, thin dendrites. Cell bodies of type 3 neurons were small and either ovoid or round. Immunostaining showed that the most numerous were neurons expressing PV that belonged to all three types. Density of the PV-immunopositive fibers and puncta correlated with the density of the PV-labeled neurons. Labeling for CB resulted mainly in the light staining of neuropil in both parts of the nucleus, while the CB-expressing cells (mainly of the type 2) were scarce and placed only along the border of the globus pallidus and putamen. Staining for calretinin resulted in labeling almost exclusively the immunoreactive puncta and fibers that were distributed with medium-to-high density throughout the nucleus. Close to the border of globus pallidus with the putamen these fibers (probably dendrites) were long, thin and varicous, while more medially bundles of thick, short and smooth fibers predominated. Single CR-ir neurons (all of the type 3) were scattered through the globus pallidus. Colocalization of two calcium binding proteins in one neuron was. never observed. The CB-ir puncta (probably terminals of axons projecting to the nucleus) frequently formed basket-like structures around the PV-ir neurons. Therefore, the globus pallidus

  19. Characterization of beta(2)-microglobulin coding sequence from three non-placental mammals: the duckbill platypus, the short-beaked echidna, and the grey short-tailed opossum.

    PubMed

    Miska, Katarzyna B; Hellman, Lars; Miller, Robert D

    2003-03-01

    To further characterize genes of immunological importance from non-placental mammals, cDNAs encoding beta(2)-microglobulin (beta(2)m) were isolated from two prototherians, the platypus and an echidna, and one metatherian, a grey short-tailed opossum. In addition, a second allele of beta(2)m was identified in another metatherian species, the brushtail possum. Analysis of the deduced translations revealed conservation of key residues in these molecules over a long evolutionary history. The types of nucleotide substitutions present among the various taxa are also consistent with purifying selection at this conserved locus. An evolutionary tree of beta(2)m was constructed that supports the classic view of evolution with prototherians as the basal mammalian group.

  20. Studies on the energy metabolism of opossum (Didelphis virginiana) erythrocytes: V. Utilization of hypoxanthine for the synthesis of adenine and guanine nucleotides in vitro

    SciTech Connect

    Bethlenfalvay, N.C.; White, J.C.; Chadwick, E.; Lima, J.E. )

    1990-06-01

    High pressure liquid radiochromatography was used to test the ability of opossum erythrocytes to incorporate tracer amounts of (G-{sup 3}H) hypoxanthine (Hy) into ({sup 3}H) labelled triphosphates of adenine and guanine. In the presence of supraphysiologic (30 mM) phosphate which is optimal for PRPP synthesis, both ATP and GTP are extensively labelled. When physiologic (1 mM) medium phosphate is used, red cells incubated under an atmosphere of nitrogen accumulate ({sup 3}H) ATP in a linear fashion suggesting ongoing PRPP synthesis in red cells whose hemoglobin is deoxygenated. In contrast, a lesser increase of labelled ATP is observed in cells incubated under oxygen, suggesting that conditions for purine nucleotide formation from ambient Hy are more favorable in the venous circulation.

  1. Sex differences and the role of aromatization in the control of sexually dimorphic behavior and morphology in gray short-tailed opossums (Monodelphis domestica).

    PubMed

    Fadem, B H; Corbett, A

    1993-09-01

    Sex differences in the activating effects of an aromatizable (testosterone, T) and a nonaromatizable (dihydrotestosterone, DHT) androgen on sexually dimorphic scent marking and aggressive behavior were examined in gonadectomized gray short-tailed opossums. When compared with males, females showed less chest, head, flank, and hip marking and more fighting behavior in tests with stimulus females and threat behavior in tests with stimulus males following receipt of subcutaneous T, DHT, or blank (B) implants. Testosterone but not DHT activated hip and head marking while both T and DHT activated flank marking. In tests with stimulus females, only males showed clicking vocalizations and T but not DHT or B stimulated clicking. Animals that received T had significantly larger suprasternal scent glands than those that received DHT or B. The significance of these findings is discussed with respect to the development of sex differences in behavior in eutherian mammals.

  2. Age-related differences in the local cellular and molecular responses to injury in developing spinal cord of the opossum, Monodelphis domestica.

    PubMed

    Lane, M A; Truettner, J S; Brunschwig, J-P; Gomez, A; Bunge, M B; Dietrich, W D; Dziegielewska, K M; Ek, C J; Vandeberg, J L; Saunders, N R

    2007-03-01

    Immature spinal cord, unlike adult, has an ability to repair itself following injury. Evidence for regeneration, structural repair and development of substantially normal locomotor behaviour comes from studies of marsupials due to their immaturity at birth. We have compared morphological, cellular and molecular changes in spinal cords transected at postnatal day (P)7 or P14, from 3 h to 2 weeks post-injury, in South American opossums (Monodelphis domestica). A bridge between severed ends of cords was apparent 5 days post-injury in P7 cords, compared to 2 weeks in P14. The volume of neurofilament (axonal) material in the bridge 2 weeks after injury was 30% of control in P7- but < 10% in P14-injured cords. Granulocytes accumulated at the site of injury earlier (3 h) in P7 than in P14 (24 h)-injured animals. Monocytes accumulated 24 h post-injury and accumulation was greater in P14 cords. Accumulation of GFAP-positive astrocytes at the lesion occurred earlier in P14-injured cords. Neurites and growth cones were identified ultrastructurally in contact with astrocytes forming the bridge. Results using mouse inflammatory gene arrays showed differences in levels of expression of many TGF, TNF, cytokine, chemokine and interleukin gene families. Most of the genes identified were up-regulated to a greater extent following injury at P7. Some changes were validated and quantified by RT-PCR. Overall, the results suggest that at least some of the greater ability to recover from spinal cord transection at P7 compared to P14 in opossums is due to differences in inflammatory cellular and molecular responses.

  3. Formation of 5alpha-reduced androgens in the testes and urogenital tract of the grey short-tailed opossum, Monodelphis domestica.

    PubMed

    Wilson, Jean D; Renfree, Marilyn B; Auchus, Richard J; Pask, Andrew J; Shaw, Geoffrey

    2009-01-01

    Testicular 5alpha-reduced androgens, largely 5alpha-androstane-3alpha,17beta-diol (androstanediol), are responsible for virilisation of pouch young in one marsupial (the tammar wallaby), but are not formed until later in development in another marsupial (the brushtail possum) and in rodents. Because the mechanism of virilisation of the urogenital tract in the grey short-tailed opossum Monodelphis domestica has never been defined, androgen formation and metabolism were investigated in this species. Testis fragments from grey short-tailed opossums of a wide range of ages were incubated with [3H]-progesterone and the metabolites were separated by high-performance liquid chromatography (HPLC). The only 19-carbon metabolites identified in the youngest ages (5-26 days) and the major metabolites in adult testes were testosterone and androstenedione. At 30, 42 and 49 days of age, dihydrotestosterone and small amounts of androstanediol were present. Time-sequence studies indicated that dihydrotestosterone and androstanediol were formed from the 5alpha-reduction (and 3-keto reduction) of testosterone. In a second series of experiments, tissue fragments of a variety of urogenital tract tissues were incubated with [3H]-testosterone and the metabolites separated by HPLC. During the interval in which male urogenital tract differentiation takes place in this species (between Days 15 and 28), the major metabolite identified was dihydrotestosterone. We conclude that the timing of 5alpha-reductase expression in the testes of the grey short-tailed possum resembles that of rodents and the brushtail possum rather than that of the tammar wallaby and that dihydrotestosterone is probably the intracellular androgen responsible for virilisation of the urogenital tract in this species.

  4. Functional effectiveness of the blood-brain barrier to small water-soluble molecules in developing and adult opossum (Monodelphis domestica).

    PubMed

    Ek, Carl Joakim; Dziegielewska, Katarzyna Magdalena; Stolp, Helen; Saunders, Norman Ruthven

    2006-05-01

    We have evaluated a small water-soluble molecule, biotin ethylenediamine (BED, 286 Da), as a permeability tracer across the blood-brain barrier. This molecule was found to have suitable characteristics in that it is stable in plasma, has low plasma protein binding, and appears to behave in a similar manner across brain barriers as established by permeability markers such as sucrose. BED, together with a 3000-Da biotin-dextran (BDA3000), was used to investigate the effectiveness of tight junctions in cortical vessels during development and adulthood of a marsupial opossum (Monodelphis domestica). Marsupial species are born at an early stage of brain development when cortical vessels are just beginning to appear. The tracers were administered systemically to opossums at various ages and localized in brains with light and electron microscopy. In adults, the tight junctions restricted the movement of both tracers. In neonates, as soon as vessels grow into the neocortex, their tight junctions are functionally restrictive, a finding supported by the presence of claudin-5 in endothelial cells. However, both tracers are also found within brain extracellular space soon after intraperitoneal administration. The main route of entry for the tracers into immature neocortex appears to be via the cerebrospinal fluid over the outer (subarachnoid) and inner (ventricular) surfaces of the brain. These experiments demonstrate that the previously described higher permeability of barriers to small molecules in the developing brain does not seem to be due to leakiness of cerebral endothelial tight junctions, but to a route of entry probably via the choroid plexuses and cerebrospinal fluid.

  5. Functional conservation of the lncRNA NEAT1 in the ancestrally diverged marsupial lineage: Evidence for NEAT1 expression and associated paraspeckle assembly during late gestation in the opossum Monodelphis domestica.

    PubMed

    Cornelis, Guillaume; Souquere, Sylvie; Vernochet, Cécile; Heidmann, Thierry; Pierron, Gérard

    2016-09-01

    Long non-coding RNAs (lncRNAs) are widely expressed and play various roles in cell homeostasis. However, because of their low conservation at the sequence level, recapitulating lncRNA evolutionary history is often challenging. While performing an ultrastructural analysis of viral particles present in uterine glands of gestating opossum females, we serendipitously noticed the presence of numerous structures similar to paraspeckles, nuclear bodies which in human and mouse cells are assembled around an architectural NEAT1/MENϵ/β lncRNA. Here, using an opossum kidney (OK) cell line, we confirmed by immuno-electron microscopy the presence of paraspeckles in marsupials. We then identified the orthologous opossum NEAT1 gene which, although poorly conserved at the sequence level, displays NEAT1 characteristic features such as short and long isoforms expressed from a unique promoter and for the latter an RNase P cleavage site at its 3'-end. Combining tissue-specific qRT-PCR, in situ hybridization at the optical and electron microscopic levels, we show that (i) NEAT1 is paraspeckle-associated in opossum (ii) NEAT1 expression is strongly induced in late gestation in uterine/placental extracts (iii) NEAT1 induction occurs in the uterine gland nuclei in which paraspeckles were detected. Finally, treatment of OK cells with proteasome inhibitors induces paraspeckle assembly, as previously observed in human cells. Altogether, these results demonstrate that paraspeckles are tissue-specific, stress-responding nuclear bodies in marsupials, illustrating their structural and functional continuity over 200 My of evolution throughout the mammalian lineage. In contrast, the rapid evolution of the NEAT1 transcripts highlights the relaxed constraint that, despite functional conservation, is exerted on this lncRNA.

  6. The marsupial CD8 gene locus: molecular cloning and expression analysis of the alpha and beta sequences in the gray short-tailed opossum (Monodelphis domestica) and the tammar wallaby (Macropus eugenii).

    PubMed

    Duncan, Louise G; Nair, Sham V; Deane, Elizabeth M

    2009-05-15

    In eutherian mammals, CD8 is a key receptor of cytotoxic T cells and plays a pivotal role in the recognition and elimination of infected host cells by cell-mediated cytotoxicity. Here, we report the molecular cloning and expression analysis of CD8alpha and CD8beta cDNAs in two marsupial species, the gray short-tailed opossum and the tammar wallaby. The opossum and tammar CD8 sequences share a high degree of amino acid identity of 63% (CD8alpha) and 57% (CD8beta) to each other as well as 36-45% (CD8alpha) and 38-41% (CD8beta) with their eutherian counterparts. In addition, many of the signature features of eutherian CD8alpha and CD8beta are preserved in both marsupials including the two invariant cysteines that form the intra-chain disulphide bond in the extracellular IgSfV domain and the two hinge region cysteines involved in dimerisation between the two subunits. The p56(lck) binding motif in the cytoplasmic tail of the CD8alpha subunit is also conserved. Interestingly, the opossum CD8alpha and the tammar CD8beta sequences have a truncated cytoplasmic tail. RT-PCR analysis of CD8alpha and CD8beta transcripts in the tissues of the adult opossum and tammar showed broad tissue expression with a high level of expression observed in the lymphoid tissues of both marsupials. Furthermore, RT-PCR analysis of CD8alpha and CD8beta transcripts in the immune tissues of tammar young over the first 120 days of pouch life revealed a pattern of expression analogous to the maturation of the lymphoid tissues. This is the first report confirming the presence of CD8 in the tissues of a marsupial and will provide the tools to further analyse T cell subsets in this unique group of mammals.

  7. Analysis of the morphology and distribution of argentaffin, argyrophil and insulin-immunoreactive endocrine cells in the small intestine of the adult opossum Didelphis aurita (Wied-Neuwied, 1826).

    PubMed

    Basile, D R S; Novaes, R D; Marques, D C S; Fialho, M C Q; Neves, C A; Fonseca, C C

    2012-10-01

    The aim of this study was to identify and quantify the argyrophil, argentaffin and insulin-immunoreactive cells (IIC) in the small intestine of the opossum Didelphis aurita. Seven adult male specimens of opossums were investigated. The animals were captured, and their blood insulin levels were determined. After euthanasia, fragments of the small intestine were processed for light microscopy and transmission electron microscopy, and submitted to histochemistry and immunohistochemistry for identification of argyrophil and argentaffin endocrine cells, and IIC. Argyrophil and argentaffin cells were identified in the intestinal villi and Liberkühn crypts, whereas IIC were present exclusively in the crypts. Ultrastructure of the IIC revealed cytoplasmic granules of different sizes and electron densities. The numbers of IIC per mm(2) in the duodenum and jejunum were higher than in the ileum (p<0.05). The animals had low levels of blood insulin (2.8 ± 0.78 μIU/ml). There was no correlation between insulin levels and the number of IIC in the small intestine. The IIC presented secretory granules, elongated and variable morphology. It is believed that insulin secretion by the IIC may influence the proliferation of cells in the Liberkühn crypts, and local glucose homeostasis, primarily in animals with low serum insulin levels, such as the opossum.

  8. Topographic Organization and Corticocortical Connections of the Forepaw Representation in Areas S1 and SC of the Opossum: Evidence for a Possible Role of Area SC in Multimodal Processing

    PubMed Central

    Anomal, Renata Figueiredo; Rocha-Rego, Vanessa; Franca, João G.

    2011-01-01

    In small-brained mammals, such as opossums, the cortex is organized in fewer sensory and motor areas than in mammals endowed with larger cortical sheets. The presence of multimodal fields, involved in the integration of sensory inputs has not been clearly characterized in those mammals. In the present study, the corticocortical connections of the forepaw representation in the somatosensory caudal (SC) area of the Didelphis aurita opossum was studied with injections of fluorescent anatomical tracers in SC. Electrophysiological mapping of S1 was used to delimit its respective rostral and caudal borders, and to guide SC injections. The areal borders of S1 and the location of area SC were further confirmed by myeloarchitecture. In S1, we found a well-delimited forepaw representation, although it presented a crude internal topographic organization. Cortical projections to S1 originate in somatosensory areas of the parietal cortex, and appeared to be mostly homotopic. Physiological and connectional evidence were provided for a topographic organization in opossum area SC as well. Most notably, corticocortical projections to the forepaw representation of SC originated from somatosensory cortical areas and from cortex representing other sensory modalities, especially the visual peristriate cortex. This suggests that SC might be involved in multimodal processing similar to the posterior parietal cortex of species with larger brains. PMID:22069381

  9. Isolation and genetic characterisation of Toxoplasma gondii from a red-handed howler monkey (Alouatta belzebul), a jaguarundi (Puma yagouaroundi), and a black-eared opossum (Didelphis aurita) from Brazil.

    PubMed

    Pena, H F J; Marvulo, M F V; Horta, M C; Silva, M A; Silva, J C R; Siqueira, D B; Lima, P-A C P; Vitaliano, S N; Gennari, S M

    2011-02-10

    Toxoplasma gondii isolates are highly diverse in domestic animals from Brazil. However, little is known about the genetics of this parasite from wild mammals in the same region. Reveal genetic similarity or difference of T. gondii among different animal populations is necessary for us to understand transmission of this parasite. Here we reported isolation and genetic characterisation of three T. gondii isolates from wild animals in Brazil. The parasite was isolated by bioassay in mice from tissues of a young male red handed howler monkey (Alouatta belzebul), an adult male jaguarundi (Puma yagouaroundi), and an adult female black-eared opossum (Didelphis aurita). The monkey and the jaguarundi had inhabited the Zoo of Parque Estadual Dois Irmãos, Pernambuco State, Northeastern Brazil, for 1 year and 8 years, respectively. The wild black-eared opossum was captured in São Paulo State, Southeastern Brazil, and euthanised for this study because it was seropositive for T. gondii (titre 1:100 by the modified agglutination test, MAT). Ten PCR-RFLP (Polymerase Chain Reaction-Restriction Fragment Length Polymorphism) markers, SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico, were used to genotype the isolates. T. gondii was isolated from the brain and heart homogenate of the monkey, the muscle homogenate of the jaguarundi, and the heart homogenate of the black-eared opossum. This was the first isolation of T. gondii from a neotropical felid from Brazil. The isolate from the monkey (TgRhHmBr1) was not virulent in mice, whereas the isolates from the jaguarundi (TgJagBr1) and the black-eared opossum (TgOpBr1) were virulent in mice. The genotype of the isolate from the monkey has been identified in isolates from a goat and ten chickens in the same region of Brazil, suggesting that it may be a common lineage circulating in this region. The genotypes of the isolates from the jaguarundi and the black-eared opossum have not been previously reported. Although there

  10. First-generation linkage map of the gray, short-tailed opossum, Monodelphis domestica, reveals genome-wide reduction in female recombination rates.

    PubMed Central

    Samollow, Paul B; Kammerer, Candace M; Mahaney, Susan M; Schneider, Jennifer L; Westenberger, Scott J; VandeBerg, John L; Robinson, Edward S

    2004-01-01

    The gray, short-tailed opossum, Monodelphis domestica, is the most extensively used, laboratory-bred marsupial resource for basic biologic and biomedical research worldwide. To enhance the research utility of this species, we are building a linkage map, using both anonymous markers and functional gene loci, that will enable the localization of quantitative trait loci (QTL) and provide comparative information regarding the evolution of mammalian and other vertebrate genomes. The current map is composed of 83 loci distributed among eight autosomal linkage groups and the X chromosome. The autosomal linkage groups appear to encompass a very large portion of the genome, yet span a sex-average distance of only 633.0 cM, making this the most compact linkage map known among vertebrates. Most surprising, the male map is much larger than the female map (884.6 cM vs. 443.1 cM), a pattern contrary to that in eutherian mammals and other vertebrates. The finding of genome-wide reduction in female recombination in M. domestica, coupled with recombination data from two other, distantly related marsupial species, suggests that reduced female recombination might be a widespread metatherian attribute. We discuss possible explanations for reduced female recombination in marsupials as a consequence of the metatherian characteristic of determinate paternal X chromosome inactivation. PMID:15020427

  11. Claudin-4 forms a paracellular barrier, revealing the interdependence of claudin expression in the loose epithelial cell culture model opossum kidney cells.

    PubMed

    Borovac, Jelena; Barker, Reid S; Rievaj, Juraj; Rasmussen, Andrew; Pan, Wanling; Wevrick, Rachel; Alexander, R Todd

    2012-12-15

    The effect of claudins on paracellular fluxes has been predominantly studied in either Madin-Darby canine kidney (MDCK) or LLCPK cells. Neither model system has a very low transepithelial resistance (TER) as observed in leaky epithelia. Moreover, results from one model system are not always consistent with another. Opossum kidney (OK) cells form tight junctions yet have a very low TER. We therefore set out to characterize the paracellular transport properties of this cell culture model. Ussing chamber dilution potential measurements revealed that OK cells exhibit a very low TER (11.7 ± 1.4 Ω·cm(2)), slight cation selectivity (P(Na)/P(Cl) = 1.10 ± 0.01), and the Eisenman permeability sequence IV; the permeability of monovalent cations ranking K(+) > Cs(+) > Rb(+) > Na(+) > Li(+). Quantitative real-time PCR studies found that OK cells endogenously express claudin-4 > -1 > -6 > -20 > -9 > -12 > -11 > -15. Overexpression of claudin-4 significantly increased TER, decreased Na(+) and Cl(-) permeability, and increased levels of claudin-1, -6, and -9 mRNA. Knockdown of claudin-4 in the overexpressing cells significantly decreased TER without altering claudin expression; thus claudin-4 forms a barrier in OK cells. Knockdown of endogenous claudin-4 decreased claudin-1, -9, and -12 expression without altering TER. Claudin-2 overexpression decreased TER, significantly increased Na(+) and Cl(-) permeability, and decreased claudin-12 and -6 expression. Together these results demonstrate that claudin expression is tightly coupled in OK cells.

  12. Development, inheritance, and linkage-group assignment of 60 novel microsatellite markers for the gray, short-tailed opossum Monodelphis domestica.

    PubMed

    Gouin, Nicolas; Westenberger, Scott J; Mahaney, Susan M; Lindley, Peter; VandeBerg, John L; Samollow, Paul B

    2005-12-01

    Short-tandem-repeat (SSR) or microsatellite polymorphisms are some of the most extensively employed genetic markers in contemporary linkage mapping studies. To date, only a limited number of microsatellites have been isolated in the gray, short-tailed opossum Monodelphis domestica, a South American marsupial widely used for comparative biological and biomedical research. To increase the number of potentially useful mapping markers, we screened 2 microsatellite-enriched genomic libraries containing alternatively (CA)n or (GA)n repeats. A total of 184 clones were sequenced, from which 60 polymorphic microsatellite markers were successfully optimized. The efficiency of this enrichment protocol for M. domestica microsatellite isolation is discussed, and suggestions to improve the outcome are made. All 60 loci showed high allelic diversity, with allele numbers ranging from 2 to 10 in a subset of 33 unrelated animals. Normal Mendelian inheritance was confirmed for all loci by analyzing allelic segregation in 5 two-generation families. One microsatellite appeared to be X linked, and null alleles were found in 5 others. Two-point linkage analyses were implemented using the data on the 5 families, leading to the assignment of 59 of these loci to the existing linkage groups. The 60 novel microsatellites developed in this study will contribute significantly to the M. domestica linkage map, and further QTL mapping studies.

  13. Quantification of endocrine cells and ultrastructural study of insulin granules in the large intestine of opossum Didelphis aurita (Wied-Neuwied, 1826).

    PubMed

    dos Santos, Daiane Cristina Marques; Cupertino, Marli do Carmo; Fialho, Maria do Carmo Queiroz; Barbosa, Alfredo Jose Afonso; Fonseca, Cláudio Cesar; Sartori, Sirlene Souza Rodrigues; da Matta, Sérgio Luis Pinto

    2014-02-01

    This study aimed to investigate the distribution of argyrophil, argentaffin, and insulin-immunoreactive endocrine cells in the large intestine of opossums (Didelphis aurita) and to describe the ultrastructure of the secretory granules of insulin-immunoreactive endocrine cells. Fragments of the large intestine of 10 male specimens of D. aurita were collected, processed, and subjected to staining, immunohistochemistry, and transmission electron microscopy. The argyrophil, the argentaffin, and the insulin-immunoreactive endocrine cells were sparsely distributed in the intestinal glands of the mucous layer, among other cell types of the epithelium in all regions studied. Proportionally, the argyrophil, the argentaffin, and the insulin-immunoreactive endocrine cells represented 62.75%, 36.26%, and 0.99% of the total determined endocrine cells of the large intestine, respectively. Quantitatively, there was no difference between the argyrophil and the argentaffin endocrine cells, whereas insulin-immunoreactive endocrine cells were less numerous. The insulin-immunoreactive endocrine cells were elongated or pyramidal, with rounded nuclei of irregularly contoured, and large amounts of secretory granules distributed throughout the cytoplasm. The granules have different sizes and electron densities and are classified as immature and mature, with the mature granules in predominant form in the overall granular population. In general, the granule is shown with an external electron-lucent halo and electron-dense core. The ultrastructure pattern in the granules of the insulin-immunoreactive endocrine cells was similar to that of the B cells of pancreatic islets in rats.

  14. Sarcocystis neurona infections in sea otter (Enhydra lutris): evidence for natural infections with sarcocysts and transmission of infection to opossums (Didelphis virginiana)

    USGS Publications Warehouse

    Dubey, J.P.; Rosypal, A.C.; Rosenthal, B.M.; Thomas, N.J.; Lindsay, D.S.; Stanek, J.F.; Reed, S.M.; Saville, W.J.A.

    2001-01-01

    Although Sarcocystis neurona has been identified in an array of terrestrial vertebrates, recent recognition of its capacity to infect marine mammals was unexpected. Here, sarcocysts from 2 naturally infected sea otters (Enhydra lutris) were characterized biologically, ultrastructurally, and genetically. DNA was extracted from frozen muscle of the first of these sea otters and was characterized as S. neurona by polymerase chain reation (PCR) amplification followed by restriction fragment length polymorphism analysis and sequencing. Sarcocysts from sea otter no. 1 were up to 350 I?m long, and the villar protrusions on the sarcocyst wall were up to 1.3 I?m long and up to 0.25 I?m wide. The villar protrusions were tapered towards the villar tip. Ultrastructurally, sarcocysts were similar to S. neurona sarcocysts from the muscles of cats experimentally infected with S. neurona sporocysts. Skeletal muscles from a second sea otter failed to support PCR amplification of markers considered diagnostic for S. neurona but did induce the shedding of sporocysts when fed to a laboratory-raised opossum (Didelphis virginiana). Such sporocysts were subsequently fed to knockout mice for the interferon-gamma gene, resulting in infections with an agent identified as S. neurona on the basis of immunohistochemistry, serum antibodies, and diagnostic sequence detection. Thus, sea otters exposed to S. neurona may support the development of mature sarcocysts that are infectious to competent definitive hosts.

  15. Genome-wide histone state profiling of fibroblasts from the opossum, Monodelphis domestica, identifies the first marsupial-specific imprinted gene

    PubMed Central

    2014-01-01

    Background Imprinted genes have been extensively documented in eutherian mammals and found to exhibit significant interspecific variation in the suites of genes that are imprinted and in their regulation between tissues and developmental stages. Much less is known about imprinted loci in metatherian (marsupial) mammals, wherein studies have been limited to a small number of genes previously known to be imprinted in eutherians. We describe the first ab initio search for imprinted marsupial genes, in fibroblasts from the opossum, Monodelphis domestica, based on a genome-wide ChIP-seq strategy to identify promoters that are simultaneously marked by mutually exclusive, transcriptionally opposing histone modifications. Results We identified a novel imprinted gene (Meis1) and two additional monoallelically expressed genes, one of which (Cstb) showed allele-specific, but non-imprinted expression. Imprinted vs. allele-specific expression could not be resolved for the third monoallelically expressed gene (Rpl17). Transcriptionally opposing histone modifications H3K4me3, H3K9Ac, and H3K9me3 were found at the promoters of all three genes, but differential DNA methylation was not detected at CpG islands at any of these promoters. Conclusions In generating the first genome-wide histone modification profiles for a marsupial, we identified the first gene that is imprinted in a marsupial but not in eutherian mammals. This outcome demonstrates the practicality of an ab initio discovery strategy and implicates histone modification, but not differential DNA methylation, as a conserved mechanism for marking imprinted genes in all therian mammals. Our findings suggest that marsupials use multiple epigenetic mechanisms for imprinting and support the concept that lineage-specific selective forces can produce sets of imprinted genes that differ between metatherian and eutherian lines. PMID:24484454

  16. Distribution and ultrastructure of neurons in opossum piriform cortex displaying immunoreactivity to GABA and GAD and high-affinity tritiated GABA uptake

    SciTech Connect

    Haberly, L.B.; Hansen, D.J.; Feig, S.L.; Presto, S.

    1987-12-08

    GABAergic neurons have been identified in the piriform cortex of the opossum at light and electron microscopic levels by immunocytochemical localization of GABA and the GABA-synthesizing enzyme glutamic acid decarboxylase and by autoradiographic visualization of high-affinity /sup 3/H-GABA uptake. Four major neuron populations have been distinguished on the basis of soma size, shape, and segregation at specific depths and locations: large horizontal cells in layer Ia of the anterior piriform cortex, small globular cells with thin dendrites concentrated in layers Ib and II of the posterior piriform cortex, and multipolar and fusiform cells concentrated in the deep part of layer III in anterior and posterior parts of the piriform cortex and the subjacent endopiriform nucleus. All four populations were well visualized with both antisera, but the large layer Ia horizontal cells displayed only very light /sup 3/H-GABA uptake, thus suggesting a lack of local axon collaterals or lack of high-affinity GABA uptake sites. The large, ultrastructurally distinctive somata of layer Ia horizontal cells receive a very small number of symmetrical synapses; the thin, axonlike dendrites of small globular cells are exclusively postsynaptic and receive large numbers of both symmetrical and asymmetrical synapses, in contrast to somata which receive a small number of both types; and the deep multipolar and fusiform cells receive a highly variable number of symmetrical and asymmetrical synapses on somata and proximal dendrites. Labeled puncta of axon terminal dimensions were found in large numbers in the neuropil surrounding pyramidal cell somata in layer II and in the endopiriform nucleus. Moderately large numbers of labeled puncta were found in layer I at the depth of pyramidal cell apical dendrites with greater numbers in layer Ia at the depth of distal apical segments than in layer Ib.

  17. Morphological, morphometric and genetic variation among cryptic and sympatric species of southeastern South American three-striped opossums (Monodelphis: Mammalia: Didelphidae).

    PubMed

    Duda, Rafaela; Costa, Leonora Pires

    2015-03-23

    Monodelphis is the most diverse genus of the family Didelphidae, whose systematics and taxonomy have not yet been well established. Two of the included species, Monodelphis americana and M. iheringi, are difficult to distinguish because both present three dorsal black stripes. Furthermore, they show intra- and interspecific variation related to body size and pelage coloration. Because this variation is not well understood, there are problems in correctly identifying these species, which remain poorly collected and thus rare in zoological collections. This study evaluated the morphological and genetic variations in a sample of striped opossums from a single location in southeastern Brazil to understand if the morphological variation observed in individuals from the same location was indicative of the existence of more than one taxon. The comparative analyses of a series from this single locality with museum specimens of other locations revealed variations in the skin and skull qualitative characters that were related to age and sex. Morphological comparisons led to the identification of two morphogroups, which were corroborated by molecular data; the analysis of cytochrome b sequences indicated the existence of two clades, with an average divergence of 14%. Thus, the results support the existence of two taxa in the sample, defined as M. americana and M. iheringi. We confirmed the sympatry of these two species in a location in southeastern Brazil, presented morphological diagnostic characters to distinguish the two species, provided novel phylogenetic information on the group, and also demonstrated the existence of important intra- and interspecific morphological variations related to sexual dimorphism and ontogeny in the group. These results significantly contribute to information on the systematics of the genus.

  18. Transforming growth factor-β1 reduces megalin- and cubilin-mediated endocytosis of albumin in proximal-tubule-derived opossum kidney cells

    PubMed Central

    Gekle, Michael; Knaus, Petra; Nielsen, Rikke; Mildenberger, Sigrid; Freudinger, Ruth; Wohlfarth, Verena; Sauvant, Christoph; Christensen, Erik I

    2003-01-01

    Transforming growth factor (TGF)-β1 is a member of a superfamily of multifunctional cytokines involved in several pathological processes of the kidney, including fibrogenesis, apoptosis and epithelial-mesenchymal transition. These events lead to tubulointerstitial fibrosis and glomerulosclerosis. Less is known about TGF-β1-induced alterations of cell function. An important function of proximal tubular cells is reabsorption of filtered proteins, including albumin, via megalin-cubilin-dependent receptor-mediated endocytosis. In this study we used a well established cell culture model (proximal-tubule-derived opossum kidney (OK) cells) in order to test the hypothesis that TGF-β1 reduces megalin-cubilin-mediated endocytosis. Previously we have shown that albumin endocytosis in OK cells is mediated by megalin/cubulin. TGF-β1 led to a time- and dose-dependent downregulation of megalin-cubilin-mediated endocytosis without affecting two other transport systems tested. Binding, internalization and intracellular trafficking of the ligand albumin were affected. Decreased binding resulted from reduced cubilin and megalin expression in the 200 000 g membrane fraction. The underlying mechanism of TGF-β1 action does not involve mitogen-activated protein kinases, protein kinase C or A, or reactive oxygen species. In contrast, TGF-β1-induced downregulation of megalin-cubilin-mediated endocytosis was sensitive to inhibition of translation and transcription and was preceded by Smad2 and 3 phosphorylation. Dominant negative Smad2/3 constructs prevented the effect of TGF-β1. In conclusion our data indicate that enhanced levels of TGF-β1 occurring in various nephropathies can lead to downregulation of megalin-cubilin-dependent endocytosis. Probably, TGF-β1 leads to Smad2- and Smad3-dependent expression of negative regulators of receptor-mediated endocytosis. PMID:14561830

  19. Transforming growth factor-beta1 reduces megalin- and cubilin-mediated endocytosis of albumin in proximal-tubule-derived opossum kidney cells.

    PubMed

    Gekle, Michael; Knaus, Petra; Nielsen, Rikke; Mildenberger, Sigrid; Freudinger, Ruth; Wohlfarth, Verena; Sauvant, Christoph; Christensen, Erik I

    2003-10-15

    Transforming growth factor (TGF)-beta1 is a member of a superfamily of multifunctional cytokines involved in several pathological processes of the kidney, including fibrogenesis, apoptosis and epithelial-mesenchymal transition. These events lead to tubulointerstitial fibrosis and glomerulosclerosis. Less is known about TGF-beta1-induced alterations of cell function. An important function of proximal tubular cells is reabsorption of filtered proteins, including albumin, via megalin-cubilin-dependent receptor-mediated endocytosis. In this study we used a well established cell culture model (proximal-tubule-derived opossum kidney (OK) cells) in order to test the hypothesis that TGF-beta1 reduces megalin-cubilin-mediated endocytosis. Previously we have shown that albumin endocytosis in OK cells is mediated by megalin/cubulin. TGF-beta1 led to a time- and dose-dependent downregulation of megalin-cubilin-mediated endocytosis without affecting two other transport systems tested. Binding, internalization and intracellular trafficking of the ligand albumin were affected. Decreased binding resulted from reduced cubilin and megalin expression in the 200 000 g membrane fraction. The underlying mechanism of TGF-beta1 action does not involve mitogen-activated protein kinases, protein kinase C or A, or reactive oxygen species. In contrast, TGF-beta1-induced downregulation of megalin-cubilin-mediated endocytosis was sensitive to inhibition of translation and transcription and was preceded by Smad2 and 3 phosphorylation. Dominant negative Smad2/3 constructs prevented the effect of TGF-beta1. In conclusion our data indicate that enhanced levels of TGF-beta1 occurring in various nephropathies can lead to downregulation of megalin-cubilin-dependent endocytosis. Probably, TGF-beta1 leads to Smad2- and Smad3-dependent expression of negative regulators of receptor-mediated endocytosis.

  20. Potassium transport in opossum kidney cells: effects of Na-selective and K-selective ionizable cryptands, and of valinomycin, FCCP and nystatin.

    PubMed

    Loiseau, A; Leroy, C; Castaing, M

    1997-11-13

    The effects of two ionizable cryptands, the Na-selective (221)C10 and the K-selective (222)C10, and of valinomycin, FCCP and nystatin on K+ fluxes in opossum kidney (OK) cells have been quantified. The Na,K-ATPase (ouabain-sensitive 86Rb influx) was stimulated by nystatin (> or = 20%), and inhibited by the other ionophores (50-80%), by barium (K-channel blocker) (61%) and by amiloride (Na entry blocker) (34%). The Vmax of the Na,K-ATPase phosphatase activity was unmodified by the ionophores, indicating the absence of direct interaction with the enzyme. The ATPi content was unmodified by the inhibitors and nystatin, but was lowered by (221)C10 (47%), (222)C10 (75%), valinomycin (72%) and FCCP (88%). Amiloride was found to partially remove the inhibition caused by (222)C10 (51%) and valinomycin (49%). Rb efflux was stimulated by nystatin (32%), unmodified by valinomycin, and was inhibited by (221)C10 (19%), (222)C10 (19%) and FCCP (10%). Barium (39%) and amiloride (32%) inhibited this efflux and, in their presence, the nystatin effect persisted, whereas that of the other ionophores vanished. At pH 6.4, the Rb efflux decreased by 14% of its value at pH 7.4, with no additional inhibition by cryptands. Cryptands are shown to inhibit the pH-sensitive K+-conductance, probably by inducing a K+-H+ exchange at the plasma membrane, and by uncoupling oxidative phosphorylation by inducing the entry of K+ and H+ (and possibly Ca2+) ions into the mitochondria.

  1. Evaluation of a rapid immunochromatographic dipstick test for detection of antibodies to Trypanosoma cruzi in dogs experimentally infected with isolates obtained from opossums (Didelphis virginiana), armadillos (Dasypus novemcinctus), and dogs (Canis familiaris) from the United States.

    PubMed

    Rosypal, Alexa C; Hill, Roderick; Lewis, Samantha; Barr, Stephen C; Valadas, Samantha; Gennari, Solange Maria; Lindsay, David S

    2011-02-01

    Dogs are reservoir hosts for Trypanosoma cruzi , the causative agent of American trypanosomiasis. A rapid immunochromatographic dipstick test (ICT) is available commercially for canine serological testing. The ICT was developed with the use of sera from South American dogs, but it is not routinely used in the United States. We evaluated the utility of the ICT in detecting anti-T. cruzi antibodies in dogs from the United States. Dogs (N  =  64) were experimentally infected with United States' isolates of T. cruzi from an opossum (Didelphis virginiana), an armadillo (Dasypus novemcinctus), and a domestic dog (Canis familiaris), and were tested after experimental infection. Sera from uninfected United States dogs (n  =  79; hemaculture negative) were used as negative controls. In a blind study, sera were tested by the ICT and compared to the indirect immunofluorescent antibody test with the use of Brazil-strain epimastigotes as antigen. The sensitivity of the ICT was 91% and the specificity was 98% in dogs experimentally infected with United States isolates. Our study indicates that the ICT could be a useful screening tool for serological surveillance of canine T. cruzi exposure in the United States.

  2. Molecular characterisation of the CD79a and CD79b subunits of the B cell receptor complex in the gray short-tailed opossum (Monodelphis domestica) and tammar wallaby (Macropus eugenii): Delayed B cell immunocompetence in marsupial neonates.

    PubMed

    Duncan, Louise; Webster, Koa; Gupta, Varun; Nair, Sham; Deane, Elizabeth

    2010-08-15

    The B cell receptor (BCR) is a multiprotein complex that is pivotal to antigen recognition and signal transduction in B cells. It consists of an antigen binding component, membrane Ig (mIg), non-covalently associated with the signaling component, a disulphide-linked heterodimer of CD79a and CD79b. In this study, the gene and corresponding cDNA for CD79a and CD79b in the gray short-tailed opossum, as well as the cDNA sequences for CD79a and CD79b in the tammar wallaby, are described. Many of the structural and functional features of CD79a and CD79b were conserved in both marsupials, including the ITAM regulatory motif in the cytoplasmic tails of both subunits. The marsupial CD79 sequences shared a high degree of amino acid identities of 76% (CD79a) and 72% (CD79b) to each other, as well as 60-61% (CD79a) and 58-59% (CD79b) with their eutherian counterparts. RT-PCR analysis of CD79a and CD79b transcripts in the immune tissues of tammar pouch young revealed CD79a transcripts in the bone marrow, cervical thymus and spleen at day 10 postpartum. CD79b transcripts were detected in the bone marrow and cervical thymus at day 10 but were not detected in the spleen until day 21 postpartum. These results suggest that a functional BCR may not be assembled until day 21 postpartum and the tammar neonate may not be capable of mounting an effective adaptive immune response until this time. The molecular information presented here will allow further investigation of the role of the CD79 subunits in marsupial B cell signaling, especially during ontogeny and disease.

  3. Photoreception in the opossum shrimp, Mysis relicta Loven

    USGS Publications Warehouse

    Beeton, Alfred M.

    1959-01-01

    SUMMARY: Evidence from live trapping tests indicated that Peromyscus leucopus did not leave their home ranges because of the attraction of trap bait in nearby areas. A trap line down the center of a heavily live-trapped area caught as many mice before the area trapping as afterward. Thus, there was reason to believe that the area trapping did not serve to pre-bait the mice. Two unbaited lines of live traps caught an equal number of Peromyscus. When one line was baited with rolled oats and peanut butter the efficiency of the traps was improved to the extent that the baited line captured more than twice as many mice as the unbaited line. It is concluded that for the species and habitat tested it is safe to make population calculations based on the assumption that the animals remain within their home ranges and do not tend to move into the trapped area because of the attraction of the trap bait.

  4. Marsupial morphology of reproduction: South America opossum male model.

    PubMed

    De Barros, Michelle Andrade; Panattoni Martins, João Flávio; Samoto, Vivian Yochiko; Oliveira, Vanessa Cristina; Gonçalves, Natalia; Mançanares, Celina Almeida Furlaneto; Vidane, Atanasio; Carvalho, Ana Flávia; Ambrósio, Carlos Eduardo; Miglino, Maria Angélica

    2013-04-01

    This study aims to describe the morphology of Didelphis sp. male genital organs (penis, testes, epididymis, ductus deferens, prostate, and bulbourethral gland). Ten male animals were used, eight for macroscopic and light microscopy analysis, and two for scanning electron microscopy. The testes and epididymis showed similarity to other eutherian mammals. The bifid penis showed the urethra ending in the medial region where the bifurcation begins, occurring in each segment extension of the urethral groove until the beginning of the glans. Histologically, the penis consists of a cavernous and spongy body, covered by stratified squamous epithelium with loose connective tissue. The urethra was lined by transitional stratified epithelium. In the prostate, prostatic segments were found consisting of tubular glands in a radial arrangement around the urethra, coated externally by a dense connective tissue associated with a relatively thick layer of smooth muscle arranged in two layers that surround the glandular tissue. The animals had three pairs of bulbourethral glands placed at the membranous and cavernous urethra junction with descending and parallel excretory ducts ending caudally in the urethral lumen.

  5. Effects of Seawater Acidification on the Life Cycle and fitness of Opossum Shrimp Populations

    EPA Science Inventory

    Much of the current concern about ecological effects of ocean acidification focuses on molluscs and coccolithophores because of their importance in the global calcium cycle. However, many other marine organisms are likely to be affected by acidification because of their known ph...

  6. Redescription of Spirura guianensis (Nematoda: Spiruridae) from a rare South American Gracile Opossum.

    PubMed

    Torres, E J Lopes; Maldonado, A; Anjos, D H da Silva; de Souza, W; Miranda, K

    2015-10-01

    Spirura genus Blanchard, 1849 comprise of nematode parasites that infect primate and marsupial species. Although several taxonomical studies have shown that the infection by this species occurs primarily in the esophagus of primates, evidence for the occurrence of these parasites in other hosts (marsupials, rodents and bats) has become the subject of investigation by several groups. In this work, we describe the presence of Spirura guianensis Ortlepp, 1924 in the marsupial Gracilinanus agilis (Marsupialia: Didelphidae) found in the Pantanal of Mato Grosso do Sul state of Brazil. Structural characteristics of this nematode were identified using light microscopy (bright field and fluorescence stereomicroscopy) and scanning electron microscopy (SEM) approaches. Details of the surface topography such as cephalic projections, ventral boss, details of the caudal papillae and cuticular ornamentations were shown, providing taxonomic characteristics that may help in the establishment of diagnostic protocols. In addition, the presence of this species in a new host and new geographical area of Brazil provide grounds for a revision on the distribution of S. guianensis in South America.

  7. Environmental DNA Marker Development with Sparse Biological Information: A Case Study on Opossum Shrimp (Mysis diluviana)

    PubMed Central

    Carim, Kellie J.; Christianson, Kyle R.; McKelvey, Kevin M.; Pate, William M.; Silver, Douglas B.; Johnson, Brett M.; Galloway, Bill T.; Young, Michael K.; Schwartz, Michael K.

    2016-01-01

    The spread of Mysis diluviana, a small glacial relict crustacean, outside its native range has led to unintended shifts in the composition of native fish communities throughout western North America. As a result, biologists seek accurate methods of determining the presence of M. diluviana, especially at low densities or during the initial stages of an invasion. Environmental DNA (eDNA) provides one solution for detecting M. diluviana, but building eDNA markers that are both sensitive and species-specific is challenging when the distribution and taxonomy of closely related non-target taxa are poorly understood, published genetic data are sparse, and tissue samples are difficult to obtain. To address these issues, we developed a pair of independent eDNA markers to increase the likelihood of a positive detection of M. diluviana when present and reduce the probability of false positive detections from closely related non-target species. Because tissue samples of closely-related and possibly sympatric, non-target taxa could not be obtained, we used synthetic DNA sequences of closely related non-target species to test the specificity of eDNA markers. Both eDNA markers yielded positive detections from five waterbodies where M. diluviana was known to be present, and no detections in five others where this species was thought to be absent. Daytime samples from varying depths in one waterbody occupied by M. diluviana demonstrated that samples near the lake bottom produced 5 to more than 300 times as many eDNA copies as samples taken at other depths, but all samples tested positive regardless of depth. PMID:27551919

  8. Postnatal development of the reproductive system in the grey short-tailed opossum, Monodelphis domestica.

    PubMed

    Mackay, S; Xie, Q; Ullmann, S L; Gilmore, D P; Payne, A P

    2004-05-01

    Postnatal phenotypic sex differentiation has been investigated in a laboratory marsupial, Monodelphis domestica, as part of a larger study to resolve apparent discrepancies between eutherian and marsupial mammals. These include the formation of sex-specific structures in marsupials prior to gonadal differentiation and the retention in both sexes of structures which are sex-specific in eutherians. The time-course and nature of differentiation was investigated in 131 specimens ranging in age from the day of birth to 56 days. Patent wolffian ducts extend to the urogenital sinus in both sexes at birth, while müllerian ducts are identified on day 1 and grow in a cranio-caudal direction to reach the urogenital sinus on day 6. The male müllerian duct shows signs of regression at its cranial end on day 10 and throughout its length on day 12; its lumen has completely disappeared by day 15. By this time the epididymis and vas deferens have developed from the wolffian duct; their histological differentiation occurs between days 26 and 56. Prostatic buds are identifiable in tissue surrounding the male urethra on day 14. In the female, the wolffian duct is larger than the müllerian duct until day 14; thereafter the wolffian duct begins to regress at its cranial end, disappearing by day 17, whereas the müllerian duct begins to enlarge, converging with its fellow at the urogenital sinus by day 19. Lateral vaginae, vaginal culs-de-sac, uteri and oviducts have differentiated from the müllerian ducts by day 25. Gonads of both sexes are elongated in shape at birth, attached along the medial aspect of the large mesonephroi in the abdominal cavity. However, from day 3 onwards the testis becomes more rounded than the ovary. Degeneration of the male mesonephros begins about day 10 and is almost completed by day 19; the female mesonephros is still relatively large at day 14 though it too has almost disappeared by day 19. By postnatal day 13 the abdominal phase of testis descent is underway and the inguinal phase begins at day 15. Testes have reached the scrotal sac by day 24 and achieve their final position at the base of the scrotum by day 28. In summary, postnatal reproductive tract development and gonadal descent has been examined in this important biomedical model, where differentiation of the wolffian and müllerian ducts takes place after gonadal differentiation, according to the normal eutherian pattern.

  9. Mammary glands in male marsupials: I. Primordia in neonatal opossums Didelphis virginiana and Monodelphis domestica.

    PubMed

    Renfree, M B; Robinson, E S; Short, R V; Vandeberg, J L

    1990-10-01

    Neonates of the American didelphid marsupials Didelphis virginiana and Monodelphis domestica were sexed by karyotype and histologically examined on the day of birth. Mammary anlagen were found in both sexes of both species, but the neonatal males had less than one-third of the full female complement of mammary glands. Male neonates of both species also had paired scrotal bulges anterior to the genital tubercle but these were never present in females, once again raising the question of whether the pouch and scrotum are homologous structures. Mammary anlagen are not found in male neonates of the Australian marsupial species so far studied, which suggests a dichotomy in the control of some aspects of sexual differentiation in the two marsupial lineages.

  10. Effects of Seawater Acidification on the Liffe Cycle and Fitness of Opossum Shrimp Population

    EPA Science Inventory

    Much of the current concern about ecological effects of ocean acidification focuses on molluscs and coccolithophores because of their importance in the global calcium cycle. However, many other marine organisms are likely to be affected by acidification because of their known se...

  11. Resistance of the Opossum (Didelphis Virginiana) to Envenomation by Snakes of the Crotalidae Family.

    DTIC Science & Technology

    1976-12-01

    treatment of snakebites . 12 \\l~ C’ ~~~~0 _~~~~ - . Although the lethal doses of venom Vick 1 ~ cites were an average of those used in dogs and...actual snakebite or intravenous injection of 4 to 20 times the dose known to be lethal to susceptible mammals. Some animals that survived the... snakebite were given venom intravenously 40 to 90 minutes after the bite. Heart and respiratory rate, EKG, and blood pressure were monitored for 2 hours

  12. Opossum peptide that can neutralize rattlesnake venom is expressed in Escherichia coli

    PubMed Central

    Komives, Claire F.; Sanchez, Elda E.; Rathore, Anurag S.; White, Brandon; Suntravat, Montamas; Balderrama, Michael; Cifelli, Angela; Joshi, Varsha

    2016-01-01

    An eleven amino acid ribosomal peptide was shown to completely neutralize Western Diamondback Rattlesnake (Crotalus atrox) venom in mice when a lethal dose of the venom was pre-incubated with the peptide prior to intravenous injection. We have expressed the peptide as a concatenated chain of peptides and cleaved them apart from an immobilized metal affinity column using a protease. After ultrafiltration steps, the mixture was shown to partially neutralize rattlesnake venom in mice. Preliminary experiments are described here that suggest a potential life-saving therapy could be developed. To date, no recombinant therapies targeting cytotoxic envenomation have been reported. PMID:27718338

  13. Endocrine cells and nerve ganglia of the small intestine of the Opossum Didelphis aurita Wied-Neuwied, 1826 (Mammalia: Didelphidae).

    PubMed

    Freitas-Ribeiro, Gláucia M; Fonseca, Cláudio C; Sartori, Sirlene S R; Loures-Ribeiro, Alan; Neves, Clóvis A

    2012-09-01

    The nervous and endocrine systems jointly control intestinal movements, secretions of their glands and also participate of the processes of nutrient digestion and absorption. Therefore, the central objective of this study was to verify the existence of a possible relationship between the number of nervous cells and ganglia of the submucosal and myenteric plexuses and the number of endocrine cells in the small intestine of adult D. aurita. The utilized staining techniques were Grimelius, modified Masson-Fontana, direct immunoperoxidase and H-E. Argyrophillic, argentaffin and insulin immunoreactive endocrine cells do not numerically vary between the initial, mid and final regions of the duodenum, jejunum and ileum (P>0.05), except for argyrophillic cells in the jejunum (P>0.05). No numerical relationship has yet been verified between the number of nerve ganglia and endocrine cells, and also between nervous and endocrine cells. We recommended the use of new immunohistochemical techniques to confirm the numerical correlation between the nervous and endocrine systems in the small intestine. The morphology and distribution of endocrine cells and the nerve ganglia studied were similar to those encountered in eutherian mammals.

  14. Demographic consequences of population subdivision on the long-furred woolly mouse opossum ( Micoureus paraguayanus) from the Atlantic Forest

    NASA Astrophysics Data System (ADS)

    Brito, Daniel; da Fonseca, Gustavo A. B.

    2007-01-01

    Habitat destruction and fragmentation severely affected the Atlantic Forest. Formerly contiguous populations may become subdivided into a larger number of smaller populations, threatening their long-term persistence. The computer package VORTEX was used to simulate the consequences of habitat fragmentation and population subdivision on Micoureus paraguayanus, an endemic arboreal marsupial of the Atlantic Forest. Scenarios simulated hypothetical populations of 100 and 2000 animals being partitioned into 1-10 populations, linked by varying rates of inter-patch dispersal, and also evaluated male-biased dispersal. Results demonstrated that a single population was more stable than an ensemble of populations of equal size, irrespective of dispersal rate. Small populations (10-20 individuals) exhibited high instability due to demographic stochasticity, and were characterized by high rates of extinction, smaller values for metapopulation growth and larger fluctuations in population size and growth rate. Dispersal effects on metapopulation persistence were related to the size of the populations and to the sexes that were capable of dispersing. Male-biased dispersal had no noticeable effects on metapopulation extinction dynamics, whereas scenarios modelling dispersal by both sexes positively affected metapopulation dynamics through higher growth rates, smaller fluctuations in growth rate, larger final metapopulation sizes and lower probabilities of extinction. The present study highlights the complex relationships between metapopulation size, population subdivision, habitat fragmentation, rate of inter-patch dispersal and sex-biased dispersal and indicates the importance of gaining a better understanding of dispersal and its interactions with correlations between disturbance events.

  15. Ultrastructural changes in the uterine luminal and glandular epithelium during the oestrous cycle of the marsupial Monodelphis domestica (grey short-tailed opossum).

    PubMed

    Wick, Regula; Kress, Annetrudi

    2002-01-01

    Ultrastructural changes in the endometrium associated with the oestrous cycle were studied in the South American marsupial Monodelphis domestica. The most conspicuous changes include the height and the differentiation of the uterine luminal and glandular epithelium, which consists of ciliated and non-ciliated cells. The glandular epithelium attains its maximum development during oestrus, the luminal epithelium at postoestrus. A distinct increase in the number of ciliated cells can be observed during pro-oestrus, reaching a maximum number at oestrus; this is followed by a process of deciliation. The presence of solitary cilia on the apices of non-ciliated cells is very conspicuous during all oestrous stages and can best be seen on the luminal epithelium. These findings differ from the observations in eutherian mammals, where solitary cilia are only found in the immature uterus or after ovariectomy. The secretory activity of non-ciliated cells of the luminal epithelium is hardly noticeable along the apical membrane and stains only very faintly with Alcian blue. The glandular epithelium cells are filled apically with exocytotic vesicles at oestrus and early postoestrus. However, in contrast to the cervical gland cells, they hardly stain with Alcian blue, indicating that mucins of a different type must be present. Mechanisms for the remodelling of the luminal and glandular epithelium are especially conspicuous at metoestrus and early pro-oestrus and include the presence of autolysosomes, residual bodies and apoptotic bodies. In the endometrial stroma, around the uterine glands, macrophages accumulate and attain a typical oestrous stage-dependent appearance during their phagocytotic activities.

  16. Age-dependent transcriptome and proteome following transection of neonatal spinal cord of Monodelphis domestica (South American grey short-tailed opossum).

    PubMed

    Saunders, Norman R; Noor, Natassya M; Dziegielewska, Katarzyna M; Wheaton, Benjamin J; Liddelow, Shane A; Steer, David L; Ek, C Joakim; Habgood, Mark D; Wakefield, Matthew J; Lindsay, Helen; Truettner, Jessie; Miller, Robert D; Smith, A Ian; Dietrich, W Dalton

    2014-01-01

    This study describes a combined transcriptome and proteome analysis of Monodelphis domestica response to spinal cord injury at two different postnatal ages. Previously we showed that complete transection at postnatal day 7 (P7) is followed by profuse axon growth across the lesion with near-normal locomotion and swimming when adult. In contrast, at P28 there is no axon growth across the lesion, the animals exhibit weight-bearing locomotion, but cannot use hind limbs when swimming. Here we examined changes in gene and protein expression in the segment of spinal cord rostral to the lesion at 24 h after transection at P7 and at P28. Following injury at P7 only forty genes changed (all increased expression); most were immune/inflammatory genes. Following injury at P28 many more genes changed their expression and the magnitude of change for some genes was strikingly greater. Again many were associated with the immune/inflammation response. In functional groups known to be inhibitory to regeneration in adult cords the expression changes were generally muted, in some cases opposite to that required to account for neurite inhibition. For example myelin basic protein expression was reduced following injury at P28 both at the gene and protein levels. Only four genes from families with extracellular matrix functions thought to influence neurite outgrowth in adult injured cords showed substantial changes in expression following injury at P28: Olfactomedin 4 (Olfm4, 480 fold compared to controls), matrix metallopeptidase (Mmp1, 104 fold), papilin (Papln, 152 fold) and integrin α4 (Itga4, 57 fold). These data provide a resource for investigation of a priori hypotheses in future studies of mechanisms of spinal cord regeneration in immature animals compared to lack of regeneration at more mature stages.

  17. Molecular phylogeny implicates new world opossums (Didelphidae) as the definitive hosts of Sarcocystis ramphastosi, a parasite of the keel-billed toucan (Ramphasotos sulfuratus)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Macroscopic sarcocysts of Sarcocystis ramphastosi Dubey, Lane, and van Wilpe, 2006 were found in a tocan ((Ramphastos sulfuratus) from Costa Rica. The DNA extracted from 11 individual sarcocysts was subjected to PCR amplification assays targeting 1208 bp of 18S ribosomal DNA; data revealed a close ...

  18. Estimating Stage-Specific Vital Rate Responses to Stress within Mixed Age Populations of the Opossum Shrimp Americamysis Bahia Using Digital Imaging (NAC SETAC 2011)

    EPA Science Inventory

    Most observations of stressor effects on marine crustaceans are made on individuals or even-aged cohorts. Results of these studies are difficult to translate into ecological predictions, either because life cycle models are incomplete, or because stressor effects on mixed age po...

  19. Estimating Stage Specific Vital Rate Responses to Stress Within Mixed Age Populations of the Opossum Shrimp Americamysis bahia Using Digital Imaging

    EPA Science Inventory

    Most observations of stressor effects on marine crustaceans are made on individuals or even-aged cohorts. Results of these studies are difficult to translate into ecological predictions, either because life cycle models are incomplete, or because stressor effects on mixed age po...

  20. Which Factors Determine Spatial Segregation in the South American Opossums (Didelphis aurita and D. albiventris)? An Ecological Niche Modelling and Geometric Morphometrics Approach

    PubMed Central

    Cáceres, Nilton Carlos; de Moraes Weber, Marcelo; Melo, Geruza Leal; Meloro, Carlo; Sponchiado, Jonas; Carvalho, Renan dos Santos; Bubadué, Jamile de Moura

    2016-01-01

    Didelphis albiventris and D. aurita are Neotropical marsupials that share a unique evolutionary history and both are largely distributed throughout South America, being primarily allopatric throughout their ranges. In the Araucaria moist forest of Southern Brazil these species are sympatric and they might potentially compete having similar ecology. For this reason, they are ideal biological models to address questions about ecological character displacement and how closely related species might share their geographic space. Little is known about how two morphologically similar species of marsupials may affect each other through competition, if by competitive exclusion and competitive release. We combined ecological niche modeling and geometric morphometrics to explore the possible effects of competition on their distributional ranges and skull morphology. Ecological niche modeling was used to predict their potential distribution and this method enabled us to identify a case of biotic exclusion where the habit generalist D. albiventris is excluded by the presence of the specialist D. aurita. The morphometric analyses show that a degree of shape discrimination occurs between the species, strengthened by allometric differences, which possibly allowed them to occupy marginally different feeding niches supplemented by behavioral shift in contact areas. Overlap in skull morphology is shown between sympatric and allopatric specimens and a significant, but weak, shift in shape occurs only in D. aurita in sympatric areas. This could be a residual evidence of a higher past competition between both species, when contact zones were possibly larger than today. Therefore, the specialist D. aurita acts a biotic barrier to D. albiventris when niche diversity is not available for coexistence. On the other hand, when there is niche diversification (e.g. habitat mosaic), both species are capable to coexist with a minimal competitive effect on the morphology of D. aurita. PMID:27336371

  1. Age-Dependent Transcriptome and Proteome Following Transection of Neonatal Spinal Cord of Monodelphis domestica (South American Grey Short-Tailed Opossum)

    PubMed Central

    Saunders, Norman R.; Noor, Natassya M.; Dziegielewska, Katarzyna M.; Wheaton, Benjamin J.; Liddelow, Shane A.; Steer, David L.; Ek, C. Joakim; Habgood, Mark D.; Wakefield, Matthew J.; Lindsay, Helen; Truettner, Jessie; Miller, Robert D.; Smith, A. Ian; Dietrich, W. Dalton

    2014-01-01

    This study describes a combined transcriptome and proteome analysis of Monodelphis domestica response to spinal cord injury at two different postnatal ages. Previously we showed that complete transection at postnatal day 7 (P7) is followed by profuse axon growth across the lesion with near-normal locomotion and swimming when adult. In contrast, at P28 there is no axon growth across the lesion, the animals exhibit weight-bearing locomotion, but cannot use hind limbs when swimming. Here we examined changes in gene and protein expression in the segment of spinal cord rostral to the lesion at 24 h after transection at P7 and at P28. Following injury at P7 only forty genes changed (all increased expression); most were immune/inflammatory genes. Following injury at P28 many more genes changed their expression and the magnitude of change for some genes was strikingly greater. Again many were associated with the immune/inflammation response. In functional groups known to be inhibitory to regeneration in adult cords the expression changes were generally muted, in some cases opposite to that required to account for neurite inhibition. For example myelin basic protein expression was reduced following injury at P28 both at the gene and protein levels. Only four genes from families with extracellular matrix functions thought to influence neurite outgrowth in adult injured cords showed substantial changes in expression following injury at P28: Olfactomedin 4 (Olfm4, 480 fold compared to controls), matrix metallopeptidase (Mmp1, 104 fold), papilin (Papln, 152 fold) and integrin α4 (Itga4, 57 fold). These data provide a resource for investigation of a priori hypotheses in future studies of mechanisms of spinal cord regeneration in immature animals compared to lack of regeneration at more mature stages. PMID:24914927

  2. Disparate Igf1 expression and growth in the fore- and hind limbs of a marsupial mammal (Monodelphis domestica).

    PubMed

    Sears, Karen E; Patel, Ankit; Hübler, Merla; Cao, Xiaoyi; Vandeberg, John L; Zhong, Sheng

    2012-06-01

    Proper regulation of growth is essential to all stages of life, from development of the egg into an embryo to the maintenance of normal cell cycle progression in adults. However, despite growth's importance to basic biology and health, little is known about how mammalian growth is regulated. In this study, we investigated the molecular basis of the highly disparate growth of opossum fore- and hind limbs in utero. We first used a novel, opossum-specific microarray to identify several growth-related genes that are differentially expressed in opossum fore- and hind limbs of comparable developmental stages. These genes included Igf1. Given Igf1's role in the growth of other systems, we further investigated the role of Igf1 in opossum limb growth. Supporting the microarray results, RT-PCR indicated that Igf1 levels are approximately two times higher in opossum fore- than hind limbs. Consistent with this, while Igf1 transcripts were readily detectable in opossum forelimbs using whole-mount in situ hybridization, they were not detectable in opossum hind limbs. Furthermore, opossum limbs treated with exogenous Igf1 protein experienced significantly greater cellular proliferation and growth than control limbs in vitro. Taken together, results suggest that the differential expression of Igf1 in developing opossum limbs contributes to their divergent rate of growth, and the unique limb phenotype of opossum newborns. This study establishes the opossum limb as a new mammalian model system for study of organ growth.

  3. Husbandry of Monodelphis domestica in the study of mammalian embryogenesis.

    PubMed

    Rousmaniere, Holly; Silverman, Rachel; White, Rachel A; Sasaki, Mark M; Wilson, Siobhan D; Morrison, Jeremy T; Cruz, Yolanda P

    2010-07-01

    Monodelphis domestica, commonly called the laboratory opossum, is a useful laboratory animal for studying marsupial embryogenesis and mammalian development. Females breed year-round and the animals can be sustainably bred indoors. The authors draw on their own laboratory's experience to supplement previously published research on laboratory opossums. They describe a breeding protocol that reliably produces timed-pregnant M. domestica. Additionally, the authors discuss general laboratory opossum husbandry techniques and describe how to collect, handle and culture embryos.

  4. 16 CFR 301.0 - Fur products name guide.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    .... Opossum, Water ......do ......do Chironectes minimus. Otter Carnivora Mustelidae Lutra canadensis, Pteronura brasitionsis, Lutra annectens and Lutra lutra. Otter, Sea ......do ......do Enhydra lutris....

  5. 16 CFR 301.0 - Fur products name guide.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    .... Opossum, Water ......do ......do Chironectes minimus. Otter Carnivora Mustelidae Lutra canadensis, Pteronura brasitionsis, Lutra annectens and Lutra lutra. Otter, Sea ......do ......do Enhydra lutris....

  6. 16 CFR 301.0 - Fur products name guide.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    .... Opossum, Water ......do ......do Chironectes minimus. Otter Carnivora Mustelidae Lutra canadensis, Pteronura brasitionsis, Lutra annectens and Lutra lutra. Otter, Sea ......do ......do Enhydra lutris....

  7. Experimental infection of Didelphis marsupialis with Vesicular Stomatitis New Jersey Virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although vesicular stomatitis has been present for many years in the Americas, many aspects of its natural history remain undefined. In this study we challenged five adult Virginia opossums (Didelphis marsupialis) with vesicular stomatitis New Jersey serotype virus (VSNJV). Opossums had no detecta...

  8. Cellular and molecular drivers of differential organ growth: insights from the limbs of Monodelphis domestica.

    PubMed

    Dowling, Anna; Doroba, Carolyn; Maier, Jennifer A; Cohen, Lorna; VandeBerg, John; Sears, Karen E

    2016-06-01

    A fundamental question in biology is "how is growth differentially regulated during development to produce organs of particular sizes?" We used a new model system for the study of differential organ growth, the limbs of the opossum (Monodelphis domestica), to investigate the cellular and molecular basis of differential organ growth in mammals. Opossum forelimbs grow much faster than hindlimbs, making opossum limbs an exceptional system with which to study differential growth. We first used the great differences in opossum forelimb and hindlimb growth to identify cellular processes and molecular signals that underlie differential limb growth. We then used organ culture and pharmacological addition of FGF ligands and inhibitors to test the role of the Fgf/Mitogen-activated protein kinases (MAPK) signaling pathway in driving these cellular processes. We found that molecular signals from within the limb drive differences in cell proliferation that contribute to the differential growth of the forelimb and hindlimbs of opossums. We also found that alterations in the Fgf/MAPK pathway can generate differences in cell proliferation that mirror those observed between wild-type forelimb and hindlimbs of opossums and that manipulation of Fgf/MAPK signaling affects downstream focal adhesion-extracellular matrix (FA-ECM) and Wnt signaling in opossum limbs. Taken together, these findings suggest that evolutionary changes in the Fgf/MAPK pathway could help drive the observed differences in cell behaviors and growth in opossum forelimb and hindlimbs.

  9. Molecular characterization and development of Sarcocystis speeri sarcocysts in gamma interferon gene knockout mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The North American opossum (Didelphis virginiana) is the definitive host for at least three named species of Sarcocystis: S. falcatula, S. neurona, and S. speeri. It appears that there may be additional undescribed species of Sarcocystis in D. virginiana feces. The South American opossums (D. albive...

  10. A new mammalian model system for thalidomide teratogenesis: Monodelphis domestica.

    PubMed

    Sorensen, Daniel; Sackett, Amanda; Urban, Daniel J; Maier, Jennifer; Vargesson, Neil; Sears, Karen E

    2017-01-24

    From 1957 to 1962, thalidomide caused birth defects in >10,000 children. While the drug was pulled from the market, thalidomide is currently prescribed to treat conditions including leprosy. As a result, a new generation of babies with thalidomide defects is being born in the developing world. This represents a serious problem, as the mechanisms by which thalidomide disrupts development remain unresolved. This lack of resolution is due, in part, to the absence of an appropriate mammalian model for thalidomide teratogenesis. We test the hypothesis that opossum (Monodelphis domestica) is well suited to model human thalidomide defects. Results suggest that opossum embryos exposed to thalidomide display a range of phenotypes (e.g., heart, craniofacial, limb defects) and penetrance similar to humans. Furthermore, all opossums with thalidomide defects exhibit vascular disruptions. Results therefore support the hypotheses that opossums make a good mammalian model for thalidomide teratogenesis, and that thalidomide can severely disrupt angiogenesis in mammals.

  11. A Boy or a Girl: Is It Possible to Load the Dice?

    ERIC Educational Resources Information Center

    Ridley, Matt

    1993-01-01

    Presents scientific theories and related research concerning the possibility that animal species, among which are humans, can consciously, or otherwise, biologically determine the sex of their children. Discusses cases involving insects, fish, opossums, primates, and New Zealand women. (MDH)

  12. A new developmental mechanism for the separation of the mammalian middle ear ossicles from the jaw

    PubMed Central

    Urban, Daniel J.; Anthwal, Neal; Luo, Zhe-Xi; Maier, Jennifer A.; Sadier, Alexa

    2017-01-01

    Multiple mammalian lineages independently evolved a definitive mammalian middle ear (DMME) through breakdown of Meckel's cartilage (MC). However, the cellular and molecular drivers of this evolutionary transition remain unknown for most mammal groups. Here, we identify such drivers in the living marsupial opossum Monodelphis domestica, whose MC transformation during development anatomically mirrors the evolutionary transformation observed in fossils. Specifically, we link increases in cellular apoptosis and TGF-BR2 signalling to MC breakdown in opossums. We demonstrate that a simple change in TGF-β signalling is sufficient to inhibit MC breakdown during opossum development, indicating that changes in TGF-β signalling might be key during mammalian evolution. Furthermore, the apoptosis that we observe during opossum MC breakdown does not seemingly occur in mouse, consistent with homoplastic DMME evolution in the marsupial and placental lineages. PMID:28179517

  13. Long-term reduction of Trypanosoma cruzi infection in sylvatic mammals following deforestation and sustained vector surveillance in northwestern Argentina.

    PubMed

    Ceballos, L A; Cardinal, M V; Vazquez-Prokopec, G M; Lauricella, M A; Orozco, M M; Cortinas, R; Schijman, A G; Levin, M J; Kitron, U; Gürtler, R E

    2006-07-01

    Long-term variations in the dynamics and intensity of sylvatic transmission of Trypanosoma cruzi were investigated around eight rural villages in the semiarid Argentine Chaco in 2002-2004 and compared to data collected locally in 1984-1991. Of 501 wild mammals from 13 identified species examined by xenodiagnosis, only 3 (7.9%) of 38 Didelphis albiventris opossums and 1 (1.1%) of 91 Conepatus chinga skunks were infected by T. cruzi. The period prevalence in opossums was four-fold lower in 2002-2004 than in 1984-1991 (32-36%). The infection prevalence of skunks also decreased five-fold from 4.1-5.6% in 1984-1991 to 1.1% in 2002-2004. Infection in opossums increased with age and from summer to spring in both study periods. The force of infection per 100 opossum-months after weaning declined more than six-fold from 8.2 in 1988-1991 to 1.2 in 2002-2004. Opossums were mainly infected by T. cruzi lineage I and secondarily by lineage IId in 1984-1991, and only by T. cruzi I in 2002-2004; skunks were infected by T. cruzi IId in 1984-1991 and by IIc in 2002-2004. The striking decline of T. cruzi infection in opossums and skunks occurred in parallel to community-wide insecticide spraying followed by selective sprays leading to very low densities of infected Triatoma infestans in domestic and peridomestic habitats since 1992; to massive deforestation around one of the villages or selective extraction of older trees, and apparent reductions in opossum abundance jointly with increases in foxes and skunks. These factors may underlie the dramatic decrease of T. cruzi infection in wild reservoir hosts.

  14. Long-term reduction of Trypanosoma cruzi infection in sylvatic mammals following deforestation and sustained vector surveillance in northwestern Argentina

    PubMed Central

    Ceballos, L.A.; Cardinal, M.V.; Vazquez-Prokopec, G.M.; Lauricella, M.A.; Orozco, M.M.; Cortinas, R.; Schijman, A.G.; Levin, M.J.; Kitron, U.; Gürtler, R.E.

    2007-01-01

    Long-term variations in the dynamics and intensity of sylvatic transmission of Trypanosoma cruzi were investigated around eight rural villages in the semiarid Argentine Chaco in 2002–2004 and compared to data collected locally in 1984–1991. Of 501 wild mammals from 13 identified species examined by xenodiagnosis, only 3 (7.9%) of 38 Didelphis albiventris opossums and 1 (1.1%) of 91 Conepatus chinga skunks were infected by T. cruzi. The period prevalence in opossums was four-fold lower in 2002–2004 than in 1984–1991 (32–36%). The infection prevalence of skunks also decreased five-fold from 4.1–5.6% in 1984–1991 to 1.1% in 2002–2004. Infection in opossums increased with age and from summer to spring in both study periods. The force of infection per 100 opossum-months after weaning declined more than six-fold from 8.2 in 1988–1991 to 1.2 in 2002–2004. Opossums were mainly infected by T. cruzi lineage I and secondarily by lineage IId in 1984–1991, and only by T. cruzi I in 2002–2004; skunks were infected by T. cruzi IId in 1984–1991 and by IIc in 2002–2004. The striking decline of T. cruzi infection in opossums and skunks occurred in parallel to community-wide insecticide spraying followed by selective sprays leading to very low densities of infected Triatoma infestans in domestic and peridomestic habitats since 1992; to massive deforestation around one of the villages or selective extraction of older trees, and apparent reductions in opossum abundance jointly with increases in foxes and skunks. These factors may underlie the dramatic decrease of T. cruzi infection in wild reservoir hosts. PMID:16839513

  15. Modest genetic differentiation among North American populations of Sarcocystic neurona may reflect expansion in its geographic range

    USGS Publications Warehouse

    Sundar, N.; Asmundsson, I.M.; Thomas, N.J.; Samuel, M.D.; Dubey, J.P.; Rosenthal, B.M.

    2008-01-01

    Sarcocystis neurona is an important cause of neurological disease in horses (equine protozoal myeloencephalitis, EPM) and sea otters in the United States. In addition, EPM-like disease has been diagnosed in several other land and marine mammals. Opossums are its only definitive hosts. Little genetic diversity among isolates of S. neurona from different hosts has been reported. Here, we used 11 microsatellites to characterize S. neurona DNA isolated from natural infections in 22 sea otters (Enhydra lutris) from California and Washington and in 11 raccoons (Procyon lotor) and 1 striped skunk (Mephitis mephitis) from Wisconsin. By jointly analyzing these 34 isolates with 26 isolates previously reported, we determined that geographic barriers may limit S. neurona dispersal and that only a limited subset of possible parasite genotypes may have been introduced to recently established opossum populations. Moreover, our study confirms that diverse intermediate hosts share a common infection source, the opossum (Didelphis virginiana).

  16. Studies on the Feeding Habits of Lutzomyia (Lutzomyia) longipalpis (Lutz & Neiva, 1912) (Diptera: Psychodidae: Phlebotominae) Populations from Endemic Areas of American Visceral Leishmaniasis in Northeastern Brazil

    PubMed Central

    Afonso, Margarete Martins dos Santos; Duarte, Rosemere; Miranda, José Carlos; Caranha, Lindenbergh; Rangel, Elizabeth Ferreira

    2012-01-01

    The aim of this study was to identify potential blood feeding sources of L. (L.) longipalpis specimens from populations in Northeastern Brazil, endemic areas of American Visceral Leishmaniasis (AVL) and its correlation with the transmission of L. (L.) i. chagasi. The ELISA technique was applied using bird, dog, goat, opossum, equine, feline, human, sheep, and rodent antisera to analyze 609 females, resulting in an overall positivity of 60%. In all municipalities, females showed higher positivity for bird followed by dog antiserum and sand fly specimens were also positive for equine, feline, human, sheep, goat, opossum, and rodent antisera. The finding for 17 combinations of two or three types of blood in some females corroborates the opportunistic habit of this sand fly species. The results demonstrating the association between L. (L.) longipalpis and opossum suggest the need for further evaluation of the real role of this synanthropic mammal in the eco-epidemiology of AVL. PMID:22315621

  17. Modest genetic differentiation among North American populations of Sarcocystis neurona may reflect expansion in its geographic range.

    PubMed

    Sundar, N; Asmundsson, I M; Thomas, N J; Samuel, M D; Dubey, J P; Rosenthal, B M

    2008-03-25

    Sarcocystis neurona is an important cause of neurological disease in horses (equine protozoal myeloencephalitis, EPM) and sea otters in the United States. In addition, EPM-like disease has been diagnosed in several other land and marine mammals. Opossums are its only definitive hosts. Little genetic diversity among isolates of S. neurona from different hosts has been reported. Here, we used 11 microsatellites to characterize S. neurona DNA isolated from natural infections in 22 sea otters (Enhydra lutris) from California and Washington and in 11 raccoons (Procyon lotor) and 1 striped skunk (Mephitis mephitis) from Wisconsin. By jointly analyzing these 34 isolates with 26 isolates previously reported, we determined that geographic barriers may limit S. neurona dispersal and that only a limited subset of possible parasite genotypes may have been introduced to recently established opossum populations. Moreover, our study confirms that diverse intermediate hosts share a common infection source, the opossum (Didelphis virginiana).

  18. Development of the marsupial shoulder girdle complex: a case study in Monodelphis domestica.

    PubMed

    Hübler, Merla; Molineaux, Anna C; Keyte, Anna; Schecker, Teresa; Sears, Karen E

    2013-01-01

    During their embryogenesis, marsupials transiently develop a unique structure, the shoulder arch, which provides the structural support and muscle-attachments necessary for the newborn's crawl to the teat. One of the most pronounced and functionally important aspects of the shoulder arch is an enlarged coracoid. The goal of this study is to determine the molecular basis of shoulder arch formation in marsupials. To achieve this goal, this study investigates the relative expression of several genes with known roles in shoulder girdle morphogenesis in a marsupial-the opossum, Monodelphis domestica-and a placental, the mouse, Mus musculus. Results indicate that Hoxc6, a gene involved in coracoid patterning, is expressed for a longer period of time and at higher levels in opossum relative to mouse. Functional manipulation suggests that these differences in Hoxc6 expression are independent of documented differences in retinoic acid signaling in opossum and mouse forelimbs. Results also indicate that Emx2, a gene involved in scapular blade condensation, is upregulated in opossum relative to mouse. However, several other genes involved in shoulder girdle patterning (e.g., Gli3, Pax1, Pbx1, Tbx15) are comparably expressed in these species. These findings suggest that the upregulation of Hoxc6 and Emx2 occurs through independent genetic modifications in opossum relative to mouse. In summary, this study documents a correlation between gene expression and the divergent shoulder girdle morphogenesis of marsupial (i.e., opossum) and placental (i.e., mouse) mammals, and thereby provides a foundation for future research into the genetic basis of shoulder girdle morphogenesis in marsupials. Furthermore, this study supports the hypothesis that the mammalian shoulder girdle is a highly modular structure whose elements are relatively free to evolve independently.

  19. The lamina propria of vertebrate seminiferous tubules: a comparative light and electron microscopic investigation.

    PubMed

    Christl, H W

    1990-01-01

    The lamina propria of the seminiferous tubules was compared by means of light and electron microscopy in specimens obtained from the following vertebrates: Mute swan, northern mallard, blackbird, grey short-tailed opossum, north american opossum, european rabbit, mouse, rat, golden hamster, mini pig, bull, llama, roebuck, horse, coati, cat, dog, java monkey, orang utan. The lamina propria consists of basal lamina, ground substance, collagen fibers, fibroblasts and myofibroblasts. Myofibroblasts are characterized by myofilaments, dense patches and a basal lamina covering their plasmalemma. The layers of myofibroblasts always lie adjacent to the germinal epithelium, while the surrounding fibroblast layers are located peripherally.

  20. Evolution of the Genotype-to-Phenotype Map and the Cost of Pleiotropy in Mammals.

    PubMed

    Porto, Arthur; Schmelter, Ryan; VandeBerg, John L; Marroig, Gabriel; Cheverud, James M

    2016-12-01

    Evolutionary studies have long emphasized that the genetic architecture of traits holds important microevolutionary consequences. Yet, studies comparing the genetic architecture of traits across species are rare, and discussions of the evolution of genetic systems are made on theoretical arguments rather than on empirical evidence. Here, we compared the genetic architecture of cranial traits in two different mammalian model organisms: the gray short-tailed opossum, Monodelphis domestica, and the laboratory mouse, Mus musculus We show that both organisms share a highly polygenic genetic architecture for craniofacial traits, with many loci of small effect. However, these two model species differ significantly in the overall degree of pleiotropy, N, of the genotype-to-phenotype map, with opossums presenting a higher average N They also diverge in their degree of genetic modularity, with opossums presenting less modular patterns of genetic association among traits. We argue that such differences highlight the context dependency of gene effects, with developmental systems shaping the variational properties of genetic systems. Finally, we also demonstrate based on the opossum data that current measurements for the relationship between the mutational effect size and N need to be re-evaluated in relation to the importance of the cost of pleiotropy for mammals.

  1. Aurora-A as a Modifier of Breast Cancer Risk in BRCA 1/2 Mutation Carriers

    DTIC Science & Technology

    2007-06-01

    Dieter Schaefer, Institute of Human Genetics, University of Frankfurt, Frankfurt, Germany; Norbert Arnold, University of Schleswig- Holstein , Campus...Intron 2 Opossum Mouse Rat Cow Dog Intron 1 Figure 3 | The FGFR2 locus. a, Map of the whole FGFR2 gene, viewed relative to common SNPs on HapMap

  2. Development of Marine Sediment Toxicity Data for Ordnance Compounds and Toxicity Identification Evaluation Studies at Select Naval Facilities

    DTIC Science & Technology

    2000-08-01

    macro-alga Ulva fasciata; survival and reproductive success of the polychaete Dinophilus gyrociliatus; larvae survival with the redfish Sciaenops ... ocellatus ; and survival of juveniles of the opossum shrimp Mysidopsis bahia. The overall toxicity, chemistry, and TIE test results indicate that ordnance

  3. Bobcat (Lynx rufus) as a new natural intermediate host for Sarcocystis neurona

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The protozoan Sarcocystis neurona is an important cause of severe clinical disease of horses (called equine protozoal myeloencephalitis, EPM), marine mammals, companion animals, and several species of wildlife animals in the Americas. The Virginia opossum (Didelphis virginiana) is its definitive hos...

  4. Making Connections. A Curriculum and Activity Guide to Mammoth Cave National Park. [Grades] K-3.

    ERIC Educational Resources Information Center

    National Park Service (Dept. of Interior), Washington, DC.

    Kentucky's Mammoth Cave National Park is important because of its diversity of life on the surface and underground. Some of the plants in the park include trees such as oaks, hickories, tulip poplars, sycamores, and many types of bushes. The animal population is also very diverse and includes bats, squirrels, deer, raccoons, opossums, chipmunks,…

  5. ISOLATION OF TOXOPLASMA GONDII FROM ANIMALS IN DURANGO, MEXICO

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little is known concerning the epidemiology of Toxoplasma gondii infection in people and animals in rural Mexico. Serum samples and tissues from 150 dogs, 150 cats, 65 opossums (Didelphis virginianus), 249 rats (Rattus spp.), 127 mice (Mus musculus), and 69 squirrels (Spermophilus variegatus) from t...

  6. Qin, Han, and Huang: Text Reproduction and Literacy in Rural China, A Case for Euclid and Homer.

    ERIC Educational Resources Information Center

    Bain, Bruce; Yu, Agnes

    1991-01-01

    Debates the merits of the claim that "symbolic technologies push cognitive growth earlier and longer." The results of an assessment are presented that involved three adult male peasants (two literate, one nonliterate) living in rural China and their ability to recall the text of "The Lonesome Opossum." (25 references) (GLR)

  7. Value-based customer grouping from large retail data sets

    NASA Astrophysics Data System (ADS)

    Strehl, Alexander; Ghosh, Joydeep

    2000-04-01

    In this paper, we propose OPOSSUM, a novel similarity-based clustering algorithm using constrained, weighted graph- partitioning. Instead of binary presence or absence of products in a market-basket, we use an extended 'revenue per product' measure to better account for management objectives. Typically the number of clusters desired in a database marketing application is only in the teens or less. OPOSSUM proceeds top-down, which is more efficient and takes a small number of steps to attain the desired number of clusters as compared to bottom-up agglomerative clustering approaches. OPOSSUM delivers clusters that are balanced in terms of either customers (samples) or revenue (value). To facilitate data exploration and validation of results we introduce CLUSION, a visualization toolkit for high-dimensional clustering problems. To enable closed loop deployment of the algorithm, OPOSSUM has no user-specified parameters. Thresholding heuristics are avoided and the optimal number of clusters is automatically determined by a search for maximum performance. Results are presented on a real retail industry data-set of several thousand customers and products, to demonstrate the power of the proposed technique.

  8. Besnoitia oryctofelisi n. sp. (Protozoa: Apicomplexa) from domestic rabbits.

    PubMed

    Dubey, J P; Sreekumar, C; Lindsay, D S; Hill, D; Rosenthal, B M; Venturini, L; Venturini, M C; Greiner, E C

    2003-06-01

    A species of Besnoitia from naturally infected rabbits from Argentina was propagated experimentally in mice, gerbils, rabbits, cats, and cell cultures. Cats fed tissue cysts from rabbits shed oocysts with a prepatent period of nine to 13 days. Sporulated oocysts were infective to gerbils, rabbits, outbred Swiss Webster and interferon gamma gene knockout mice. Bradyzoites were infective orally to gerbils and cats. Tachyzoites were successfully cultivated and maintained in vitro in bovine monocytes and African green monkey kidney cells. Schizonts were seen in the lamina propria of the small intestine of cats fed tissue cysts; the largest ones measured 52 x 45 microm. Schizonts were also present in mesenteric lymph nodes, livers, and other extra-intestinal organs of cats fed tissue cysts. Oocysts were 10-14 x 10-13 microm in size. This rabbit-derived species of Besnoitia resembled B. darlingi of the North American opossum, Didelphis virginiana with an opossum-cat cycle, but it was not transmissible to D. virginiana, and B. darlingi of opossums was not transmissible to rabbits. Based on biological, serological, antigenic, and molecular differences between the rabbit and the opossum Besnoitia, a new name, B. oryctofelisi is proposed for the parasite from domestic rabbits from Argentina.

  9. 77 FR 57066 - Proposed Flood Elevation Determinations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-17

    ... Run (backwater effects from Sandlick Creek), Plum Creek (backwater effects from Green River), Plum... Run (backwater effects from Sandlick Creek), Plum Creek (backwater effects from Green River), Plum... Muhlenberg County. 1,175 feet upstream of Opossum Lane. Plum Creek (backwater effects from From the...

  10. 75 FR 28511 - Proposed Flood Elevation Determinations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-21

    ... County. approximately 1,175 feet upstream of Opossum Lane. Plum Creek (Backwater effects from From the... 300 feet of Muhlenberg County. downstream of the confluence with Plum Creek Tributary 4. Plum Creek... Plum Creek to Muhlenberg County. approximately 0.65 mile upstream of the confluence with Plum...

  11. Epidemiologic Evidence for Different Roles of Ultraviolet A and B Radiation in Melanoma Mortality Rates

    DTIC Science & Technology

    2003-03-11

    melanoma is the miniature opossum, Monodelphis domestica . Some adults of these animals develop melanoma upon prolonged exposure to mixed UVB-UVA radiation...Ultraviolet A and melanoma in Monodelphis domestica sucklings. J Natl Cancer Inst 2000. 60. Hutchinson PE, Osborne JE, Lear JT, Smith AG, Bowers PW

  12. Toxocara cati (Nematoda: Ascarididae) in Didelphis albiventris (Marsupialia: Didelphidae) from Brazil: a case of pseudoparasitism.

    PubMed

    Pinto, Hudson Alves; Mati, Vitor Luís Tenório; Melo, Alan Lane de

    2014-01-01

    Eggs of Toxocara cati were found in the feces of Didelphis albiventris from a peridomestic urban environment in Brazil. Negative fecal tests following short-term captivity of the opossums, as well as the absence of ascaridids during necropsy, suggest the occurrence of pseudoparasitism. Implications of the findings for the epidemiology of toxocariasis are discussed.

  13. 50 CFR 32.32 - Illinois.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... quail, raccoon, opossum, red fox, grey fox, and coyote on designated areas of the refuge in accordance... Hunting. We allow hunting of white-tailed deer and turkey on designated areas of the refuge in accordance... B4 apply. 2. We require all deer and turkey hunters using the “restricted use area” (as described...

  14. 50 CFR 32.68 - West Virginia.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., cottontail rabbit, snowshoe hare, red fox, gray fox, bobcat, woodchuck, coyote, opossum, striped skunk, and... allow the hunting of white-tailed deer, black bear, and turkey on designated areas of the refuge in... deer and black bear in the rifle zone. 4. When using shotguns for big game hunting, we only...

  15. 50 CFR 32.68 - West Virginia.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... of this chapter). 9. We close the Research Natural Area except for deer hunting, which we allow for... rabbit, snowshoe hare, red fox, gray fox, bobcat, woodchuck, coyote, opossum, striped skunk, and raccoon... allow the hunting of white-tailed deer, black bear, and turkey on designated areas of the refuge...

  16. 50 CFR 32.32 - Illinois.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... quail, raccoon, opossum, red fox, grey fox, and coyote on designated areas of the refuge in accordance... Hunting. We allow hunting of white-tailed deer and turkey on designated areas of the refuge in accordance... B4 apply. 2. We require all deer and turkey hunters using the “restricted use area” (as described...

  17. 50 CFR 32.32 - Illinois.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... squirrel, rabbit, bobwhite quail, raccoon, opossum, red fox, grey fox, and coyote on designated areas of... of this chapter). C. Big Game Hunting. We allow hunting of white-tailed deer and turkey on designated.... Conditions A1 through A5 and A7, A8, and B4 apply. 2. We require all deer and turkey hunters using...

  18. 50 CFR 32.68 - West Virginia.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... of this chapter). 9. We close the Research Natural Area except for deer hunting, which we allow for... rabbit, snowshoe hare, red fox, gray fox, bobcat, woodchuck, coyote, opossum, striped skunk, and raccoon... allow the hunting of white-tailed deer, black bear, and turkey on designated areas of the refuge...

  19. 50 CFR 32.32 - Illinois.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... quail, raccoon, opossum, red fox, grey fox, and coyote on designated areas of the refuge in accordance... Hunting. We allow hunting of white-tailed deer and turkey on designated areas of the refuge in accordance... B4 apply. 2. We require all deer and turkey hunters using the “restricted use area” (as described...

  20. 50 CFR 32.68 - West Virginia.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... of this chapter). 9. We close the Research Natural Area except for deer hunting, which we allow for... rabbit, snowshoe hare, red fox, gray fox, bobcat, woodchuck, coyote, opossum, striped skunk, and raccoon... allow the hunting of white-tailed deer, black bear, and turkey on designated areas of the refuge...

  1. 50 CFR 32.34 - Iowa.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., litter, fish or any parts thereof, on the banks, in the water, or on the ice. 10. We prohibit digging or..., goose, coot, rail (Virginia and sora only), woodcock, and snipe on the Buffalo Creek Bottoms and Schwob...), groundhog, raccoon, opossum, fox, coyote, and crow on Buffalo Creek Bottoms, Schwob Marsh, and the Core...

  2. The striped skunk (Mephitis mephitis) is an intermediate host for Sarcocystis neurona.

    PubMed

    Cheadle, M A; Yowell, C A; Sellon, D C; Hines, M; Ginn, P E; Marsh, A E; MacKay, R J; Dame, J B; Greiner, E C

    2001-06-01

    Striped skunks, initially negative for antibodies to Sarcocystis neurona, formed sarcocysts in skeletal muscles after inoculation with S. neurona sporocysts collected from a naturally infected Virginia opossum (Didelphis virginiana). Skunks developed antibodies to S. neurona by immunoblot and muscles containing sarcocysts were fed to laboratory-reared opossums which then shed sporulated Sarcocystis sporocysts in their faeces. Mean dimensions for sporocysts were 11.0 x 7.5 microm and each contained four sporozoites and a residuum. Sarcocysts from skunks and sporocysts from opossums fed infected skunk muscle were identified as S. neurona using PCR and DNA sequence analysis. A 2-month-old, S. neurona-naive pony foal was orally inoculated with 5 x 10(5) sporocysts. Commercial immunoblot for antibodies to S. neurona performed using CSF collected from the inoculated pony was low positive at 4 weeks p.i., positive at 6 weeks p.i., and strong positive at 8 weeks p.i. Gamma-interferon gene knockout mice inoculated with skunk/opossum derived sporocysts developed serum antibodies to S. neurona and clinical neurologic disease. Merozoites of S. neurona present in the lung, cerebrum, and cerebellum of mice were detected by immunohistochemistry using polyclonal antibodies to S. neurona. Based on the results of this study, the striped skunk is an intermediate host of S. neurona.

  3. New Sylvatic Hosts of Trypanosoma cruzi and Their Reservoir Competence in the Humid Chaco of Argentina: A Longitudinal Study

    PubMed Central

    Orozco, M. Marcela; Enriquez, Gustavo F.; Alvarado-Otegui, Julián A.; Cardinal, M. Victoria; Schijman, Alejandro G.; Kitron, Uriel; Gürtler, Ricardo E.

    2013-01-01

    A four-year longitudinal study of the structure of sylvatic transmission cycles of Trypanosoma cruzi, reservoir host competence and parasite discrete typing units was conducted in a disturbed rural area of the humid Chaco in Argentina. Among 190 mammals examined by xenodiagnosis and polymerase chain reaction amplification, the composite prevalence of infection was substantially higher in Dasypus novemcinctus armadillos (57.7%) and Didelphis albiventris opossums (38.1%) than in Euphractus sexcinctus (20.0%), Tolypeutes matacus (12.5%), and Chaetophractus vellerosus (6.3%) armadillos. Trypanosoma cruzi was detected for the first time in Thylamys pusilla small opossums and in two unidentified small rodents. Infection was spatially aggregated only in armadillos. All Didelphis were infected with T. cruzi I and all armadillo species were infected with T. cruzi III, implying two distinct sylvatic cycles with no inputs from the domestic cycle. Dasypus armadillos and Didelphis opossums were much more infectious to vectors than other armadillos, small opossums, or rodents. PMID:23530075

  4. Learning Excitement.

    ERIC Educational Resources Information Center

    Sudore, Gail M.

    1987-01-01

    Provides directions for 18 environmental activities/concepts for adventure programming including games (clam free, habitat lap sit, spirals); warm-ups/stretches (bug tug, stork stretch); trust builders/group initiatives (willow in wind, opossum ferry); low elements (all aboard, trolley); medium elements (rebirth, tire on pole); and high elements…

  5. Rickettsial Infections among Ctenocephalides felis and Host Animals during a Flea-Borne Rickettsioses Outbreak in Orange County, California

    PubMed Central

    Fogarty, Carrie; Krueger, Laura; Macaluso, Kevin R.; Odhiambo, Antony; Nguyen, Kiet; Farris, Christina M.; Luce-Fedrow, Alison; Bennett, Stephen; Jiang, Ju; Sun, Sokanary; Cummings, Robert F.; Richards, Allen L.

    2016-01-01

    Due to a resurgence of flea-borne rickettsioses in Orange County, California, we investigated the etiologies of rickettsial infections of Ctenocephalides felis, the predominant fleas species obtained from opossums (Didelphis virginiana) and domestic cats (Felis catus), collected from case exposure sites and other areas in Orange County. In addition, we assessed the prevalence of IgG antibodies against spotted fever group (SFGR) and typhus group (TGR) rickettsiae in opossum sera. Of the 597 flea specimens collected from opossums and cats, 37.2% tested positive for Rickettsia. PCR and sequencing of rickettsial genes obtained from C. felis flea DNA preparations revealed the presence of R. typhi (1.3%), R. felis (28.0%) and R. felis-like organisms (7.5%). Sera from opossums contained TGR-specific (40.84%), but not SFGR-specific antibodies. The detection of R. felis and R. typhi in the C. felis fleas in Orange County highlights the potential risk for human infection with either of these pathogens, and underscores the need for further investigations incorporating specimens from humans, animal hosts, and invertebrate vectors in endemic areas. Such studies will be essential for establishing a link in the ongoing flea-borne rickettsioses outbreaks. PMID:27537367

  6. Immunohistochemical confirmation of Sarcocystis neurona infections in raccoons, mink, cat, skunk, and pony.

    PubMed

    Dubey, J P; Hamir, A N

    2000-10-01

    In the central nervous system of 2 raccoons, 1 cat, 1 pony, 2 mink, and 1 skunk, protozoa previously thought to be Sarcocystis-like reacted positively to Sarcocystis neurona-specific antibodies in an immunohistochemical test. In addition, S. neurona was identified in the brain of another skunk. These observations indicate that S. neurona is not confined to opossums and horses.

  7. The subventricular zone is the developmental milestone of a 6-layered neocortex: comparisons in metatherian and eutherian mammals.

    PubMed

    Cheung, Amanda F P; Kondo, Shinichi; Abdel-Mannan, Omar; Chodroff, Rebecca A; Sirey, Tamara M; Bluy, Lisa E; Webber, Natalie; DeProto, Jamin; Karlen, Sarah J; Krubitzer, Leah; Stolp, Helen B; Saunders, Norman R; Molnár, Zoltán

    2010-05-01

    The major lineages of mammals (Eutheria, Metatheria, and Monotremata) diverged more than 100 million years ago and have undergone independent changes in the neocortex. We found that adult South American gray short-tailed opossum (Monodelphis domestica) and tammar wallaby (Macropus eugenii) possess a significantly lower number of cerebral cortical neurons compared with the mouse (Mus musculus). To determine whether the difference is reflected in the development of the cortical germinal zones, the location of progenitor cell divisions was examined in opossum, tammar wallaby, and rat. The basic pattern of the cell divisions was conserved, but the emergence of a distinctive band of dividing cells in the subventricular zone (SVZ) occurred relatively later in the opossum (postnatal day [P14]) and the tammar wallaby (P40) than in rodents. The planes of cell divisions in the ventricular zone (VZ) were similar in all species, with comparable mRNA expression patterns of Brn2, Cux2, NeuroD6, Tbr2, and Pax6 in opossum (P12 and P20) and mouse (embryonic day 15 and P0). In conclusion, the marsupial neurodevelopmental program utilizes an organized SVZ, as indicated by the presence of intermediate (or basal) progenitor cell divisions and gene expression patterns, suggesting that the SVZ emerged prior to the Eutherian-Metatherian split.

  8. Serological response of cats to experimental Besnoitia darlingi and Besnoitia neotomofelis infections and prevalence of antibodies to these parasites in cats from Virginia and Pennsylvania

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Besnoitia darlingi and B. neotomofelis are tissue cyst-forming apicomplexan parasite that use domestic cats (Felis domesticus) as definitive hosts and opossums (Didelphis virginiana) and southern planes woodrats (Neotoma micropus) as intermediate hosts, respectively. Nothing is known about the preva...

  9. Natural infection of Didelphis aurita (Mammalia: Marsupialia) with Leishmania infantum in Brazil

    PubMed Central

    2012-01-01

    Background The opossum Didelphis have been considered as natural hosts of Leishmania parasites in the New World, suggesting an important role in the epidemiology of Visceral Leishmaniasis (VL). Among six extant species that belong to the genus Didelphis, only two (D. marsupialis and D. albiventris), have been mentioned as natural hosts of Leishmania infantum in Brazil and Colombia. In the present paper, it is reported for the first time, the observation of intracellular parasites (amastigotes) in tissues of Didelphis aurita naturally infected with Leishmania infantum in Brazil. We also discuss some aspects associated to the relationship between L. infantum and the geographical distribution of some species of the genus Didelphis. Methods The opossums studied were caught by wire traps (Tomahawk) in Barra de Guaratiba, a peri-urban area in Rio de Janeiro. The opossums were killed with an overdose of Thiopental sodium.At necropsy, macroscopic alterations were examined and samples from liver, spleen, lymph nodes, ear, abdominal skin, scent glands and bone marrow were collected for parasitological and molecular diagnoses. Results Forty-eight opossums were captured in an AVL endemic region, 30 being caught in a mangrove area and eighteen animals in a forest area near to some residential-yards. Among the thirty opossums trapped in the mangrove area, all of them were negative by both imprint and sera samples assayed on Dipstick Tests, that is a test based on a combination of protein-A colloidal gold conjugate and rk39 Leishmania antigen to detect anti-Leishmania antibody in serum or plasma. At the macroscopic examination one out of eighteen opossums, caught close to the forest, presented alterations compatible with spleen hypertrophy and three were positive by Dipstick Tests (16.6%) and presented amastigotes in the spleen and in one of them, the parasites were also observed in a submandibular lymph node. Leishmania infantum infections were confirmed through dot blot

  10. Expression patterns of Oct4, Cdx2, Tead4, and Yap1 proteins during blastocyst formation in embryos of the marsupial, Monodelphis domestica Wagner.

    PubMed

    Morrison, J T; Bantilan, N S; Wang, V N; Nellett, K M; Cruz, Y P

    2013-05-01

    The marsupial blastocyst forms in an entirely different manner from its eutherian counterpart, involving cell-zona rather than cell-cell adhesion during the 8- to-16-cell transition. While the eutherian blastocyst consists of a spherical trophoblast completely enveloping a pluripotent inner cell mass, or pluriblast, the marsupial blastocyst forms initially as a bowl-shaped monolayer of cells lining the zona pellucida at the embryonic pole (ep). This monolayer contains a small patch of centrally positioned pluriblast cells edged with trophoblast cells that later coalesce at the abembryonic pole. Using immunocytochemistry, we examined the localization of the proteins Oct4, Cdx2, Tead4, Sox2, and Yap1 in opossum embryos to determine if their temporal expression pattern differed from that in the mouse, given the important differences in cell behavior preceding blastocyst formation in these mammals. Our results indicate that these proteins are expressed in similar temporal patterns despite the topological differences between mouse and opossum cleavage-stage embryos and blastocysts. That the Hippo-pathway protein Yap1 localized specifically around the approximately 128-cell stage to opossum trophoblast nuclei but remained in the cytoplasm of pluriblast cells suggests that this transcriptional regulator participates in allocating cells to the trophoblast lineage, as it does in mouse. Interestingly, in both mouse and opossum embryos, expression of the pluripotency marker Oct4 persisted after Cdx2, which signals trophoblast specification, began to be expressed in trophoblast cells. This and the observation that Cdx2 is present in opossum embryos well before blastomere-zona adhesion even occurs suggests that the proteins studied may have other roles in early mammalian embryonic development.

  11. Mitochondrial tRNA-lookalikes in nuclear chromosomes: could they be functional?

    PubMed

    Telonis, Aristeidis G; Kirino, Yohei; Rigoutsos, Isidore

    2015-01-01

    The presence in human nuclear chromosomes of multiple sequences that are highly similar to human mitochondrial tRNAs (tRNA-lookalikes) raises intriguing questions about the possible functionality of these genomic loci. In this perspective, we explore the significance of the mitochondrial tRNA-lookalikes based on a series of properties that argue for their non-accidental nature. We particularly focus on the possibility of transcription as well as on potential functional roles for these sequences that can range from their acting as DNA regulatory elements to forming functional mature tRNAs or tRNA-derived fragments. Extension of our analysis to other simians (chimp, gorilla, rhesus, and squirrel monkey), 2 rodents (mouse and rat), a marsupial (opossum) and 3 invertebrates (fruit-fly, worm, and sponge) revealed that mitochondrial tRNA-lookalikes are prevalent in primates and the opossum but absent from the other analyzed organisms.

  12. Philodryas chamissonis (Reptilia: Squamata: Colubridae) preys on the arboreal marsupial Dromiciops gliroides (Mammalia: Microbiotheria: Microbiotheriidae).

    PubMed

    Muñoz-Leal, S; Ardiles, K; Figueroa, R A; González-Acuña, D

    2013-02-01

    Philodryas chamissonis, the Chilean long-tailed snake, is a diurnal predator mainly of Liolaemus lizards, but also of amphibians, birds, rodents and juvenile rabbits. Dromiciops gliroides (Colocolo opossum) is an arboreal marsupial endemic of temperate rainforest of southern South America. Little information is available about this marsupial's biology and ecology. Here we report the predation of one Colocolo opossum by an adult female P. chamissonis in a mixed Nothofagus forest, composed mainly by N. dombeyi, N. glauca and N. alpina trees, in the "Huemules de Niblinto" National Reserve, Nevados de Chillán, Chile. Since these two species have different activity and habitat use patterns, we discuss how this encounter may have occurred. Although it could just have been an opportunistic event, this finding provides insights into the different components of food chains in forest ecosystems of Chile.

  13. 13C Nuclear magnetic resonance studies to the binding of isocyanides to various hemoglobins and myoglobins.

    PubMed

    Dill, K; Satterlee, J D; Richards, J H

    1978-10-03

    Interactions between ethyl and isopropyl isocyanides and various hemoglobins and myoglobins have been studied by 13C nuclear magnetic resonance. The results indicate that the chemical shift of the bound isocyanide depends on the structure of the hemoglobin subunit or myoglobin. The resonances exhibited by isocyanides bound to myoglobin are sensitive to pH in contrast to the situation with rabbit and human hemoglobins. beta subunits of opossum, rabbit, and human hemoglobins show a significantly greater preferential affinity for CO relative to EIC than do alpha subunits which have allowed the assignment of resonances. Rabbit, human, and opossum hemoglobin subunits bind ethyl isocyanide without observable preferences and an excess of DPG does not appear to affect this random order of ligation. In contrast, an excess of IHP seems to cause preferential ligation of the alpha subunits in these hemoglobins. The results have been used to gain insights into the differing characteristics of the ligand binding pockets of these various hemoglobins.

  14. Common procedures in hedgehogs, prairie dogs, exotic rodents, and companion marsupials.

    PubMed

    Johnson-Delaney, Cathy A

    2006-05-01

    Nondomesticated species are commonly being kept as companion animals. These include the African pygmy hedgehog (Atelerix albi-ventris), the North American black-tailed prairie dog (Cynomys lu-dovicianus), and exotic rodents such as the degu (Octodon degus)and duprasi or fat-tailed gerbil (Pachyuromys duprasi). Common companion marsupials include the sugar glider (Petaurus breviceps),Bennett's or Tammar (Dama) wallabies (Macropus rufogriseus rufo-griseus and Macropus eugenii, respectively), the Brazilian or South American gray short-tailed opossum (Monodelphis domestica), and the North American Virginia opossum (Didelphis virginiana). Although many of these animals are now bred domestically and are fairly docile when human-raised, they are essentially wild animals and hence have strong instincts to hide illness and pain.

  15. Leishmaniasis in Texas: Isolation of Leishmania mexicana from Neotoma Micropus

    DTIC Science & Technology

    1990-01-01

    leishmaniasis cases in Texas, 2) Lutzomyia anthophora, a sand fly which has transmitted Leishmania mexicana under laboratory conditions (Endris et al., 1984... temperatures > 37 C are all suggestive of L. mexicana. Isozyme characterization determined that the parasite isolated from N. micropus collected in Texas is L...Addis, 1945). Other vertebrates such as opossums, hispid cotton rats, and armadillos and other sand flies such as Lutzomyia diabolica and Lutzomyia texana

  16. Proceedings of the Annual Meeting (14th) Aquatic Plant Control Research Planning and Operations Review, Held at Lake Eufaula, Oklahoma on 26-29 November 1979.

    DTIC Science & Technology

    1980-10-01

    ganisms were selected for inclusion in the LSOMT: a. Neochetina eichhorniac - this insect, the mottled water - hyacinth weevil , has already been...Sigmodon hispidus) and rice rats (Iryzonrys palustris). Because Florida water rats (Neofiber alleni) are relatively invulnerable to capture by...extremes in water levels. Winter and spring trapping produced 26 hispid cotton rats, 8 opossums, 3 rice rats, 4 raccoons, 1 marsh rabbit, 1 river otter

  17. Detection of Lawsonia intracellularis by real-time PCR in the feces of free-living animals from equine farms with documented occurrence of equine proliferative enteropathy.

    PubMed

    Pusterla, Nicola; Mapes, Samantha; Rejmanek, Daniel; Gebhart, Connie

    2008-10-01

    The objective of this study was to determine whether Lawsonia intracellularis was present in the feces of free-living animals collected on two equine premises with documented occurrence of equine proliferative enteropathy (EPE). Fresh feces from black-tailed jackrabbits (Lepus californicus, n=100), striped skunks (Mephitis mephitis, n=22), feral cats (Felis catus, n=14), Brewer's Blackbirds (Euphagus cyanocephalus, n=10), Virginian opossums (Didelphis virginiana, n=9), raccoons (Procyon lotor, n=4), California ground squirrels (Spermophilus beecheyi, n=3), and coyotes (Canis latrans, n=2) were collected from August 2006 to January 2007 either from the ground while walking the premises or after trapping the animals using live traps. Nucleic acid purified from feces was directly processed for polymerase chain reaction (PCR) analysis using a real-time PCR assay targeting the aspartate ammonia lyase gene of L. intracellularis. Purified DNA samples were also precipitated, preamplified for L. intracellularis, and analyzed using the same real-time PCR assay, to increase the detection limit to one L. intracellularis organism per extracted sample. Feces from jackrabbits, striped skunks, Virginian opossums, and coyotes tested PCR positive for L. intracellularis, whereas all feces from feral cats, Brewer's Blackbirds, raccoons, and ground squirrels tested PCR negative for L. intracellularis. PCR testing on DNA extracted directly from feces was positive for L. intracellularis in six of 164 fecal samples. When DNA purification from feces was followed by a precipitation and preamplification step, five additional fecal samples tested PCR positive for L. intracellularis (11/164). The largest number of PCR positive L. intracellularis fecal samples was observed in striped skunks, followed by Virginian opossums, jackrabbits, and coyotes. This is the first description of L. intracellularis in these four species. Because the fecal samples were collected at equine farms with confirmed

  18. Relevance of in vivo models in melanoma skin cancer

    SciTech Connect

    Setlow, R.B.

    1995-12-31

    A discussion of possible wavelength dependence of induction of cutaneous malignant melanoma (CMM) is provided. Strengths and weaknesses of various experimental approaches to better understanding of the prevalence of CMM in different human populations including latitude effects are compared. Further the advantages and limitations of the use of the laboratory opossum (Monodelphis domestic), transgenic mice containing SV40 ongogene sequences under tyrosinase promoter control, and a backcross hybrid fish of the genus Xenophorus are contrasted.

  19. The evolution of whisker-mediated somatosensation in mammals: Sensory processing in barrelless S1 cortex of a marsupial, Monodelphis domestica.

    PubMed

    Ramamurthy, Deepa L; Krubitzer, Leah A

    2016-12-01

    Movable tactile sensors in the form of whiskers are present in most mammals, but sensory coding in the cortical whisker representation has been studied almost exclusively in mice and rats. Many species that possess whiskers lack the modular "barrel" organization found in the primary somatosensory cortex (S1) of mice and rats, but it is unclear how whisker-related input is represented in these species. We used single-unit extracellular recording techniques to characterize receptive fields and response properties in S1 of Monodelphis domestica (short-tailed opossum), a nocturnal, terrestrial marsupial that shared its last common ancestor with placental mammals over 160 million years ago. Short-tailed opossums lack barrels and septa in S1 but show active whisking behavior similar to that of mice and rats. Most neurons in short-tailed opossum S1 exhibited multiwhisker receptive fields, including a single best whisker (BW) and lower magnitude responses to the deflection of surrounding whiskers. Mean tuning width was similar to that reported for mice and rats. Both symmetrical and asymmetrical receptive fields were present. Neurons tuned to ventral whiskers tended to show broad tuning along the rostrocaudal axis. Thus, despite the absence of barrels, most receptive field properties were similar to those reported for mice and rats. However, unlike those species, S1 neuronal responses to BW and surround whisker deflection showed comparable latencies in short-tailed opossums. This dissimilarity suggests that some aspects of barrel cortex function may not generalize to tactile processing across mammalian species and may be related to differences in the architecture of the whisker-to-cortex pathway. J. Comp. Neurol. 524:3587-3613, 2016. © 2016 Wiley Periodicals, Inc.

  20. A Study on the Bionomics of Anopheles darlingi Root (Diptera: Culicidae) in Belize, Central America

    DTIC Science & Technology

    2004-03-01

    Plantation (Figure 11). An observational census of terrestrial animals includes: coral and fer-de-lance snakes; iguana; koatomundi; deer; tapir ...terrestrial animals includes: coral and fer-de-lance snakes; iguana; koatomundi; deer; tapir ; porcupine; opossum; gibnut; yellow-headed parrots; toucans...each distance buffer zone, other wildlife (i.e., tapir , monkey, porcupine, gibnut, armadillos, koatamundi, etc.) abounded in this area and

  1. Epidemiology of Sarcocystis neurona infections in domestic cats (Felis domesticus) and its association with equine protozoal myeloencephalitis (EPM) case farms and feral cats from a mobile spay and neuter clinic.

    PubMed

    Stanek, J F; Stich, R W; Dubey, J P; Reed, S M; Njoku, C J; Lindsay, D S; Schmall, L M; Johnson, G K; LaFave, B M; Saville, W J A

    2003-11-28

    Equine protozoal myeloencephalitis (EPM) is a serious neurologic disease in the horse most commonly caused by Sarcocystis neurona. The domestic cat (Felis domesticus) is an intermediate host for S. neurona. In the present study, nine farms, known to have prior clinically diagnosed cases of EPM and a resident cat population were identified and sampled accordingly. In addition to the farm cats sampled, samples were also collected from a mobile spay and neuter clinic. Overall, serum samples were collected in 2001 from 310 cats, with samples including barn, feral and inside/outside cats. Of these 310 samples, 35 were from nine horse farms. Horse serum samples were also collected and traps were set for opossums at each of the farms. The S. neurona direct agglutination test (SAT) was used for both the horse and cat serum samples (1:25 dilution). Fourteen of 35 (40%) cats sampled from horse farms had circulating S. neurona agglutinating antibodies. Twenty-seven of the 275 (10%) cats from the spay/neuter clinic also had detectable S. neurona antibodies. Overall, 115 of 123 (93%) horses tested positive for anti-S. neurona antibodies, with each farm having greater than a 75% exposure rate among sampled horses. Twenty-one opossums were trapped on seven of the nine farms. Eleven opossums had Sarcocystis sp. sporocysts, six of them were identified as S. neurona sporocysts based on bioassays in gamma-interferon gene knockout mice with each opossum representing a different farm. Demonstration of S. neurona agglutinating antibodies in domestic and feral cats corroborates previous research demonstrating feral cats to be naturally infected, and also suggests that cats can be frequently infected with S. neurona and serve as one of several natural intermediate hosts for S. neurona.

  2. The 1980 Archeological Investigations at the Big Hill Lake, Kansas.

    DTIC Science & Technology

    1980-01-01

    rodents and other mammals such as coyotes, raccoons, bobcats, opossums, etc. The bottomland forests are also represented on a small scale in the Big... forests are adjacent to Big Hill creek and its feeder tributaries. These streams, some intermittent, provide suitable habitation for many groups of...points recovered from the areas near the hearths have suggested Preceramic cultural affiliations and have been identified as Afton , Ellis, Lange

  3. Archeological Test Excavations at the Proposed Dry Boat Storage Facility and Archeological Survey of the Neal Road Extension Corridor, Redstone Arsenal, Huntsville, Alabama

    DTIC Science & Technology

    1991-11-19

    populations inhabiting the region 7 include white-tailed deer (Odocoileus virginianus), turkey (Meleagris gallopavo), black bear (Euarctos americanus...remains indicate that the most commonly taken animals were white-tailed deer , raccoon, wild turkey, and opossum. These animals were hunted from about...N. 1977 The Food Crisis in Prehistory: Overpopulation and the Origins of Agriculture. Yale University Press, New Haven. 105 Collins, M. B. 1979 The

  4. The foods of fur animals of the Patuxent Research Refuge, Maryland

    USGS Publications Warehouse

    Llewellyn, L.M.; Uhler, F.M.

    1952-01-01

    Approximately 300 digestive tracts of fur animals obtained mostly during the winter trapping season and 560 scats from animals live-trapped on the Patuxent Research Refuge near Laure!, Maryland, were analyzed. The resulting data are summarized and a brief description of the area and important habitat types is given. The animals studied include the raccoon, red fox, gray fox, mink, New York weasel, skunk, opossum, and house cat.

  5. Medical Surveillance Monthly Report (MSMR). Volume 22, Number 8, August 2015

    DTIC Science & Technology

    2015-08-01

    dogs and lived with her parents and one sibling in a rural area of Texas where there are feral cats , as well as opossums, raccoons, boars, and...coyotes. Th e patient indicated that she does bring feral cats into her bedroom. Shortly aft er arrival at SAMMC, the patient was admitted to the...reservoirs such as rats, opos- sums, and other small animals, including domestic dogs and cats . Murine typhus can cause a mild fever, with rash on the

  6. The role of fragmentation and landscape changes in the ecological release of common nest predators in the Neotropics

    PubMed Central

    Spínola, R. Manuel; Jackson, Victoria L.; Saénz, Joel C.

    2014-01-01

    Loss of large mammalian carnivores may allow smaller mesopredators to become abundant and threaten other community members. There is considerable debate about mesopredator release and the role that other potential factors such as landscape variables and human alterations to land cover lead to increased mesopredator abundance. We used camera traps to detect four mesopredators (tayra, Eira barbara; white-nosed coati, Nasua narica; northern raccoon, Procyon lotor; and common opossum, Didelphis opossum) in a biological corridor in Costa Rica to estimate habitat covariates that influenced the species’ detection and occurrence. We selected these mesopredators because as semi-arboreal species they might be common nest predators, posing a serious threat to resident and migratory songbirds. Pineapple production had a pronounced positive effect on the detectability of tayras, while forest cover had a negative effect on the detection of coatis. This suggests that abundance might be elevated due to the availability of agricultural food resources and foraging activities are concentrated in forest fragments and pineapple edge habitats. Raccoon and opossum models exhibited little influence on detection from habitat covariates. Occurrence models did not suggest any significant factors influencing site use by nest predators, revealing that all four species are habitat generalists adapted to co-existing in human altered landscapes. Furthermore, fragmentation and land cover changes may predispose nesting birds, herpetofauna, and small mammals to heightened predation risk by mesopredators in the Neotropics. PMID:25071989

  7. Seasonal source-sink dynamics at the edge of a species' range

    USGS Publications Warehouse

    Kanda, L.L.; Fuller, T.K.; Sievert, P.R.; Kellogg, R.L.

    2009-01-01

    The roles of dispersal and population dynamics in determining species' range boundaries recently have received theoretical attention but little empirical work. Here we provide data on survival, reproduction, and movement for a Virginia opossum (Didelphis virginiana) population at a local distributional edge in central Massachusetts (USA). Most juvenile females that apparently exploited anthropogenic resources survived their first winter, whereas those using adjacent natural resources died of starvation. In spring, adult females recolonized natural areas. A life-table model suggests that a population exploiting anthropogenic resources may grow, acting as source to a geographically interlaced sink of opossums using only natural resources, and also providing emigrants for further range expansion to new human-dominated landscapes. In a geographical model, this source-sink dynamic is consistent with the local distribution identified through road-kill surveys. The Virginia opossum's exploitation of human resources likely ameliorates energetically restrictive winters and may explain both their local distribution and their northward expansion in unsuitable natural climatic regimes. Landscape heterogeneity, such as created by urbanization, may result in source-sink dynamics at highly localized scales. Differential fitness and individual dispersal movements within local populations are key to generating regional distributions, and thus species ranges, that exceed expectations. ?? 2009 by the Ecological Society of America.

  8. Synanthropic Mammals as Potential Hosts of Tick-Borne Pathogens in Panama.

    PubMed

    Bermúdez, Sergio E; Gottdenker, Nicole; Krishnvajhala, Aparna; Fox, Amy; Wilder, Hannah K; González, Kadir; Smith, Diorene; López, Marielena; Perea, Milixa; Rigg, Chystrie; Montilla, Santiago; Calzada, José E; Saldaña, Azael; Caballero, Carlos M; Lopez, Job E

    2017-01-01

    Synanthropic wild mammals can be important hosts for many vector-borne zoonotic pathogens. The aim of this study was determine the exposure of synanthropic mammals to two types of tick-borne pathogens in Panama, spotted fever group Rickettsia (SFGR) and Borrelia relapsing fever (RF) spirochetes. One hundred and thirty-one wild mammals were evaluated, including two gray foxes, two crab-eating foxes (from zoos), four coyotes, 62 opossum and 63 spiny rats captured close to rural towns. To evaluate exposure to SFGR, serum samples from the animals were tested by indirect immunofluorescence assay (IFA) using Rickettsia rickettsii and Candidatus Rickettsia amblyommii antigen. Immunoblotting was performed using Borrelia turicatae protein lysates and rGlpQ, to assess infection caused by RF spirochetes. One coyote (25%) and 27 (43%) opossums showed seroreactivity to SFGR. Of these opossums, 11 were seroreactive to C. R. amblyommii. Serological reactivity was not detected to B. turicatae in mammal samples. These findings may reflect a potential role of both mammals in the ecology of tick-borne pathogens in Panama.

  9. Experimental inoculation of domestic cats (Felis domesticus) with Sarcocystis neurona or S. neurona-like merozoites.

    PubMed

    Butcher, M; Lakritz, J; Halaney, A; Branson, K; Gupta, G D; Kreeger, J; Marsh, A E

    2002-07-29

    Sarcocystis neurona is the parasite most commonly associated with equine protozoal myeloencephalitis (EPM). Recently, cats (Felis domesticus) have been demonstrated to be an experimental intermediate host in the life cycle of S. neurona. This study was performed to determine if cats experimentally inoculated with culture-derived S. neurona merozoites develop tissue sarcocysts infectious to opossums (Didelphis virginiana), the definitive host of S. neurona. Four cats were inoculated with S. neurona or S. neurona-like merozoites and all developed antibodies reacting to S. neurona merozoite antigens, but tissue sarcocysts were detected in only two cats. Muscle tissues from the experimentally inoculated cats with and without detectable sarcocysts were fed to laboratory-reared opossums. Sporocysts were detected in gastrointestinal (GI) scrapings of one opossum fed experimentally infected feline tissues. The study results suggest that cats can develop tissue cysts following inoculation with culture-derived Sarcocystis sp. merozoites in which the particular isolate was originally derived from a naturally infected cat with tissue sarcocysts. This is in contrast to cats which did not develop tissue cysts when inoculated with S. neurona merozoites originally derived from a horse with EPM. These results indicate present biological differences between the culture-derived merozoites of two Sarcocystis isolates, Sn-UCD 1 and Sn-Mucat 2.

  10. Synanthropic Mammals as Potential Hosts of Tick-Borne Pathogens in Panama

    PubMed Central

    Bermúdez, Sergio E.; Gottdenker, Nicole; Krishnvajhala, Aparna; Fox, Amy; Wilder, Hannah K.; González, Kadir; Smith, Diorene; López, Marielena; Perea, Milixa; Rigg, Chystrie; Montilla, Santiago; Calzada, José E.; Saldaña, Azael; Caballero, Carlos M.

    2017-01-01

    Synanthropic wild mammals can be important hosts for many vector-borne zoonotic pathogens. The aim of this study was determine the exposure of synanthropic mammals to two types of tick-borne pathogens in Panama, spotted fever group Rickettsia (SFGR) and Borrelia relapsing fever (RF) spirochetes. One hundred and thirty-one wild mammals were evaluated, including two gray foxes, two crab-eating foxes (from zoos), four coyotes, 62 opossum and 63 spiny rats captured close to rural towns. To evaluate exposure to SFGR, serum samples from the animals were tested by indirect immunofluorescence assay (IFA) using Rickettsia rickettsii and Candidatus Rickettsia amblyommii antigen. Immunoblotting was performed using Borrelia turicatae protein lysates and rGlpQ, to assess infection caused by RF spirochetes. One coyote (25%) and 27 (43%) opossums showed seroreactivity to SFGR. Of these opossums, 11 were seroreactive to C. R. amblyommii. Serological reactivity was not detected to B. turicatae in mammal samples. These findings may reflect a potential role of both mammals in the ecology of tick-borne pathogens in Panama. PMID:28060928

  11. The sylvatic transmission cycle of Trypanosoma cruzi in a rural area in the humid Chaco of Argentina

    PubMed Central

    Alvarado-Otegui, J.A.; Ceballos, L.A.; Orozco, M.M.; Enriquez, G.F.; Cardinal, M.V.; Cura, C.; Schijman, A.G.; Kitron, U.; Gürtler, R.E.

    2012-01-01

    Little is known about the sylvatic transmission cycle of Trypanosoma cruzi in the Gran Chaco ecoregion. We conducted surveys to identify the main sylvatic hosts of T. cruzi, parasite discrete typing units and vector species involved in Pampa del Indio, a rural area in the humid Argentinean Chaco. A total of 44 mammals from 14 species was captured and examined for infection by xenodiagnosis and polymerase chain reaction amplification of the hyper-variable region of kinetoplast DNA minicircles of T. cruzi (kDNA-PCR). Ten (22.7%) mammals were positive by xenodiagnosis or kDNA-PCR. Four of 11 (36%) Didelphis albiventris (white-eared opossums) and six of nine (67%) Dasypus novemcinctus (nine-banded armadillos) were positive by xenodiagnosis and or kDNA-PCR. Rodents, other armadillo species, felids, crab-eating raccoons, hares and rabbits were not infected. Positive animals were highly infectious to the bugs that fed upon them as determined by xenodiagnosis. All positive opossums were infected with T. cruzi I and all positive nine-banded armadillos with T. cruzi III. Extensive searches in sylvatic habitats using 718 Noireau trap-nights only yielded Triatoma sordida whereas no bug was collected in 26 light-trap nights. Four armadillos or opossums fitted with a spool-and-line device were successfully tracked to their refuges; only one Panstrongylus geniculatus was found in an armadillo burrow. No sylvatic triatomine was infected with T. cruzi by microscopical examination or kDNA-PCR. Our results indicate that two independent sylvatic transmission cycles of T. cruzi occur in the humid Chaco. The putative vectors of both cycles need to be identified conclusively. PMID:22771688

  12. Retroviral envelope gene captures and syncytin exaptation for placentation in marsupials

    PubMed Central

    Cornelis, Guillaume; Vernochet, Cécile; Carradec, Quentin; Souquere, Sylvie; Mulot, Baptiste; Catzeflis, François; Nilsson, Maria A.; Menzies, Brandon R.; Renfree, Marilyn B.; Pierron, Gérard; Zeller, Ulrich; Heidmann, Odile; Dupressoir, Anne; Heidmann, Thierry

    2015-01-01

    Syncytins are genes of retroviral origin captured by eutherian mammals, with a role in placentation. Here we show that some marsupials—which are the closest living relatives to eutherian mammals, although they diverged from the latter ∼190 Mya—also possess a syncytin gene. The gene identified in the South American marsupial opossum and dubbed syncytin-Opo1 has all of the characteristic features of a bona fide syncytin gene: It is fusogenic in an ex vivo cell–cell fusion assay; it is specifically expressed in the short-lived placenta at the level of the syncytial feto–maternal interface; and it is conserved in a functional state in a series of Monodelphis species. We further identify a nonfusogenic retroviral envelope gene that has been conserved for >80 My of evolution among all marsupials (including the opossum and the Australian tammar wallaby), with evidence for purifying selection and conservation of a canonical immunosuppressive domain, but with only limited expression in the placenta. This unusual captured gene, together with a third class of envelope genes from recently endogenized retroviruses—displaying strong expression in the uterine glands where retroviral particles can be detected—plausibly correspond to the different evolutionary statuses of a captured retroviral envelope gene, with only syncytin-Opo1 being the present-day bona fide syncytin active in the opossum and related species. This study would accordingly recapitulate the natural history of syncytin exaptation and evolution in a single species, and definitely extends the presence of such genes to all major placental mammalian clades. PMID:25605903

  13. Prevalence of antibodies to Neospora caninum, Sarcocystis neurona, and Toxoplasma gondii in wild horses from central Wyoming.

    PubMed

    Dubey, J P; Mitchell, S M; Morrow, J K; Rhyan, J C; Stewart, L M; Granstrom, D E; Romand, S; Thulliez, P; Saville, W J; Lindsay, D S

    2003-08-01

    Sarcocystis neurona, Neospora caninum, N. hughesi, and Toxoplasma gondii are 4 related coccidians considered to be associated with encephalomyelitis in horses. The source of infection for N. hughesi is unknown, whereas opossums, dogs, and cats are the definitive hosts for S. neurona, N. caninum, and T. gondii, respectively. Seroprevalence of these coccidians in 276 wild horses from central Wyoming outside the known range of the opossum (Didelphis virginiana) was determined. Antibodies to T. gondii were found only in 1 of 276 horses tested with the modified agglutination test using 1:25, 1:50, and 1:500 dilutions. Antibodies to N. caninum were found in 86 (31.1%) of the 276 horses tested with the Neospora agglutination test--the titers were 1:25 in 38 horses, 1:50 in 15, 1:100 in 9, 1:200 in 8, 1:400 in 4, 1:800 in 2, 1:1,600 in 2, 1:3,200 in 2, and 1:12,800 in 1. Antibodies to S. neurona were assessed with the serum immunoblot; of 276 horses tested, 18 had antibodies considered specific for S. neurona. Antibodies to S. neurona also were assessed with the S. neurona direct agglutination test (SAT). Thirty-nine of 265 horses tested had SAT antibodies--in titers of 1:50 in 26 horses and 1:100 in 13. The presence of S. neurona antibodies in horses in central Wyoming suggests that either there is cross-reactivity between S. neurona and some other infection or a definitive host other than opossum is the source of infection. In a retrospective study, S. neurona antibodies were not found by immunoblot in the sera of 243 horses from western Canada outside the range of D. virginiana.

  14. Tracking Marsupial Evolution Using Archaic Genomic Retroposon Insertions

    PubMed Central

    Nilsson, Maria A.; Churakov, Gennady; Sommer, Mirjam; Tran, Ngoc Van; Zemann, Anja; Brosius, Jürgen; Schmitz, Jürgen

    2010-01-01

    The Australasian and South American marsupial mammals, such as kangaroos and opossums, are the closest living relatives to placental mammals, having shared a common ancestor around 130 million years ago. The evolutionary relationships among the seven marsupial orders have, however, so far eluded resolution. In particular, the relationships between the four Australasian and three South American marsupial orders have been intensively debated since the South American order Microbiotheria was taxonomically moved into the group Australidelphia. Australidelphia is significantly supported by both molecular and morphological data and comprises the four Australasian marsupial orders and the South American order Microbiotheria, indicating a complex, ancient, biogeographic history of marsupials. However, the exact phylogenetic position of Microbiotheria within Australidelphia has yet to be resolved using either sequence or morphological data analysis. Here, we provide evidence from newly established and virtually homoplasy-free retroposon insertion markers for the basal relationships among marsupial orders. Fifty-three phylogenetically informative markers were retrieved after in silico and experimental screening of ∼217,000 retroposon-containing loci from opossum and kangaroo. The four Australasian orders share a single origin with Microbiotheria as their closest sister group, supporting a clear divergence between South American and Australasian marsupials. In addition, the new data place the South American opossums (Didelphimorphia) as the first branch of the marsupial tree. The exhaustive computational and experimental evidence provides important insight into the evolution of retroposable elements in the marsupial genome. Placing the retroposon insertion pattern in a paleobiogeographic context indicates a single marsupial migration from South America to Australia. The now firmly established phylogeny can be used to determine the direction of genomic changes and

  15. A comparative study of Trypanosoma cruzi infection in sylvatic mammals from a protected and a disturbed area in the Argentine Chaco.

    PubMed

    Orozco, M M; Enriquez, G F; Cardinal, M V; Piccinali, R V; Gürtler, R E

    2016-03-01

    Understanding the complex epidemiology of Trypanosoma cruzi transmission cycles requires comparative studies in widely different environments. We assessed the occurrence of T. cruzi infection in sylvatic mammals, their infectiousness to the vector, and parasite genotypes in a protected area of the Argentine Chaco, and compared them with information obtained similarly in a nearby disturbed area. A total of 278 mammals from >23 species in the protected area were diagnosed for T. cruzi infection using xenodiagnosis, kDNA-PCR and nuclear satellite DNA-PCR (SAT) from blood samples. The relative abundance and species composition differed substantially between areas. Didelphis albiventris opossums were less abundant in the protected area; had a significantly lower body mass index, and a stage structure biased toward earlier stages. The capture of armadillos was lower in the protected area. The composite prevalence of T. cruzi infection across host species was significantly lower in the protected area (11.1%) than in the disturbed area (22.1%), and heterogeneous across species groups. The prevalence of infection in D. albiventris and Thylamys pusilla opossums was significantly lower in the protected area (nil for D. albiventris), whereas infection in sigmodontine rodents was three times higher in the protected area (17.5 versus 5.7%). Parasite isolates from the two xenodiagnosis-positive mammals (1 Dasypus novemcinctus and 1 Conepatus chinga) were typed as TcIII; both specimens were highly infectious to Triatoma infestans. Fat-tailed opossums, bats and rodents were kDNA-PCR-positive and xenodiagnosis-negative. Desmodus rotundus and Myotis bats were found infected with T. cruzi for the first time in the Gran Chaco.

  16. A behaviorally-explicit approach for delivering vaccine baits to mesopredators to control epizootics in fragmented landscapes

    SciTech Connect

    Beasley, James C.; Atwood, Todd C.; Byrne, Michael E.; Vercauteren, Kurt C.; Johnson, Shylo R.; Olin E. Rhodes, Jr.; Schnell, Matthias Johannes

    2015-01-14

    Despite the widespread use of aerial baiting to manage epizootics among free-ranging populations,particularly in rabies management, bait acceptance and seroconversion rates often are lower than required to eliminate spread of disease. Our objectives in this study, therefore, were to evaluate the performance of stratified bait distribution models derived from resource selection functions (RSF) on uptake of placebo rabies baits by raccoons (Procyon lotor) and Virginia opossums (Didelphis virginiana), as well as the probability of bait uptake as a function of proximity to bait distribution areas in fragmented agricultural ecosystems. Among 478 raccoons and 108 opossums evaluated for presence of Rhodamine B (RB) across 8 sites, only 26% of raccoons and 20% of opossums exhibited marking consistent with bait consumption 14–24 days post-baiting. The effective area treated, based on 90% kernel density estimators of marked individuals, ranged from 99–240 ha larger than bait distribution zones, with RB marked individuals captured up to 753m beyond the bait zone. Despite incorporation of RSF data into bait distribution models, no differences in uptake rates were observed between treatment and control sites. These data likely reflect the underlying constraints imposed by the loss and fragmentation of habitat on animal movement in heterogeneous landscapes, forcing individuals to optimize movements at coarse (i.e., patch-level) rather than fine spatial scales in highly fragmented environments. Our data also confirm that the probability of bait acceptance decreases with increasing distance from bait zone interiors, even within the zone itself. Thus, although bait acceptance was confirmed beyond bait zone boundaries, the proportion of vaccinated individuals may comprise a small minority of the population at increasing distances from baiting interiors. These data suggest focal baiting creates a buffered area of treated individuals around bait zones or bait stations

  17. A behaviorally-explicit approach for delivering vaccine baits to mesopredators to control epizootics in fragmented landscapes

    DOE PAGES

    Beasley, James C.; Atwood, Todd C.; Byrne, Michael E.; ...

    2015-01-14

    Despite the widespread use of aerial baiting to manage epizootics among free-ranging populations,particularly in rabies management, bait acceptance and seroconversion rates often are lower than required to eliminate spread of disease. Our objectives in this study, therefore, were to evaluate the performance of stratified bait distribution models derived from resource selection functions (RSF) on uptake of placebo rabies baits by raccoons (Procyon lotor) and Virginia opossums (Didelphis virginiana), as well as the probability of bait uptake as a function of proximity to bait distribution areas in fragmented agricultural ecosystems. Among 478 raccoons and 108 opossums evaluated for presence of Rhodaminemore » B (RB) across 8 sites, only 26% of raccoons and 20% of opossums exhibited marking consistent with bait consumption 14–24 days post-baiting. The effective area treated, based on 90% kernel density estimators of marked individuals, ranged from 99–240 ha larger than bait distribution zones, with RB marked individuals captured up to 753m beyond the bait zone. Despite incorporation of RSF data into bait distribution models, no differences in uptake rates were observed between treatment and control sites. These data likely reflect the underlying constraints imposed by the loss and fragmentation of habitat on animal movement in heterogeneous landscapes, forcing individuals to optimize movements at coarse (i.e., patch-level) rather than fine spatial scales in highly fragmented environments. Our data also confirm that the probability of bait acceptance decreases with increasing distance from bait zone interiors, even within the zone itself. Thus, although bait acceptance was confirmed beyond bait zone boundaries, the proportion of vaccinated individuals may comprise a small minority of the population at increasing distances from baiting interiors. These data suggest focal baiting creates a buffered area of treated individuals around bait zones or bait stations, but

  18. The cellular composition of the marsupial neocortex.

    PubMed

    Seelke, Adele M H; Dooley, James C; Krubitzer, Leah A

    2014-07-01

    In the current investigation we examined the number and proportion of neuronal and non-neuronal cells in the primary sensory areas of the neocortex of a South American marsupial, the short-tailed opossum (Monodelphis domestica). The primary somatosensory (S1), auditory (A1), and visual (V1) areas were dissected from the cortical sheet and compared with each other and the remaining neocortex using the isotropic fractionator technique. We found that although the overall sizes of V1, S1, A1, and the remaining cortical regions differed from each other, these divisions of the neocortex contained the same number of neurons, but the remaining cortex contained significantly more non-neurons than the primary sensory regions. In addition, the percent of neurons was higher in A1 than in the remaining cortex and the cortex as a whole. These results are similar to those seen in non-human primates. Furthermore, these results indicate that in some respects, such as number of neurons, the neocortex is homogenous across its extent, whereas in other aspects of organization, such as non-neuronal number and percentage of neurons, there is non-uniformity. Whereas the overall pattern of neuronal distribution is similar between short-tailed opossums and eutherian mammals, short-tailed opossum have a much lower cellular and neuronal density than other eutherian mammals. This suggests that the high neuronal density cortices of mammals such as rodents and primates may be a more recently evolved characteristic that is restricted to eutherians, and likely contributes to the complex behaviors we see in modern mammals.

  19. Metabolic changes in the nucleus of the optic tract after monocular enucleation as revealed by cytochrome oxidase histochemistry.

    PubMed

    Vargas, C D; Sousa, A O; Santos, C M; Pereira, A; Bernardes, R F; Rocha-Miranda, C E; Volchan, E

    2001-03-01

    The histochemistry for the mitochondrial enzyme cytochrome oxidase (CO) was used to evaluate the levels of metabolic activity in neurons of the nucleus of the optic tract (NOT) and dorsal terminal nucleus (DTN) in the opossum (Didelphis aurita). The observations were performed in four groups: normal juveniles (4 months old), monocularly enucleated juveniles analysed when adults, normal adults (8 to 18 months old) and monocularly enucleated adults. CO labeled cells were observed to have a similar distribution along the NOT-DTN anteroposterior axis in both juvenile and adult normal animals. Monocular enucleation performed in adults produced a significant reduction of the reactive neuropil but not of the number of CO labeled cells in the deafferented NOT-DTN: the number of labeled neurons per section in the deafferented side matched those of the ipsilateral complex. In juveniles, however, this procedure caused a systematic reduction of the number of CO labeled cells in the contralateral NOT-DTN in comparison to the spared complex. The lack of reduction in the number of neurons found on the deafferented side of the NOT-DTN of monocularly enucleated adult opossums compared with the ipsilateral side might result from the presence of compensatory inputs to maintain their metabolic equivalence. However, when the monocular enucleation was performed in juvenile opossums, a statistically significant asymmetry of CO neurons in the NOT-DTN was observed. In other words, the compensatory mechanisms proposed for the adults were either absent or insufficient to achieve symmetry in juveniles, suggesting a more heavily reliance in the retinal input.

  20. The sylvatic transmission cycle of Trypanosoma cruzi in a rural area in the humid Chaco of Argentina.

    PubMed

    Alvarado-Otegui, J A; Ceballos, L A; Orozco, M M; Enriquez, G F; Cardinal, M V; Cura, C; Schijman, A G; Kitron, U; Gürtler, R E

    2012-10-01

    Little is known about the sylvatic transmission cycle of Trypanosoma cruzi in the Gran Chaco ecoregion. We conducted surveys to identify the main sylvatic hosts of T. cruzi, parasite discrete typing units and vector species involved in Pampa del Indio, a rural area in the humid Argentinean Chaco. A total of 44 mammals from 14 species were captured and examined for infection by xenodiagnosis and polymerase chain reaction amplification of the hyper-variable region of kinetoplast DNA minicircles of T. cruzi (kDNA-PCR). Ten (22.7%) mammals were positive by xenodiagnosis or kDNA-PCR. Four of 11 (36%) Didelphis albiventris (white-eared opossums) and six of nine (67%) Dasypus novemcinctus (nine-banded armadillos) were positive by xenodiagnosis and or kDNA-PCR. Rodents, other armadillo species, felids, crab-eating raccoons, hares and rabbits were not infected. Positive animals were highly infectious to the bugs that fed upon them as determined by xenodiagnosis. All positive opossums were infected with T. cruzi I and all positive nine-banded armadillos with T. cruzi III. Extensive searches in sylvatic habitats using 718 Noireau trap-nights only yielded Triatoma sordida whereas no bug was collected in 26 light-trap nights. Four armadillos or opossums fitted with a spool-and-line device were successfully tracked to their refuges; only one Panstrongylus geniculatus was found in an armadillo burrow. No sylvatic triatomine was infected with T. cruzi by microscopical examination or kDNA-PCR. Our results indicate that two independent sylvatic transmission cycles of T. cruzi occur in the humid Chaco. The putative vectors of both cycles need to be identified conclusively.

  1. Flea (Pulex simulans) infestation in captive giant anteaters (Myrmecophaga tridactyla).

    PubMed

    Mutlow, Adrian G; Dryden, Michael W; Payne, Patricia A

    2006-09-01

    A pair of captive adult giant anteaters (Myrmecophaga tridactyla) presented heavily infested with a flea species (Pulex simulans) commonly found on Virginia opossums (Didelphis virginiana) and raccoons (Procyon lotor) in the central United States. In this case, the flea was demonstrated to have completed its entire life cycle with the anteaters as the host. A single treatment of topical imidacloprid, coupled with removal and replacement of infested bedding, was rapidly effective at controlling the infestation and no adverse effects of the drug were noted. Control of the anteater infestation also removed the flea infestation of aardvarks in the same building.

  2. Those other mammals: the immunoglobulins and T cell receptors of marsupials and monotremes.

    PubMed

    Miller, Robert D

    2010-02-01

    This review summarizes analyses of marsupial and monotreme immunoglobulin and T cell receptor genetics and expression published over the past decade. Analyses of recently completed whole genome sequences from the opossum and the platypus have yielded insight into the evolution of the common antigen receptor systems, as well as discovery of novel receptors that appear to have been lost in eutherian mammals. These species are also useful for investigation of the development of the immune system in organisms notable for giving birth to highly altricial young, as well as the evolution of maternal immunity through comparison of oviparous and viviparous mammals.

  3. Neosporosis in South America.

    PubMed

    Moore, D P

    2005-01-20

    This work gathers reports about Neospora-infections in South America. Neospora-infections have been reported from Argentina, Brazil, Chile, Paraguay, Peru and Uruguay. Evidence of exposure to N. caninum was mentioned in cattle, goats, sheep, dogs, cats, water buffaloes, alpacas, llamas, South American opossums, wolves and other wild canids. No antibodies were found in horses. Interesting epidemiological and pathological data were described. Two isolations were performed from dogs, one from cattle, and recently five from water buffaloes. Since the cattle industry is important in South America and reproductive losses caused by Neospora-infection have been identified, more investigations are needed in order to understand its epidemiology and control the disease.

  4. Disposal and Reuse of Bergstrom Air Force Base, Texas. Final Environmental Impact Statement.

    DTIC Science & Technology

    1993-07-01

    Scavenger species detected in the landfill area include the opossum (Didelphis marsupialis) and northern raccoon (Procyon lotor). House mice ( Mus musculus ...a, ~ a, CC CU 00 .C UC CC CU m oca Em - ~< 0 EE mU CCJ -a)UCE c:E .0 , 2 48~ C In CC 0 0~ 0 m CU .2~ z. CaU. (C 0U CU CU E C) C- 7E m CU o C E C z E...Disturbed By Phase - Proposed Action ............................ 2-11 2.2-4 Projected Flight Operations - Proposed Action

  5. Common plankton of Twin Lakes, Colorado

    SciTech Connect

    Lieberman, D.M.

    1983-02-01

    A series of studies is being performed to evaluate the effects of the Mt. Elbert Pumped-Storage Powerplant on the ecology of Twin Lakes. Twin Lakes are a pair of connected dimictic lakes, formed as the result of glacial action on alluvial deposits. This report presents a taxonomic species study of the common plankton collected since 1974 from Twin Lakes. A total of 11 zooplankters and 14 phytoplankters were identified from the limnetic zone of Twin Lakes and the associated Mt. Elbert Forebay. The four divisions of zooplankton included four species of Rotifera (rotifer), three species of Copepoda (copepod), three species of Cladocera (cladoceran), and one species of Mysidacea (opossum shrimp).

  6. Evidence to support horses as natural intermediate hosts for Sarcocystis neurona.

    PubMed

    Mullaney, Thomas; Murphy, Alice J; Kiupel, Matti; Bell, Julia A; Rossano, Mary G; Mansfield, Linda S

    2005-10-10

    Opossums (Didelphis spp.) are the definitive host for the protozoan parasite Sarcocystis neurona, the causative agent of equine protozoal myeloencephalitis (EPM). Opossums shed sporocysts in feces that can be ingested by true intermediate hosts (cats, raccoons, skunks, armadillos and sea otters). Horses acquire the parasite by ingestion of feed or water contaminated by opossum feces. However, horses have been classified as aberrant intermediate hosts because the terminal asexual sarcocyst stage that is required for transmission to the definitive host has not been found in their tissues despite extensive efforts to search for them [Dubey, J.P., Lindsay, D.S., Saville, W.J., Reed, S.M., Granstrom, D.E., Speer, C.A., 2001b. A review of Sarcocystis neurona and equine protozoal myeloencephalitis (EPM). Vet. Parasitol. 95, 89-131]. In a 4-month-old filly with neurological disease consistent with EPM, we demonstrate schizonts in the brain and spinal cord and mature sarcocysts in the tongue and skeletal muscle, both with genetic and morphological characteristics of S. neurona. The histological and electron microscopic morphology of the schizonts and sarcocysts were identical to published features of S. neurona [Stanek, J.F., Dubey, J.P., Oglesbee, M.J., Reed, S.M., Lindsay, D.S., Capitini, L.A., Njoku, C.J., Vittitow, K.L., Saville, W.J., 2002. Life cycle of Sarcocystis neurona in its natural intermediate host, the raccoon, Procyon lotor. J. Parasitol. 88, 1151-1158]. DNA from schizonts and sarcocysts from this horse produced Sarcocystis specific 334bp PCR products [Tanhauser, S.M., Yowell, C.A., Cutler, T.J., Greiner, E.C., MacKay, R.J., Dame, J.B., 1999. Multiple DNA markers differentiate Sarcocystis neurona and Sarcocystis falcatula. J. Parasitol. 85, 221-228]. Restriction fragment length polymorphism (RFLP) analysis of these PCR products showed banding patterns characteristic of S. neurona. Sequencing, alignment and comparison of both schizont and sarcocyst DNA

  7. ECRbase: Database of Evolutionary Conserved Regions, Promoters, and Transcription Factor Binding Sites in Vertebrate Genomes

    DOE Data Explorer

    Loots, Gabriela G. [LLNL; Ovcharenko, I. [LLNL

    Evolutionary conservation of DNA sequences provides a tool for the identification of functional elements in genomes. This database of evolutionary conserved regions (ECRs) in vertebrate genomes features a database of syntenic blocks that recapitulate the evolution of rearrangements in vertebrates and a comprehensive collection of promoters in all vertebrate genomes generated using multiple sources of gene annotation. The database also contains a collection of annotated transcription factor binding sites (TFBSs) in evolutionary conserved and promoter elements. ECRbase currently includes human, rhesus macaque, dog, opossum, rat, mouse, chicken, frog, zebrafish, and fugu genomes. (taken from paper in Journal: Bioinformatics, November 7, 2006, pp. 122-124

  8. Detection of Rickettsia felis in Wild Mammals from Three Municipalities in Yucatan, Mexico.

    PubMed

    Panti-May, Jesús Alonso; Torres-Castro, Marco; Hernández-Betancourt, Silvia; Dzul-Rosado, Karla; Zavala-Castro, Jorge; López-Avila, Karina; Tello-Martín, Raúl

    2015-09-01

    The aim of this study was to provide information of the occurrence of Rickettsia felis in wild mammals from three municipalities in Yucatan, Mexico. The reactivity of rodent serum to Rickettsia antigens was detected in 80.9% (17 of 21) samples using immunofluorescence assay. Polymerase chain reaction identified rickettsial DNA in spleens of 43.5% (10 of 23) rodents and 57.1% (4 of 7) opossums. The identification of the rickettsial DNA was confirmed as R. felis by restriction fragment length polymorphism and DNA sequencing. This study comprises the first report of R. felis detection in wild mammals in Yucatan.

  9. Snake River fall Chinook salmon life history investigations, 1/1/2012 - 12/31/2012: Annual report 2002-032-00

    USGS Publications Warehouse

    Tiffan, Kenneth F.; Connor, Willam P.; Bellgraph, Brian J.; Chittaro, Paul M.

    2014-01-01

    Finally, we examined the role of different invasive invertebrates in lower Snake River reservoir food webs that are food, or competitors for food, for juvenile fall Chinook salmon. The Siberian prawn, a relatively new invader, is relatively abundant but its role on the food web is largely unexplored. Prawns are successfully reproducing and their diet is 81% Neomysis (an invasive opossum shrimp) which is heavily used at times by juvenile salmon for food. Neomysis has become very abundant in lower Snake River reservoirs in recent years and may be a profitable food item for many fish species.

  10. Myosin 1b Regulates Amino Acid Transport by Associating Transporters with the Apical Plasma Membrane of Kidney Cells.

    PubMed

    Komaba, Shigeru; Coluccio, Lynne M

    2015-01-01

    Amino acid transporters (AATers) in the brush border of the apical plasma membrane (APM) of renal proximal tubule (PT) cells mediate amino acid transport (AAT). We found that the membrane-associated class I myosin myosin 1b (Myo1b) localized at the apical brush border membrane of PTs. In opossum kidney (OK) 3B/2 epithelial cells, which are derived from PTs, expressed rat Myo1b-GFP colocalized in patched microvilli with expressed mouse V5-tagged SIT1 (SIT1-V5), which mediates neutral amino acid transport in OK cells. Lentivirus-mediated delivery of opossum Myo1b-specific shRNA resulted in knockdown (kd) of Myo1b expression, less SIT1-V5 at the APM as determined by localization studies, and a decrease in neutral AAT as determined by radioactive uptake assays. Myo1b kd had no effect on Pi transport or noticeable change in microvilli structure as determined by rhodamine phalloidin staining. The studies are the first to define a physiological role for Myo1b, that of regulating renal AAT by modulating the association of AATers with the APM.

  11. Active vibrissal sensing in rodents and marsupials

    PubMed Central

    Mitchinson, Ben; Grant, Robyn A.; Arkley, Kendra; Rankov, Vladan; Perkon, Igor; Prescott, Tony J.

    2011-01-01

    In rats, the long facial whiskers (mystacial macrovibrissae) are repetitively and rapidly swept back and forth during exploration in a behaviour known as ‘whisking’. In this paper, we summarize previous evidence from rats, and present new data for rat, mouse and the marsupial grey short-tailed opossum (Monodelphis domestica) showing that whisking in all three species is actively controlled both with respect to movement of the animal's body and relative to environmental structure. Using automatic whisker tracking, and Fourier analysis, we first show that the whisking motion of the mystacial vibrissae, in the horizontal plane, can be approximated as a blend of two sinusoids at the fundamental frequency (mean 8.5, 11.3 and 7.3 Hz in rat, mouse and opossum, respectively) and its second harmonic. The oscillation at the second harmonic is particularly strong in mouse (around 22 Hz) consistent with previous reports of fast whisking in that species. In all three species, we found evidence of asymmetric whisking during head turning and following unilateral object contacts consistent with active control of whisker movement. We propose that the presence of active vibrissal touch in both rodents and marsupials suggests that this behavioural capacity emerged at an early stage in the evolution of therian mammals. PMID:21969685

  12. Feeding Patterns of Mosquitoes (Diptera: Culicidae) in the Atlantic Forest, Rio de Janeiro, Brazil.

    PubMed

    Alencar, Jeronimo; Mello, Cecília Ferreira de; Gil-Santana, Hélcio R; Giupponi, Alessandro Ponce de Leão; Araújo, Andressa Nunes; Lorosa, Elias Seixas; Guimarães, Anthony Érico; Silva, Júlia Dos Santos

    2015-09-01

    The stomach contents of culicids from the Atlantic Forest in Rio de Janeiro state, Brazil, were analyzed using the precipitin technique to evaluate the feeding patterns of the species. Sampling was performed from February 2012 to December 2013, using CO2-baited Centers for Disease Control and Prevention traps to catch mosquitoes from 15 00 to 07 00 hours. The following antisera were used: bird, rodent, opossum, human, horse, capybara, lizard, and frog. Of the 325 adult bloodfed females caught and analyzed, 273 (84.0%) reacted in the precipitin test. The percentage of specimens with a positive reaction to a single antiserum included bird (39.2%), rodent (22.5%), opossum (13.2%), capybara (6.6%), horse (5.7%), frog (6.2%), human (4.0%), and lizard (2.6%). The specimens that reacted positively against more than one blood source (46) most frequently presented the following combinations: bird + rodent and bird + frog (17.4%), followed by bird + human (13.0%). The predominance of positive results for birds suggested that the avian-rich environment might have influenced the feeding behavior of the culicids.

  13. The divergent development of the apical ectodermal ridge in the marsupial Monodelphis domestica.

    PubMed

    Doroba, Carolyn K; Sears, Karen E

    2010-08-01

    Marsupials give birth after short gestation times to neonates that have an intriguing combination of precocial and altricial features, based on their functional necessity after birth. Perhaps most noticeably, marsupial newborns have highly developed forelimbs, which provide the propulsion necessary for the newborn's crawl to the teat. To achieve their advanced state at birth, the development of marsupial forelimbs is accelerated. The development of the newborn's hind limb, which plays no part in the crawl, is not accelerated, and is likely even delayed. Given the large differences in the rate of limb outgrowth among marsupials and placentals, we hypothesize that the pathways underlying the early development and outgrowth of marsupial limbs, especially that of their forelimbs, will also be divergent. As a first step toward testing this, we examine the development of one of the two major signaling centers of the developing limb, the apical ectodermal ridge (AER), in a marsupial, Monodelphis domestica. We found that, while both opossum limbs have reduced physical AER's, in the opossum forelimb this reduction has been taken to the extreme. Where the M. domestica forelimb should have an AER, it instead has only a few patches of disorganized cells. These results make the marsupial, M. domestica, the only known amniote (without reduced limbs) to exhibit no morphological AER. However, both M. domestica limbs normally express Fgf8, a molecular marker of the AER.

  14. Evolutionary analysis of DNA-protein-coding regions based on a genetic code cube metric.

    PubMed

    Sanchez, Robersy

    2014-01-01

    The right estimation of the evolutionary distance between DNA or protein sequences is the cornerstone of the current phylogenetic analysis based on distance methods. Herein, it is demonstrated that the Manhattan distance (dw), weighted by the evolutionary importance of the nucleotide bases in the codon, is a naturally derived metric in the standard genetic code cube inserted into the three-dimensional Euclidean space. Based on the application of distance dw, a novel evolutionary model is proposed. This model includes insertion/deletion mutations that are very important for cancer studies, but usually discarded in classical evolutionary models. In this study, the new evolutionary model was applied to the phylogenetic analysis of the DNA protein-coding regions of 13 mammal mitochondrial genomes and of four cancer genetic- susceptibility genes (ATM, BRCA1, BRCA2 and p53) from nine mammals. The opossum (a marsupial) was used as an out-group species for both sets of sequences. The new evolutionary model yielded the correct topology, while the current models failed to separate the evolutionarily distant species of mouse and opossum.

  15. Differential changes in the cellular composition of the developing marsupial brain.

    PubMed

    Seelke, Adele M H; Dooley, James C; Krubitzer, Leah A

    2013-08-01

    Throughout development both the body and the brain change at remarkable rates. Specifically, the number of cells in the brain undergoes dramatic nonlinear changes, first exponentially increasing in cell number and then decreasing in cell number. Different cell types, such as neurons and glia, undergo these changes at different stages of development. The current investigation used the isotropic fractionator method to examine the changes in cellular composition at multiple developmental milestones in the short-tailed opossum, Monodelphis domestica. Here we report several novel findings concerning marsupial brain development and organization. First, during the later stages of neurogenesis (P18), neurons make up most of the cells in the neocortex, although the total number of neurons remains the same throughout the life span. In contrast, in the subcortical regions, the number of neurons decreases dramatically after P18, and a converse relationship is observed for nonneuronal cells. In the cerebellum, the total number of cells gradually increases until P180 and then remains constant, and then the number of neurons is consistent across the developmental ages examined. For the three major structures examined, neuronal density and the percentage of neurons within a structure are highest during neurogenesis and then decrease after this point. Finally, the total number of neurons in the opossum brain is relatively low compared with other small-brained mammals such as mice. The relatively low number of neurons and correspondingly high number of nonneurons suggests that in the marsupial brain nonneurons may play a significant role in signal processing.

  16. Life cycle of Sarcocystis neurona in its natural intermediate host, the raccoon, Procyon lotor.

    PubMed

    Stanek, J F; Dubey, J P; Oglesbee, M J; Reed, S M; Lindsay, D S; Capitini, L A; Njoku, C J; Vittitow, K L; Saville, W J A

    2002-12-01

    Sarcocystis neurona causes encephalomyelitis in many species of mammals and is the most important cause of neurologic disease in the horse. Its complete life cycle is unknown, particularly its development and localization in the intermediate host. Recently, the raccoon (Procyon lotor) was recognized as a natural intermediate host of S. neurona. In the present study, migration and development of S. neurona was studied in 10 raccoons that were fed S. neurona sporocysts from experimentally infected opossums; 4 raccoons served as controls. Raccoons were examined at necropsy 1, 3, 5, 7, 10, 14, 15, 22, 37, and 77 days after feeding on sporocysts (DAFS). Tissue sections of most of the organs were studied histologically and reacted with anti-S. neurona-specific polyclonal rabbit serum in an immunohistochemical test. Parasitemia was demonstrated in peripheral blood of raccoons 3 and 5 DAFS. Individual zoites were seen in histologic sections of intestines of raccoons euthanized 1, 3, and 5 DAFS. Schizonts and merozoites were seen in many tissues 7 to 22 DAFS, particularly in the brain. Sarcocysts were seen in raccoons killed 22 DAFS. Sarcocysts at 22 DAFS were immature and seen only in skeletal muscle. Mature sarcocysts were seen in all skeletal samples, particularly in the tongue of the raccoon 77 DAFS; these sarcocysts were infective to laboratory-raised opossums. This is the first report of the complete development of S. neurona schizonts and sarcocysts in a natural intermediate host.

  17. Sarcocyst Development in Raccoons (Procyon lotor) Inoculated with Different Strains of Sarcocystis neurona Culture-Derived Merozoites.

    PubMed

    Dryburgh, E L; Marsh, A E; Dubey, J P; Howe, D K; Reed, S M; Bolten, K E; Pei, W; Saville, W J A

    2015-08-01

    Sarcocystis neurona is considered the major etiologic agent of equine protozoal myeloencephalitis (EPM), a neurological disease in horses. Raccoon ( Procyon lotor ) is considered the most important intermediate host in the life cycle of S. neurona in the United States; S. neurona sarcocysts do mature in raccoon muscles, and raccoons also develop clinical signs simulating EPM. The focus of this study was to determine if sarcocysts would develop in raccoons experimentally inoculated with different host-derived strains of in vitro-cultivated S. neurona merozoites. Four raccoons were inoculated with strains derived from a raccoon, a sea otter, a cat, and a horse. Raccoon tissues were fed to laboratory-raised opossums ( Didelphis virginiana ), the definitive host of S. neurona . Intestinal scraping revealed sporocysts in opossums who received muscle tissue from raccoons inoculated with the raccoon-derived or the sea otter-derived isolates. These results demonstrate that sarcocysts can mature in raccoons inoculated with in vitro-derived S. neurona merozoites. In contrast, the horse and cat-derived isolates did not produce microscopically or biologically detected sarcocysts. Immunoblot analysis revealed both antigenic and antibody differences when testing the inoculated raccoons. Immunohistochemical staining indicated differences in staining between the merozoite and sarcocyst stages. The successful infections achieved in this study indicates that the life cycle can be manipulated in the laboratory without affecting subsequent stage development, thereby allowing further purification of strains and artificial maintenance of the life cycle.

  18. Evolutionary insights into the unique electromotility motor of mammalian outer hair cel

    PubMed Central

    Okoruwa, Oseremen E.; Weston, Michael D.; Sanjeevi, Divvya C.; Millemon, Amanda R.; Fritzsch, Bernd; Hallworth, Richard; Beisel, Kirk W.

    2009-01-01

    SUMMARY Prestin (SLC26A5) is the molecular motor responsible for cochlear amplification by mammalian cochlea outer hair cells and has the unique combined properties of energy-independent motility, voltage sensitivity, and speed of cellular shape change. The ion transporter capability, typical of SLC26A members, was exchanged for electromotility function and is a newly derived feature of the therian cochlea. A putative minimal essential motif for the electromotility motor (meEM) was identified through the amalgamation of comparative genomic, evolution, and structural diversification approaches. Comparisons were done among nonmammalian vertebrates, eutherian mammalian species, and the opossum and platypus. The opossum and platypus SLC26A5 proteins were comparable to the eutherian consensus sequence. Suggested from the point-accepted mutation analysis, the meEM motif spans all the transmembrane segments and represented residues 66–503. Within the eutherian clade, the meEM was highly conserved with a substitution frequency of only 39/7497 (0.5%) residues, compared with 5.7% in SLC26A4 and 12.8% in SLC26A6 genes. Clade-specific substitutions were not observed and there was no sequence correlation with low or high hearing frequency specialists. We were able to identify that within the highly conserved meEM motif two regions, which are unique to all therian species, appear to be the most derived features in the SLC26A5 peptide. PMID:18460092

  19. Development of an automated dispenser for the delivery of medicinal or vaccine-laden baits to raccoons (Procyon lotor).

    PubMed

    Smyser, Timothy J; Redding, James V; Bevis, Crystal M; Page, L Kristen; Swihart, Robert K

    2015-04-01

    Medicinal baits are distributed to manage zoonotic diseases, including raccoon (Procyon lotor) rabies, but efficient distribution strategies are needed for suburban environments. We developed an automated dispenser that transfers fishmeal polymer baits at user-specified intervals from a magazine to a receptacle fitted with a filter that exploits raccoon dexterity to limit consumption by nontarget species. We introduce the concept of automated dispensers and describe bait removal success rates for raccoons versus nontarget species. We monitored visitation with remote cameras after deploying a dispenser, programmed to present two baits per night, in three disjunct forest patches in northwest Indiana. Raccoons removed 72% of baits; nontarget, white-footed mice (Peromyscus leucopus) removed 11%; Virginia opossums (Didelphis virginiana) removed 9%. Bait removal success varied significantly between raccoons (76%) and opossums (21%), improving bait delivery specificity relative to hand baiting. Accumulation of baits in receptacles resulted in excess (more than one) bait consumption (39% of baits consumed by raccoons were excess), suggesting design improvements are needed to present additional baits only after previous baits have been consumed. Automated dispensers successfully sustained bait availability throughout the operational period. Subsequent research is needed to determine whether a sustained availability of baits achieved with automated dispensers is more effective for the treatment of raccoons in suburban environments than traditional distribution methods.

  20. Scat removal: A source of bias in feces-related studies

    USGS Publications Warehouse

    Livingston, T.R.; Gipson, P.S.; Ballard, W.B.; Sanchez, D.M.; Krausman, P.R.

    2005-01-01

    Consumption of feces (coprophagy) may alter findings of dietary studies and population estimates based on fecal analyses, but its magnitude is poorly understood. We investigated seasonal incidence of scat removal on Fort Riley, Kansas, from January through December 2000. We placed feces from captive bobcats (Lynx rufus), captive coyotes (Canis latrans), and free-ranging coyotes randomly on tracking stations in forest and prairie landscapes to determine rates of scat removal by local wildlife. Rates of removal of feces from captive bobcats, captive coyotes, and free-ranging coyotes varied from 7% during spring to 50% during summer. We identified opossums (Didelphis virginiana) as the most common species present at stations where scat removal occurred. Feces may be an important seasonal source of food for opossums and may provide seasonal dietary supplements for other species. Other factors responsible for disturbance of feces included a woodrat (Neotoma floridana) caching coyote feces, removal of captive coyote feces by free-ranging coyotes accompanied by deposition of fresh feces, a bobcat burying a captive bobcat sample and depositing fresh feces, and rain storms. Dietary studies based on fecal analyses could be biased by scat removal, assuming that contents in feces are representative of the proportion of foods consumed.

  1. Relative abundance of mesopredators and size of oak patches in the cross-timbers ecoregion

    USGS Publications Warehouse

    Disney, M.R.; Hellgren, E.C.; Davis, C.A.; Leslie, David M.; Engle, David M.

    2008-01-01

    Mesopredators (e.g., raccoon Procyon lotor, Virginia opossum Didelphis virginiana, striped skunk Mephitis mephitis) have received considerable attention because of links to population declines in birds via increased nest predation, especially in landscapes fragmented by anthropogenic forces. Relationships of abundance of mesopredators to size of habitat patches have received less attention than relationships to other metrics of fragmentation, particularly edge characteristics. We tested the hypothesis that relative abundance of mesopredators (e.g., raccoons and Virginia opossums) was related negatively to size of forest patch. We delineated 15 patches of oak (Quercus) forest ranging from 0.2 to 55.3 ha within a grassland-woodland mosaic in the cross-timbers ecoregion of Oklahoma. Scent stations and live traps within these patches were used to index relative abundance of mesopredators in summers 2003 and 2004. Both indices of relative abundance were related weakly and negatively to area of forest patch. However, rate of capture and visitation to scent station were not correlated consistently throughout the study. Our results suggested that the two methods to index abundance provided separate information on functional and numerical responses to size of patch. Our evidence that mesopredators within the cross timbers were more likely to be in smaller patches of oak forest may have implications to success of avian nesting in these patches.

  2. FGF2, FGF3 and FGF4 expression pattern during molars odontogenesis in Didelphis albiventris.

    PubMed

    Dos Santos, Íria Gabriela Dias; Jorge, Erika Cristina; Copola, Aline Gonçalves Lio; Bertassoli, Bruno Machado; Goes, Alfredo Miranda de; Silva, Gerluza Aparecida Borges

    2017-03-01

    Odontogenesis is guided by a complex signaling cascade in which several molecules, including FGF2-4, ensure all dental groups development and specificity. Most of the data on odontogenesis derives from rodents, which does not have all dental groups. Didelphis albiventris is an opossum with the closest dentition to humans, and the main odontogenesis stages occur when the newborns are in the pouch. In this study, D. albiventris postnatals were used to characterize the main stages of their molars development; and also to establish FGF2, FGF3 and FGF4 expression pattern. D. albiventris postnatals were processed for histological and indirect immunoperoxidase analysis of the tooth germs. Our results revealed similar dental structures between D. albiventris and mice. However, FGF2, FGF3 and FGF4 expression patterns were observed in a larger number of dental structures, suggesting broader functions for these molecules in this opossum species. The knowledge of the signaling that determinates odontogenesis in an animal model with complete dentition may contribute to the development of therapies for the replacement of lost teeth in humans. This study may also contribute to the implementation of D. albiventris as model for Developmental Biology studies.

  3. Effects of urbanization on carnivore species distribution and richness

    USGS Publications Warehouse

    Ordenana, Miguel A.; Crooks, Kevin R.; Boydston, Erin E.; Fisher, Robert N.; Lyren, Lisa M.; Siudyla, Shalene; Haas, Christopher D.; Harris, Sierra; Hathaway, Stacie A.; Turschak, Greta M.; Miles, A. Keith; Van Vuren, Dirk H.

    2010-01-01

    Urban development can have multiple effects on mammalian carnivore communities. We conducted a meta-analysis of 7,929 photographs from 217 localities in 11 camera-trap studies across coastal southern California to describe habitat use and determine the effects of urban proximity (distance to urban edge) and intensity (percentage of area urbanized) on carnivore occurrence and species richness in natural habitats close to the urban boundary. Coyotes (Canis latrans) and bobcats (Lynx rufus) were distributed widely across the region. Domestic dogs (Canis lupus familiaris), striped skunks (Mephitis mephitis), raccoons (Procyon lotor), gray foxes (Urocyon cinereoargenteus), mountain lions (Puma concolor), and Virginia opossums (Didelphis virginiana) were detected less frequently, and long-tailed weasels (Mustela frenata), American badgers (Taxidea taxus), western spotted skunks (Spilogale gracilis), and domestic cats (Felis catus) were detected rarely. Habitat use generally reflected availability for most species. Coyote and raccoon occurrence increased with both proximity to and intensity of urbanization, whereas bobcat, gray fox, and mountain lion occurrence decreased with urban proximity and intensity. Domestic dogs and Virginia opossums exhibited positive and weak negative relationships, respectively, with urban intensity but were unaffected by urban proximity. Striped skunk occurrence increased with urban proximity but decreased with urban intensity. Native species richness was negatively associated with urban intensity but not urban proximity, probably because of the stronger negative response of individual species to urban intensity.

  4. Experimental infection of Didelphis marsupialis with vesicular stomatitis New Jersey virus.

    PubMed

    Trujillo, Carlos M; Rodriguez, Luis; Rodas, Juan D; Arboleda, John Jairo

    2010-01-01

    Although vesicular stomatitis has been present for many years in the Americas, many aspects of its natural history remain undefined. In this study, we challenged five adult Virginia opossums (Didelphis marsupialis) with vesicular stomatitis New Jersey serotype virus (VSNJV). Opossums had no detectable antibodies against VSNJV prior to being inoculated with 10(6.5) median tissue culture infective doses (TCID(50)) of VSNJV by two routes; intraepithelial/subepithelial (IE/SE) inoculation and scarification in the muzzle (SM). Clinical response was monitored daily and animals were tested for viral shedding. All infected animals developed vesicles and ulcers on the tongue and inflammation of the nasal alar folds. Virus was isolated from esophagus-pharynx, nasal, and from ocular swabs and lesions samples. The failure to detect viremia in these animals indicates that a source other than blood may be required for transmission to insect vectors. Our results suggest that D. marsupialis could play a role in the maintenance of VSNJV outside of domestic animal populations and could provide a model to study vesicular stomatitis virus pathogenesis.

  5. Sex determination in marsupials: evidence for a marsupial-eutherian dichotomy.

    PubMed

    Renfree, M B; Short, R V

    1988-12-01

    In this paper, we review briefly the current state of knowledge about sexual differentiation in eutherian mammals, and then describe the situation in detail in two marsupial species: the North American opossum and the tammar wallaby. The conventional explanation for the genesis of all male somatic sexual dimorphisms in mammals is that they are a consequence of the systemic action of testicular hormones. In the absence of testes, the embryo will develop a female phenotype. We present evidence for the tammar wallaby that calls into question the universal applicability of this hormonal theory of mammalian sexual differentiation. We have shown that extensive somatic sexual dimorphisms precede by many days the first morphological evidence of testicular formation, which does not occur until around the third day of pouch life. Male foetuses, and pouch young on the day of birth, already have a well-developed gubernaculum and processus vaginalis, paired scrotal anlagen, and a complete absence of mammary anlagen, whereas female foetuses and newborn pouch young have a poorly developed gubernaculum and processus vaginalis, no scrotal anlagen, and well-developed mammary anlagen. Because it seems unlikely that the male gonad could begin hormone secretion until after the Sertoli and Leydig cells are developed, our results strongly suggest that some sexually dimorphic somatic characteristics develop autonomously, depending on their genotype rather than the hormonal environment to which they are exposed. We have been able to confirm the hormonal independence of the scrotum, pouch and mammary gland by administering testosterone propionate daily by mouth to female pouch young from the day of birth; although the Wolffian duct was hyperstimulated, there was no sign of scrotal development, or pouch or mammary inhibition. When male pouch young were treated with oestradiol benzoate in a similar fashion, there was hyperstimulation of the Müllerian duct and inhibition of testicular

  6. Identification of tammar wallaby SIRH12, derived from a marsupial-specific retrotransposition event

    PubMed Central

    Ono, Ryuichi; Kuroki, Yoko; Naruse, Mie; Ishii, Masayuki; Iwasaki, Sawa; Toyoda, Atsushi; Fujiyama, Asao; Shaw, Geoff; Renfree, Marilyn B.; Kaneko-Ishino, Tomoko; Ishino, Fumitoshi

    2011-01-01

    In humans and mice, there are 11 genes derived from sushi-ichi related retrotransposons, some of which are known to play essential roles in placental development. Interestingly, this family of retrotransposons was thought to exist only in eutherian mammals, indicating their significant contributions to the eutherian evolution, but at least one, PEG10, is conserved between marsupials and eutherians. Here we report a novel sushi-ichi retrotransposon-derived gene, SIRH12, in the tammar wallaby, an Australian marsupial species of the kangaroo family. SIRH12 encodes a protein highly homologous to the sushi-ichi retrotransposon Gag protein in the tammar wallaby, while SIRH12 in the South American short-tailed grey opossum is a pseudogene degenerated by accumulation of multiple nonsense mutations. This suggests that SIRH12 retrotransposition occurred only in the marsupial lineage but acquired and retained some as yet unidentified novel function, at least in the lineage of the tammar wallaby. PMID:21636603

  7. Detection of Leptospira spp. in wildlife reservoir hosts in Ontario through comparison of immunohistochemical and polymerase chain reaction genotyping methods

    PubMed Central

    Shearer, Karen E.; Harte, Michael J.; Ojkic, Davor; DeLay, Josepha; Campbell, Douglas

    2014-01-01

    A total of 460 kidney samples from wildlife (beavers, coyotes, deer, foxes, opossums, otters, raccoons, skunks) were obtained from road-kill and hunter/trapper donations in Ontario between January 2010 and November 2012. The objectives of the study were to detect Leptospira spp. by immunohistochemistry and polymerase chain reaction (PCR), to map presence of leptospires in wildlife relative to livestock and human populations, and to characterize positive samples by sequencing and comparison to leptospires known to affect domestic animals and humans. The proportion of samples that tested positive ranged from 0% to 42%, with the highest rates in skunks and raccoons. Leptospira spp. were present in kidneys of wildlife across Ontario, particularly in areas of high human density, and areas in which livestock populations are abundant. The PCR was too weak in most samples to permit genotyping and examination of the relationship between the leptospires found in this study and those affecting domestic animals and humans. PMID:24587507

  8. Electron microscopic study of Tetratrichomonas didelphidis and its interaction with a prokaryotic cell.

    PubMed

    Tasca, Tiana; De Carli, Geraldo Attilio

    2004-01-01

    Tetratrichomonas didelphidis is a flagellate protozoan found in the intestine of the opossum. The parasite lives in a hostile and stressed environment, where it interacts with microorganisms and can survive under extreme conditions for growth, involving strict anaerobiosis or equilibration with air and abundance or absence of nutrients. The in vitro cultivation of this protozoan depends upon Escherichia coli as a growth-promoting partner. In this study, we used scanning and transmission electron microscopy to observe the phagocytosis of bacteria by the protozoan, confirming the strong association between both cells and the growth dependence of T. didelphidis upon E. coli. After adherence to the protozoan surface, the bacteria induced the appearance of crater-like depressions and the ingested bacteria were intracellularly degraded.

  9. The isolation and identification of Trypanosoma cruzi from raccoons in Maryland

    USGS Publications Warehouse

    Walton, B.C.; Bauman, P.M.; Diamond, L.S.; Herman, C.M.

    1958-01-01

    Five raccoons trapped at Patuxent Research Refuge, Laurel, Maryland, were found to have trypanosomes in the blood which were morphologically indistinguishable from Trypanosoma cruzi on stained smears. The organism grew well in culture. It developed and reproduced in Triatoma protracta, T. infestans, T. phyllosoma, and Rhodnius prolixus. Experimental infections were produced in raccoons, opossums, mice, rats, and monkeys by inoculation of blood, culture, and triatome forms. Typical leishmaniform bodies were found in tissue sections of cardiac muscle fibers from naturally and experimentally infected animals. Cross agglutinations carried out with Iiving cultural forms and rabbit antisera demonstrated a close antigenic relationship between the raccoon trypanosome and T. cruzi (Brazil strain). On the basis of (1) morphology, (2) presence of leishmaniform tissue stages, (3) development in triatomes, (4) infectivity to a variety of mammals, (5) culture characteristics, and (6) cross reactions in serological tests, this parasite is considered conspecific with Trypanosoma cruzi (Chagas, 1909), the causative agent of American human trypanosomiasis.

  10. Trichinella infection in wildlife of the southwestern United States.

    PubMed

    Pozio, E; Pence, D B; La Rosa, G; Casulli, A; Henke, S E

    2001-10-01

    Several potential mammalian reservoirs of sylvatic species of Trichinella were examined from Texas, New Mexico, and Arizona. During 1998-99, tongues were collected from a black bear (Ursus americanus) in Arizona; from 9 black bears, a coyote (Canis latrans), and a mountain lion (Felis concolor) in New Mexico; and from 154 coyotes, 32 raccoons (Procyon lotor), 13 opossums (Didelphis marsupialis), 4 ocelots (Leopardus pardalis), 3 bobcats (Lynx rufus), and 5 feral hogs (Sus scrofa) in southern Texas. Larvae of Trichinella murrelli were identified by a multiple-polymerase chain reaction analysis in 1 black bear (11.1%) from New Mexico and in 7 coyotes (4.5%) of Texas, whereas Trichinella spiralis larvae were detected in the black bear of Arizona. This is the first report of Trichinella infection in wildlife of New Mexico and Texas and extends the distribution of T. murrelli into the southwestern United States near the border of Mexico.

  11. Effects of climatic warming on Lakes of the central boreal forest

    SciTech Connect

    Schindler, D.W.; Beaty, K.G.; Fee, E.J.; Cruikshank, D.R.; DeBruyn, E.R.; Findlay, D.L.; Linsey, G.A.; Shearer, J.A.; Stainton, M.P.; Turner, M.A. )

    1990-11-16

    Twenty years of climatic, hydrologic, and ecological records for the Experimental Lakes Area of northwestern Ontario show that air and lake temperatures have increased by 2{degree}C and the length of the ice-free season has increased by 3 weeks. Higher than normal evaporation and lower than average precipitation have decreased rates of water renewal in lakes. Concentrations of most chemicals have increased in both lakes and streams because of decreased water renewal and forest fires in the catchments. In Lake 239, populations and diversity of phytoplankton also increased, but primary production showed no consistent trend. Increased wind velocities, increased transparency, and increased exposure to wind of lakes in burned catchments caused thermoclines to deepen. As a result, summer habitats for cold stenothermic organisms like lake trout and opossum shrimp decreased. Our observations may provide a preview of the effects of increased greenhouse warming on boreal lakes. 27 refs., 1 fig.

  12. Comparative biology of the sculpins of Lake Superior

    USGS Publications Warehouse

    Selgeby, James H.

    1988-01-01

    The slimy sculpin (Cottus cognatus), spoonhead sculpin (Cottus ricei), and deepwater sculpin (Myoxocephalus thompsoni) are abundant fishes in Lake Superior. Slimy and spoonhead sculpins occupy a zone from near shore to depths of 210 m but are generally most abundant in waters 50 to 90 m deep. Deepwater sculpins are found in waters from 15 to 407 m deep and are most abundant at depths greater than 70 m. All three species of sculpins eat mainly burrowing amphipods (Pontoporeia affinis) although deepwater sculpins also eat substantial quantities of opossum shrimp (Mysis relicta). The three sculpins grow at similar rates. Among the fishes aged, the maximum age of slimy sculpins was 5 years, compared with 6 years for spoonhead sculpins, and 7 years for deepwater sculpins. Indirect evidence indicates that slimy and spoonhead sculpins spawn in the spring, and deepwater sculpins spawn in midwinter.

  13. Environmental Assessment on Construction of the Cabinet Gorge Kokanee Hatchery.

    SciTech Connect

    United States. Bonneville Power Administration.

    1984-10-01

    Bonneville Power Administration, the Washington Water Power Company, and Idaho Department of Fish and Game plan to enter into a cooperative cost-sharing agreement for the design, construction, operation, and maintenance of a kokanee hatchery in northern Idaho. The proposed hatchery shall supplement mitigation of adverse federal and non-federal hydroelectric and nonhydroelectric impacts. Hydroelectric impacts were primarily degradation of the Lake Pend Oreille shoreline kokanee habitat and blockage of migrating Clark Fork River kokanee. The introduction and establishment of Mysis relicta, the opossum shrimp, created further adverse effects on the kokanee fishery. The proposed hatchery will produce 20 million advanced-stage kokanee fry which will restore the Lake Pend Oreille kokanee fishery level to 744,000 harvestable adults after the first 5 years of operation. 6 references, 4 figures.

  14. Palm trees and Chagas' disease in Panama.

    PubMed

    Whitlaw, J T; Chaniotis, B N

    1978-09-01

    An ecological survey of triatomines in the sylvan ecosystem of the Canal Zone and selected sites in Panama disclosed for the first time a close association of Rhodnius pullescens and Triatoma dimidiata, the two most important vector species of Chagas' disease in Panama, with a single species of a widely distributed palm tree, Scheelea zonensis. This association may explain why Chagas' disease is prevalent in certain rural communities in Central Panama and rare in others. An immense focus of zoonotic Trypanosoma cruzi infection exists in the forests of the Canal Zone with presence of large populations of triatomines, associated with scheelea zonensis and other yet undescribed microhabitats, and high (50--60%) trypanosome infections in all of the major triatomine species. Common opossums, anteaters, and spiny rats seem to be the principal animal reservoirs of T. cruzi in this complex and relatively undisturbed ecosystem.

  15. An X chromosome microRNA cluster in the marsupial species Monodelphis domestica.

    PubMed

    Devor, Eric J; Huang, Lingyan; Wise, Amanda; Peek, Andrew S; Samollow, Paul B

    2011-01-01

    MicroRNAs (miRNAs) are an important class of posttranscriptional gene expression regulators. In the course of mapping novel marsupial-specific miRNAs in the genome of the gray short-tailed opossum, Monodelphis domestica, we encountered a cluster of 39 actual and potential miRNAs spanning 102 kb of the X chromosome. Analysis of the cluster revealed that 37 of the 39 miRNAs are predicted to form thermodynamically stable hairpins, and at least 3 members have been directly cloned from M. domestica tissues. The sequence characteristics of these miRNAs suggest that they all descended from a single common ancestor. Further, 2 distinct families appear to have diversified from the ancestral sequence through different duplication mechanisms: one through a series of simple tandem duplications and the other through a recurrent transposon-mediated duplication process.

  16. Photoreactivation of UV-induced pyrimidine dimers and erythema in the marsupial Monodelphis domestica

    SciTech Connect

    Ley, R.D.

    1985-04-01

    Post-UV treatment of the gray, short-tailed opossum Monodelphis domestica with photoreactivating light (320-400 nm) suppressed the appearance of UV-induced erythema as evidenced by an increase in the dose of UV required to elicit an erythemal response. Pre-UV exposure to photoreactivating light had no effect on the UV induction of erythema. The dose-response for the photoreversal of pyrimidine dimers in epidermal DNA of M. domestica was similar to that for the photoreactivation of erythema induction. These data not only support the notion that DNA is the primary chromophore involved in the induction of erythema but also identify pyrimidine dimers as the major DNA change responsible for its induction. These results also identify M. domestica as a useful whole-animal system with which to determine the role of pyrimidine dimers in other photobiological responses of mammalian skin.

  17. In vitro and in silico annotation of conserved and nonconserved microRNAs in the genome of the marsupial Monodelphis domestica.

    PubMed

    Devor, Eric J; Samollow, Paul B

    2008-01-01

    The gray short-tailed opossum, Monodelphis domestica, is the world's most widely utilized marsupial model for biomedical research. Recent completion of the initial M. domestica genome assembly offers the first opportunity to examine genome-wide phenomena in a marsupial. Using in silico methods, we have mapped 124 conserved microRNAs (miRNAs) to 94 loci in the M. domestica genome. In addition, using RNA pooled from 5 tissues, we cloned 85 miRNAs. Seventy-two of these are conserved miRNAs that we had mapped in silico. The additional 13 are nonconserved candidate miRNAs in 11 loci. Nine of these 13 are also found in the wallaby (Macropus eugenii) genome. Two of the candidate miRNA clones, located on the X chromosome, are part of a cluster containing a total of 24 potential miRNAs spanning more than 100 kb.

  18. Serological Investigation of Heartland Virus (Bunyaviridae: Phlebovirus) Exposure in Wild and Domestic Animals Adjacent to Human Case Sites in Missouri 2012–2013

    PubMed Central

    Bosco-Lauth, Angela M.; Panella, Nicholas A.; Root, J. Jeffrey; Gidlewski, Tom; Lash, R. Ryan; Harmon, Jessica R.; Burkhalter, Kristen L.; Godsey, Marvin S.; Savage, Harry M.; Nicholson, William L.; Komar, Nicholas; Brault, Aaron C.

    2015-01-01

    Heartland virus (HRTV; Bunyaviridae: Phlebovirus) has recently emerged as a causative agent of human disease characterized by thrombocytopenia and leukopenia in the United States. The lone star tick (Amblyomma americanum L.) has been implicated as a vector. To identify candidate vertebrate amplification hosts associated with enzootic maintenance of the virus, sera and ticks were sampled from 160 mammals (8 species) and 139 birds (26 species) captured near 2 human case residences in Andrew and Nodaway Counties in northwest Missouri. HRTV-specific neutralizing antibodies were identified in northern raccoons (42.6%), horses (17.4%), white-tailed deer (14.3%), dogs (7.7%), and Virginia opossums (3.8%), but not in birds. Virus isolation attempts from sera and ticks failed to detect HRTV. The high antibody prevalence coupled with local abundance of white-tailed deer and raccoons identifies these species as candidate amplification hosts. PMID:25870419

  19. Human Trypanosomiasis in the Eastern Region of the Panama Province: New Endemic Areas for Chagas Disease

    PubMed Central

    Calzada, José E.; Pineda, Vanesa; Garisto, Juan D.; Samudio, Franklyn; Santamaria, Ana Maria; Saldaña, Azael

    2010-01-01

    The epidemiology of Chagas disease was studied in five rural communities located in the eastern region of the Panama Province. Serological tests for Trypanosoma cruzi infection revealed a prevalence of 5.88% (12/204). Hemocultures coupled with polymerase chain reaction (PCR) analysis showed a Trypanosoma rangeli infection rate of 5.88% (12/204). An overall trypanosome infection index of 11.76% (24/204) was detected in this population. A total of 121 triatomine specimens were collected in domestic and peridomestic habitats. Rhodnius pallescens was confirmed as the predominant species. Molecular analysis showed that 17.8% (13/73) of the examined insects were positive for T. cruzi, 17.8% (13/73) for T. rangeli, and 35.6% (26/73) presented mixed infections. Among 73 R. pallescens evaluated, 16.4% (12/73) contained opossum blood meals. The epidemiological implications of these findings are discussed. PMID:20348502

  20. Serologic responses of cats against experimental Sarcocystis neurona infections.

    PubMed

    Dubey, J P; Lindsay, D S; Saville, W J A

    2002-08-02

    Sarcocystis neurona is the most important cause of a neurologic disease of horses, equine protozoal myeloencephalitis (EPM). Cats and other carnivores can act as its intermediate hosts and horses are aberrant hosts. Little is known of the sero-epidemiology of S. neurona infections in cats. In the present study, antibodies to S. neurona were evaluated by the S. neurona agglutination test (SAT). Cats fed sporocysts from the feces of naturally infected opossums or inoculated intramuscularly with S. neurona merozoites developed high levels (> or =1:4000) of SAT antibodies. Antibodies to S. neurona were not found in a cat inoculated with merozoites of the closely related parasite, Sarcocystis falcatula. These results should be useful in studying sero-epidemiology of S. neurona infections in cats.

  1. Murine typhus: an unrecognized suburban vectorborne disease.

    PubMed

    Civen, Rachel; Ngo, Van

    2008-03-15

    Murine typhus, an acute febrile illness caused by Rickettsia typhi, is distributed worldwide. Mainly transmitted by the fleas of rodents, it is associated with cities and ports where urban rats (Rattus rattus and Rattus norvegicus) are abundant. In the United States, cases are concentrated in suburban areas of Texas and California. Contrary to the classic rat-flea-rat cycle, the most important reservoirs of infection in these areas are opossums and cats. The cat flea, Ctenocephalides felis, has been identified as the principal vector. In Texas, murine typhus cases occur in spring and summer, whereas, in California, cases have been documented in summer and fall. Most patients present with fever, and many have rash and headache. Serologic testing with the indirect immunofluorescence assay is the preferred diagnostic method. Doxycycline is the antibiotic of choice and has been shown to shorten the course of illness.

  2. Panamanian forest mammals as carriers of Salmonella.

    PubMed

    Kourany, M; Bowdre, L; Herrer, A

    1976-05-01

    Enteric bacteria pathogenic to man were sought in a total of 974 forest mammals collected from a variety of sites in rural and jungle areas of Panamá. The highest incidence of infection among the mammals was observed during the Panamanian dry season, which normally extends from January through April. A minimum of 10 Salmonella serotypes including, three of the Arizona group and Ewardsiella tarda, was isolated. Opossums of the genera Philander, 11 of 54 (20.1%), and Didelphis, 12 of 102 (11.8%) demonstrated high infection rates. One sloth of the genus Choloepus and specimens of two genera of rodents also were infected to varying degrees: 1(11.1%) of 9 Choloepus, 8 (1.1%) of 704 Proechimys and 1 (16.7%) of 6 Diplomys.

  3. Feeding ecology of non-native Siberian prawns, Palaemon modestus (Heller, 1862) (Decapoda, Palaemonidae), in the lower Snake River, Washington, U.S.A.

    USGS Publications Warehouse

    Tiffan, Kenneth F.; Hurst, William

    2016-01-01

    We used both stomach content and stable isotope analyses to describe the feeding ecology of Siberian prawns Palaemon modestus (Heller, 1862), a non-native caridean shrimp that is a relatively recent invader of the lower Snake River. Based on identifiable prey in stomachs, the opossum shrimp Neomysis mercedis Holmes, 1896 comprised up to 34-55% (by weight) of diets of juvenile to adult P. modestus, which showed little seasonal variation. Other predominant items/taxa consumed included detritus, amphipods, dipteran larvae, and oligochaetes. Stable isotope analysis supported diet results and also suggested that much of the food consumed by P. modestus that was not identifiable came from benthic sources — predominantly invertebrates of lower trophic levels and detritus. Palaemon modestus consumption of N. mercedis may pose a competitive threat to juvenile salmon and resident fishes which also rely heavily on that prey.

  4. [Investigation of vectors and reservoirs in an acute Chagas outbreak due to possible oral transmission in Aguachica, Cesar, Colombia].

    PubMed

    Soto, Hugo; Tibaduiza, Tania; Montilla, Marleny; Triana, Omar; Suárez, Diana Carolina; Torres Torres, Mariela; Arias, María Teresa; Lugo, Ligia

    2014-04-01

    Colombia recorded 11 cases of acute Chagas disease and 80 cases of oral contamination with Trypanosoma cruzi. The current study analyzes the entomological and parasitological characteristics of the outbreak in Aguachica, Cesar Department, in 2010. An interdisciplinary group of health professionals and regional university personnel conducted the laboratory tests in the patients and the investigation of the transmission focus. Eleven cases of acute Chagas diseases were detected in a single family in a dwelling with domiciliated triatomines and Rhodnius pallescens, Pantrongylus geniculatus, Eratyrus cuspidatus, and two Didelphis marsupialis opossums infected with T. cruzi in Attalea butyracea and Elaeis oleifera palm trees in the urban area of Aguachica. The study analyzes the role of R. pallescens and palm trees in the wild cycle of T. cruzi and in oral transmission of Chagas disease. Sporadic incursions by wild R. pallescens, P. geniculatus, and E. cuspidatus from the nearby palm trees into human dwellings may cause increasingly frequent outbreaks of oral Chagas disease.

  5. Comparative uptake of uranium, thorium, and plutonium by biota inhabiting a contaminated Tennessee floodplain

    SciTech Connect

    Garten, C.T. Jr.; Bondietti, E.A.; Walker, R.L.

    1981-04-01

    The uptake of /sup 238/U, /sup 232/Th, and /sup 239/Pu from soil by fescue, grasshoppers, and small mammals was compared at the contaminated White Oak Creek floodplain in East Tennessee. Comparisons of actinide uptake were based on analyses of radionuclide ratios (U/Pu and Th/Pu) in soil and biota. U:Pu ratios in small mammal carcasses (shrews, mice, and rats) and bone samples from larger mammals (rabbit, woodchuck, opossum, and raccoon) were significantly greater (P less than or equal to 0.05) than U/Pu ratios in soil (based on 8M HNO/sub 3/ extractable). There was no significant difference between Th/Pu ratios in animals and soil. The order of actinide accumulation by biota from the site relative to contaminated soil was U > Th approx. = Pu.

  6. Large number of ultraconserved elements were already present in the jawed vertebrate ancestor.

    PubMed

    Wang, Jianli; Lee, Alison P; Kodzius, Rimantas; Brenner, Sydney; Venkatesh, Byrappa

    2009-03-01

    Stephen (2008) identified 13,736 ultraconserved elements (UCEs) in placental mammals and investigated their evolution in opossum, chicken, frog, and fugu. They found that there was a massive expansion of UCEs during tetrapod evolution and the substitution rate in UCEs showed a significant decline in tetrapods compared with fugu, suggesting they were exapted in tetrapods. They considered it unlikely that these elements are ancient but evolved at a higher rate in teleost fishes. In this study, we investigated the evolution of UCEs in a cartilaginous fish, the elephant shark and show that nearly half the UCEs were present in the jawed vertebrate ancestor. The substitution rate in UCEs is higher in fugu than in elephant shark, and approximately one-third of ancient UCEs have diverged beyond recognition in teleost fishes. These data indicate that UCEs have evolved at a higher rate in teleost fishes, which may have implications for their vast diversity and evolutionary success.

  7. Agglutinins to Coxiella burnetii and Brucella spp, with particular reference to Brucella canis, in wild animals of southern Texas.

    PubMed

    Randhawa, A S; Kelly, V P; Baker, E F

    1977-11-01

    The prevalence of agglutinins to Coxiella burnetii and Brucella spp, particularly Brucella canis, was determined in 269 wild animals (14 species) in southern Texas. Serologic evidence of coxiellosis and brucellosis, including B canis infection, was shown for coyotes, raccoons, opossums, badgers, jackrabbits, and feral hogs. Using the microagglutination test, the seroprevalence of C burnetii, phases I and II (titer greater than or equal to 4) was 4.1 and 27.9%, respectively. For brucella agglutinins, prevalence rates were 7.1, 8.9, and 6.7%, as determined by the brucellosis card test, the rapid slide agglutination test, and the salt 2-mercaptoethanol tube agglutination (titer greater than or equal to 50) test, respectively.

  8. Morphology of the lingual papillae in the brush-tailed rat kangaroo.

    PubMed

    Emura, Shoichi; Okumura, Toshihiko; Chen, Huayue

    2014-01-01

    We examined the dorsal lingual surface of an adult brush-tailed rat kangaroo (Bettongia penicillata) by scanning electron microscopy. The filiform and fungiform papillae on the lingual apex and body consisted of a main papilla and secondary papillae. The connective tissue core of the filiform papillae on the lingual apex was cylindrical in shape with a crushed top. The connective tissue core of the filiform papillae on the lingual body had one large and several small processes. The fungiform papillae were round in shape. The connective tissue core of the fungiform papillae had several depressions on its top. The surface of the vallate papillae was rough and the papillae were surrounded by a groove and a pad. Several long conical papillae derived from the posterolateral margin of the tongue where foliate papillae have been shown to be distributed in many other animal species. The long conical papillae were very similar to those of the koala and opossum.

  9. ECRbase: Database of Evolutionary Conserved Regions, Promoters, and Transcription Factor Binding Sites in Vertebrate Genomes

    SciTech Connect

    Loots, G; Ovcharenko, I

    2006-08-08

    Evolutionary conservation of DNA sequences provides a tool for the identification of functional elements in genomes. We have created a database of evolutionary conserved regions (ECRs) in vertebrate genomes entitled ECRbase that is constructed from a collection of pairwise vertebrate genome alignments produced by the ECR Browser database. ECRbase features a database of syntenic blocks that recapitulate the evolution of rearrangements in vertebrates and a collection of promoters in all vertebrate genomes presented in the database. The database also contains a collection of annotated transcription factor binding sites (TFBS) in all ECRs and promoter elements. ECRbase currently includes human, rhesus macaque, dog, opossum, rat, mouse, chicken, frog, zebrafish, and two pufferfish genomes. It is freely accessible at http://ECRbase.dcode.org.

  10. Parastrongylus (=Angiostrongylus) cantonensis now endemic in Louisiana wildlife.

    PubMed

    Kim, D Y; Stewart, T B; Bauer, R W; Mitchell, M

    2002-10-01

    Parastrongylus (=Angiostrongylus) cantonensis, a lung worm of rats, was first reported in the United States in 1987, with a probable introduction by infected rats from ships docking in New Orleans, Louisiana, during the mid-1980s. Since then, it has been reported in nonhuman primates and a boy from New Orleans, and in a horse from Picayune, Mississippi, a distance of 87 km from New Orleans. Parastrongylus cantonensis infection is herein reported in a lemur (Varencia variegata rubra) from New Iberia, Louisiana, a distance of 222 km from New Orleans, and in a wood rat (Neotomafloridanus) and in 4 opossums (Didelphis virginiana) from Baton Rouge, Louisiana, a distance of 124 km from New Orleans. The potential of a great variety of gastropods serving as intermediate hosts in Louisiana may pose a threat to wildlife as well as to domesticated animals in the areas where infected Norway rats (Rattus norvegicus) are present.

  11. [American cutaneous leishmaniasis in municipalities in the northwestern region of Paraná State: use of remote sensing for analysis of vegetation types and places with disease occurrence].

    PubMed

    Arraes, Sandra Mara Alessi Aristides; Veit, Renata Tonon; Bernal, Marcos Vinícius Zandonadi; Becker, Tânia Cristina Alexandrino; Nanni, Marcos Rafael

    2008-01-01

    American cutaneous leishmaniasis, an endemic disease in the northwestern region of Paraná, Brazil, is transmitted by phlebotomines to man and animals like dogs, armadillos, opossums and wild rodents. This disease has been occurring in places where forests have been felled and on the banks of rivers and lakes with arboreal vegetation, where man comes into contact with infected insects. This disease is a public health problem because of the occurrence of epidemic outbreaks throughout Paraná. Because of the importance of finding out about endemic areas, this study used epidemiological file data on patients attended between 1999 and 2004. These data were correlated with areas of forest felling that were identified by means of satellite remote sensing techniques and products. The results showed that the occurrences of cases in the municipalities of this region coincided with the presumed likely areas for patient infection.

  12. Activation of outward K+ currents: effect of VIP in oesophagus

    PubMed Central

    Jury, Jennifer; Daniel, Edwin E

    1999-01-01

    Electrical field stimulations (EFS) of the opossum and canine lower oesophageal sphincters (OLOS and CLOS respectively) and opossum oesophageal body circular muscle (OOBCM) induce non-adrenergic, non-cholinergic (NANC) relaxations of any active tension and NO-mediated hyperpolarization. VIP relaxes the OLOS and CLOS and any tone in OOBCM without major electrophysiological effects. These relaxations are not blocked by NOS inhibitors. Using isolated smooth muscle cells, we tested whether VIP acted through myogenic NO production.Outward currents were similar in OOBCM and OLOS and NO increased them regardless of pipette Ca2+i, from 50–8000 nM. L-NAME or L-NOARG did not block outward currents in OLOS at 200 nM pipette Ca2+.Outward currents in CLOS cells decreased at 200 nM pipette Ca2+ or less but NO donors still increased them. VIP had no effect on outward currents in cells from OOBCM, OLOS or CLOS under conditions of pipette Ca2+ at which NO donors increased outward K+ currents.We conclude, VIP does not mimic electrophysiological effects of NO donors on isolated cells of OOBCM, OLOS or CLOS. VIP relaxes the OLOS and CLOS and inhibits contraction of OOBCM by a mechanism unrelated to release of myogenic NO or an increase in outward current.Also, the different dependence of outward currents of OOBCM and OLOS on pipette Ca2+ from those of CLOS suggests that different K+ channels are involved and that myogenic NO production contributes to K+ channel activity in CLOS but not in OLOS or OOBCM. PMID:10385258

  13. Outbreak of Campylobacteriosis Associated with Raccoon Contact at a Wildlife Rehabilitation Centre, Minnesota, 2013.

    PubMed

    Saunders, S; Smith, K; Schott, R; Dobbins, G; Scheftel, J

    2016-08-30

    Campylobacteriosis is an enteric illness caused by bacteria of the genus Campylobacter. There are approximately 900 culture-confirmed cases of campylobacteriosis reported annually to the Minnesota Department of Health (MDH). Case patients are interviewed about risk factors, including foods eaten, recreational and drinking water exposures and animal contact. In September 2013, MDH identified two Campylobacter jejuni cases who reported working at the same wildlife rehabilitation centre before illness onset. This report describes the investigation, which used a case-control study design, and identified 16 additional ill persons, for a total of 18 ill persons. Both cases and controls reported working with a variety of animals, including squirrels, chipmunks, mice, raccoons, opossums, rabbits, songbirds, waterfowl and reptiles. In univariate analyses, contact with a number of different animal species was significantly associated with illness, including raccoons (odds ratio [OR], 11.1; P < 0.001), chipmunks (OR, 3.65; P = 0.01), opossums (OR, 4.38; P = 0.005), mice (OR, 4.18; P = 0.01) and rabbits (OR, 4.36; P = 0.003). In a multivariate model, contact with raccoons was the only exposure independently associated with illness (adjusted OR, 12.2; P = 0.01). Bacterial culture and subtyping of the outbreak strain of C. jejuni from raccoon faecal samples further implicated raccoons as the source of the outbreak. Not all of the cases reported handling raccoons, suggesting that environmental contamination contributed to transmission. MDH worked with the wildlife rehabilitation centre's management to strengthen biosecurity and infection control protocols.

  14. Platypus Pou5f1 reveals the first steps in the evolution of trophectoderm differentiation and pluripotency in mammals.

    PubMed

    Niwa, Hitoshi; Sekita, Yoko; Tsend-Ayush, Enkhjargal; Grützner, Frank

    2008-01-01

    Uterine nourishment of embryos by the placenta is a key feature of mammals. Although a variety of placenta types exist, they are all derived from the trophectoderm (TE) cell layer of the developing embryo. Egg-laying mammals (platypus and echidnas) are distinguished by a very short intrauterine embryo development, in which a simple placenta forms from TE-like cells. The Pou5f1 gene encodes a class V POU family transcription factor Oct3/4. In mice, Oct3/4 together with the highly conserved caudal-related homeobox transcription factor Cdx2, determines TE fate in pre-implantation development. In contrast to Cdx2, Pou5f1 has only been identified in eutherian mammals and marsupials, whereas, in other vertebrates, pou2 is considered to be the Pou5f1 ortholog. Here, we show that platypus and opossum genomes contain a Pou5f1 and pou2 homolog, pou2-related, indicating that these two genes are paralogues and arose by gene duplication in early mammalian evolution. In a complementation assay, we found that platypus or human Pou5f1, but not opossum or zebrafish pou2, restores self-renewal in Pou5f1-null mouse ES cells, showing that platypus possess a fully functional Pou5f1 gene. Interestingly, we discovered that parts of one of the conserved regions (CR4) is missing from the platypus Pou5f1 promoter, suggesting that the autoregulation and reciprocal inhibition between Pou5f1 and Cdx2 evolved after the divergence of monotremes and may be linked to the development of more elaborate placental types in marsupial and eutherian mammals.

  15. Phosphorylation of rat kidney Na-K pump at Ser938 is required for rapid angiotensin II-dependent stimulation of activity and trafficking in proximal tubule cells.

    PubMed

    Massey, Katherine J; Li, Quanwen; Rossi, Noreen F; Keezer, Susan M; Mattingly, Raymond R; Yingst, Douglas R

    2016-02-01

    How angiotensin (ANG) II acutely stimulates the Na-K pump in proximal tubules is only partially understood, limiting insight into how ANG II increases blood pressure. First, we tested whether ANG II increases the number of pumps in plasma membranes of native rat proximal tubules under conditions of rapid activation. We found that exposure to 100 pM ANG II for 2 min, which was previously shown to increase affinity of the Na-K pump for Na and stimulate activity threefold, increased the amount of the Na-K pump in plasma membranes of native tubules by 33%. Second, we tested whether previously observed increases in phosphorylation of the Na-K pump at Ser(938) were part of the stimulatory mechanism. These experiments were carried out in opossum kidney cells, cultured proximal tubules stably coexpressing the ANG type 1 (AT1) receptor, and either wild-type or a S938A mutant of rat kidney Na-K pump under conditions found by others to stimulate activity. We found that 10 min of incubation in 10 pM ANG II stimulated activity of wild-type pumps from 2.3 to 3.5 nmol K · mg protein(-1) · min(-1) and increased the amount of the pump in the plasma membrane by 80% but had no effect on cells expressing the S938A mutant. We conclude that acute stimulation of Na-K pump activity in native rat proximal tubules includes increased trafficking to the plasma membrane and that phosphorylation at Ser(938) is part of the mechanism by which ANG II directly stimulates activity and trafficking of the rat kidney Na-K pump in opossum kidney cells.

  16. Regional Extinctions and Quaternary Shifts in the Geographic Range of Lestodelphys halli, the Southernmost Living Marsupial: Clues for Its Conservation.

    PubMed

    Formoso, Anahí E; Martin, Gabriel M; Teta, Pablo; Carbajo, Aníbal E; Sauthier, Daniel E Udrizar; Pardiñas, Ulyses F J

    2015-01-01

    The Patagonian opossum (Lestodelphys halli), the southernmost living marsupial, inhabits dry and open environments, mainly in the Patagonian steppe (between ~32 °S and ~49 °S). Its rich fossil record shows its occurrence further north in Central Argentina during the Quaternary. The paleoenvironmental meaning of the past distribution of L. halli has been mostly addressed in a subjective framework without an explicit connection with the climatic "space" currently occupied by this animal. Here, we assessed the potential distribution of this species and the changes occurred in its geographic range during late Pleistocene-Holocene times and linked the results obtained with conservation issues. To this end, we generated three potential distribution models with fossil records and three with current ones, using MaxEnt software. These models showed a decrease in the suitable habitat conditions for the species, highlighting a range shift from Central-Eastern to South-Western Argentina. Our results support that the presence of L. halli in the Pampean region during the Pleistocene-Holocene can be related to precipitation and temperature variables and that its current presence in Patagonia is more related to temperature and dominant soils. The models obtained suggest that the species has been experiencing a reduction in its geographic range since the middle Holocene, a process that is in accordance with a general increase in moisture and temperature in Central Argentina. Considering the findings of our work and the future scenario of global warming projected for Patagonia, we might expect a harsh impact on the distribution range of this opossum in the near future.

  17. Lipid- and mechanosensitivities of sodium/hydrogen exchangers analyzed by electrical methods

    PubMed Central

    Fuster, Daniel; Moe, Orson W.; Hilgemann, Donald W.

    2004-01-01

    Sodium/hydrogen exchangers (NHEs) are ubiquitous ion transporters that serve multiple cell functions. We have studied two mammalian isoforms, NHE1 (ubiquitous) and NHE3 (epithelial-specific), by measuring extracellular proton (H+) gradients during whole-cell patch clamp with perfusion of the cell interior. Maximal Na+-dependent H+ fluxes (JH+) are equivalent to currents >20 pA for NHE1 in Chinese hamster ovary fibroblasts, >200 pA for NHE1 in guinea pig ventricular myocytes, and 5–10 pA for NHE3 in opossum kidney cells. The fluxes are blocked by an NHE inhibitor, ethylisopropylamiloride, and are absent in NHE-deficient AP-1 cells. NHE1 activity is stable with perfusion of nonhydrolyzable ATP [adenosine 5′-(β,γ-imido)triphosphate], is abolished by ATP depletion (2 deoxy-d-glucose with oligomycin or perfusion of apyrase), can be restored with phosphatidylinositol 4,5-bisphosphate, and is unaffected by actin cytoskeleton disruption (latrunculin or pipette perfusion of gelsolin). NHE3 (but not NHE1) is reversibly activated by phosphatidylinositol 3,4,5-trisphosphate. Both NHE1 and NHE3 activities are disrupted in giant patches during gigaohm seal formation. NHE1 (but not NHE3) is reversibly activated by cell shrinkage, even at neutral cytoplasmic pH without ATP, and inhibited by cell swelling. NHE1 in Chinese hamster ovary fibroblasts (but not NHE3 in opossum kidney cells) is inhibited by agents that thin the membrane (l-α-lysophosphatidylcholine and octyl-β-d-glucopyranoside) and activated by cholesterol enrichment, which thickens membranes. Expressed in AP-1 cells, however, NHE1 is insensitive to these agents but remains sensitive to volume changes. Thus, changes of hydrophobic mismatch can modulate NHE1 but do not underlie its volume sensitivity. PMID:15240890

  18. Expression of major gap junction connexin types in the working myocardium of eight chordates.

    PubMed

    Becker, D L; Cook, J E; Davies, C S; Evans, W H; Gourdie, R G

    1998-01-01

    The alpha1 connexin (connexin43) is regarded as the major gap junction protein of the myocardium because it predominates there in mammals. Here, we show that it is not the major connexin of the working myocardium in non-mammalian vertebrates, which instead express beta1-like connexins homologous to mammalian connexin32. A phylogenetic series of hearts was immunostained with seven antibodies raised against peptide sequences specific for three distinct members of the gap junction connexin family: alpha1, beta1 and alpha5 (mammalian connexin40/avian connexin42). Working myocardium from two ascidian chordates (Ciona and Mogula), a teleost (Carassius), a frog (Xenopus) and two reptiles (Anolis and Alligator) was found to express a beta1-like connexin, rather than an alpha1-like connexin. An alpha1-like connexin was nevertheless often detected in other cardiac tissues. In the chicken (by ancestry a reptile), the developing myocardium expressed a beta1-like connexin strongly on embryonic day 6 but less strongly at hatching, and minimally in the adult. Myocardial expression of alpha5 connexin increased during development, but remained strongest in the coronary vascular endothelial and cardiac conduction tissues. The arteriolar smooth muscle of the chicken expressed alpha1 connexin throughout development, but its myocardium did not. In contrast, the working myocardium of a marsupial mammal (the opossum Trichosurus) strongly expressed an alpha1 connexin just like placental mammals. These results imply that a shift from beta1 to alpha1 connexin expression in the heart occurred prior to the evolution of the opossums. The beta and alpha connexin subfamilies have different permeabilities and gating properties, and we discuss factors that might have made this shift beneficial.

  19. Opportunistic Sampling of Roadkill as an Entry Point to Accessing Natural Products Assembled by Bacteria Associated with Non-anthropoidal Mammalian Microbiomes

    PubMed Central

    2016-01-01

    Few secondary metabolites have been reported from mammalian microbiome bacteria despite the large numbers of diverse taxa that inhabit warm-blooded higher vertebrates. As a means to investigate natural products from these microorganisms, an opportunistic sampling protocol was developed, which focused on exploring bacteria isolated from roadkill mammals. This initiative was made possible through the establishment of a newly created discovery pipeline, which couples laser ablation electrospray ionization mass spectrometry (LAESIMS) with bioassay testing, to target biologically active metabolites from microbiome-associated bacteria. To illustrate this process, this report focuses on samples obtained from the ear of a roadkill opossum (Dideiphis virginiana) as the source of two bacterial isolates (Pseudomonas sp. and Serratia sp.) that produced several new and known cyclic lipodepsipeptides (viscosin and serrawettins, respectively). These natural products inhibited biofilm formation by the human pathogenic yeast Candida albicans at concentrations well below those required to inhibit yeast viability. Phylogenetic analysis of 16S rRNA gene sequence libraries revealed the presence of diverse microbial communities associated with different sites throughout the opossum carcass. A putative biosynthetic pathway responsible for the production of the new serrawettin analogues was identified by sequencing the genome of the Serratia sp. isolate. This study provides a functional roadmap to carrying out the systematic investigation of the genomic, microbiological, and chemical parameters related to the production of natural products made by bacteria associated with non-anthropoidal mammalian microbiomes. Discoveries emerging from these studies are anticipated to provide a working framework for efforts aimed at augmenting microbiomes to deliver beneficial natural products to a host. PMID:28335605

  20. The Transcriptomic Evolution of Mammalian Pregnancy: Gene Expression Innovations in Endometrial Stromal Fibroblasts

    PubMed Central

    Kin, Koryu; Maziarz, Jamie; Chavan, Arun R.; Kamat, Manasi; Vasudevan, Sreelakshmi; Birt, Alyssa; Emera, Deena; Lynch, Vincent J.; Ott, Troy L.; Pavlicev, Mihaela; Wagner, Günter P.

    2016-01-01

    The endometrial stromal fibroblast (ESF) is a cell type present in the uterine lining of therian mammals. In the stem lineage of eutherian mammals, ESF acquired the ability to differentiate into decidual cells in order to allow embryo implantation. We call the latter cell type “neo-ESF” in contrast to “paleo-ESF” which is homologous to eutherian ESF but is not able to decidualize. In this study, we compare the transcriptomes of ESF from six therian species: Opossum (Monodelphis domestica; paleo-ESF), mink, rat, rabbit, human (all neo-ESF), and cow (secondarily nondecidualizing neo-ESF). We find evidence for strong stabilizing selection on transcriptome composition suggesting that the expression of approximately 5,600 genes is maintained by natural selection. The evolution of neo-ESF from paleo-ESF involved the following gene expression changes: Loss of expression of genes related to inflammation and immune response, lower expression of genes opposing tissue invasion, increased markers for proliferation as well as the recruitment of FOXM1, a key gene transiently expressed during decidualization. Signaling pathways also evolve rapidly and continue to evolve within eutherian lineages. In the bovine lineage, where invasiveness and decidualization were secondarily lost, we see a re-expression of genes found in opossum, most prominently WISP2, and a loss of gene expression related to angiogenesis. The data from this and previous studies support a scenario, where the proinflammatory paleo-ESF was reprogrammed to express anti-inflammatory genes in response to the inflammatory stimulus coming from the implanting conceptus and thus paving the way for extended, trans-cyclic gestation. PMID:27401177

  1. Effects of climate and exurban development on nest predation and predator presence in the southern Appalachian Mountains (USA).

    PubMed

    Lumpkin, Heather A; Pearson, Scott M; Turner, Monica G

    2012-08-01

    In the eastern United States, land-use and climate change have likely contributed to declines in the abundance of Neotropical migrant birds that occupy forest interiors, but the mechanisms are not well understood. We conducted a nest-predation experiment in southern Appalachian Mountain forests (North Carolina, U.S.A.) during the 2009 and 2010 breeding seasons to determine the effects of exurban development and temperature on predator presence and the average number of days until eggs in an artificial nest were disturbed by predators. We baited artificial nests with quail (Excalfactoria chinensi) eggs and monitored them for 18 days. We used clay eggs, track plates, and motion-triggered cameras to detect and identify nest predators. The average number of days a nest was undisturbed decreased as mean temperature increased and, to a lesser extent, as the density of buildings increased. Nests on the ground were more often depredated than those in trees, likely due to increased predation by opossum (Didelphis virginiana) and other carnivores. Raccoons (Procyon lotor), opossums, corvids (Corvus brachyrhynchos and Cyanocitta cristata), chipmunks (Tamias striatus), black bears (Ursus americanus), and domestic cats (Felis catus) were the most commonly detected predators. Presence of these predators did not vary as a function of mean temperature. Domestic cats and corvids were detected more frequently in plots with high rather than low densities of buildings. Forest-interior specialists and Neotropical migrants often nest in cool, high-elevation areas with low housing density. These bird species, especially those that nest on the ground, may be most vulnerable to increased nest predation if temperature and exurban development increase at higher elevations as anticipated.

  2. Changes in consumption by alewives and lake whitefish after dreissenid mussel invasions in Lakes Michigan and Huron

    USGS Publications Warehouse

    Pothoven, S.A.; Madenjian, C.P.

    2008-01-01

    Growth of alewives Alosa pseudoharengus and lake whitefish Coregonus clupeaformis has declined since the arrival and spread of dreissenid mussels in Lakes Michigan and Huron. Alewives are the main forage for the salmonids in Lake Michigan, and lake whitefish are the most important commercial species in both lakes. Bioenergetics modeling was used to determine consumption by the average individual fish before and after the dreissenid invasion and to provide insight into the invasion's effects on fish growth and food web dynamics. Alewives feed on both Zooplankton and benthic macroinvertebrates, and lake whitefish are benthivores. Annual consumption of zooplankton by an average alewife in Lake Michigan was 37% lower and consumption of benthic macroinvertebrates (amphipods Diporeia spp., opossum shrimp Mysis relicta, and Chironomidae) was 19% lower during the postinvasion period (1995-2005) than during the preinvasion period (1983-1994). Reduced consumption by alewives corresponded with reduced alewife growth. In Lakes Michigan and Huron, consumption of nonmollusk macroinvertebrates (Diporeia spp., opossum shrimp, Chironomidae) by the average lake whitefish was 46-96% lower and consumption of mollusks (mainly dreissenids and gastropods) was 2-5 times greater during the postinvasion period than during the preinvasion period. Even though total food consumption by lake whitefish did not differ between the two periods in Lake Huron or the Southern Management Unit in Lake Michigan, postinvasion weight at age was at least 38% lower than preinvasion weight at age. Under the current postinvasion diet regime, consumption by lake whitefish would have to increase by up to 122% to achieve preinvasion growth rates. ?? Copyright by the American Fisheries Society 2008.

  3. Isolation of deer tick virus (Powassan virus, lineage II) from Ixodes scapularis and detection of antibody in vertebrate hosts sampled in the Hudson Valley, New York State

    PubMed Central

    2013-01-01

    Background Deer tick virus, DTV, is a genetically and ecologically distinct lineage of Powassan virus (POWV) also known as lineage II POWV. Human incidence of POW encephalitis has increased in the last 15 years potentially due to the emergence of DTV, particularly in the Hudson Valley of New York State. We initiated an extensive sampling campaign to determine whether POWV was extant throughout the Hudson Valley in tick vectors and/or vertebrate hosts. Methods More than 13,000 ticks were collected from hosts or vegetation and tested for the presence of DTV using molecular and virus isolation techniques. Vertebrate hosts of Ixodes scapularis (black-legged tick) were trapped (mammals) or netted (birds) and blood samples analyzed for the presence of neutralizing antibodies to POWV. Maximum likelihood estimates (MLE) were calculated to determine infection rates in ticks at each study site. Results Evidence of DTV was identified each year from 2007 to 2012, in nymphal and adult I. scapularis collected from the Hudson Valley. 58 tick pools were positive for virus and/or RNA. Infection rates were higher in adult ticks collected from areas east of the Hudson River. MLE limits ranged from 0.2-6.0 infected adults per 100 at sites where DTV was detected. Virginia opossums, striped skunks and raccoons were the source of infected nymphal ticks collected as replete larvae. Serologic evidence of POWV infection was detected in woodchucks (4/6), an opossum (1/6), and birds (4/727). Lineage I, prototype POWV, was not detected. Conclusions These data demonstrate widespread enzootic transmission of DTV throughout the Hudson Valley, in particular areas east of the river. High infection rates were detected in counties where recent POW encephalitis cases have been identified, supporting the hypothesis that lineage II POWV, DTV, is responsible for these human infections. PMID:24016533

  4. Cortical plasticity following stripe rearing in the marsupial Monodelphis domestica: neural response properties of V1.

    PubMed

    Dooley, James C; Donaldson, Michaela S; Krubitzer, Leah A

    2017-02-01

    The functional organization of the primary visual area (V1) and the importance of sensory experience in its normal development have been well documented in eutherian mammals. However, very few studies have investigated the response properties of V1 neurons in another large class of mammals, or whether sensory experience plays a role in shaping their response properties. Thus we reared opossums (Monodelphis domestica) in normal and vertically striped cages until they reached adulthood. They were then anesthetized using urethane, and electrophysiological techniques were used to examine neuronal responses to different orientations, spatial and temporal frequencies, and contrast levels. For normal opossums, we observed responses to the temporal and spatial characteristics of the stimulus to be similar to those described in small, nocturnal, eutherian mammals such as rats and mice; neurons in V1 responded maximally to stimuli at 0.09 cycles per degree and 2.12 cycles per second. Unlike other eutherians, but similar to other marsupials investigated, only 40% of the neurons were orientation selective. In stripe-reared animals, neurons were significantly more likely to respond to vertical stimuli at a wider range of spatial frequencies, and were more sensitive to gratings at lower contrast values compared with normal animals. These results are the first to demonstrate experience-dependent plasticity in the visual system of a marsupial species. Thus the ability of cortical neurons to alter their properties based on the dynamics of the visual environment predates the emergence of eutherian mammals and was likely present in our earliest mammalian ancestors.

  5. Evolution of mammalian sensorimotor cortex: thalamic projections to parietal cortical areas in Monodelphis domestica.

    PubMed

    Dooley, James C; Franca, João G; Seelke, Adele M H; Cooke, Dylan F; Krubitzer, Leah A

    2014-01-01

    The current experiments build upon previous studies designed to reveal the network of parietal cortical areas present in the common mammalian ancestor. Understanding this ancestral network is essential for highlighting the basic somatosensory circuitry present in all mammals, and how this basic plan was modified to generate species specific behaviors. Our animal model, the short-tailed opossum (Monodelphis domestica), is a South American marsupial that has been proposed to have a similar ecological niche and morphology to the earliest common mammalian ancestor. In this investigation, we injected retrograde neuroanatomical tracers into the face and body representations of primary somatosensory cortex (S1), the rostral and caudal somatosensory fields (SR and SC), as well as a multimodal region (MM). Projections from different architectonically defined thalamic nuclei were then quantified. Our results provide further evidence to support the hypothesized basic mammalian plan of thalamic projections to S1, with the lateral and medial ventral posterior thalamic nuclei (VPl and VPm) projecting to S1 body and S1 face, respectively. Additional strong projections are from the medial division of posterior nucleus (Pom). SR receives projections from several midline nuclei, including the medial dorsal, ventral medial nucleus, and Pom. SC and MM show similar patterns of connectivity, with projections from the ventral anterior and ventral lateral nuclei, VPm and VPl, and the entire posterior nucleus (medial and lateral). Notably, MM is distinguished from SC by relatively dense projections from the dorsal division of the lateral geniculate nucleus and pulvinar. We discuss the finding that S1 of the short-tailed opossum has a similar pattern of projections as other marsupials and mammals, but also some distinct projections not present in other mammals. Further we provide additional support for a primitive posterior parietal cortex which receives input from multiple modalities.

  6. Animal and environmental impact on the presence and distribution of Salmonella and Escherichia coli in hydroponic tomato greenhouses.

    PubMed

    Orozco R, Leopoldo; Iturriaga, Montserrat H; Tamplin, Mark L; Fratamico, Pina M; Call, Jeffrey E; Luchansky, John B; Escartin, Eduardo F

    2008-04-01

    From 2003 to 2004, we studied the impact of environmental influences on the microbiological quality of a hydroponic tomato farm. The presence of Salmonella was investigated on 906 samples of tomatoes and 714 environmental samples. The farm comprised 14 greenhouses and a technologically advanced packinghouse, and operated under a sanitary agricultural practices plan. The objective of the present study was to determine the operating sources of contamination. During the course of the study, two independent natural events affected the farm. In 2003, water runoff entered some of the greenhouses. A year later, wild animals (opossums, mice, and sparrows) gained entry into several of the greenhouses. Salmonella and Escherichia coli were found in samples of tomatoes, water puddles, soil, shoes, and the feces of local wild and farm animals. Salmonella Montevideo, Salmonella Newport, and strains of the F serogroup were isolated from tomatoes. Almost all of the Salmonella Newport strains were isolated from samples collected during or immediately after the flood. Analysis by pulsed-field gel electrophoresis revealed that some Salmonella Montevideo isolates from tomatoes, opossums, and mice displayed identical XbaI or AvrII patterns, suggesting that these wild animals represented one source of contamination. F serogroup strains were found mostly on samples of goat feces and personnel shoes when standard working practices were in place. Shoes were found to be an important vehicle for dissemination of Salmonella into the greenhouses. The level of protection provided by hydroponic greenhouses does not exclude the eventuality that enteric pathogenic bacteria can gain access through various avenues.

  7. Evolution of glyoxylate cycle enzymes in Metazoa: evidence of multiple horizontal transfer events and pseudogene formation

    PubMed Central

    Kondrashov, Fyodor A; Koonin, Eugene V; Morgunov, Igor G; Finogenova, Tatiana V; Kondrashova, Marie N

    2006-01-01

    Background The glyoxylate cycle is thought to be present in bacteria, protists, plants, fungi, and nematodes, but not in other Metazoa. However, activity of the glyoxylate cycle enzymes, malate synthase (MS) and isocitrate lyase (ICL), in animal tissues has been reported. In order to clarify the status of the MS and ICL genes in animals and get an insight into their evolution, we undertook a comparative-genomic study. Results Using sequence similarity searches, we identified MS genes in arthropods, echinoderms, and vertebrates, including platypus and opossum, but not in the numerous sequenced genomes of placental mammals. The regions of the placental mammals' genomes expected to code for malate synthase, as determined by comparison of the gene orders in vertebrate genomes, show clear similarity to the opossum MS sequence but contain stop codons, indicating that the MS gene became a pseudogene in placental mammals. By contrast, the ICL gene is undetectable in animals other than the nematodes that possess a bifunctional, fused ICL-MS gene. Examination of phylogenetic trees of MS and ICL suggests multiple horizontal gene transfer events that probably went in both directions between several bacterial and eukaryotic lineages. The strongest evidence was obtained for the acquisition of the bifunctional ICL-MS gene from an as yet unknown bacterial source with the corresponding operonic organization by the common ancestor of the nematodes. Conclusion The distribution of the MS and ICL genes in animals suggests that either they encode alternative enzymes of the glyoxylate cycle that are not orthologous to the known MS and ICL or the animal MS acquired a new function that remains to be characterized. Regardless of the ultimate solution to this conundrum, the genes for the glyoxylate cycle enzymes present a remarkable variety of evolutionary events including unusual horizontal gene transfer from bacteria to animals. Reviewers Arcady Mushegian (Stowers Institute for Medical

  8. Dramatic variation of the vomeronasal pheromone receptor gene repertoire among five orders of placental and marsupial mammals.

    PubMed

    Grus, Wendy E; Shi, Peng; Zhang, Ya-ping; Zhang, Jianzhi

    2005-04-19

    Pheromones are chemicals emitted and sensed by conspecifics to elicit social and sexual responses and are perceived in terrestrial vertebrates primarily by the vomeronasal organ (VNO). Pheromone receptors in the mammalian VNO are encoded by the V1R and V2R gene superfamilies. The V1R superfamily contains 187 and 102 putatively functional genes in the mouse and rat, respectively. To investigate whether this large repertoire size is typical among mammals with functional VNOs, we here describe the V1R repertoires of dog, cow, and opossum based on their draft genome sequences. The dog and cow have only 8 and 32 intact V1R genes, respectively. Thus, the intact V1R repertoire size varies by at least 23-fold among placental mammals with functional VNOs. To our knowledge, this size ratio represents the greatest among-species variation in gene family size of all mammalian gene families. Phylogenetic analysis of placental V1R genes suggests multiple losses of ancestral genes in carnivores and artiodactyls and gains of many new genes by gene duplication in rodents, manifesting massive gene births and deaths. We also identify 49 intact opossum V1R genes and discover independent expansions of the repertoire in placentals and marsupials. We further show a concordance between the V1R repertoire size and the complexity of VNO morphology, suggesting that the latter could indicate the sophistication of pheromone communications within species. In sum, our results demonstrate tremendous diversity and rapid evolution of mammalian V1R gene inventories and caution the generalization of VNO biology from rodents to all mammals.

  9. Molecular identification and functional characterization of the kisspeptin/kisspeptin receptor system in lower vertebrates.

    PubMed

    Biran, Jakob; Ben-Dor, Shifra; Levavi-Sivan, Berta

    2008-10-01

    The KISS1 gene encodes the kisspeptin neuropeptide, which activates the KISS1 receptor (KISS1R; G protein-coupled receptor 54; GPR54) and participates in neuroendocrine regulation of GnRH secretion. To study the physiological function(s) and evolutionary conservation of KISS1, we cloned opossum, Xenopus, and zebrafish kiss1 cDNAs. Processing zebrafish, Xenopus, or opossum KISS proteins would liberate a carboxy-terminal amidated peptide with 52, 54, or 53 amino acid residues, respectively. Phylogenetic analysis of all known vertebrate KISS1 peptides showed clear clustering of the sequences according to canonical vertebrate classes. The zebrafish kiss1 gene consists of two exons and one intron. Real-time PCR analysis of two kiss1R cloned from zebrafish brain found expression of kiss1, kiss1ra, and kiss1rb, with kiss1ra-more similar to other piscine Kiss1 receptors-highly expressed in the gonads and kiss1rb in other nonbrain tissues. In females kiss1 mRNA levels gradually increased during the first few weeks of life to peak in fish with ovaries containing mature oocytes, while in males kiss1 mRNA levels peaked after 6 wk postfertilization when the testes exhibited initial stages of spermatogenesis and decreased after puberty. Zebrafish kiss1ra and kiss1rb were expressed differentially with similar patterns in both genders. These results indicate that the Kiss1/Kiss1r system may participate in puberty initiation in fish as well. Like human KISS1R, Kiss1ra transduces its activity via the PKC pathway, whereas Kiss1rb does so via both PKC and PKA pathways. The human KISS1R was highly activated by both huKISS10amide and zfKISS10amide, whereas both zebrafish Kiss1 receptor types were less sensitive to amidation.

  10. Epidemiology and potential land-sea transfer of enteric bacteria from terrestrial to marine species in the Monterey Bay Region of California.

    PubMed

    Oates, Stori C; Miller, Melissa A; Byrne, Barbara A; Chouicha, Nadira; Hardin, Dane; Jessup, David; Dominik, Clare; Roug, Annette; Schriewer, Alexander; Jang, Spencer S; Miller, Woutrina A

    2012-07-01

    Marine mammals are at risk for infection by fecal-associated zoonotic pathogens when they swim and feed in polluted nearshore marine waters. Because of their tendency to consume 25-30% of their body weight per day in coastal filter-feeding invertebrates, southern sea otters (Enhydra lutris nereis) can act as sentinels of marine ecosystem health in California. Feces from domestic and wildlife species were tested to determine prevalence, potential virulence, and diversity of selected opportunistic enteric bacterial pathogens in the Monterey Bay region. We hypothesized that if sea otters are sentinels of coastal health, and fecal pollution flows from land to sea, then sea otters and terrestrial animals might share the same enteric bacterial species and strains. Twenty-eight percent of fecal samples tested during 2007-2010 were positive for one or more potential pathogens. Campylobacter spp. were isolated most frequently, with an overall prevalence of 11%, followed by Vibrio cholerae (9%), Salmonella spp. (6%), V. parahaemolyticus (5%), and V. alginolyticus (3%). Sea otters were found positive for all target bacteria, exhibiting similar prevalences for Campylobacter and Salmonella spp. but greater prevalences for Vibrio spp. when compared to terrestrial animals. Fifteen Salmonella serotypes were detected, 11 of which were isolated from opossums. This is the first report of sea otter infection by S. enterica Heidelberg, a serotype also associated with human clinical disease. Similar strains of S. enterica Typhimurium were identified in otters, opossums, and gulls, suggesting the possibility of land-sea transfer of enteric bacterial pathogens from terrestrial sources to sea otters.

  11. Early Developmental and Evolutionary Origins of Gene Body DNA Methylation Patterns in Mammalian Placentas.

    PubMed

    Schroeder, Diane I; Jayashankar, Kartika; Douglas, Kory C; Thirkill, Twanda L; York, Daniel; Dickinson, Pete J; Williams, Lawrence E; Samollow, Paul B; Ross, Pablo J; Bannasch, Danika L; Douglas, Gordon C; LaSalle, Janine M

    2015-08-01

    Over the last 20-80 million years the mammalian placenta has taken on a variety of morphologies through both divergent and convergent evolution. Recently we have shown that the human placenta genome has a unique epigenetic pattern of large partially methylated domains (PMDs) and highly methylated domains (HMDs) with gene body DNA methylation positively correlating with level of gene expression. In order to determine the evolutionary conservation of DNA methylation patterns and transcriptional regulatory programs in the placenta, we performed a genome-wide methylome (MethylC-seq) analysis of human, rhesus macaque, squirrel monkey, mouse, dog, horse, and cow placentas as well as opossum extraembryonic membrane. We found that, similar to human placenta, mammalian placentas and opossum extraembryonic membrane have globally lower levels of methylation compared to somatic tissues. Higher relative gene body methylation was the conserved feature across all mammalian placentas, despite differences in PMD/HMDs and absolute methylation levels. Specifically, higher methylation over the bodies of genes involved in mitosis, vesicle-mediated transport, protein phosphorylation, and chromatin modification was observed compared with the rest of the genome. As in human placenta, higher methylation is associated with higher gene expression and is predictive of genic location across species. Analysis of DNA methylation in oocytes and preimplantation embryos shows a conserved pattern of gene body methylation similar to the placenta. Intriguingly, mouse and cow oocytes and mouse early embryos have PMD/HMDs but their placentas do not, suggesting that PMD/HMDs are a feature of early preimplantation methylation patterns that become lost during placental development in some species and following implantation of the embryo.

  12. Development of the ethmoid in Caluromys philander (Didelphidae, Marsupialia) with a discussion on the homology of the turbinal elements in marsupials.

    PubMed

    Macrini, Thomas E

    2014-11-01

    Homology of turbinals, or scroll bones, of the mammalian ethmoid bone is poorly known and complicated by a varied terminology. Positionally, there are two main types of ossified adult turbinals known as endoturbinals and ectoturbinals, and their cartilaginous precursors are called ethmoturbinals and frontoturbinals, respectively. Endoturbinals are considered to be serially homologous due to similarity in their developmental patterns. Consequently, endoturbinals from mammals with differing numbers of elements cannot be individually homogenized. In this study, the development of the ethmoid of Caluromys philander, the bare-tailed woolly opossum, is described based on serial sections of six pouchlings ranging in age from 20 to 84 days postnatal (PND-84), and computed tomography images of an adult skull. I found that four ethmoturbinals initially develop as seen in PND-20 and PND-30 individuals but by PND-64 an interturbinal (corresponding to endoturbinal III in adults) is present between ethmoturbinals II and III. This developmental pattern is identical to that of Monodelphis domestica, the gray short-tailed opossum, and is probably also present in the marsupials Didelphis marsupialis, and Thylacinus cynocephalus based on work of previous authors. These data suggest that endoturbinal III has a developmental pattern that differs from other endoturbinals, and the name interturbinal should be retained for the adult structure in recognition of this difference. These results may prove useful for homologizing this individual turbinal element across marsupials, the majority of which have five endoturbinals as adults. This might also explain the presumed placental ancestral condition of four endoturbinals if the marsupial interturbinal is lost.

  13. Evolution of mammalian sensorimotor cortex: thalamic projections to parietal cortical areas in Monodelphis domestica

    PubMed Central

    Dooley, James C.; Franca, João G.; Seelke, Adele M. H.; Cooke, Dylan F.; Krubitzer, Leah A.

    2015-01-01

    The current experiments build upon previous studies designed to reveal the network of parietal cortical areas present in the common mammalian ancestor. Understanding this ancestral network is essential for highlighting the basic somatosensory circuitry present in all mammals, and how this basic plan was modified to generate species specific behaviors. Our animal model, the short-tailed opossum (Monodelphis domestica), is a South American marsupial that has been proposed to have a similar ecological niche and morphology to the earliest common mammalian ancestor. In this investigation, we injected retrograde neuroanatomical tracers into the face and body representations of primary somatosensory cortex (S1), the rostral and caudal somatosensory fields (SR and SC), as well as a multimodal region (MM). Projections from different architectonically defined thalamic nuclei were then quantified. Our results provide further evidence to support the hypothesized basic mammalian plan of thalamic projections to S1, with the lateral and medial ventral posterior thalamic nuclei (VPl and VPm) projecting to S1 body and S1 face, respectively. Additional strong projections are from the medial division of posterior nucleus (Pom). SR receives projections from several midline nuclei, including the medial dorsal, ventral medial nucleus, and Pom. SC and MM show similar patterns of connectivity, with projections from the ventral anterior and ventral lateral nuclei, VPm and VPl, and the entire posterior nucleus (medial and lateral). Notably, MM is distinguished from SC by relatively dense projections from the dorsal division of the lateral geniculate nucleus and pulvinar. We discuss the finding that S1 of the short-tailed opossum has a similar pattern of projections as other marsupials and mammals, but also some distinct projections not present in other mammals. Further we provide additional support for a primitive posterior parietal cortex which receives input from multiple modalities. PMID

  14. DNA damage is involved in the induction of opacification and neovascularization of the cornea by ultraviolet radiation.

    PubMed

    Applegate, L A; Ley, R D

    1991-04-01

    Studies were conducted to examine ultraviolet radiation (UVR)-induced alterations of the cornea of the gray, short-tailed opossum. Monodelphis domestica, and the effect of post-UVR illumination to photoreactivation light (PRL, 320-500 nm). As photoreactivation treatment specifically monomerizes pyrimidine dimers, an amelioration of the UVR-induced biological end-point would implicate DNA as being a primary chromophore for induction of that end-point. Corneas of anesthetized, four-month-old, opossums were exposed to 250 J m-2 (0.025 J cm-2) from a Westinghouse FS20 sunlamp either one or three times a week for up to 13 exposures. The corneas of 4-5 animals received either: (a) 90 min of PRL immediately prior to UVR; (b) PRL immediately following UVR; (c) PRL alone; or (d) UVR alone. Eyes were examined with a slit lamp microscope 24 hr following each exposure and scored for the appearance of opacification and neovascularization of the cornea. In animals exposed to UVR alone, 2-5 exposures, depending on whether the exposures were given once or three times per week, were required to obtain opacification and neovascularization in 50% of the irradiated corneas. The onset of both opacification and neovascularization in 50% of the corneas required 8-11 exposures when the UVR was immediately followed by PRL. Based on the specificity of photoreactivation repair to act solely on pyrimidine dimers, these observations suggest that UVR-induced pyrimidine dimers in corneal DNA are involved in UVR-induced opacification and neovascularization of the cornea of Monodelphis domestica.

  15. Dramatic variation of the vomeronasal pheromone receptor gene repertoire among five orders of placental and marsupial mammals

    PubMed Central

    Grus, Wendy E.; Shi, Peng; Zhang, Ya-ping; Zhang, Jianzhi

    2005-01-01

    Pheromones are chemicals emitted and sensed by conspecifics to elicit social and sexual responses and are perceived in terrestrial vertebrates primarily by the vomeronasal organ (VNO). Pheromone receptors in the mammalian VNO are encoded by the V1R and V2R gene superfamilies. The V1R superfamily contains 187 and 102 putatively functional genes in the mouse and rat, respectively. To investigate whether this large repertoire size is typical among mammals with functional VNOs, we here describe the V1R repertoires of dog, cow, and opossum based on their draft genome sequences. The dog and cow have only 8 and 32 intact V1R genes, respectively. Thus, the intact V1R repertoire size varies by at least 23-fold among placental mammals with functional VNOs. To our knowledge, this size ratio represents the greatest among-species variation in gene family size of all mammalian gene families. Phylogenetic analysis of placental V1R genes suggests multiple losses of ancestral genes in carnivores and artiodactyls and gains of many new genes by gene duplication in rodents, manifesting massive gene births and deaths. We also identify 49 intact opossum V1R genes and discover independent expansions of the repertoire in placentals and marsupials. We further show a concordance between the V1R repertoire size and the complexity of VNO morphology, suggesting that the latter could indicate the sophistication of pheromone communications within species. In sum, our results demonstrate tremendous diversity and rapid evolution of mammalian V1R gene inventories and caution the generalization of VNO biology from rodents to all mammals. PMID:15790682

  16. Rickettsial Infection in Animals, Humans and Ticks in Paulicéia, Brazil.

    PubMed

    Silveira, I; Martins, T F; Olegário, M M; Peterka, C; Guedes, E; Ferreira, F; Labruna, M B

    2015-11-01

    A previous study in Paulicéia Municipality, south-eastern Brazil, reported 9.7% of the Amblyomma triste ticks to be infected by Rickettsia parkeri, a bacterial pathogen that causes spotted fever in humans. These A. triste ticks were shown to be associated with marsh areas, where the marsh deer Blastocerus dichotomus is a primary host for this tick species. During 2008-2009, blood serum samples were collected from 140 horses, 41 dogs, 5 opossums (Didelphis albiventris) and 26 humans in farms from Pauliceia Municipality. Ticks were collected from these animals, from vegetation and from additional wildlife in these farms. Overall, 25% (35/140) of the horses, 7.3% (3/41) of the dogs, 3.8% (1/26) of the humans and 100% (5/5) of the opossums were seroreactive (titre ≥64) to spotted fever group (SFG) Rickettsia spp. Multivariate statistical analysis indicated that horses that were allowed to forage in the marsh were 4.8 times more likely to be seroreactive to spotted fever group (SFG) Rickettsia spp than horses that did not forage in the marsh. In addition, horses that had been living in the farm for more than 8.5 years were 2.8 times more likely to be seroreactive to SFG Rickettsia spp than horses that were living for ≤8.5 years. Ticks collected from domestic animals or from vegetation included Amblyomma cajennense, Amblyomma coelebs, Amblyomma dubitatum, Dermacentor nitens and Rhipicephalus microplus. By PCR analyses, only one pool of A. coelebs ticks from the vegetation was shown to be infected by rickettsiae, for which DNA sequencing revealed to be Rickettsia amblyommii. Ticks (not tested by PCR) collected from wildlife encompassed A. cajennense and Amblyomma rotundatum on lizards (Tupinambis sp), and A. cajennense and A. triste on the bird Laterallus viridis. Our results indicate that the marsh area of Paulicéia offers risks of infection by SFG rickettsiae.

  17. Neural progenitor cell transplants into the developing and mature central nervous system.

    PubMed

    Sakaguchi, D S; Van Hoffelen, S J; Grozdanic, S D; Kwon, Y H; Kardon, R H; Young, M J

    2005-05-01

    When developing cell transplant strategies to repair the diseased or injured central nervous system (CNS), it is essential to consider host-graft interactions and how they may influence the outcome of the transplants. Recent studies have demonstrated that transplanted neural progenitor cells (NPCs) can differentiate and integrate morphologically into developing mammalian retinas. Is the ability to differentiate and to undergo structural integration into the CNS unique to specific progenitor cells, or is this plasticity a function of host environment, or both? To address these issues we have used the developing retina of the Brazilian opossum and have compared the structural integration of brain and retinal progenitor cells transplanted into the eyes at different developmental stages. The Brazilian opossum, Monodelphis domestica, is a small pouchless marsupial native to South America. This animal's lack of a pouch and fetal-like nature at birth circumvents the need for in utero surgical procedures, and thus provides an ideal environment in which to study the interactions between developing host tissues and transplanted NPCs. To test whether NPCs affect visual function we transplanted adult hippocampal progenitor cells (AHPCs) into normal, healthy adult rat eyes and performed noninvasive functional recordings. Monitoring of the retina and optic nerve over time by electroretinography and pupillometry revealed no severe perturbation in visual function in the transplant recipient eyes. Taken together, our findings suggest that the age of the host environment can strongly influence NPC differentiation and that transplantation of neural progenitor cells may be a useful strategy aimed at treating neurodegeneration and pathology of the CNS.

  18. Estimating Contact Process Saturation in Sylvatic Transmission of Trypanosoma cruzi in the United States

    PubMed Central

    Kribs-Zaleta, Christopher

    2010-01-01

    Although it has been known for nearly a century that strains of Trypanosoma cruzi, the etiological agent for Chagas' disease, are enzootic in the southern U.S., much remains unknown about the dynamics of its transmission in the sylvatic cycles that maintain it, including the relative importance of different transmission routes. Mathematical models can fill in gaps where field and lab data are difficult to collect, but they need as inputs the values of certain key demographic and epidemiological quantities which parametrize the models. In particular, they determine whether saturation occurs in the contact processes that communicate the infection between the two populations. Concentrating on raccoons, opossums, and woodrats as hosts in Texas and the southeastern U.S., and the vectors Triatoma sanguisuga and Triatoma gerstaeckeri, we use an exhaustive literature review to derive estimates for fundamental parameters, and use simple mathematical models to illustrate a method for estimating infection rates indirectly based on prevalence data. Results are used to draw conclusions about saturation and which population density drives each of the two contact-based infection processes (stercorarian/bloodborne and oral). Analysis suggests that the vector feeding process associated with stercorarian transmission to hosts and bloodborne transmission to vectors is limited by the population density of vectors when dealing with woodrats, but by that of hosts when dealing with raccoons and opossums, while the predation of hosts on vectors which drives oral transmission to hosts is limited by the population density of hosts. Confidence in these conclusions is limited by a severe paucity of data underlying associated parameter estimates, but the approaches developed here can also be applied to the study of other vector-borne infections. PMID:20436914

  19. Regional Extinctions and Quaternary Shifts in the Geographic Range of Lestodelphys halli, the Southernmost Living Marsupial: Clues for Its Conservation

    PubMed Central

    Formoso, Anahí E.; Martin, Gabriel M.; Teta, Pablo; Carbajo, Aníbal E.; Sauthier, Daniel E. Udrizar; Pardiñas, Ulyses F. J.

    2015-01-01

    The Patagonian opossum (Lestodelphys halli), the southernmost living marsupial, inhabits dry and open environments, mainly in the Patagonian steppe (between ~32°S and ~49°S). Its rich fossil record shows its occurrence further north in Central Argentina during the Quaternary. The paleoenvironmental meaning of the past distribution of L. halli has been mostly addressed in a subjective framework without an explicit connection with the climatic “space” currently occupied by this animal. Here, we assessed the potential distribution of this species and the changes occurred in its geographic range during late Pleistocene-Holocene times and linked the results obtained with conservation issues. To this end, we generated three potential distribution models with fossil records and three with current ones, using MaxEnt software. These models showed a decrease in the suitable habitat conditions for the species, highlighting a range shift from Central-Eastern to South-Western Argentina. Our results support that the presence of L. halli in the Pampean region during the Pleistocene-Holocene can be related to precipitation and temperature variables and that its current presence in Patagonia is more related to temperature and dominant soils. The models obtained suggest that the species has been experiencing a reduction in its geographic range since the middle Holocene, a process that is in accordance with a general increase in moisture and temperature in Central Argentina. Considering the findings of our work and the future scenario of global warming projected for Patagonia, we might expect a harsh impact on the distribution range of this opossum in the near future. PMID:26203650

  20. First finding of Trypanosoma cruzi II in vampire bats from a district free of domestic vector-borne transmission in Northeastern Argentina.

    PubMed

    Argibay, Hernán D; Orozco, M Marcela; Cardinal, M Victoria; Rinas, Miguel A; Arnaiz, María; Mena Segura, Carlos; Gürtler, Ricardo E

    2016-09-01

    Establishing the putative links between sylvatic and domestic transmission cycles of Trypanosoma cruzi, the etiological agent of Chagas disease, is of public health relevance. We conducted three surveys to assess T. cruzi infection in wild mammals from a rural and a preserved area in Misiones Province, Northeastern Argentina, which had recently been declared free of vector- and blood-borne transmission of human T. cruzi infection. A total of 200 wild mammals were examined by xenodiagnosis (XD) and/or polymerase chain reaction (PCR) amplification of the hyper-variable region of kinetoplast DNA minicircles of T. cruzi (kDNA-PCR). The overall prevalence of T. cruzi infection was 8%. Nine (16%) of 57 Didelphis albiventris opossums and two (7%) of 29 Desmodus rotundus vampire bats were positive by both XD and kDNA-PCR. Additionally, one D. rotundus positive for T. cruzi by kDNA-PCR tested positive by satellite-DNA-PCR (SAT-DNA-PCR). The T. cruzi-infected bats were captured indoors and in the yard of a vacant dwelling. All D. albiventris were infected with TcI and both XD-positive D. rotundus by TcII. Fifty-five opossum cubs within the marsupium were negative by XD. The mean infectiousness to the vector was 62% in D. albiventris and 50% in D. rotundus. Mice experimentally infected with a parasite isolate from a vampire bat displayed lesions typically caused by T. cruzi. Our study documents the presence of the genotype TcII in a sylvatic host for the first time in Argentina, and the occurrence of two transmission cycles of T. cruzi in a district free of domestic vector-borne transmission.

  1. Emerging factors associated with the decline of a gray fox population and multi-scale land cover associations of mesopredators in the Chicago metropolitan area.

    SciTech Connect

    Willingham, Alison N.; /Ohio State U.

    2008-01-01

    Statewide surveys of furbearers in Illinois indicate gray (Urocyon cinereoargenteus) and red (Vulpes vulpes) foxes have experienced substantial declines in relative abundance, whereas other species such as raccoons (Procyon lotor) and coyotes (Canis latrans) have exhibited dramatic increases during the same time period. The cause of the declines of gray and red foxes has not been identified, and the current status of gray foxes remains uncertain. Therefore, I conducted a large-scale predator survey and tracked radiocollared gray foxes from 2004 to 2007 in order to determine the distribution, survival, cause-specific mortality sources and land cover associations of gray foxes in an urbanized region of northeastern Illinois, and examined the relationships between the occurrence of gray fox and the presence other species of mesopredators, specifically coyotes and raccoons. Although generalist mesopredators are common and can reach high densities in many urban areas their urban ecology is poorly understood due to their secretive nature and wariness of humans. Understanding how mesopredators utilize urbanized landscapes can be useful in the management and control of disease outbreaks, mitigation of nuisance wildlife issues, and gaining insight into how mesopredators shape wildlife communities in highly fragmented areas. I examined habitat associations of raccoons, opossums (Didelphis virginiana), domestic cats (Felis catus), coyotes, foxes (gray and red), and striped skunks (Mephitis mephitis) at multiple spatial scales in an urban environment. Gray fox occurrence was rare and widely dispersed, and survival estimates were similar to other studies. Gray fox occurrence was negatively associated with natural and semi-natural land cover types. Fox home range size increased with increasing urban development suggesting that foxes may be negatively influenced by urbanization. Gray fox occurrence was not associated with coyote or raccoon presence. However, spatial avoidance and

  2. Natural history of Ehrlichia chaffeensis (Rickettsiales: Ehrlichieae) in the piedmont physiographic province of Georgia.

    PubMed

    Lockhart, J M; Davidson, W R; Stallknecht, D E; Dawson, J E; Little, S E

    1997-10-01

    The roles of wild mammals and ticks in the epidemiology of Ehrlichia chaffeensis at a suspected endemic site were investigated using serologic testing, culture, and polymerase chain reaction (PCR) supported by restriction endonuclease analysis and DNA sequencing. Antibodies reactive to E. chaffeensis (> or = 1:64) were detected in 92% of white-tailed deer (Odocoileus virginianus), 21% of raccoons (Procyon lotor), and 8% of opossums (Didelphis virginianus), but not in 8 other species of mammals. Of 7 species of ticks found by host and environmental sampling, Amblyomma americanum was the dominant species, accounting for greater than 99% of all ticks collected. Deer, raccoons, and opossums were the only species parasitized by all life stages of A. americanum, and A. americanum was the only tick parasitizing deer. A nested PCR protocol incorporating E. chaffeensis-specific primers detected E. chaffeensis DNA in blood, lymph nodes, or spleen from 54% of deer examined. The nested PCR detected E. chaffeensis DNA in 6 of 50 (12%) individual adult A. americanum collected from the environment, in 14 of 79 (18%) pools representing 402 adult A. americanum collected from the environment, and in 7 of 25 (28%) pools of mixed stages of A. americanum collected from deer. Although no Ehrlichia spp. were isolated in culture, sequencing of representative amplicons from deer and ticks confirmed PCR products as E. chaffeensis. These data provide strong evidence that white-tailed deer and lone star ticks are the primary reservoir and vector of E. chaffeensis, respectively. The same PCR protocol, incorporating primers specific for an Ehrlichia-like organism of white-tailed deer, detected this organism in blood, lymph nodes, or spleen from 96% of these deer. The Ehrlichia-like organism of deer was detected by PCR from 0 of 50 individual ticks, 7 of 79 (9%) pools, and 1 of 25 (4%) pools of A. americanum collected from deer. Sequencing of representative amplicons from deer and ticks

  3. Forelimb preferences in quadrupedal marsupials and their implications for laterality evolution in mammals

    PubMed Central

    2013-01-01

    Background Acquisition of upright posture in evolution has been argued to facilitate manual laterality in primates. Owing to the high variety of postural habits marsupials can serve as a suitable model to test whether the species-typical body posture shapes forelimb preferences in non-primates or this phenomenon emerged only in the course of primate evolution. In the present study we aimed to explore manual laterality in marsupial quadrupeds and compare them with the results in the previously studied bipedal species. Forelimb preferences were assessed in captive grey short-tailed opossum (Monodelphis domestica) and sugar glider (Petaurus breviceps) in four different types of unimanual behaviour per species, which was not artificially evoked. We examined the possible effects of sex, age and task, because these factors have been reported to affect motor laterality in placental mammals. Results In both species the direction of forelimb preferences was strongly sex-related. Male grey short-tailed opossums showed right-forelimb preference in most of the observed unimanual behaviours, while male sugar gliders displayed only a slight, not significant rightward tendency. In contrast, females in both species exhibited consistent group-level preference of the left forelimb. We failed to reveal significant differences in manual preferences between tasks of potentially differing complexity: reaching a stable food item and catching live insects, as well as between the body support and food manipulation. No influence of subjects’ age on limb preferences was found. Conclusions The direction of sex-related differences in the manual preferences found in quadrupedal marsupials seems to be not typical for placental mammals. We suggest that the alternative way of interhemispheric connection in absence of corpus callosum may result in a fundamentally distinct mechanism of sex effect on limb preferences in marsupials compared to placentals. Our data confirm the idea that non

  4. Diversity, Seasonality, and Context of Mammalian Roadkills in the Southern Great Plains

    NASA Astrophysics Data System (ADS)

    Smith-Patten, Brenda D.; Patten, Michael A.

    2008-06-01

    Thousands of mammals are killed annually from vehicle collisions, making the issue an important one for conservation biologists and environmental managers. We recorded all readily identifiable kills on or immediately adjacent to roads in the southern Great Plains from March 2004-March 2007. We also recorded distance traveled, whether a road was paved or divided, the number of lanes, and prevailing habitat. Surveys were opportunistic and were conducted by car during conditions of good visibility. Over our 239 surveys and >16,500 km traveled, we recorded 1412 roadkills from 18 different mammal species (size ranged from Sciurus squirrels to the white-tailed deer, Odocolieus virginianus). The overall kill rate was 8.50 / 100 km. Four species were prone to collisions: the Virginia opossum ( Didelphis virginiana), nine-banded armadillo ( Dasypus novemcinctus), striped skunk ( Mephitis mephitis), and northern raccoon ( Procyon lotor). Together they accounted for approximately 85% (1198) of all roadkills. Mortality rate differed significantly between 2- and 4-lane roads (8.39 versus 7.79 / 100 km). Kill rates were significantly higher on paved versus unpaved roads (8.60 versus 3.65 / 100 km), but did not depend on whether a road was divided. Roadkills were higher in spring than in fall (1.5×), winter (1.4×), or summer (1.3×). The spring peak (in kills / 100 km) was driven chiefly by the armadillo (2.76 in spring/summer versus 0.73 in autumn/winter) and opossum (2.65 versus 1.47). By contrast, seasonality was dampened by a late winter/early spring peak in skunk mortalities, for which 41% occurred in the 6-week period of mid-February through March. The raccoon did not exhibit a strong seasonal pattern. Our data are consistent with dispersal patterns of these species. Our results underscore the high rate of highway mortality in the southern plains, as well as differences in seasonality and road type that contribute to mortality. Conservation and management efforts should

  5. Southern plains woodrats (Neotoma micropus) from southern Texas are important reservoirs of two genotypes of Trypanosoma cruzi and host of a putative novel Trypanosoma species.

    PubMed

    Charles, Roxanne A; Kjos, Sonia; Ellis, Angela E; Barnes, John C; Yabsley, Michael J

    2013-01-01

    Trypanosoma cruzi, the causative agent of Chagas' disease, is an important public health and veterinary pathogen. Although human cases are rare in the United States, infections in wildlife, and in some areas domestic dogs, are common. In 2008 and 2010, we investigated T. cruzi prevalence in possible vertebrate reservoirs in southern Texas, with an emphasis on southern plains woodrats (Neotoma micropus). Infection status was determined using a combination of culture isolation, polymerase chain reaction (PCR), and serologic testing. Based on PCR and/or culture, T. cruzi was detected in 35 of 104 (34%) woodrats, 3 of 4 (75%) striped skunks (Mephitis mephitis), 12 of 20 (60%) raccoons (Procyon lotor), and 5 of 28 (18%) other rodents including a hispid cotton rat (Sigmodon hispidus), rock squirrel (Otospermophilus variegatus), black rat (Rattus rattus), and two house mice (Mus musculus). Additionally, another Trypanosoma species was detected in 41 woodrats, of which 27 were co-infected with T. cruzi. Genetic characterization of T. cruzi revealed that raccoon, rock squirrel, and cotton rat isolates were genotype TcIV, while woodrats and skunks were infected with TcI and TcIV. Based on the Chagas Stat-Pak assay, antibodies were detected in 27 woodrats (26%), 13 raccoons (65%), 4 skunks (100%), and 5 other rodents (18%) (two white-ankled mice [Peromyscus pectoralis laceianus], two house mice, and a rock squirrel). Seroprevalence based on indirect immunofluorescence antibody testing was higher for both woodrats (37%) and raccoons (90%), compared with the Chagas Stat-Pak. This is the first report of T. cruzi in a hispid cotton rat, black rat, rock squirrel, and white-ankled mouse. These data indicate that based on culture and PCR testing, the prevalence of T. cruzi in woodrats is comparable with other common reservoirs (i.e., raccoons and opossums) in the United States. However, unlike raccoons and opossums, which tend to be infected with a particular genotype, southern

  6. The unique paired retinal vascular pattern in marsupials: structural, functional and evolutionary perspectives based on observations in a range of species

    PubMed Central

    McMenamin, Paul G

    2007-01-01

    Background In the few marsupial species studied to date that possess a retinal vasculature, the arterial and venous segments, down to the smallest calibre capillaries, have been shown to occur in pairs. It is a pattern seen in the marsupial central nervous system (CNS) but not in other tissues in this group or in any tissues in eutherian mammals. The aim of the present study was to investigate the presence of retinal vessels in a range of non‐eutherian mammalian species (marsupials and monotremes) and to determine if the pattern of paired vessels was a widespread phenomenon within this animal group. Methods Species studied included a monotreme, the short‐billed echidna (Tachyglossus aculeatus) and a range of Australian marsupials, the honey possum (Tarispedidae rostratus), fat‐tailed dunnart (Sminthopsis crassicaudata), grey‐bellied dunnart (Sminthopsis griseoventer), numbat (Myrmecobius fasciatus), broad‐footed marsupial mouse (Antechinus godmani) and the North American opossum (Didelphis virginiana). Eyes were fixed in glutaraldehyde or paraformaldehyde and retinas were embedded in resin for light and electron microscopic analysis. Results Examination revealed that in those species with retinal vessels (fat‐tailed dunnart, grey‐bellied dunnart, numbat, marsupial mouse, North American opossum) the pattern of vessels differs from the conventional plexus‐like arrangement of mammalian retinal vasculature (that is, anastomotic networks of capillaries between arterioles and venules). In marsupials retinal vessels always occur in closely related pairs, with the arteriolar limb usually situated on the vitread aspect. Vessels penetrate the retina and branch to form layers of paired capillaries as far as the outer nuclear layer in some species. The capillaries form blind‐ended hairpin loops and display classical morphological features of CNS capillaries Conclusion The phylogenetic relations of this vascular pattern in the marsupial CNS and retina, and in

  7. Direct molecular identification of Trypanosoma cruzi discrete typing units in domestic and peridomestic Triatoma infestans and Triatoma sordida from the Argentine Chaco.

    PubMed

    Maffey, L; Cardinal, M V; Ordóñez-Krasnowski, P C; Lanati, L A; Lauricella, M A; Schijman, A G; Gürtler, R E

    2012-10-01

    We assessed the distribution of Trypanosoma cruzi Discrete Typing Units (DTUs) in domestic and peridomestic Triatoma infestans and Triatoma sordida specimens collected in a well-defined rural area in Pampa del Indio, northeastern Argentina. Microscopically-positive bugs were randomly selected with a multi-level sampling design, and DTUs were identified using direct PCR strategies. TcVI predominated in 61% of 69 T. infestans and in 56% of 9 T. sordida. TcV was the secondary DTU in T. infestans (16%) and was found in 1 T. sordida specimen (11%). Three T. sordida (33%) were found infected with TcI, a DTU also identified in local Didelphis albiventris opossums. Mixed DTU infections occurred rarely (5%) and were detected both directly from the bugs' rectal ampoule and parasite cultures. The identified DTUs and bug collection sites of T. infestans were significantly associated. Bugs infected with TcV were almost exclusively captured in domiciles whereas those with TcVI were found similarly in domiciles and peridomiciles. All mixed infections occurred in domiciles. TcV-infected bugs fed more often on humans than on dogs, whereas TcVI-infected bugs showed the reverse pattern. T. sordida is a probable sylvatic vector of TcI linked to D. albiventris, and could represent a secondary vector of TcVI and TcV in the domestic/peridomestic cycle.

  8. Direct molecular identification of Trypanosoma cruzi Discrete Typing Units in domestic and peridomestic Triatoma infestans and Triatoma sordida from the Argentine Chaco

    PubMed Central

    MAFFEY, L.; CARDINAL, M.V.; ORDÓÑEZ-KRASNOWSKI, P.C.; LANATI, L.A.; LAURICELLA, M.A.; SCHIJMAN, A.G.; GÜRTLER, R.E.

    2013-01-01

    SUMMARY We assessed the distribution of Trypanosoma cruzi Discrete Typing Units (DTUs) in domestic and peridomestic Triatoma infestans and Triatoma sordida specimens collected in a well-defined rural area in Pampa del Indio, northeastern Argentina. Microscopically-positive bugs were randomly selected with a multi-level sampling design, and DTUs were identified using direct PCR strategies. TcVI predominated in 61% of 69 T. infestans and in 56% of 9 T. sordida. TcV was the secondary DTU in T. infestans (16%) and was found in one T. sordida specimen (11%). Three T. sordida (33%) were found infected with TcI, a DTU also identified in local Didelphis albiventris opossums. Mixed DTU infections occurred rarely (5%) and were detected both directly from the bugs’ rectal ampoule and parasite cultures. The identified DTUs and bug collection sites of T. infestans were significantly associated. Bugs infected with TcV were almost exclusively captured in domiciles whereas those with TcVI were found similarly in domiciles and peridomiciles. All mixed infections occurred in domiciles. TcV-infected bugs fed more often on humans than on dogs, whereas TcVI-infected bugs showed the reverse pattern. T. sordida is a probable sylvatic vector of TcI linked to D. albiventris, and could represent a secondary vector of TcVI and TcV in the domestic/peridomestic cycle. PMID:23036510

  9. An In Silico Insight into Novel Therapeutic Interaction of LTNF Peptide-LT10 and Design of Structure Based Peptidomimetics for Putative Anti-Diabetic Activity

    PubMed Central

    Chavan, Sonali Gopichand; Deobagkar, Deepti Dileep

    2015-01-01

    Lethal Toxin Neutralizing Factor (LTNF) obtained from Opossum serum (Didephis virginiana) is known to exhibit toxin-neutralizing activity for envenomation caused by animals, plants and bacteria. Small synthetic peptide- LT10 (10mer) derived from N-terminal fraction of LTNF exhibit similar anti-lethal and anti-allergic property. In our in silico study, we identified Insulin Degrading Enzyme (IDE) as a potential target of LT10 peptide followed by molecular docking and molecular dynamic (MD) simulation studies which revealed relatively stable interaction of LT10 peptide with IDE. Moreover, their detailed interaction analyses dictate IDE-inhibitory interactions of LT10 peptide. This prediction ofLT10 peptide as a novel putative IDE-inhibitor suggests its possible role in anti-diabetic treatment since IDE- inhibitors are known to assist treatment of Diabetes mellitus by enhancing insulin signalling. Furthermore, series of structure based peptidomimetics were designed from LT10 peptide and screened for their inhibitory interactions which ultimately led to a small set of peptidomimetic inhibitors of IDE. These peptidomimetic thus might provide a new class of IDE-inhibitors, those derived from LT10 peptide. PMID:25816209

  10. Masticatory motor programs in Australian herbivorous mammals: diprotodontia.

    PubMed

    Crompton, Alfred W

    2011-08-01

    Movement of the jaw during molar occlusion is determined by the sequence of activity in the adductor muscles and this sequence is one way to define a masticatory motor program. Based on the similarity of molar structure, it is probable that the American opossum and the early Tertiary mammals that gave rise to all Australian marsupials probably shared a common "primitive" masticatory motor program. The distinct and various patterns of movement of the jaw in the major groups of Australian marsupial herbivores (diprotodontids) are achieved by both subtle and substantial shifts in the timing of the primitive sequence. All diprotodonts divide jaw movements during occlusion into a vertical Phase Im and horizontal Phase IIm, but the number of muscles involved and the level of activity associated with each phase varies considerably. In macropodids (potoroos and kangaroos) Phase Im dominates; in wombats Phase IIm dominates and in koalas the two phases are more evenly divided, with a more equal distribution of muscles between them. The motor program of koalas parallels that of some placental ungulates, while both macropodids and wombats have motor programs unique among mammals.

  11. Feeding preferences of Lutzomyia longipalpis (Diptera: Psychodidae), the sand fly vector, for Leishmania infantum (Kinetoplastida: Trypanosomatidae).

    PubMed

    Macedo-Silva, Virgínia P; Martins, Daniella R A; De Queiroz, Paula Vivianne Souza; Pinheiro, Marcos Paulo G; Freire, Caio C M; Queiroz, José W; Dupnik, Kathryn M; Pearson, Richard D; Wilson, Mary E; Jeronimo, Selma M B; Ximenes, Maria De Fátima F M

    2014-01-01

    Leishmania infantum, the causative agent of visceral leishmaniasis (VL) in Brazil, is spread mostly by the bite of the sand fly Lutzomyia longipalpis (Lutz & Neiva). We trapped sand flies in endemic neighborhoods near Natal, Brazil, where cases of human and dog VL were documented. Amplification of species-specific cytochrome b (Cyt b) genes by polymerase chain reaction revealed that sand flies from rural and periurban areas harbored blood from different sources. The most common source ofbloodmeal was human, but blood from dog, chicken, and armadillo was also present. We tested the preference for a source of bloodmeal experimentally by feeding L. longipalpis F1 with blood from different animals. There were significant differences between the proportion of flies engorged and number of eggs laid among flies fed on different sources, varying from 8.4 to 19 (P < 0.0001). Blood from guinea pig or horse was best to support sand fly oviposition, but human blood also supported sand fly oviposition well. No sand flies fed on cats, and sand flies feeding on the opossum Monodelphis domestica Wagner produced no eggs. These data support the hypothesis that L. longipalpis is an eclectic feeder, and humans are an important source of blood for this sand fly species in periurban areas of Brazil.

  12. Thalamo-striatal projections in the hedgehog tenrec.

    PubMed

    Künzle, Heinz

    2006-07-19

    Unlike the basal ganglia input from the midline and intralaminar nuclei, the origin and prominence of striatal projections arising in the lateral thalamus varies considerably among mammals being most restricted in the opossum and monkey, most extensive in the rat. To get further insight into the evolution of thalamo-striatal pathways the Madagascar lesser hedgehog tenrec (Afrotheria) was investigated using anterograde and retrograde flow techniques. An extensive medial thalamic region (including presumed equivalents to the paraventricular, parataenial and dorsomedial nuclei as well as the reuniens complex), the rostral (central) and caudal (parafascicular) intralaminar nuclei were shown to give rise to striatal projections. Additional projections originated in the ventral anterolateral nuclear group and regions within and around the medial geniculate complex. Similar to the rat there was also substantial projections from the lateral posterior-pulvinar complex and the ventral posterior nucleus. The fibers terminated extensively across the striatum in a mainly homogeneous fashion. Isolated patches of low-density terminations were found in the caudoputamen. This inhomogeneous labeling pattern appeared similar to one described in the cat with the unlabeled islands showing features of striosomes. The medial and intralaminar nuclei also projected heavily upon the olfactory tubercle. Differential innervation patterns were noted in the polymorphous layer, the deep and the superficial molecular layer.

  13. Transposition and Intermingling of Galphai2 and Galphao afferences into single vomeronasal glomeruli in the Madagascan lesser Tenrec Echinops telfairi.

    PubMed

    Suárez, Rodrigo; Villalón, Aldo; Künzle, Heinz; Mpodozis, Jorge

    2009-11-24

    The vomeronasal system (VNS) mediates pheromonal communication in mammals. From the vomeronasal organ, two populations of sensory neurons, expressing either Galphai2 or Galphao proteins, send projections that end in glomeruli distributed either at the rostral or caudal half of the accessory olfactory bulb (AOB), respectively. Neurons at the AOB contact glomeruli of a single subpopulation. The dichotomic segregation of AOB glomeruli has been described in opossums, rodents and rabbits, while Primates and Laurasiatheres present the Galphai2-pathway only, or none at all (such as apes, some bats and aquatic species). We studied the AOB of the Madagascan lesser tenrec Echinops telfairi (Afrotheria: Afrosoricida) and found that Galphai2 and Galphao proteins are expressed in rostral and caudal glomeruli, respectively. However, the segregation of vomeronasal glomeruli at the AOB is not exclusive, as both pathways contained some glomeruli transposed into the adjoining subdomain. Moreover, some glomeruli seem to contain intermingled afferences from both pathways. Both the transposition and heterogeneity of vomeronasal afferences are features, to our knowledge, never reported before. The organization of AOB glomeruli suggests that synaptic integration might occur at the glomerular layer. Whether intrinsic AOB neurons may make synaptic contact with axon terminals of both subpopulations is an interesting possibility that would expand our understanding about the integration of vomeronasal pathways.

  14. Discovery of alpha-defensins in basal mammals.

    PubMed

    Lynn, David J; Bradley, Daniel G

    2007-01-01

    Alpha-defensins are essential molecules of the innate immune system that have broad spectrum antimicrobial activity against a range of bacteria and viruses. To date, alpha-defensins have only been identified in the Euarchontoglires branch of the mammals. This has led to speculation that alpha-defensins may be specific to this group, a somewhat surprising finding, given their importance in the immune system. The mammalian genome project provided us with the opportunity to search for alpha-defensins in previously unexamined mammalian superorders. Using hidden Markov model (HMM) profile searching, we report the discovery of alpha-defensins in the African savanna elephant, the lesser hedgehog tenrec, and the nine-banded armadillo genomes representing two of the most basal mammalian superorders, Afrotheria and Xenarthra. Furthermore, we identify an alpha-defensin-like gene in the gray short-tailed opossum, suggesting that alpha-defensins may have evolved much earlier than previously thought, before the divergence of placental mammals and marsupials approximately 130 mya.

  15. Tracing thalamo-cortical connections in tenrecA further attempt to characterize poorly differentiated neocortical regions, particularly the motor cortex.

    PubMed

    Künzle, Heinz

    2009-02-09

    The hedgehog tenrec (Afrosoricidae) has a very poorly differentiated neocortex. Previously its primary sensory regions have been characterized with hodological and electrophysiological techniques. Unlike the marsupial opossum the tenrec may also have a separate motor area as far as there are cortico-spinal cells located rostral to the primary somatosensory cortex. However, not knowing its thalamic input it may be premature to correlate this area with the true (mirror-image-like) primary motor cortex in higher mammals. For this reason the tenrec's thalamo-cortical connections were studied following tracer injections into various neocortical regions. The main sensory areas were confirmed by their afferents from the principal thalamic nuclei. The dorsal lateral geniculate nucleus, in addition, was connected with the retrosplenial area and a rostromedial visual region. Unlike the somatosensory cortex the presumed motor area did not receive afferents from the ventrobasal thalamus but fibers from the cerebello-thalamic target regions. These projections, however, were not restricted to the motor area, but involved the entire somatosensorimotor field as well as adjacent regions. The projections appeared similar to those arising in the rat thalamic ventromedial nucleus known to have a supporting function rather than a specific motor task. The question was raised whether the input from the basal ganglia might play a crucial role in the evolution of the mammalian motor cortex? Certainly, in the tenrec, the poor differentiation of the motor cortex coincides with the virtual absence of an entopeduncular projection to the ventrolateral thalamus.

  16. Development and embryonic staging in non-model organisms: the case of an afrotherian mammal.

    PubMed

    Werneburg, Ingmar; Tzika, Athanasia C; Hautier, Lionel; Asher, Robert J; Milinkovitch, Michel C; Sánchez-Villagra, Marcelo R

    2013-01-01

    Studies of evolutionary developmental biology commonly use 'model organisms' such as fruit flies or mice, and questions are often functional or epigenetic. Phylogenetic investigations, in contrast, typically use species that are less common and mostly deal with broad scale analyses in the tree of life. However, important evolutionary transformations have taken place at all taxonomic levels, resulting in such diverse forms as elephants and shrews. To understand the mechanisms underlying morphological diversification, broader sampling and comparative approaches are paramount. Using a simple, standardized protocol, we describe for the first time the development of soft tissues and some parts of the skeleton, using μCT-imaging of developmental series of Echinops telfairi and Tenrec ecaudatus, two tenrecid afrotherian mammals. The developmental timing of soft tissue and skeletal characters described for the tenrecids is briefly compared with that of other mammals, including mouse, echidna, and the opossum. We found relatively few heterochronic differences in development in the armadillo vs. tenrec, consistent with a close relationship of Xenarthra and Afrotheria. Ossification in T. ecaudatus continues well into the second half of overall gestation, resembling the pattern seen in other small mammals and differing markedly from the advanced state of ossification evident early in the gestation of elephants, sheep, and humans.

  17. Repeated horizontal transfer of a DNA transposon in mammals and other tetrapods.

    PubMed

    Pace, John K; Gilbert, Clément; Clark, Marlena S; Feschotte, Cédric

    2008-11-04

    Horizontal transfer (HT) is central to the evolution of prokaryotic species. Selfish and mobile genetic elements, such as phages, plasmids, and transposons, are the primary vehicles for HT among prokaryotes. In multicellular eukaryotes, the prevalence and evolutionary significance of HT remain unclear. Here, we identified a set of DNA transposon families dubbed SPACE INVADERS (or SPIN) whose consensus sequences are approximately 96% identical over their entire length (2.9 kb) in the genomes of murine rodents (rat/mouse), bushbaby (prosimian primate), little brown bat (laurasiatherian), tenrec (afrotherian), opossum (marsupial), and two non-mammalian tetrapods (anole lizard and African clawed frog). In contrast, SPIN elements were undetectable in other species represented in the sequence databases, including 19 other mammals with draft whole-genome assemblies. This patchy distribution, coupled with the extreme level of SPIN identity in widely divergent tetrapods and the overall lack of selective constraint acting on these elements, is incompatible with vertical inheritance, but strongly indicative of multiple horizontal introductions. We show that these germline infiltrations likely occurred around the same evolutionary time (15-46 mya) and spawned some of the largest bursts of DNA transposon activity ever recorded in any species lineage (nearly 100,000 SPIN copies per haploid genome in tenrec). The process also led to the emergence of a new gene in the murine lineage derived from a SPIN transposase. In summary, HT of DNA transposons has contributed significantly to shaping and diversifying the genomes of multiple mammalian and tetrapod species.

  18. Large Mesozoic mammals fed on young dinosaurs.

    PubMed

    Hu, Yaoming; Meng, Jin; Wang, Yuanqing; Li, Chuankui

    2005-01-13

    Mesozoic mammals are commonly portrayed as shrew- or rat-sized animals that were mainly insectivorous, probably nocturnal and lived in the shadow of dinosaurs. The largest known Mesozoic mammal represented by substantially complete remains is Repenomamus robustus, a triconodont mammal from the Lower Cretaceous of Liaoning, China. An adult individual of R. robustus was the size of a Virginia opossum. Here we report a new species of the genus, represented by a skeleton with most of the skull and postcranium preserved in articulation. The new species is 50% larger than R. robustus in skull length. In addition, stomach contents associated with a skeleton of R. robustus reveal remains of a juvenile Psittacosaurus, a ceratopsian dinosaur. Our discoveries constitute the first direct evidence that some triconodont mammals were carnivorous and fed on small vertebrates, including young dinosaurs, and also show that Mesozoic mammals had a much greater range of body sizes than previously known. We suggest that Mesozoic mammals occupied diverse niches and that some large mammals probably competed with dinosaurs for food and territory.

  19. Prevalence of antibodies to Toxoplasma gondii in wild mammals of Missouri and east central Kansas: biologic and ecologic considerations of transmission.

    PubMed

    Smith, D D; Frenkel, J K

    1995-01-01

    Sera from 273 wild mammals from Missouri and Kansas (USA), collected between December 1974 and December 1987, were tested for the presence of antibodies to Toxoplasma gondii using the Sabin-Feldman dye test. Sixty-five (24%) had antibodies at titers of > or = 1:8, including 38 (66%) of 58 carnivores, 14 (15%) of 94 omnivores, 13 (11%) of 117 herbivores, and none of four insectivores. The prevalence of antibodies in mice (Mus musculus and Peromyscus spp.) and rats (Rattus norvegicus and Sigmodon hispidus) was low (3%), while medium sized herbivores such as squirrels (Sciurus spp.), rabbits (Sylvilagus floridanus), and muskrats (Ondatra zibethicus) had prevalences of about 18%. Red foxes (Vulpes fulva) and mink (Mustela vison) had the highest prevalence of antibodies with frequencies of 90 and 66%, respectively. In 32 attempts to isolate Toxoplasma gondii from wild mammals with positive (> or = 1:4) titers, only six (19%) were successful: a gray squirrel (Sciurus carolinensis), a beaver (Castor canadensis), an opossum (Didelphis marsupialis), a red fox and two mink. These findings are consistent with the hypothesis that the probability of infection with Toxoplasma gondii, and therefore prevalence of antibodies in wildlife, is greatest in carnivores.

  20. Trichinella infection in wild animals from endemic regions of Argentina.

    PubMed

    Ribicich, Mabel; Gamble, H R; Bolpe, Jorge; Scialfa, Exequiel; Krivokapich, Silvio; Cardillo, Natalia; Betti, Adriana; Holzmann, Maria Laura Cambiaggi; Pasqualetti, Mariana; Fariña, Fernando; Rosa, Adriana

    2010-07-01

    Natural infection with Trichinella has been described in more than 150 mammalian species. However, few reports of Trichinella infection in wild animals have come from Argentina. In this study, muscle tissue was obtained from wild animals in Argentina with the aim of evaluating the presence of Trichinella. A total of 169 muscle samples were collected to determine the presence of Trichinella larvae by artificial digestion. The 169 muscle samples originated from 12 species including 36 opossums (Didelphis albiventris), 19 armadillos (Chaetophractus villosus), 9 capybaras (Hydrocaeris hydrocaeris), 1 puma (Puma concolor), 3 grey fox (Lycalopex gymnocercus), 6 coypus (Myocastor coypus), 6 skunks (Conepatus chinga), 2 ferrets (Galictis cuja), 66 rats (Rattus norvegicus), 6 mice (Mus musculus), 12 wild boars (Sus scrofa), and 3 wild cats (Felis geoffroyi). Trichinella infection was detected in 1 puma [2 larvae per gram (LPG)], 3 wild boars (8-420 LPG), 3 armadillos (0.04-0.08 LPG), and 9 rats (0.1 to 150 LPG). Only 3 Trichinella isolates, of 1 rat and 2 wild boars from Neuquén, were identified as Trichinella spiralis by nested PCR. The presence of Trichinella infection among wild animal populations suggests a sylvatic cycle of transmission in Argentina, which can serve as a reservoir for humans and domestic animals. Further, evidence of high prevalence in rats emphasizes the need to improve pig management, mainly in small individual farms without adequate technology, to enhance the quality of feeds, and to improve veterinary services to avoid exposure of pigs to Trichinella.

  1. Structural and functional analyses of DM43, a snake venom metalloproteinase inhibitor from Didelphis marsupialis serum.

    PubMed

    Neves-Ferreira, Ana G C; Perales, Jonas; Fox, Jay W; Shannon, John D; Makino, Débora L; Garratt, Richard C; Domont, Gilberto B

    2002-04-12

    DM43, an opossum serum protein inhibitor of snake venom metalloproteinases, has been completely sequenced, and its disulfide bond pattern has been experimentally determined. It shows homology to human alpha(1)B-glycoprotein, a plasma protein of unknown function and a member of the immunoglobulin supergene family. Size exclusion and dynamic laser light scattering data indicated that two monomers of DM43, each composed of three immunoglobulin-like domains, associated to form a homodimer in solution. Analysis of its glycan moiety showed the presence of N-acetylglucosamine, mannose, galactose, and sialic acid, most probably forming four biantennary N-linked chains. DM43 inhibited the fibrinogenolytic activities of bothrolysin and jararhagin and formed 1:1 stoichiometric stable complexes with both metalloproteinases. DM43 was ineffective against atrolysin C or A. No complex formation was detected between DM43 and jararhagin C, indicating the essential role of the metalloproteinase domain for interaction. Homology modeling based on the crystal structure of a killer cell inhibitory receptor suggested the existence of an I-type Ig fold, a hydrophobic dimerization surface and six surface loops potentially forming the metalloproteinase-binding surface on DM43.

  2. The Araguaia River as an Important Biogeographical Divide for Didelphid Marsupials in Central Brazil.

    PubMed

    Rocha, Rita Gomes; Ferreira, Eduardo; Loss, Ana Carolina; Heller, Rasmus; Fonseca, Carlos; Costa, Leonora Pires

    2015-01-01

    The riverine barrier model suggests that rivers play a significant role in separating widespread organisms into isolated populations. In this study, we used a comparative approach to investigate the phylogeography of 6 didelphid marsupial species in central Brazil. Specifically, we evaluate the role of the mid-Araguaia River in differentiating populations and estimate divergence time among lineages to assess the timing of differentiation of these species, using mitochondrial DNA sequence data. The 6 didelphid marsupials revealed different intraspecific genetic patterns and structure. The 3 larger and more generalist species, Didelphis albiventris, Didelphis marsupialis, and Philander opossum, showed connectivity across the Araguaia River. In contrast the genetic structure of the 3 smaller and specialist species, Gracilinanus agilis, Marmosa (Marmosa) murina, and Marmosa (Micoureus) demerarae was shaped by the mid-Araguaia. Moreover, the split of eastern and western bank populations of the 2 latter species is consistent with the age of Araguaia River sediments formation. We hypothesize that the role of the Araguaia as a riverine barrier is linked to the level of ecological specialization among the 6 didelphid species and differences in their ability to cross rivers or disperse through the associated habitat types.

  3. Natural phospholipase A(2) myotoxin inhibitor proteins from snakes, mammals and plants.

    PubMed

    Lizano, Sergio; Domont, Gilberto; Perales, Jonas

    2003-12-15

    A renewed interest in the phenomenon of inter- and intra-species resistance towards the toxicity of snake venoms, coupled with the search for new strategies for treatment of snake envenomations, has prompted the discovery of proteins which neutralize the major toxic components of these venoms. Among these emerging groups of proteins are inhibitors of toxic phospholipases A2 (PLA2s), many of which exhibit a wide range of toxic effects including muscle-tissue damage, neurotoxicity, and inflammation. These proteins have been isolated from both venomous and non-venomous snakes, mammals, and most recently from medicinal plant extracts. The snake blood-derived inhibitors have been grouped into three major classes, alpha, beta, and gamma, based on common structural motifs found in other proteins with diverse physiological properties. In mammals, DM64, an anti-myotoxic protein isolated from opossum serum, belongs to the immunoglobulin super gene family and is homologous to human alpha1B-glycoprotein and DM43, a metalloproteinase inhibitor from the same organism. In plants, a short note is made of WSG, a newly described anti-toxic-PLA2 glycoprotein isolated from Withania somnifera (Ashwaganda), a medicinal plant whose aqueous extracts neutralize the PLA2 activity of the Naja naja venom. The implications of these new groups of PLA2 toxin inhibitors in the context of our current understanding of snake biology as well as in the development of novel therapeutic reagents in the treatment of snake envenomations worldwide are discussed.

  4. The Relationship between Gene Network Structure and Expression Variation among Individuals and Species

    PubMed Central

    Sears, Karen E.; Maier, Jennifer A.; Rivas-Astroza, Marcelo; Poe, Rachel; Zhong, Sheng; Kosog, Kari; Marcot, Jonathan D.; Behringer, Richard R.; Rasweiler, John J.; Rapti, Zoi

    2015-01-01

    Abstract Variation among individuals is a prerequisite of evolution by natural selection. As such, identifying the origins of variation is a fundamental goal of biology. We investigated the link between gene interactions and variation in gene expression among individuals and species using the mammalian limb as a model system. We first built interaction networks for key genes regulating early (outgrowth; E9.5–11) and late (expansion and elongation; E11-13) limb development in mouse. This resulted in an Early (ESN) and Late (LSN) Stage Network. Computational perturbations of these networks suggest that the ESN is more robust. We then quantified levels of the same key genes among mouse individuals and found that they vary less at earlier limb stages and that variation in gene expression is heritable. Finally, we quantified variation in gene expression levels among four mammals with divergent limbs (bat, opossum, mouse and pig) and found that levels vary less among species at earlier limb stages. We also found that variation in gene expression levels among individuals and species are correlated for earlier and later limb development. In conclusion, results are consistent with the robustness of the ESN buffering among-individual variation in gene expression levels early in mammalian limb development, and constraining the evolution of early limb development among mammalian species. PMID:26317994

  5. Severe mammal declines coincide with proliferation of invasive Burmese pythons in Everglades National Park

    USGS Publications Warehouse

    Dorcas, Michael E.; Wilson, John D.; Reed, Robert N.; Snow, Ray W.; Rochford, Michael R.; Miller, Melissa A.; Meshaka, Walter E.; Andreadis, Paul T.; Mazzotti, Frank J.; Romagosa, Christina M.; Hart, Kristen M.

    2012-01-01

    Invasive species represent a significant threat to global biodiversity and a substantial economic burden. Burmese pythons, giant constricting snakes native to Asia, now are found throughout much of southern Florida, including all of Everglades National Park (ENP). Pythons have increased dramatically in both abundance and geographic range since 2000 and consume a wide variety of mammals and birds. Here we report severe apparent declines in mammal populations that coincide temporally and spatially with the proliferation of pythons in ENP. Before 2000, mammals were encountered frequently during nocturnal road surveys within ENP. In contrast, road surveys totaling 56,971 km from 2003–2011 documented a 99.3% decrease in the frequency of raccoon observations, decreases of 98.9% and 87.5% for opossum and bobcat observations, respectively, and failed to detect rabbits. Road surveys also revealed that these species are more common in areas where pythons have been discovered only recently and are most abundant outside the python's current introduced range. These findings suggest that predation by pythons has resulted in dramatic declines in mammals within ENP and that introduced apex predators, such as giant constrictors, can exert significant top-down pressure on prey populations. Severe declines in easily observed and/or common mammals, such as raccoons and bobcats, bode poorly for species of conservation concern, which often are more difficult to sample and occur at lower densities.

  6. Trypanosoma (Megatrypanum) lainsoni n. sp. from Mesomys hispidus (Rodentia: Echimyidae) in Brazil: trypomastigotes described from experimentally infected laboratory mice.

    PubMed

    Naiff, Roberto Daibes; Barrett, Toby Vincent

    2013-01-01

    We report the detection, isolation and description of Trypanosoma (Megatrypanum) lainsoni n. sp. from a caviomorph rodent, Mesomys hispidus (Rodentia: Echimyidae), obtained in the Rio Negro region of the state of Amazonas, in northern Brazil. Laboratory-bred white mice (Mus musculus) and rats (Rattus rattus) were inoculated with large numbers of culture forms by intraperitoneal route, and trypomastigotes appeared in their blood 3-8 days post-inoculation. One single epimastigote was also found in Mus musculus. Similar attempts to infect Rattus norvegicus, hamsters (Mesocricetus auratus), the opossum Didelphis marsupialis, the anteater Tamandua tetradactyla and triatomine bugs were unsuccessful, following six months of observations and microscopic examinations of blood films and blood cultures. As we have found no previous record of a Trypanosoma (Megatrypanum) species naturally infecting a member of the family Echimyidae, or any other caviomorph rodent, we conclude that this is the first time such an infection has been reported. The new species is unusual in the subgenus for its infectivity to laboratory mice.

  7. Long-term effects of a trophic cascade in a large lake ecosystem.

    PubMed

    Ellis, Bonnie K; Stanford, Jack A; Goodman, Daniel; Stafford, Craig P; Gustafson, Daniel L; Beauchamp, David A; Chess, Dale W; Craft, James A; Deleray, Mark A; Hansen, Barry S

    2011-01-18

    Introductions or invasions of nonnative organisms can mediate major changes in the trophic structure of aquatic ecosystems. Here we document multitrophic level impacts in a spatially extensive system that played out over more than a century. Positive interactions among exotic vertebrate and invertebrate predators caused a substantial and abrupt shift in community composition resulting in a trophic cascade that extended to primary producers and to a nonaquatic species, the bald eagle. The opossum shrimp, Mysis diluviana, invaded Flathead Lake, Montana, the largest freshwater lake in the western United States. Lake trout had been introduced 80 y prior but remained at low densities until nonnative Mysis became established. The bottom-dwelling mysids eliminated a recruitment bottleneck for lake trout by providing a deep water source of food where little was available previously. Lake trout subsequently flourished on mysids and this voracious piscivore now dominates the lake fishery; formerly abundant kokanee were extirpated, and native bull and westslope cutthroat trout are imperiled. Predation by Mysis shifted zooplankton and phytoplankton community size structure. Bayesian change point analysis of primary productivity (27-y time series) showed a significant step increase of 55 mg C m(-2) d(-1) (i.e., 21% rise) concurrent with the mysid invasion, but little trend before or after despite increasing nutrient loading. Mysis facilitated predation by lake trout and indirectly caused the collapse of kokanee, redirecting energy flow through the ecosystem that would otherwise have been available to other top predators (bald eagles).

  8. A comparative study of lymph node mast cell populations in five marsupial species.

    PubMed

    Chiarini-Garcia, H; Pereira, F M

    1999-06-01

    In order to determine whether different subpopulations of mast cells exist, mast cells of mandibular and axillary lymph nodes from five species (Didelphis aurita, Metachirus nudicaudatus, Philander opossum, Marmosops incanus and Gracilinanus agilis) of South American marsupials were studied. Our results showed that mast cells present in the connective tissue of the capsule and septa (CTMC) were similar to those described for eutherian mammals. However, a population of mast cells that was present in the lymphatic sinuses and bathed by the lymph, plus in direct contact with granulocytes, lymphocytes, macrophages, and reticular cells, were morphologically and histochemically different from the CTMC. In the five species studied, these cellular types, called lymphatic-sinus mast cells (LSMC), had a lower concentration of intragranular heparin and, in four of the five species, the cytoplasmic granules appeared to be larger than those in CTMC. Although LSMC have been rarely described in eutherian mammals, it was verified, in this study, that LSMC are nevertheless present in lymphatic sinuses of the five metatherian species studied. These observations suggest that the presence of LSMC may be a characteristic of the marsupials and important in the immune response and adaptive success of the Didelphidae.

  9. Trypanosoma cruzi and Chagas' Disease in the United States

    PubMed Central

    Bern, Caryn; Kjos, Sonia; Yabsley, Michael J.; Montgomery, Susan P.

    2011-01-01

    Summary: Chagas' disease is caused by the protozoan parasite Trypanosoma cruzi and causes potentially life-threatening disease of the heart and gastrointestinal tract. The southern half of the United States contains enzootic cycles of T. cruzi, involving 11 recognized triatomine vector species. The greatest vector diversity and density occur in the western United States, where woodrats are the most common reservoir; other rodents, raccoons, skunks, and coyotes are also infected with T. cruzi. In the eastern United States, the prevalence of T. cruzi is highest in raccoons, opossums, armadillos, and skunks. A total of 7 autochthonous vector-borne human infections have been reported in Texas, California, Tennessee, and Louisiana; many others are thought to go unrecognized. Nevertheless, most T. cruzi-infected individuals in the United States are immigrants from areas of endemicity in Latin America. Seven transfusion-associated and 6 organ donor-derived T. cruzi infections have been documented in the United States and Canada. As improved control of vector- and blood-borne T. cruzi transmission decreases the burden in countries where the disease is historically endemic and imported Chagas' disease is increasingly recognized outside Latin America, the United States can play an important role in addressing the altered epidemiology of Chagas' disease in the 21st century. PMID:21976603

  10. Development and embryonic staging in non-model organisms: the case of an afrotherian mammal

    PubMed Central

    Werneburg, Ingmar; Tzika, Athanasia C; Hautier, Lionel; Asher, Robert J; Milinkovitch, Michel C; Sánchez-Villagra, Marcelo R

    2013-01-01

    Studies of evolutionary developmental biology commonly use ‘model organisms’ such as fruit flies or mice, and questions are often functional or epigenetic. Phylogenetic investigations, in contrast, typically use species that are less common and mostly deal with broad scale analyses in the tree of life. However, important evolutionary transformations have taken place at all taxonomic levels, resulting in such diverse forms as elephants and shrews. To understand the mechanisms underlying morphological diversification, broader sampling and comparative approaches are paramount. Using a simple, standardized protocol, we describe for the first time the development of soft tissues and some parts of the skeleton, using μCT-imaging of developmental series of Echinops telfairi and Tenrec ecaudatus, two tenrecid afrotherian mammals. The developmental timing of soft tissue and skeletal characters described for the tenrecids is briefly compared with that of other mammals, including mouse, echidna, and the opossum. We found relatively few heterochronic differences in development in the armadillo vs. tenrec, consistent with a close relationship of Xenarthra and Afrotheria. Ossification in T. ecaudatus continues well into the second half of overall gestation, resembling the pattern seen in other small mammals and differing markedly from the advanced state of ossification evident early in the gestation of elephants, sheep, and humans. PMID:22537021

  11. IN-VIVO DIAGNOSIS OF CHEMICALLY INDUCED MELANOMA IN AN ANIMAL MODEL USING UV-VISIBLE AND NIR ELASTIC SCATTERING SPECTROSCOPY: PRELIMINARY TESTING.

    SciTech Connect

    C. A'AMAR; R. LEY; ET AL

    2001-01-01

    Elastic light scattering spectroscopy (ESS) has the potential to provide spectra that contain both morphological and chromophore information from tissue. We report on a preliminary study of this technique, with the hope of developing a method for diagnosis of highly-pigmented skin lesions, commonly associated with skin cancer. Four opossums were treated with dimethylbenz(a)anthracene to induce both malignant melanoma and benign pigmented lesions. Skin lesions were examined in vivo using both UV-visible and near infrared (NIR) ESS, with wavelength ranges of 330-900 nm and 900-1700 nm, respectively. Both portable systems used identical fiber-optic probe geometry throughout all of the measurements. The core diameters for illuminating and collecting fibers were 400 and 200 {micro}m, respectively, with center-to-center separation of 350 {micro}m. The probe was placed in optical contact with the tissue under investigation. Biopsies from lesions were analyzed by two standard histopathological procedures. Taking into account only the biopsied lesions, UV-visible ESS showed distinct spectral correlation for 11/13 lesions. The NIR-ESS correlated well with 12/13 lesions correctly. The results of these experiments showed that UV-visible and NIR-ESS have the potential to classify benign and malignant skin lesions, with encouraging agreement to that provided by standard histopathological examination. These initial results show potential for ESS based diagnosis of pigmented skin lesions, but further trials are required in order to substantiate the technique.

  12. Characterization and evolution of vertebrate indoleamine 2, 3-dioxygenases IDOs from monotremes and marsupials.

    PubMed

    Yuasa, Hajime J; Ball, Helen J; Ho, Yuen Fern; Austin, Christopher J D; Whittington, Camilla M; Belov, Katherine; Maghzal, Ghassan J; Jermiin, Lars S; Hunt, Nicholas H

    2009-06-01

    Indoleamine 2,3-dioxygenase (IDO1) and tryptophan 2,3-dioxygenase (TDO) are tryptophan-degrading enzymes that catalyze the first step in tryptophan catabolism via the kynurenine pathway. TDO is widely distributed in both eukaryotes and bacteria. In contrast, IDO has been found only in mammals and yeast. In 2007, a third enzyme, indoleamine 2,3-dioxygenase-2 (IDO2), was discovered. IDO2 is found not only in mammals but also in lower vertebrates. Interestingly, the Km value of IDO2 for L-Trp was 500-1000 fold higher than that of IDO1. In this study, we isolated both IDO1 and IDO2 cDNA from a monotreme, the platypus (Ornithorhynchus anatinus), and a marsupial, the gray short-tailed opossum (Monodelphis domestica). We characterized the recombinant proteins and those of other known IDO1/IDO2 in intact cells and a cell-free system. It was found that methylene blue may not be suitable reductant for IDO2, hence resulting in an underestimation of recombinant IDO2 activity. In intact cells, the Km value of IDO2 for L-Trp was estimated to be much higher than that of IDO1 and this high Km value appears to have been conserved during the evolution of IDO2. The protein encoded by the ancestor gene of IDO1 and IDO2 is likely to have had properties more similar to present day IDO2 than to IDO1.

  13. Characterization and evolution of vertebrate indoleamine 2, 3-dioxygenases IDOs from monotremes and marsupials.

    PubMed

    Yuasa, Hajime J; Ball, Helen J; Ho, Yuen Fern; Austin, Christopher J D; Whittington, Camilla M; Belov, Katherine; Maghzal, Ghassan J; Jermiin, Lars S; Hunt, Nicholas H

    2009-06-01

    Indoleamine 2,3-dioxygenase (IDO1) and tryptophan 2,3-dioxygenase (TDO) are tryptophan-degrading enzymes that catalyze the first step in tryptophan catabolism via the kynurenine pathway. TDO is widely distributed in both eukaryotes and bacteria. In contrast, IDO has been found only in mammals and yeast. In 2007, a third enzyme, indoleamine 2,3-dioxygenase-2 (IDO2), was discovered. IDO2 is found not only in mammals but also in lower vertebrates. Interestingly, the K(m) value of IDO2 for L-Trp was 500-1000 fold higher than that of IDO1. In this study, we isolated both IDO1 and IDO2 cDNA from a monotreme, the platypus (Ornithorhynchus anatinus), and a marsupial, the gray short-tailed opossum (Monodelphis domestica). We characterized the recombinant proteins and those of other known IDO1/IDO2 in intact cells and a cell-free system. It was found that methylene blue may not be suitable reductant for IDO2, hence resulting in an underestimation of recombinant IDO2 activity. In intact cells, the K(m) value of IDO2 for L-Trp was estimated to be much higher than that of IDO1 and this high K(m) value appears to have been conserved during the evolution of IDO2. The protein encoded by the ancestor gene of IDO1 and IDO2 is likely to have had properties more similar to present day IDO2 than to IDO1.

  14. MAP17 Is a Necessary Activator of Renal Na+/Glucose Cotransporter SGLT2.

    PubMed

    Coady, Michael J; El Tarazi, Abdulah; Santer, René; Bissonnette, Pierre; Sasseville, Louis J; Calado, Joaquim; Lussier, Yoann; Dumayne, Christopher; Bichet, Daniel G; Lapointe, Jean-Yves

    2017-01-01

    The renal proximal tubule reabsorbs 90% of the filtered glucose load through the Na(+)-coupled glucose transporter SGLT2, and specific inhibitors of SGLT2 are now available to patients with diabetes to increase urinary glucose excretion. Using expression cloning, we identified an accessory protein, 17 kDa membrane-associated protein (MAP17), that increased SGLT2 activity in RNA-injected Xenopus oocytes by two orders of magnitude. Significant stimulation of SGLT2 activity also occurred in opossum kidney cells cotransfected with SGLT2 and MAP17. Notably, transfection with MAP17 did not change the quantity of SGLT2 protein at the cell surface in either cell type. To confirm the physiologic relevance of the MAP17-SGLT2 interaction, we studied a cohort of 60 individuals with familial renal glucosuria. One patient without any identifiable mutation in the SGLT2 coding gene (SLC5A2) displayed homozygosity for a splicing mutation (c.176+1G>A) in the MAP17 coding gene (PDZK1IP1). In the proximal tubule and in other tissues, MAP17 is known to interact with PDZK1, a scaffolding protein linked to other transporters, including Na(+)/H(+) exchanger 3, and to signaling pathways, such as the A-kinase anchor protein 2/protein kinase A pathway. Thus, these results provide the basis for a more thorough characterization of SGLT2 which would include the possible effects of its inhibition on colocalized renal transporters.

  15. Sources of Blood Meals of Sylvatic Triatoma guasayana near Zurima, Bolivia, Assayed with qPCR and 12S Cloning

    PubMed Central

    Lucero, David E.; Ribera, Wilma; Pizarro, Juan Carlos; Plaza, Carlos; Gordon, Levi W.; Peña, Reynaldo; Morrissey, Leslie A.; Rizzo, Donna M.; Stevens, Lori

    2014-01-01

    Background In this study we compared the utility of two molecular biology techniques, cloning of the mitochondrial 12S ribosomal RNA gene and hydrolysis probe-based qPCR, to identify blood meal sources of sylvatic Chagas disease insect vectors collected with live-bait mouse traps (also known as Noireau traps). Fourteen T. guasayana were collected from six georeferenced trap locations in the Andean highlands of the department of Chuquisaca, Bolivia. Methodology/Principal Findings We detected four blood meals sources with the cloning assay: seven samples were positive for human (Homo sapiens), five for chicken (Gallus gallus) and unicolored blackbird (Agelasticus cyanopus), and one for opossum (Monodelphis domestica). Using the qPCR assay we detected chicken (13 vectors), and human (14 vectors) blood meals as well as an additional blood meal source, Canis sp. (4 vectors). Conclusions/Significance We show that cloning of 12S PCR products, which avoids bias associated with developing primers based on a priori knowledge, detected blood meal sources not previously considered and that species-specific qPCR is more sensitive. All samples identified as positive for a specific blood meal source by the cloning assay were also positive by qPCR. However, not all samples positive by qPCR were positive by cloning. We show the power of combining the cloning assay with the highly sensitive hydrolysis probe-based qPCR assay provides a more complete picture of blood meal sources for insect disease vectors. PMID:25474154

  16. Isolation and characterization of marsupial IL5 genes.

    PubMed

    Hawken, R J; Maccarone, P; Toder, R; Marshall Graves, J A; Maddox, J F

    1999-10-01

    The genomic nucleotide sequence and chromosomal position of the interleukin 5 (IL5) gene has been described for the model marsupial Macropus eugenii (tammar wallaby). A 272 base pair genomic IL5 polymerase chain reaction (PCR) product spanning exon 3, intron 3, and exon 4 was generated using stripe-faced dunnart (Sminthopsis macroura) DNA. This PCR product was used to isolate a genomic lambda clone containing the complete IL5 gene from a tammar wallaby EMBL3 lambda library. Sequencing revealed that the tammar wallaby IL5 gene consists of four exons separated by three introns. Comparison of the marsupial coding sequence with coding sequences from eutherian species revealed 61 to 69% identity at the nucleotide level and 48 to 63% identity at the amino acid (aa) level. A polymorphic complex compound microsatellite was identified within intron 2 of the tammar wallaby IL5 gene. This microsatellite was also found in other marsupials including the swamp wallaby, tree kangaroo, stripe-faced dunnart, South American opossum, brushtail possum, and koala. Fluorescence in situ hybridization using DNA from the IL5 clone on tammar wallaby chromosomes indicated that the IL5 gene is located on Chromosome 1.

  17. Using genomic data to unravel the root of the placental mammal phylogeny

    PubMed Central

    Murphy, William J.; Pringle, Thomas H.; Crider, Tess A.; Springer, Mark S.; Miller, Webb

    2007-01-01

    The phylogeny of placental mammals is a critical framework for choosing future genome sequencing targets and for resolving the ancestral mammalian genome at the nucleotide level. Despite considerable recent progress defining superordinal relationships, several branches remain poorly resolved, including the root of the placental tree. Here we analyzed the genome sequence assemblies of human, armadillo, elephant, and opossum to identify informative coding indels that would serve as rare genomic changes to infer early events in placental mammal phylogeny. We also expanded our species sampling by including sequence data from >30 ongoing genome projects, followed by PCR and sequencing validation of each indel in additional taxa. Our data provide support for a sister-group relationship between Afrotheria and Xenarthra (the Atlantogenata hypothesis), which is in turn the sister-taxon to Boreoeutheria. We failed to recover any indels in support of a basal position for Xenarthra (Epitheria), which is suggested by morphology and a recent retroposon analysis, or a hypothesis with Afrotheria basal (Exafricoplacentalia), which is favored by phylogenetic analysis of large nuclear gene data sets. In addition, we identified two retroposon insertions that also support Atlantogenata and none for the alternative hypotheses. A revised molecular timescale based on these phylogenetic inferences suggests Afrotheria and Xenarthra diverged from other placental mammals ∼103 (95–114) million years ago. We discuss the impacts of this topology on earlier phylogenetic reconstructions and repeat-based inferences of phylogeny. PMID:17322288

  18. Receptor-mediated endocytosis of albumin by kidney proximal tubule cells is regulated by phosphatidylinositide 3-kinase.

    PubMed Central

    Brunskill, N J; Stuart, J; Tobin, A B; Walls, J; Nahorski, S

    1998-01-01

    Receptor-mediated endocytosis of albumin is an important function of the kidney proximal tubule epithelium. We have measured endocytosis of [125I]-albumin in opossum kidney cells and examined the regulation of this process by phosphatidylinositide 3-kinase (PI 3-kinase). Albumin endocytosis was inhibited by both wortmannin (IC50 6.9 nM) and LY294002 (IC50 6.5 microM) at concentrations that suggested the involvement of PI 3-kinase in its regulation. Recycling rates were unaffected. We transfected OK cells with either a wild-type p85 subunit of PI 3-kinase, or a dominant negative form of the p85 subunit (Deltap85) using the LacSwitch expression system. Transfects were screened by immunoblotting with anti-PI 3-kinase antibodies. Under basal conditions, transfects demonstrated no expression of p85 or Deltap85, but expression was briskly induced by treatment of the cells with IPTG (EC50 13.7 microM). Inhibition of PI 3-kinase activity by Deltap85 was confirmed by in vitro kinase assay of anti-phosphotyrosine immunoprecipitates from transfected cells stimulated with insulin. Expression of Deltap85 resulted in marked inhibition of albumin endocytosis, predominantly as a result of reduction of the Vmax of the transport process. Expression of p85 had no significant effect on albumin uptake. The results demonstrate that PI 3-kinase regulates an early step in the receptor-mediated endocytosis of albumin by kidney proximal tubular cells. PMID:9593770

  19. Development of marine toxicity data for ordnance compounds

    USGS Publications Warehouse

    Nipper, M.; Carr, R.S.; Biedenbach, J.M.; Hooten, R.L.; Miller, K.; Saepoff, S.

    2001-01-01

    A toxicity database for ordnance compounds was generated using eight compounds of concern and marine toxicity tests with five species from different phyla. Toxicity tests and endpoints included fertilization success and embryological development with the sea urchin Arbacia punctulata; zoospore germination, germling length, and cell number with the green macroalga Ulva fasciata; survival and reproductive success of the polychaete Dinophilus gyrociliatus; larvae hatching and survival with the redfish Sciaenops ocellatus; and survival of juveniles of the opossum shrimp Americamysis bahia (formerly Mysidopsis bahia). The studied ordnance compounds were 2,4- and 2,6-dinitrotoluene, 2,4,6-trinitrotoluene, 1,3-dinitrobenzene, 1,3,5-trinitrobenzene, 2,4,6-trinitrophenylmethylnitramine (tetryl), 2,4,6-trinitrophenol (picric acid), and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). The most sensitive toxicity test endpoints overall were the macroalga zoospore germination and the polychaete reproduction tests. The most toxic ordnance compounds overall were tetryl and 1,3,5-trinitrobenzene. These were also the most degradable compounds, often being reduced to very low or below-detection levels at the end of the test exposure. Among the dinitro- and trinitrotoluenes and benzenes, toxicity tended to increase with the level of nitrogenation. Picric acid and RDX were the least toxic chemicals tested overall.

  20. The evolution of vertebrate Toll-like receptors

    USGS Publications Warehouse

    Roach, J.C.; Glusman, G.; Rowen, L.; Kaur, A.; Purcell, M.K.; Smith, K.D.; Hood, L.E.; Aderem, A.

    2005-01-01

    The complete sequences of Takifugu Toll-like receptor (TLR) loci and gene predictions from many draft genomes enable comprehensive molecular phylogenetic analysis. Strong selective pressure for recognition of and response to pathogen-associated molecular patterns has maintained a largely unchanging TLR recognition in all vertebrates. There are six major families of vertebrate TLRs. This repertoire is distinct from that of invertebrates. TLRs within a family recognize a general class of pathogen-associated molecular patterns. Most vertebrates have exactly one gene ortholog for each TLR family. The family including TLR1 has more species-specific adaptations than other families. A major family including TLR11 is represented in humans only by a pseudogene. Coincidental evolution plays a minor role in TLR evolution. The sequencing phase of this study produced finished genomic sequences for the 12 Takifugu rubripes TLRs. In addition, we have produced > 70 gene models, including sequences from the opossum, chicken, frog, dog, sea urchin, and sea squirt. ?? 2005 by The National Academy of Sciences of the USA.

  1. Using DNA Barcodes to Identify Road-Killed Animals in Two Atlantic Forest Nature Reserves, Brazil

    PubMed Central

    Klippel, Angélica H.; Oliveira, Pablo V.; Britto, Karollini B.; Freire, Bárbara F.; Moreno, Marcel R.; dos Santos, Alexandre R.; Banhos, Aureo; Paneto, Greiciane G.

    2015-01-01

    Road mortality is the leading source of biodiversity loss in the world, especially due to fragmentation of natural habitats and loss of wildlife. The survey of the main species victims of roadkill is of fundamental importance for the better understanding of the problem, being necessary, for this, the correct species identification. The aim of this study was to verify if DNA barcodes can be applied to identify road-killed samples that often cannot be determined morphologically. For this purpose, 222 vertebrate samples were collected in a stretch of the BR-101 highway that crosses two Discovery Coast Atlantic Forest Natural Reserves, the Sooretama Biological Reserve and the Vale Natural Reserve, in Espírito Santo, Brazil. The mitochondrial COI gene was amplified, sequenced and confronted with the BOLD database. It was possible to identify 62.16% of samples, totaling 62 different species, including Pyrrhura cruentata, Chaetomys subspinosus, Puma yagouaroundi and Leopardus wiedii considered Vulnerable in the National Official List of Species of Endangered Wildlife. The most commonly identified animals were a bat (Molossus molossus), an opossum (Didelphis aurita) and a frog (Trachycephalus mesophaeus) species. Only one reptile was identified using the technique, probably due to lack of reference sequences in BOLD. These data may contribute to a better understanding of the impact of roads on species biodiversity loss and to introduce the DNA barcode technique to road ecology scenarios. PMID:26244644

  2. Imaging Serotonergic Fibers in the Mouse Spinal Cord Using the CLARITY/CUBIC Technique.

    PubMed

    Liang, Huazheng; Schofield, Emma; Paxinos, George

    2016-02-26

    Long descending fibers to the spinal cord are essential for locomotion, pain perception, and other behaviors. The fiber termination pattern in the spinal cord of the majority of these fiber systems have not been thoroughly investigated in any species. Serotonergic fibers, which project to the spinal cord, have been studied in rats and opossums on histological sections and their functional significance has been deduced based on their fiber termination pattern in the spinal cord. With the development of CLARITY and CUBIC techniques, it is possible to investigate this fiber system and its distribution in the spinal cord, which is likely to reveal previously unknown features of serotonergic supraspinal pathways. Here, we provide a detailed protocol for imaging the serotonergic fibers in the mouse spinal cord using the combined CLARITY and CUBIC techniques. The method involves perfusion of a mouse with a hydrogel solution and clarification of the tissue with a combination of clearing reagents. Spinal cord tissue was cleared in just under two weeks, and the subsequent immunofluorescent staining against serotonin was completed in less than ten days. With a multi-photon fluorescent microscope, the tissue was scanned and a 3D image was reconstructed using Osirix software.

  3. Diffraction-Enhanced Imaging for studying pattern recognition in cranial ontogeny of bats and marsupials

    NASA Astrophysics Data System (ADS)

    Rocha, H. S.; Lopes, R. T.; Pessôa, L. M.; Hönnicke, M. G.; Tirao, G.; Cusatis, C.; Mazzaro, I.; Giles, C.

    2005-08-01

    The key to understanding evolution lies in the elucidation of mechanisms responsible for the observed underlying patterns and in the observation of sequences that emerge from those evolutionary landmarks. The comparative development can be used to access the derivation of form and the homology versus the convergence of evolution features. Phylogenetic and biological homologies are necessary to discern the evolutionary origins of these features. This work examined the patterns of cranial formation in pre-born bat specimens as well as post-born opossum by means of microradiography and Diffraction-Enhanced Radiography (DER) techniques. A direct conversion CCD camera was used to provide micrometer spatial resolution in order to acquire highly detailed density images. This technique allows the observation of structures, in early stages of development, which were impossible to be observed with traditional techniques, such as clearing and staining. Some cranial features have been described for adults in the literature, but the detailed description of the appearance sequence of those features in these species is still unknown and obscure. Microradiography and diffraction-enhanced imaging can improve quality of morphological detail analysis and permit the identification of anatomical landmarks that are useful in comparative studies and are still unknown in both species. In this study, we access evolution features in cranial morphology of bats and marsupials using both X-ray techniques.

  4. Chemical defense in harvestmen (arachnida, opiliones): do benzoquinone secretions deter invertebrate and vertebrate predators?

    PubMed

    Machado, Glauco; Carrera, Patricia C; Pomini, Armando M; Marsaioli, Anita J

    2005-11-01

    Two alkylated 1,4-benzoquinones were identified from the defensive secretion produced by the neotropical harvestman Goniosoma longipes (Gonyleptidae). They were characterized as 2,3-dimethyl-1,4-benzoquinone and 2-ethyl-3-methyl-1,4-benzoquinone. We tested the effectiveness of these benzoquinone secretions against several predator types, including invertebrates and vertebrates. Different predators were exposed to the harvestmen's gland secretion or to distilled water in laboratory bioassays. Our results indicate that secretions containing the 1,4-benzoquinones released by G. longipes can be an effective defense against predation, and that the effectiveness of the secretion is dependent on the predator type. The scent gland secretion repelled seven ant species, two species of large wandering spiders, and one frog species, but was not an effective defense against an opossum. Our study also demonstrates that the scent gland secretion of G. longipes can work as a chemical shield preventing the approach of three large predatory ants for at least 10 min. The chemical shield may protect the harvestman against successive attacks of the same ant worker and also allow the harvestman to flee before massive ant recruitment. Our data support the suggestion that chemical defenses may increase survival with some but not all potential predators. This variation in defense effectiveness may result from many interacting factors, including the attack strategy, size, learning ability, and physiology of the predators, as well as the chemical nature of the defensive compounds, type of emission, and amount of effluent released by the prey.

  5. Eco-epidemiological aspects of Trypanosoma cruzi, Trypanosoma rangeli and their vector (Rhodnius pallescens) in Panama.

    PubMed

    Vasquez, Ana Maria de; Samudio, Franklyn E; Saldaña, Azael; Paz, Hector M; Calzada, José E

    2004-01-01

    The eco-epidemiology of T. cruzi infection was investigated in the Eastern border of the Panama Canal in Central Panama. Between 1999 and 2000, 1110 triatomines were collected: 1050 triatomines (94.6%) from palm trees, 27 (2.4%) from periurban habitats and 33 (3.0%) inside houses. All specimens were identified as R. pallescens. There was no evidence of vector domiciliation. Salivary glands from 380 R. pallescens revealed a trypanosome natural infection rate of 7.6%, while rectal ampoule content from 373 triatomines was 45%. Isoenzyme profiles on isolated trypanosomes demonstrated that 85.4% (n = 88) were T. cruzi and 14.6% (n = 15) were T. rangeli. Blood meal analysis from 829 R. pallescens demonstrated a zoophilic vector behavior, with opossums as the preferential blood source. Seroprevalence in human samples from both study sites was less than 2%. Our results demonstrate that T. cruzi survives in the area in balanced association with R. pallescens, and with several different species of mammals in their natural niches. However, the area is an imminent risk of infection for its population, consequently it is important to implement a community educational program regarding disease knowledge and control measures.

  6. Integration of the mammalian shoulder girdle within populations and over evolutionary time.

    PubMed

    Sears, K E; Bianchi, C; Powers, L; Beck, A L

    2013-07-01

    Morphological integration has the potential to link morphological variation within populations with morphological evolution among species. This study begins to investigate this link by comparing integration among shoulder girdle elements (e.g. scapular blade, glenoid, coracoid, etc.) during the origin and evolution of therian mammals, and within modern bat, opossum and mouse populations. In this study, correlations among skeletal elements and patterns of allometry are used as proxies for integration. Results suggest that shoulder girdle elements tended to vary and evolve independently during the origin of mammals and subsequent radiation of placentals, consistent with the elements' distinct developmental and evolutionary origins. This finding suggests that skeletal element correlations, and therefore integration, can be conserved over large taxonomic and temporal scales. However, marsupials display a different pattern in which shoulder girdle elements tend to be more integrated, with the exception of the coracoid. This finding is consistent with a shift in the pattern of skeletal element integration coincident with the appearance of the marsupial mode of reproduction. This finding provides further evidence that development can play a significant role in the establishment of patterns of skeletal element correlation and that patterns of skeletal element correlation can themselves evolve when faced with sufficient selective pressures.

  7. Comparative aspects of subplate zone studied with gene expression in sauropsids and mammals.

    PubMed

    Wang, Wei Zhi; Oeschger, Franziska M; Montiel, Juan F; García-Moreno, Fernando; Hoerder-Suabedissen, Anna; Krubitzer, Leah; Ek, Carl Joakim; Saunders, Norman R; Reim, Kerstin; Villalón, Aldo; Molnár, Zoltán

    2011-10-01

    There is currently a debate about the evolutionary origin of the earliest generated cortical preplate neurons and their derivatives (subplate and marginal zone). We examined the subplate with murine markers including nuclear receptor related 1 (Nurr1), monooxygenase Dbh-like 1 (Moxd1), transmembrane protein 163 (Tmem163), and connective tissue growth factor (Ctgf) in developing and adult turtle, chick, opossum, mouse, and rat. Whereas some of these are expressed in dorsal pallium in all species studied (Nurr1, Ctgf, and Tmem163), we observed that the closely related mouse and rat differed in the expression patterns of several others (Dopa decarboxylase, Moxd1, and thyrotropin-releasing hormone). The expression of Ctgf, Moxd1, and Nurr1 in the oppossum suggests a more dispersed subplate population in this marsupial compared with mice and rats. In embryonic and adult chick brains, our selected subplate markers are primarily expressed in the hyperpallium and in the turtle in the main cell dense layer of the dorsal cortex. These observations suggest that some neurons that express these selected markers were present in the common ancestor of sauropsids and mammals.

  8. Diets and trophic-guild structure of a diverse fish assemblage in Chesapeake Bay, U.S.A.

    PubMed

    Buchheister, A; Latour, R J

    2015-03-01

    Dietary habits and trophic-guild structure were examined in a fish assemblage (47 species) of the Chesapeake Bay estuary, U.S.A., using 10 years of data from >25 000 fish stomachs. The assemblage was comprised of 10 statistically significant trophic guilds that were principally differentiated by the relative amounts of Mysida, Bivalvia, Polychaeta, Teleostei and other Crustacea in the diets. These guilds were broadly aggregated into five trophic categories: piscivores, zooplanktivores, benthivores, crustacivores and miscellaneous consumers. Food web structure was largely dictated by gradients in habitat (benthic to pelagic) and prey size. Size classes within piscivorous species were more likely to be classified into different guilds, reflecting stronger dietary changes through ontogeny relative to benthivores and other guilds. Relative to predator species and predator size, the month of sampling had negligible effects on dietary differences within the assemblage. A majority of sampled fishes derived most of their nutrition from non-pelagic prey sources, suggesting a strong coupling of fish production to benthic and demersal food resources. Mysida (predominantly the opossum shrimp Neomysis americana) contributed substantially to the diets of over 25% of the sampled predator groups, indicating that this species is a critical, but underappreciated, node in the Chesapeake Bay food web.

  9. Cellular transfer of macromolecules across the developing choroid plexus of Monodelphis domestica.

    PubMed

    Liddelow, Shane A; Dziegielewska, Katarzyna M; Ek, C Joakim; Johansson, Pia A; Potter, Ann M; Saunders, Norman R

    2009-01-01

    Choroid plexus epithelial cells secrete cerebrospinal fluid (CSF) and transfer molecules from blood into CSF. Tight junctions between choroidal epithelial cells are functionally effective from early in development: the route of transfer is suggested to be transcellular. Routes of transfer for endogenous and exogenous plasma proteins and dextrans were studied in Monodelphis domestica (opossum). Pups at postnatal (P) days 1-65 and young adults were injected with biotinylated dextrans (3-70 kDa) and/or foetal protein fetuin. CSF, plasma and brain samples were collected from terminally anaesthetized animals. Choroid plexus cells containing plasma proteins were detected immunocytochemically. Numbers of plasma protein-positive epithelial cells increased to adult levels by P28, but their percentage of plexus cells declined. Numbers of cells positive for biotinylated probes increased with age, while their percentage remained constant. Colocalization studies showed specificity for individual proteins in some epithelial cells. Biotinylated probes and endogenous proteins colocalized in about 10% of cells in younger animals, increasing towards 100% by adulthood. Injections of markers into the ventricles demonstrated that protein is transferred only from blood into CSF, whereas dextrans pass in both directions. These results indicate that protein and lipid-insoluble markers are transferred by separate mechanisms present in choroid plexuses from the earliest stage of brain development, and transfer of proteins from plasma across choroid plexus epithelial cells contributes to the high protein concentration in CSF in the immature brain.

  10. The developmental reduction of the marsupial coracoid: a case study in Monodelphis domestica.

    PubMed

    Hubler, Merla; Niswander, Lee A; Peters, James; Sears, Karen E

    2010-07-01

    During their embryogenesis, marsupials develop a unique structure, the shoulder arch, which provides the structural and muscle-attachment support necessary for the newborn's crawl to the teat. One of the most pronounced and important aspects of the shoulder arch is an enlarged coracoid. After marsupial newborns reach the teat, the shoulder arch is remodeled and the coracoid is reduced to a small process on the scapula. Although an understanding of marsupial coracoid reduction has the potential to provide insights into both, marsupial evolution and the origin of mammals, little is known about the morphological and cellular processes controlling this process. To remedy this situation, this study examined the morphological and cellular mechanisms behind coracoid reduction in the gray short-tailed opossum, Monodelphis domestica. A quantitative, morphometric study of shoulder girdle development revealed that the coracoid is reduced in size relative to other aspects of the shoulder girdle by growing at a slower rate. Using a series of molecular assays for cell death, no evidence was found for programmed cell death playing a role in the reduction of coracoid size in marsupials (in contrast to hypotheses of previous researchers). Although it is likely the case that coracoid growth is reduced through a relatively lower rate of cellular proliferation, differences in proliferative rates in the coracoid and scapula were not great enough to be quantified using standard molecular assays.

  11. Linkage mapping and physical localization of the major histocompatibility complex region of the marsupial Monodelphis domestica.

    PubMed

    Gouin, N; Deakin, J E; Miska, K B; Miller, R D; Kammerer, C M; Graves, J A M; VandeBerg, J L; Samollow, P B

    2006-01-01

    We used genetic linkage mapping and fluorescence in situ hybridization (FISH) to conduct the first analysis of genic organization and chromosome localization of the major histocompatibility complex (MHC) of a marsupial, the gray, short-tailed opossum Monodelphis domestica. Family based linkage analyses of two M. domestica MHC Class I genes (UA1, UG) and three MHC Class II genes (DAB, DMA, and DMB) revealed that these genes were tightly linked and positioned in the central region of linkage group 3 (LG3). This cluster of MHC genes was physically mapped to the centromeric region of chromosome 2q by FISH using a BAC clone containing the UA1 gene. An interesting finding from the linkage analyses is that sex-specific recombination rates were virtually identical within the MHC region. This stands in stark contrast to the genome-wide situation, wherein males exhibit approximately twice as much recombination as females, and could have evolutionary implications for maintaining equality between males and females in the ability to generate haplotype diversity in this region. These analyses also showed that three non-MHC genes that flank the MHC region on human chromosome 6, myelin oligodendrocyte glycoprotein (MOG), bone morphogenetic protein 6 (BMP6), and prolactin (PRL), are split among two separate linkage groups (chromosomes) in M. domestica. Comparative analysis with eight other vertebrate species suggests strong conservation of the BMP6-PRL synteny among birds and mammals, although the BMP6-PRL-MHC-ME1 synteny is not conserved.

  12. Arap3 is dysregulated in a mouse model of hypotrichosis-lymphedema-telangiectasia and regulates lymphatic vascular development.

    PubMed

    Kartopawiro, Joëlle; Bower, Neil I; Karnezis, Tara; Kazenwadel, Jan; Betterman, Kelly L; Lesieur, Emmanuelle; Koltowska, Katarzyna; Astin, Jonathan; Crosier, Philip; Vermeren, Sonja; Achen, Marc G; Stacker, Steven A; Smith, Kelly A; Harvey, Natasha L; François, Mathias; Hogan, Benjamin M

    2014-03-01

    Mutations in SOX18, VEGFC and Vascular Endothelial Growth Factor 3 underlie the hereditary lymphatic disorders hypotrichosis-lymphedema-telangiectasia (HLT), Milroy-like lymphedema and Milroy disease, respectively. Genes responsible for hereditary lymphedema are key regulators of lymphatic vascular development in the embryo. To identify novel modulators of lymphangiogenesis, we used a mouse model of HLT (Ragged Opossum) and performed gene expression profiling of aberrant dermal lymphatic vessels. Expression studies and functional analysis in zebrafish and mice revealed one candidate, ArfGAP with RhoGAP domain, Ankyrin repeat and PH domain 3 (ARAP3), which is down-regulated in HLT mouse lymphatic vessels and necessary for lymphatic vascular development in mice and zebrafish. We position this known regulator of cell behaviour during migration as a mediator of the cellular response to Vegfc signalling in lymphatic endothelial cells in vitro and in vivo. Our data refine common mechanisms that are likely to contribute during both development and the pathogenesis of lymphatic vascular disorders.

  13. Four events of host switching in Aspidoderidae (Nematoda) involve convergent lineages of mammals.

    PubMed

    Jiménez, F Agustín; Gardner, Scott L; Navone, Graciela; Ortí, Guillermo

    2012-12-01

    The Great American Interchange resulted in the mixing of faunistic groups with different origins and evolutionary trajectories that underwent rapid diversification in North and South America. As a result, groups of animals of recent arrival converged into similar habits and formed ecological guilds with some of the endemics. We present a reconstruction of the evolutionary events in Aspidoderidae, a family of nematodes that infect mammals that are part of this interchange, i.e., dasypodids, opossums, and sigmodontine, geomyid, and hystricognath rodents. By treating hosts as discrete states of character and using parsimony and Bayesian inferences to optimize these traits into the phylogeny of Aspidoderidae, we reconstructed Dasypodidae (armadillos) as the synapomorphic host for the family. In addition, 4 events of host switching were detected. One consisted of the switch from dasypodids to hystricognath rodents, and subsequently to geomyid rodents. The remaining set of events consisted of a switch from dasypodids to didelphid marsupials and then to sigmodontine rodents. The reconstruction of the ancestral distribution suggests 3 events of dispersal into the Nearctic. Two of these invasions would suggest that 2 different lineages of dasypodid parasites entered the Northern Hemisphere at different times, which is consistent with the presence of 2 lineages of armadillos in Mexico.

  14. Trypanosoma cruzi and Leishmania infantum chagasi Infection in Wild Mammals from Maranhão State, Brazil.

    PubMed

    da Costa, Andréa Pereira; Costa, Francisco Borges; Soares, Herbert Sousa; Ramirez, Diego Garcia; Mesquita, Eric Takashi Kamakura de Carvalho; Gennari, Solange Maria; Marcili, Arlei

    2015-11-01

    Trypanosoma and Leishmania are obligate parasites that cause important diseases in human and domestic animals. Wild mammals are the natural reservoirs of these parasites, which are transmitted by hematophagous arthropods. The present study aimed to detect the natural occurrence of trypanosomatids through serological diagnosis, PCR of whole blood and blood culture (hemoculture), and phylogenetic relationships using small subunit ribosomal DNA (SSU rDNA), cytochrome b, and glycosomal glyceraldehyde 3-phosphate dehydrogenase (gGAPDH) genes. Samples from 131 wild animals, including rodents, marsupials, and bats, were sampled in six areas in the state of Maranhão, in a transition zone of semiarid climates northeast of the equatorial humid Amazon. Serological analysis for Leishmania (Leishmania) infantum chagasi was performed in opossums by indirect fluorescent antibody test (IFAT), and all animals were serologically negative. Nine positive hemocultures (6.77%) were isolated and cryopreserved and from mammals of the Didelphimorphia and Chiroptera orders and positioned in phylogenies on the basis of sequences from different genes with reference strains of Trypanosoma cruzi marinkellei and T. cruzi. From primary samples (blood and tissues) only one bat, Pteronotus parnellii, was positive to SSU rDNA and gGAPDH genes and grouped with the L. infantum chagasi branch. The studies conducted in Maranhão State provide knowledge of parasite diversity. It is important to determine the presence of trypanosomatids in wild mammals with synanthropic habits.

  15. Interaction of gentamicin polycation with model and cell membranes.

    PubMed

    Kovács, Eugenia; Savopol, Tudor; Iordache, Maria-Minodora; Săplăcan, Lavinia; Sobaru, Iuliana; Istrate, Claudia; Mingeot-Leclercq, Marie-Paule; Moisescu, Mihaela-Georgeta

    2012-10-01

    The interaction of positively-charged antibiotic gentamicin with cell membranes was studied to determine if any changes in membrane organization were induced by the drug. Opossum kidney epithelia (OK) cells were used as models of eukaryotic cells. Two methods were used: laurdan fluorescence spectroscopy and fluorescence anisotropy recordings on 1-(4-trimethylammoniumphenyl)-6-phenyl-1,3,5-hexatriene p-toluenesulfonate (TMA-DPH) labeled cell suspensions. Both methods showed an altered membrane hydration and fluidity of gentamicin treated cells. Liposomes prepared from dimyristoyl-phosphatidylcholine (DMPC) mixed with cardiolipin, which mimics the heterogeneous charge composition of the natural cell membrane, were used to determine the effect of gentamicin on artificial bilayers. The membrane lipid packing as revealed by generalized polarization (GP) and fluorescence anizotropy variation with increasing temperature was studied. It was found that the generalized polarization of liposomal membranes containing a negatively charged lipid (cardiolipin) is higher in the presence of gentamicin; in the membrane of living cell (OK), gentamicin induces, on the contrary, a decrease of general polarization. Considering the role of membrane organization in the function of transmembrane channels and receptors, our findings suggest hypotheses that may explain the permeation of gentamicin through the living cell membrane by using these channels.

  16. Learning Curve for D2 Lymphadenectomy in Gastric Cancer

    PubMed Central

    Rebasa, Pere; Montmany, Sandra; Navarro, Salvador

    2013-01-01

    Background. D2 lymphadenectomy is a demanding technique which is associated with high morbidity in the West. We report our experience with D2 lymphadenectomy after a training period in Japan. Methods. Prospective, descriptive study in 133 consecutive patients undergoing radical gastrectomy for gastric adenocarcinoma from 2005 to 2011. We analysed the number of lymph nodes removed, observed morbidity/mortality compared with the predictions of POSSUM and O-POSSUM, survival, and disease-free interval for patients with D1 and D2 lymphadenectomy. Results. The morbidity rate in patients with D1 lymphadenectomy was 59.4%. For D2 it was 47.7%. The mortality rate in patients with D1 was 6.7%. In the D2 group it was 6.8%. Median survival was 42.9 months in D1 and 55 months in D2. The disease-free interval was 49 months for D1 and 58 months for D2. Conclusion. The learning curve for D2 lymphadenectomy presents acceptable rates of morbidity and mortality, providing that the technique is learnt at a center with extensive experience. PMID:23844296

  17. Comparative Structures and Evolution of Vertebrate Carboxyl Ester Lipase (CEL) Genes and Proteins with a Major Role in Reverse Cholesterol Transport.

    PubMed

    Holmes, Roger S; Cox, Laura A

    2011-01-01

    Bile-salt activated carboxylic ester lipase (CEL) is a major triglyceride, cholesterol ester and vitamin ester hydrolytic enzyme contained within pancreatic and lactating mammary gland secretions. Bioinformatic methods were used to predict the amino acid sequences, secondary and tertiary structures and gene locations for CEL genes, and encoded proteins using data from several vertebrate genome projects. A proline-rich and O-glycosylated 11-amino acid C-terminal repeat sequence (VNTR) previously reported for human and other higher primate CEL proteins was also observed for other eutherian mammalian CEL sequences examined. In contrast, opossum CEL contained a single C-terminal copy of this sequence whereas CEL proteins from platypus, chicken, lizard, frog and several fish species lacked the VNTR sequence. Vertebrate CEL genes contained 11 coding exons. Evidence is presented for tandem duplicated CEL genes for the zebrafish genome. Vertebrate CEL protein subunits shared 53-97% sequence identities; demonstrated sequence alignments and identities for key CEL amino acid residues; and conservation of predicted secondary and tertiary structures with those previously reported for human CEL. Phylogenetic analyses demonstrated the relationships and potential evolutionary origins of the vertebrate CEL family of genes which were related to a nematode carboxylesterase (CES) gene and five mammalian CES gene families.

  18. Isolation of Mycobacterium avium subsp paratuberculosis (Map) from feral cats on a dairy farm with Map-infected cattle.

    PubMed

    Palmer, Mitchell V; Stoffregen, William C; Carpenter, Jeremy G; Stabel, Judith R

    2005-07-01

    Paratuberculosis is an economically important disease of dairy cattle caused by Mycobacterium avium subsp. paratuberculosis (Map). The role of nonruminant, nondomestic animals in the epidemiology of paratuberculosis in cattle is unclear. To examine nonruminant, nondomestic animals for the presence of Map, 25 feral cats, nine mice (species unknown), eight rabbits (Sylvilagus floridanus), six raccoons (Procyon lotor), and three opossums (Didelphis virginiana) were collected from a mid-western dairy with known Map-infected cattle. Mycobacterium avium subsp. paratuberculosis was isolated from the mesenteric lymph node from seven of 25 (28%) feral cats. Ileum was culture-positive for three of these seven cats, and an isolation of Map was also made from the ileum of one of nine (11%) mice. Tissue samples from other species were negative as determined by Map culture; microscopic lesions consistent with paratuberculosis were not seen in any animal. Restriction fragment polymorphism analysis of isolates from cats and dairy cattle suggest interspecies transmission. The means by which interspecies transmission occurred may be through ingestion of Map-contaminated feces or waste milk or through ingestion of Map-infected prey. Shedding of Map from infected cats was not evaluated. The epidemiologic role of Map-infected feral cats on dairy farms requires further investigation.

  19. Stable isotope evaluation of population- and individual-level diet variability in a large, oligotrophic lake with non-native lake trout

    USGS Publications Warehouse

    Ng, Elizabeth L.; Fredericks, Jim P.; Quist, Michael C.

    2016-01-01

    Non-native piscivores can alter food web dynamics; therefore, evaluating interspecific relationships is vital for conservation and management of ecosystems with introduced fishes. Priest Lake, Idaho, supports a number of introduced species, including lake troutSalvelinus namaycush, brook trout S. fontinalis and opossum shrimp Mysis diluviana. In this study, we used stable isotopes (δ13C and δ15N) to describe the food web structure of Priest Lake and to test hypotheses about apparent patterns in lake trout growth. We found that isotopic niches of species using pelagic-origin carbon did not overlap with those using more littoral-origin carbon. Species using more littoral-origin carbon, such as brook trout and westslope cutthroat trout Oncorhynchus clarki lewisi, exhibited a high degree of isotopic niche overlap and high intrapopulation variability in resource use. Although we hypothesised that lake trout would experience an ontogenetic diet shift, no such patterns were apparent in isotopic signatures. Lake trout growth rates were not associated with patterns in δ15N, indicating that variation in adult body composition may not be related to adult diet. Understanding trophic relationships at both the individual and species levels provides a more complete understanding of food webs altered by non-native species.

  20. Long-term effects of a trophic cascade in a large lake ecosystem

    PubMed Central

    Ellis, Bonnie K.; Stanford, Jack A.; Goodman, Daniel; Stafford, Craig P.; Gustafson, Daniel L.; Beauchamp, David A.; Chess, Dale W.; Craft, James A.; Deleray, Mark A.; Hansen, Barry S.

    2011-01-01

    Introductions or invasions of nonnative organisms can mediate major changes in the trophic structure of aquatic ecosystems. Here we document multitrophic level impacts in a spatially extensive system that played out over more than a century. Positive interactions among exotic vertebrate and invertebrate predators caused a substantial and abrupt shift in community composition resulting in a trophic cascade that extended to primary producers and to a nonaquatic species, the bald eagle. The opossum shrimp, Mysis diluviana, invaded Flathead Lake, Montana, the largest freshwater lake in the western United States. Lake trout had been introduced 80 y prior but remained at low densities until nonnative Mysis became established. The bottom-dwelling mysids eliminated a recruitment bottleneck for lake trout by providing a deep water source of food where little was available previously. Lake trout subsequently flourished on mysids and this voracious piscivore now dominates the lake fishery; formerly abundant kokanee were extirpated, and native bull and westslope cutthroat trout are imperiled. Predation by Mysis shifted zooplankton and phytoplankton community size structure. Bayesian change point analysis of primary productivity (27-y time series) showed a significant step increase of 55 mg C m−2 d−1 (i.e., 21% rise) concurrent with the mysid invasion, but little trend before or after despite increasing nutrient loading. Mysis facilitated predation by lake trout and indirectly caused the collapse of kokanee, redirecting energy flow through the ecosystem that would otherwise have been available to other top predators (bald eagles). PMID:21199944

  1. Amblyomma auricularium (Ixodida: Ixodidae) in Florida: New Hosts and Distribution Records.

    PubMed

    Mertins, James W; Vigil, Stacey L; Corn, Joseph L

    2017-01-01

    Previous published evidence for the occurrence of an exotic armadillo tick, Amblyomma auricularium (Conil), in Florida is scant, but we found it is fully established and integrated into the state's tick fauna. We collected 11,192 specimens of this tick from naturalized nine-banded armadillos, Dasypus novemcinctus L., and 14 other species of wild native mammals and birds in Florida, while sampling statewide during 2004 through 2007. In all, we document its specific presence only in 14 contiguous South Florida counties. Moreover, we report the first collections of A. auricularium from the Virginia opossum (Didelphis virginiana Kerr), common raccoon [Procyon lotor (L.)], cotton deermouse [Peromyscus gossypinus (Le Conte)], gray fox [Urocyon cinereoargenteus (Schreber)], eastern spotted skunk [Spilogale putorius (L.)], and white-tailed deer [Odocoileus virginianus (Zimmerman)]. For the first time on birds, we report the collection of this tick from the broad-winged hawk [Buteo platypterus (Vieillot)], northern cardinal [Cardinalis cardinalis (L.)], Carolina wren [Thryothorus ludovicianus (Latham)], gray catbird [Dumetella carolinensis (L.)], and yellow-rumped warbler [Setophaga coronata (L.)]. In addition, we report unattached A. auricularium collected from humans for the first time, and additional new collections from domestic dogs, Canis lupus familiaris L.

  2. Genomic evidence for a large-Z effect.

    PubMed

    Ellegren, Hans

    2009-01-22

    The 'large-X effect' suggests that sex chromosomes play a disproportionate role in adaptive evolution. Theoretical work indicates that this effect may be most pronounced in genetic systems with female heterogamety under both good-genes and Fisher's runaway models of sexual selection (males ZZ, females ZW). Here, I use a comparative genomic approach (alignments of several thousands of chicken-zebra finch-human-mouse-opossum orthologues) to show that avian Z-linked genes are highly overrepresented among those bird-mammalian orthologues that show evidence of accelerated rate of functional evolution in birds relative to mammals; the data suggest a twofold excess of such genes on the Z chromosome. A reciprocal analysis of genes accelerated in mammals found no evidence for an excess of X-linkage. This would be compatible with theoretical expectations for differential selection on sex-linked genes under male and female heterogamety, although the power in this case was not sufficient to statistically show that 'large-Z' was more pronounced than 'large-X'. Accelerated Z-linked genes include a variety of functional categories and are characterized by higher non-synonymous to synonymous substitution rate ratios than both accelerated autosomal and non-accelerated genes. This points at a genomic 'large-Z effect', which is widespread and of general significance for adaptive divergence in birds.

  3. Thyroid hormone stimulates the renal Na/H exchanger NHE3 by transcriptional activation

    PubMed Central

    CANO, ADRIANA; BAUM, MICHEL; MOE, ORSON W.

    2014-01-01

    Thyroid hormone stimulates renal proximal tubule NaCl and NaHCO3 absorption in part by activating the apical membrane Na/H exchanger NHE3. We used a renal epithelial cell line, the opossum kidney (OK) cell, to define the mechanism by which 3,5,3′-triiodothyronine (T3) increases NHE3 activity. T3 stimulated NHE3 activity, an effect that was blocked by inhibition of cellular transcription or translation. The increase in activity was associated with increases in steady-state cell surface and total cellular NHE3 protein and NHE3 transcript abundance. T3 stimulated transcription of the NHE3 gene and had no effect on NHE3 transcript stability. The transcriptional activity of the 5′-flanking region of the rat NHE3 gene was stimulated by T3 when expressed in OK cells. When heterologously expressed rat NHE3 transcript levels were clamped constant with a constitutive promoter in OK cells, T3 has no effect on rat NHE3 protein abundance, suggesting the absence of regulation of NHE3 protein stability or translation. These studies demonstrate that T3 stimulates NHE3 activity by activating NHE3 gene transcription and increasing NHE3 transcript and protein abundance. PMID:9886925

  4. Ectoparasites and associated pathogens of free-roaming and captive animals in zoos of South Carolina.

    PubMed

    Nelder, Mark P; Reeves, Will K; Adler, Peter H; Wozniak, Arthur; Wills, William

    2009-10-01

    A survey of ectoparasites and their associated pathogens was conducted in two South Carolina zoos, from 2004 to 2007. Dead, wild birds and mammals, as well as captive animals examined during routine veterinary checks constituted the study populations. Ectoparasites were tested for species of Anaplasma, Bartonella, Coxiella burnetii, Ehrlichia, Rickettsia, and Trypanosoma. Forty-six species of ectoparasites were collected from 133 free-roaming and captive hosts and their associated nesting and bedding materials. Six vector-borne pathogens were detected molecularly in the ectoparasites, including Anaplasma phagocytophilum in the tick Ixodes dentatus Marx from an eastern cottontail rabbit, Bartonella clarridgeiae in the cat flea Ctenocephalides felis (Bouché) from a Virginia opossum, Bartonella sp. Oh6 in the squirrel flea Orchopeas howardi (Baker) from an eastern grey squirrel, Bartonella sp. T7498 in the sucking louse Neohaematopinus sciuri Jancke from a squirrel, Rickettsia sp. Rf2125 in C. felis from a zookeeper and a grizzly bear, and Rickettsiales sp. Ib 2006 in Ixodes brunneus Koch from an American crow. While the pathology of some of these pathogens is poorly known, Anaplasma phagocytophilum (causative agent of human granulocytic anaplasmosis) and Bartonella clarridgeiae (causative agent of a disease similar to cat-scratch disease) can infect humans. Ectoparasites and their pathogens, especially those originating from free-roaming animals, present a potential threat to captive animals and humans.

  5. Marsupials and Eutherians reunited: genetic evidence for the Theria hypothesis of mammalian evolution.

    PubMed

    Killian, J K; Buckley, T R; Stewart, N; Munday, B L; Jirtle, R L

    2001-07-01

    The three living monophyletic divisions of Class Mammalia are the Prototheria (monotremes), Metatheria (marsupials), and Eutheria ('placental' mammals). Determining the sister relationships among these three groups is the most fundamental question in mammalian evolution. Phylogenetic comparison of these mammals by either anatomy or mitochondrial DNA has resulted in two conflicting hypotheses, Theria and Marsupionta, and has fueled a "genes versus morphology" controversy. We have cloned and analyzed a large nuclear gene, the mannose 6-phosphate/insulin-like growth factor II receptor (M6P/IGF2R), from representatives of all three mammalian groups, including platypus, echidna, opossum, wallaby, hedgehog, mouse, rat, rabbit, cow, pig, bat, tree shrew, colugo, ringtail lemur, and human. Statistical analysis of this nuclear gene unambiguously supports the morphology-based Theria hypothesis that excludes monotremes from a clade of marsupials and eutherians. The M6P/IGF2R was also able to resolve the finer structure of the eutherian mammalian family tree. In particular, our analyses support sister group relationships between lagomorphs and rodents, and between the primates and Dermoptera. Statistical support for the grouping of the hedgehog with Feruungulata and Chiroptera was also strong.

  6. Screening for target toxins of the antiophidic protein DM64 through a gel-based interactomics approach.

    PubMed

    Rocha, Surza L G; Neves-Ferreira, Ana G C; Trugilho, Monique R O; Angulo, Yamileth; Lomonte, Bruno; Valente, Richard H; Domont, Gilberto B; Perales, Jonas

    2017-01-16

    DM64 is a glycosylated protein with antivenom activity isolated from the serum of the opossum Didelphis aurita. It binds non-covalently to myotoxins I (Asp49) and II (Lys49) from Bothrops asper venom and inhibits their myotoxic effect. In this study, an affinity column with immobilized DM64 as bait was used to fish potential target toxins. All ten isolated myotoxins tested were able to effectively bind to the DM64 column. To better access the specificity of the inhibitor, crude venoms from Bothrops (8 species), Crotalus (2 species) and Naja naja atra were submitted to the affinity purification. Venom fractions bound and nonbound to the DM64 column were analyzed by two-dimensional gel electrophoresis and MALDI-TOF/TOF MS. Although venom fractions bound to the column were mainly composed of basic PLA2, a few spots corresponding to acidic PLA2 were also observed. Some unexpected protein spots were also identified: C-type lectins and CRISP may represent putative new targets for DM64, whereas the presence of serine peptidases in the venom bound fraction is likely a consequence of nonspecific binding to the column matrix. The present results contribute to better delineate the inhibitory potential of DM64, providing a framework for the development of more specific antivenom therapies.

  7. Marsupial Genome Sequences: Providing Insight into Evolution and Disease

    PubMed Central

    Deakin, Janine E.

    2012-01-01

    Marsupials (metatherians), with their position in vertebrate phylogeny and their unique biological features, have been studied for many years by a dedicated group of researchers, but it has only been since the sequencing of the first marsupial genome that their value has been more widely recognised. We now have genome sequences for three distantly related marsupial species (the grey short-tailed opossum, the tammar wallaby, and Tasmanian devil), with the promise of many more genomes to be sequenced in the near future, making this a particularly exciting time in marsupial genomics. The emergence of a transmissible cancer, which is obliterating the Tasmanian devil population, has increased the importance of obtaining and analysing marsupial genome sequence for understanding such diseases as well as for conservation efforts. In addition, these genome sequences have facilitated studies aimed at answering questions regarding gene and genome evolution and provided insight into the evolution of epigenetic mechanisms. Here I highlight the major advances in our understanding of evolution and disease, facilitated by marsupial genome projects, and speculate on the future contributions to be made by such sequences. PMID:24278712

  8. Sarcocystis neurona schizonts-associated encephalitis, chorioretinitis, and myositis in a two-month-old dog simulating toxoplasmosis, and presence of mature sarcocysts in muscles.

    PubMed

    Dubey, J P; Black, S S; Verma, S K; Calero-Bernal, R; Morris, E; Hanson, M A; Cooley, A J

    2014-05-28

    Sarcocystis neurona is an unusual species of the genus Sarcocystis. Opossums (Didelphis virginianus, D. albiventris) are the definitive hosts and several other species, including dogs, cats, marine mammals, and horses are intermediate or aberrant hosts. Sarcocysts are not known to form in aberrant hosts. Sarcocystis neurona causes fatal disease in horses (Equine Protozoal Myeloencephalitis, EPM). There are numerous reports of fatal EPM-like infections in other species, usually with central nervous system signs and associated with the schizont stage of S. neurona. Here, we report fatal disseminated S. neurona infection in a nine-week-old golden retriever dog from Mississippi, USA. Protozoal merozoites were identified in smears of the cerebrospinal fluid. Microscopically, lesions and protozoa were identified in eyes, tongue, heart, liver, intestines, nasal turbinates, skeletal muscle and brain, which reacted intensely with S. neurona polyclonal antibodies. Mature sarcocysts were seen in sections of muscles. These sarcocysts were ultrastructurally similar to those of S. neurona from experimentally infected animals. These data suggest that the dog is another intermediate host for S. neurona. Data suggest that the dog was transplacentally infected.

  9. Brown-headed cowbirds (Molothrus ater) harbor Sarcocystis neurona and act as intermediate hosts.

    PubMed

    Mansfield, L S; Mehler, S; Nelson, K; Elsheikha, H M; Murphy, A J; Knust, B; Tanhauser, S M; Gearhart, P M; Rossano, M G; Bowman, D D; Schott, H C; Patterson, J S

    2008-05-06

    We tested the hypothesis that brown-headed cowbirds (Molothrus ater) harbor Sarcocystis neurona, the agent of equine protozoal myeloencephalitis (EPM), and act as intermediate hosts for this parasite. In summer 1999, wild caught brown-headed cowbirds were collected and necropsied to determine infection rate with Sarcocystis spp. by macroscopic inspection. Seven of 381 (1.8%) birds had grossly visible sarcocysts in leg muscles with none in breast muscles. Histopathology revealed two classes of sarcocysts in leg muscles, thin-walled and thick-walled suggesting two species. Electron microscopy showed that thick-walled cysts had characteristics of S. falcatula and thin-walled cysts had characteristics of S. neurona. Thereafter, several experiments were conducted to confirm that cowbirds had viable S. neurona that could be transmitted to an intermediate host and cause disease. Specific-pathogen-free opossums fed cowbird leg muscle that was enriched for muscle either with or without visible sarcocysts all shed high numbers of sporocysts by 4 weeks after infection, while the control opossum fed cowbird breast muscle was negative. These sporocysts were apparently of two size classes, 11.4+/-0.7 microm by 7.6+/-0.4 microm (n=25) and 12.6+/-0.6 microm by 8.0+/-0 microm (n=25). When these sporocysts were excysted and introduced into equine dermal cell tissue culture, schizogony occurred, most merozoites survived and replicated long term and merozoites sampled from the cultures with long-term growth were indistinguishable from known S. neurona isolates. A cowbird Sarcocystis isolate, Michigan Cowbird 1 (MICB1), derived from thin-walled sarcocysts from cowbirds that was passaged in SPF opossums and tissue culture went on to produce neurological disease in IFNgamma knockout mice indistinguishable from that of the positive control inoculated with S. neurona. This, together with the knowledge that S. falcatula does not cause lesions in IFNgamma knockout mice, showed that cowbird

  10. Phylogenetic congruence of Sarcocystis neurona Dubey et al., 1991 (Apicomplexa: Sarcocystidae) in the United States based on sequence analysis and restriction fragment length polymorphism (RFLP).

    PubMed

    Elsheikha, Hany M; Murphy, Alice J; Mansfield, Linda S

    2005-07-01

    The objectives of the present study were to assess the genetic diversity, phylogeny and phylogeographical relationships of available Sarcocystis neurona isolates from different localities in the United States. All 13 Sarcocystis isolates from different hosts were subjected to polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) analyses using two published DNA markers (25/396 and 33/54). The 334 bp sequence of the 25/396 marker of these isolates and Besnoitia darlingi, B. bennetti, Toxoplasma gondii and Neospora caninum were sequenced and compared. Phylogenetic analysis was performed using neighbour-joining (NJ), maximum parsimony (MP) and minimum evolution (ME) methods based on the sequences of the 25/396 marker of the 13 Sarcocystis isolates obtained in this study and sequences of 10 related isolates from GenBank. Phylogenetic trees revealed a close relatedness among S. neurona isolates in the US (nucleotide sequence diversity <5.0%). US isolates formed a monophyletic group and appeared more closely related to each other than to the South American isolates, which formed a separate lineage. NJ and ME trees with Kimura 2-parameter model separated S. neurona into two separate groups: a northern US group and a Southern US group. These findings suggest a correlation between grouping of the isolates and geographical segregation and were consistent with a genetic bottleneck hypothesis during opossum colonisation of North America. These data do not support either the view of S. neurona as a single super-species or its division into multiple subspecies.

  11. A genetically diverse but distinct North American population of Sarcocystis neurona includes an overrepresented clone described by 12 microsatellite alleles.

    PubMed

    Asmundsson, Ingrid M; Dubey, J P; Rosenthal, Benjamin M

    2006-09-01

    The population genetics and systematics of most coccidians remain poorly defined despite their impact on human and veterinary health. Non-recombinant parasite clones characterized by distinct transmission and pathogenesis traits persist in the coccidian Toxoplasma gondii despite opportunities for sexual recombination. In order to determine whether this may be generally true for tissue-cyst forming coccidia, and to address evolutionary and taxonomic problems within the genus Sarcocystis, we characterized polymorphic microsatellite markers in Sarcocystis neurona, the major causative agent of equine protozoal myeloencephalitis (EPM). Bayesian statistical modeling, phylogenetic reconstruction based on genotypic chord distances, and analyses of linkage disequilibrium were employed to examine the population structure within S. neurona and closely related Sarcocystis falcatula isolates from North and South America. North American S. neurona were clearly differentiated from those of South America and also from isolates of S. falcatula. Although S. neurona is characterized by substantial allelic and genotypic diversity typical of interbreeding populations, one genotype occurs with significantly excessive frequency; thus, some degree of asexual propagation of S. neurona clones may naturally occur. Finally, S. neurona isolated from disparate North American localities and diverse hosts (opossums, a Southern sea otter, and horses) comprise a single genetic population. Isolates associated with clinical neurological disease bear no obvious distinction as measured by these presumably neutral genetic markers.

  12. Sarcocystis neurona manipulation using culture-derived merozoites for bradyzoite and sporocyst production.

    PubMed

    Chaney, Sarah B; Marsh, Antoinette E; Lewis, Stephanie; Carman, Michelle; Howe, Daniel K; Saville, William J; Reed, Stephen M

    2017-03-18

    Equine protozoal myeloencephalitis (EPM) remains a significant central nervous system disease of horses in the American continents. Sarcocystis neurona is considered the primary causative agent and its intermediate life stages are carried by a wide host-range including raccoons (Procyon lotor) in North America. S. neurona sarcocysts mature in raccoon skeletal muscle and can produce central nervous system disease in raccoons, mirroring the clinical presentation in horses. The study aimed to develop laboratory tools whereby the life cycle and various life stages of S. neurona could be better studied and manipulated using in vitro and in vivo systems and compare the biology of two independent isolates. This study utilized culture-derived parasites from S. neurona strains derived from a raccoon or from a horse to initiate raccoon infections. Raccoon tissues, including fresh and cryopreserved tissues, were used to establish opossum (Didelphis virginiana) infections, which then shed sporocyts with retained biological activity to cause encephalitis in mice. These results demonstrate that sarcocysts can be generated using in vitro-derived S. neurona merozoites, including an isolate originally derived from a naturally infected horse with clinical EPM. This study indicates the life cycle can be significantly manipulated in the laboratory without affecting subsequent stage development, allowing further purification of strains and artificial maintenance of the life cycle.

  13. Efficacy of decoquinate against Sarcocystis neurona in cell cultures.

    PubMed

    Lindsay, David S; Nazir, M Mudasser; Maqbool, Azhar; Ellison, Siobhan P; Strobl, Jeannine S

    2013-09-01

    Decoquinate is a quinolone anticoccidial approved for use in the prevention of intestinal coccidiosis in farm animals. This compound has good activity against Toxoplasma gondii and Neospora caninum in cell cultures. The drug acts on the parasites' mitochondria. The activity of decoquinate against developing merozoites of 2 isolates of Sarcocystis neurona was examined in cell culture. Merozoite production at 10 days was completely inhibited when decoquinate was used at 20 or 240 nM. The IC50 of decoquinate was 0.5 ± 0.09nM for the Sn6 isolate of S. neurona from a horse and 1.1 ± 0.6 nM for the SnOP15 isolate of S. neurona from an opossum. Levamisole was toxic at 5 μg/ml and no synergism was observed when decoquinate was combined with levamisole and tested against the Sn3YFP isolate of S. neurona. Decoquinate was cidal for developing schizonts of S. neurona at 240 nM.

  14. Isolation and characterization of melanopsin (Opn4) from the Australian marsupial Sminthopsis crassicaudata (fat-tailed dunnart).

    PubMed

    Pires, Susana S; Shand, Julia; Bellingham, James; Arrese, Catherine; Turton, Michael; Peirson, Stuart; Foster, Russell G; Halford, Stephanie

    2007-11-22

    Melanopsin confers photosensitivity to a subset of retinal ganglion cells and is responsible for many non-image-forming tasks, like the detection of light for circadian entrainment. Recently, two melanopsin genes, Opn4m and Opn4x, were described in non-mammalian vertebrates. However, only one form, Opn4m, has been described in the mammals, although studies to date have been limited to the placentals and have not included the marsupials. We report here the isolation and characterization of an Opn4 gene from an Australian marsupial, the fat-tailed dunnart (Sminthopsis crassicaudata), and present evidence which suggests that the Opn4x gene was lost before the placental/marsupial split. In situ hybridization shows that the expression of Opn4 in the dunnart eye is restricted to a subset of ganglion cells, a pattern previously reported for rodents and primates. These Opn4-positive cells are randomly distributed across the dunnart retina. We also undertook a comparative analysis with the South American marsupial, the grey short-tailed opossum (Monodelphis domestica), and two placental mammals, mouse and human. This approach reveals that the two marsupials show a higher sequence identity than that seen between rodents and primates, despite separating at approximately the same point in time, some 65-85 Myr ago.

  15. Evaluation of a Mysis bioenergetics model

    USGS Publications Warehouse

    Chipps, S.R.; Bennett, D.H.

    2002-01-01

    Direct approaches for estimating the feeding rate of the opossum shrimp Mysis relicta can be hampered by variable gut residence time (evacuation rate models) and non-linear functional responses (clearance rate models). Bioenergetics modeling provides an alternative method, but the reliability of this approach needs to be evaluated using independent measures of growth and food consumption. In this study, we measured growth and food consumption for M. relicta and compared experimental results with those predicted from a Mysis bioenergetics model. For Mysis reared at 10??C, model predictions were not significantly different from observed values. Moreover, decomposition of mean square error indicated that 70% of the variation between model predictions and observed values was attributable to random error. On average, model predictions were within 12% of observed values. A sensitivity analysis revealed that Mysis respiration and prey energy density were the most sensitive parameters affecting model output. By accounting for uncertainty (95% CLs) in Mysis respiration, we observed a significant improvement in the accuracy of model output (within 5% of observed values), illustrating the importance of sensitive input parameters for model performance. These findings help corroborate the Mysis bioenergetics model and demonstrate the usefulness of this approach for estimating Mysis feeding rate.

  16. Acute leptin exposure reduces megalin expression and upregulates TGFβ1 in cultured renal proximal tubule cells.

    PubMed

    Briffa, Jessica F; Grinfeld, Esther; Mathai, Michael L; Poronnik, Phillip; McAinch, Andrew J; Hryciw, Deanne H

    2015-02-05

    Increased leptin concentrations observed in obesity can lead to proteinuria, suggesting that leptin may play a role in obesity-related kidney disease. Obesity reduces activation of AMP-activated protein kinase (AMPK) and increases transforming growth factor-β1 (TGF-β1) expression in the kidney, leading to albuminuria. Thus we investigated if elevated leptin altered AMPK and TGF-β1 signaling in proximal tubule cells (PTCs). In opossum kidney (OK) PTCs Western blot analysis demonstrated that leptin upregulates TGF-β1 secretion (0.50 µg/ml) and phosphorylated AMPKα (at 0.25, and 0.50 µg/ml), and downregulates megalin expression at all concentrations (0.05-0.50 µg/ml). Using the AMPK inhibitor, Compound C, leptin exposure regulated TGF-β1 expression and secretion in PTCs via an AMPK mediated pathway. In addition, elevated leptin exposure (0.50 µg/ml) reduced albumin handling in OK cells independently of megalin expression. This study demonstrates that leptin upregulates TGF-β1, reduces megalin, and reduces albumin handling in PTCs by an AMPK mediated pathway.

  17. Short term exposure to elevated levels of leptin reduces proximal tubule cell metabolic activity.

    PubMed

    Briffa, Jessica F; Grinfeld, Esther; McAinch, Andrew J; Poronnik, Philip; Hryciw, Deanne H

    2014-01-25

    Leptin plays a pathophysiological role in the kidney, however, its acute effects on the proximal tubule cells (PTCs) are unknown. In opossum kidney (OK) cells in vitro, Western blot analysis identified that exposure to leptin increases the phosphorylation of the mitogen-activated protein kinase (MAPK) p44/42 and the mammalian target of rapamycin (mTOR). Importantly leptin (0.05, 0.10, 0.25 and 0.50 μg/ml) significantly reduced the metabolic activity of PTCs, and significantly decreased protein content per cell. Investigation of the role of p44/42 and mTOR on metabolic activity and protein content per cell, demonstrated that in the presence of MAPK inhibitor U0126 and mTOR inhibitor Ku-63794, that the mTOR pathway is responsible for the reduction in PTC metabolic activity in response to leptin. However, p44/42 and mTOR play no role the reduced protein content per cell in OKs exposed to leptin. Therefore, leptin modulates metabolic activity in PTCs via an mTOR regulated pathway.

  18. A role for host-parasite interactions in the horizontal transfer of transposons across phyla.

    PubMed

    Gilbert, Clément; Schaack, Sarah; Pace, John K; Brindley, Paul J; Feschotte, Cédric

    2010-04-29

    Horizontal transfer (HT), or the passage of genetic material between non-mating species, is increasingly recognized as an important force in the evolution of eukaryotic genomes. Transposons, with their inherent ability to mobilize and amplify within genomes, may be especially prone to HT. However, the means by which transposons can spread across widely diverged species remain elusive. Here we present evidence that host-parasite interactions have promoted the HT of four transposon families between invertebrates and vertebrates. We found that Rhodnius prolixus, a triatomine bug feeding on the blood of various tetrapods and vector of Chagas' disease in humans, carries in its genome four distinct transposon families that also invaded the genomes of a diverse, but overlapping, set of tetrapods. The bug transposons are approximately 98% identical and cluster phylogenetically with those of the opossum and squirrel monkey, two of its preferred mammalian hosts in South America. We also identified one of these transposon families in the pond snail Lymnaea stagnalis, a cosmopolitan vector of trematodes infecting diverse vertebrates, whose ancestral sequence is nearly identical and clusters with those found in Old World mammals. Together these data provide evidence for a previously hypothesized role of host-parasite interactions in facilitating HT among animals. Furthermore, the large amount of DNA generated by the amplification of the horizontally transferred transposons supports the idea that the exchange of genetic material between hosts and parasites influences their genomic evolution.

  19. Chromosomal redistribution of male-biased genes in mammalian evolution with two bursts of gene gain on the X chromosome.

    PubMed

    Zhang, Yong E; Vibranovski, Maria D; Landback, Patrick; Marais, Gabriel A B; Long, Manyuan

    2010-10-05

    Mammalian X chromosomes evolved under various mechanisms including sexual antagonism, the faster-X process, and meiotic sex chromosome inactivation (MSCI). These forces may contribute to nonrandom chromosomal distribution of sex-biased genes. In order to understand the evolution of gene content on the X chromosome and autosome under these forces, we dated human and mouse protein-coding genes and miRNA genes on the vertebrate phylogenetic tree. We found that the X chromosome recently acquired a burst of young male-biased genes, which is consistent with fixation of recessive male-beneficial alleles by sexual antagonism. For genes originating earlier, however, this pattern diminishes and finally reverses with an overrepresentation of the oldest male-biased genes on autosomes. MSCI contributes to this dynamic since it silences X-linked old genes but not X-linked young genes. This demasculinization process seems to be associated with feminization of the X chromosome with more X-linked old genes expressed in ovaries. Moreover, we detected another burst of gene originations after the split of eutherian mammals and opossum, and these genes were quickly incorporated into transcriptional networks of multiple tissues. Preexisting X-linked genes also show significantly higher protein-level evolution during this period compared to autosomal genes, suggesting positive selection accompanied the early evolution of mammalian X chromosomes. These two findings cast new light on the evolutionary history of the mammalian X chromosome in terms of gene gain, sequence, and expressional evolution.

  20. Using DNA Barcodes to Identify Road-Killed Animals in Two Atlantic Forest Nature Reserves, Brazil.

    PubMed

    Klippel, Angélica H; Oliveira, Pablo V; Britto, Karollini B; Freire, Bárbara F; Moreno, Marcel R; Dos Santos, Alexandre R; Banhos, Aureo; Paneto, Greiciane G

    2015-01-01

    Road mortality is the leading source of biodiversity loss in the world, especially due to fragmentation of natural habitats and loss of wildlife. The survey of the main species victims of roadkill is of fundamental importance for the better understanding of the problem, being necessary, for this, the correct species identification. The aim of this study was to verify if DNA barcodes can be applied to identify road-killed samples that often cannot be determined morphologically. For this purpose, 222 vertebrate samples were collected in a stretch of the BR-101 highway that crosses two Discovery Coast Atlantic Forest Natural Reserves, the Sooretama Biological Reserve and the Vale Natural Reserve, in Espírito Santo, Brazil. The mitochondrial COI gene was amplified, sequenced and confronted with the BOLD database. It was possible to identify 62.16% of samples, totaling 62 different species, including Pyrrhura cruentata, Chaetomys subspinosus, Puma yagouaroundi and Leopardus wiedii considered Vulnerable in the National Official List of Species of Endangered Wildlife. The most commonly identified animals were a bat (Molossus molossus), an opossum (Didelphis aurita) and a frog (Trachycephalus mesophaeus) species. Only one reptile was identified using the technique, probably due to lack of reference sequences in BOLD. These data may contribute to a better understanding of the impact of roads on species biodiversity loss and to introduce the DNA barcode technique to road ecology scenarios.

  1. Transposition and Intermingling of Gαi2 and Gαo Afferences into Single Vomeronasal Glomeruli in the Madagascan Lesser Tenrec Echinops telfairi

    PubMed Central

    Suárez, Rodrigo; Villalón, Aldo; Künzle, Heinz; Mpodozis, Jorge

    2009-01-01

    The vomeronasal system (VNS) mediates pheromonal communication in mammals. From the vomeronasal organ, two populations of sensory neurons, expressing either Gαi2 or Gαo proteins, send projections that end in glomeruli distributed either at the rostral or caudal half of the accessory olfactory bulb (AOB), respectively. Neurons at the AOB contact glomeruli of a single subpopulation. The dichotomic segregation of AOB glomeruli has been described in opossums, rodents and rabbits, while Primates and Laurasiatheres present the Gαi2-pathway only, or none at all (such as apes, some bats and aquatic species). We studied the AOB of the Madagascan lesser tenrec Echinops telfairi (Afrotheria: Afrosoricida) and found that Gαi2 and Gαo proteins are expressed in rostral and caudal glomeruli, respectively. However, the segregation of vomeronasal glomeruli at the AOB is not exclusive, as both pathways contained some glomeruli transposed into the adjoining subdomain. Moreover, some glomeruli seem to contain intermingled afferences from both pathways. Both the transposition and heterogeneity of vomeronasal afferences are features, to our knowledge, never reported before. The organization of AOB glomeruli suggests that synaptic integration might occur at the glomerular layer. Whether intrinsic AOB neurons may make synaptic contact with axon terminals of both subpopulations is an interesting possibility that would expand our understanding about the integration of vomeronasal pathways. PMID:19956694

  2. Neocortical projections of the suprageniculate and posterior thalamic nuclei in the marsupial brush-tailed possum, Trichosurus vulpecula (Phalangeridae), with a comparative commentary on the organization of the posterior thalamus in marsupial and placental mammals.

    PubMed

    Neylon, L; Haight, J R

    1983-07-10

    Axonal transport methods were used to determine the extent and organisation of neocortical projections from the suprageniculate (SG) and posterior (PO) thalamic nuclei in the brush-tailed possum. Our findings show that SG projects extensively to the auditory cortex, overlapping the cortical projection field of the medial geniculate nucleus, and to the immediately neighbouring association cortex. Though the input relationships of SG appear similar to those reported for other mammals, placental and marsupial, a strong SG projection to auditory cortex has not been reported previously. Neocortical relationships of PO are characterised by an orderly point-to-point projection to all but the most rostral parts of the motor-somaesthetic cortex. There is also a substantial projection to the entire posterior parietal association cortex. The PO-neocortex projection is reciprocally organised. The PO-neocortical projection in the possum is similar to that reported in the Virginia opossum, rat, and several other mammals. There is a major difference in organisation in comparison with certain monkeys where the PO projection is much more restricted and does not involve the motor and somaesthetic cortex. We conclude that PO is similarly organised in many, though not all, mammals, including the marsupials, rodents, insectivores, and prosimian primates. The possum SG, on the other hand, is clearly distinct from other mammals in its extensive projection to auditory cortex, though we cannot say at present whether this a general property of marsupial mammals or a peculiarity restricted to this species and possibly its close relatives.

  3. Importance of light, temperature, zooplankton and fish in predicting the nighttime vertical distribution of Mysis diluviana

    USGS Publications Warehouse

    Boscarino, B.T.; Rusdtam, L.G.; Eillenberger, J.L.; O'Gorman, R.

    2009-01-01

    The opossum shrimp Mysis diluviana (formerly M. relicta) performs large amplitude diel vertical migrations in Lake Ontario and its nighttime distribution is influenced by temperature, light and the distribution of its predators and prey. At one location in southeastern Lake Ontario, we measured the vertical distribution of mysids, mysid predators (i.e. planktivorous fishes) and mysid prey (i.e. zooplankton), in addition to light and temperature, on 8 occasions from May to September, 2004 and 2005. We use these data to test 3 different predictive models of mysid habitat selection, based on: (1) laboratory-derived responses of mysids to different light and temperature gradients in the absence of predator or prey cues; (2) growth rate of mysids, as estimated with a mysid bioenergetics model, given known prey densities and temperatures at different depths in the water column; (3) ratio of growth rates (g) and mortality risk (??) associated with the distribution of predatory fishes. The model based on light and temperature preferences was a better predictor of mysid vertical distribution than the models based on growth rate and g:?? on all 8 occasions. Although mysid temperature and light preferences probably evolved as mechanisms to reduce predation while increasing foraging intake, the response to temperature and light