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1.
2.
Madtsoiids constitute a successful group of extinct snakes widely distributed across Gondwana and the European archipelago during Late Cretaceous times, surviving in reduced numbers to the Pleistocene. They are renowned for including some of the largest snakes that have ever crawled on earth, yet diverse small madtsoiids are also known. Uncovering the evolutionary trends that led these snakes into disparate body sizes has been hampered mainly by the lack of phylogenetic consensus and the paucity of taxa with novel combinations of features. Here we describe a new large madtsoiid snake based on isolated vertebrae from the La Colonia Formation (Maastrichtian–Danian) of Patagonia, Argentina. A comprehensive phylogenetic analysis recovers Madtsoiidae as a basal ophidian lineage and the new snake as sister to a clade of mostly big-to-gigantic taxa, providing insights into early stages and evolutionary trends towards madtsoiid gigantism.  相似文献   

3.
Osteoarticular brucellosis is the most frequent complication of active disease. A large amount of cells in bone are osteocytes. Since bone remodeling process is regulated by hormones we sought to study the effect of cortisol and DHEA in Brucella abortus-infected osteocytes. Cortisol treatment inhibited the expression of IL-6, TNF-α, MMP-2 and RANKL in B. abortus-infected osteocytes. DHEA could reverse the inhibitory effect of cortisol on MMP-2 production. B. abortus infection inhibited connexin 43 (Cx43) expression in osteocytes. This expression was increased when cortisol was incorporated during the infection and DHEA treatment partially reversed the effect of cortisol. Osteocytes-infected with B. abortus induced osteoclast's differentiation. Yet, the presence of cortisol, but not DHEA, during osteocyte infection inhibited osteoclastogenesis. Glucocorticoid receptor (GR) is implicated in the signaling of cortisol. Infection with B. abortus was able to increase GRα/β ratio. Levels of intracellular cortisol are not only dependent on GR expression but also a result of the activity of the isoenzymes 11β-hydroxysteroid dehydrogenase (11β-HSD)-1 (cortisone to cortisol conversion), 11β-HSD2 (cortisol to cortisone conversion). B. abortus infection increased 11β-HSD 1/2 ratio and cortisone mimicked the effect of cortisol. Our results indicated that cortisol and DHEA could modulate osteocyte responses during B. abortus infection.  相似文献   

4.
《Comptes Rendus Palevol》2019,18(3):325-334
Scelidotheriinae (Mammalia, Pilosa) is a xenarthran mylodontid clade recorded in much of South America from the middle Miocene to the early Holocene. However, studies of their Neogene representatives are still scarce compared to their Quaternary representatives. The main goal of this contribution is to report new remains of Proscelidodon rothi (Ameghino, 1908) found in the basal levels of the El Polvorín Formation (Pliocene), cropping out near the city of Olavarría (Buenos Aires Province, Argentina). On the basis of the faunistic association, these deposits were assigned to the late Pliocene. The new materials include a skull, a mandible, and a calcaneal fragment (Xen-121), which enhance the characterization of this taxon, and allow more precise comparisons with other Neogene and Quaternary Scelidotheriinae. This new record extends the biochron and geographic distribution of the species, until now recorded in the latest Pliocene (Marplatan Stage/Age, Vorohuean Subage) of Olavarría.  相似文献   

5.
Addition of nifurtimox (a nitrofuran derivative) to Trypanosoma cruzi culture (epimastigote) forms induced an increase in the respiratory rate and the release of H2O2 from the whole cells to the suspending medium. Growth-inhibiting concentrations of nifurtimox were able to stimulate O2? production by the T. cruzi mitochondrial fraction supplemented with NADH (or succinate), and also to enhance the generation of O2? by the microsomal fraction with NADPH as reductant.  相似文献   

6.
Cordyceps tenuipes is an entomopathogenic fungus that infects mostly pupae of several lepidopteran families. In Colombia the species has been reported in non-disturbed tropical rain forests and more recently in butterfly gardens. The aim of this study was to assess the genetic diversity in populations of C. tenuipes present in natural (forests) and artificial (e.g. butterfly gardens) environments in the department of Quindío, Colombia, using three molecular nuclear markers ITS, TEF-1α and RPB1. All the samples evaluated corresponded morphologically and phylogenetically to C. tenuipes. The butterfly garden of Quindio Botanical Garden (QBG) showed the highest genetic diversity among all sampling localities and was very similar to that of its adjacent forest. The Amaranta Butterfly Garden (ABG), located north of QBG, showed lower genetic diversity as well as little genetic differentiation with QBG, consistent with the hypothesis of a pathogen transfer from QBG to ABG. Higher FST values were observed for TEF-1α and ITS, revealing genetic differentiation between all demes and the southern forest population. Our research constitutes the first study of the intraspecific diversity of C. tenuipes in Colombia and can serve as the first step in identifying diversity reservoirs and management of epizootic episodes caused by this fungal species.  相似文献   

7.
The Somuncurá Plateau is a Protected Natural Area located in the middle of the northern extra-Andean arid Patagonia. Inhabited by at least 20 small mammal species, is the place with the uppermost species richness in Patagonia. The aim of this study was to examine the parasite remains from micromammal coprolites collected in association with a bone sequence recovered at the east of the Somuncurá Plateau (site “Alero Las Lechuzas”). Coprolites came from the four temporal units previously defined: unit I (4790?±?100?yrs. 14C B.P.), unit II, unit III (7840?±?120?yrs. 14C B.P.) and unit IV. Each coprolite was processed, rehydrated, homogenized, processed by spontaneous sedimentation and examined using a light microscope. Coprolites and eggs were described, measured and photographed. Samples were positive for two nematode species: Helminthoxys caudatus Freitas, Lent & Almeida, 1937 (Oxyurida, Oxyuridae) and Trichuris spp. (Trichinellida: Trichuridae). This is the first paleoparasitological study developed for the Somuncurá Plateau Protected Area. Moreover, this is the first time that the genus Helminthoxys is reported from ancient times worldwide. Coprolites were attributed to the mountain cavy Microcavia australis (Rodentia, Caviidae).The presence of H. caudatus for the Middle Holocene of northern Patagonia contributes to the study of the history of the histricomorphs and pinworms relationships.  相似文献   

8.
The aim of this study was to search for entomopathogenic fungi that infect wild cockroaches in forest ecosystems in two protected natural areas of Argentina. Two isolates of Metarhizium argentinense were obtained and identified from wild cockroaches (Blaberidae: Epilamprinae) through the use of morphological characteristics and molecular phylogenetic analyses. This novel species was found in Argentina and is a member of the Metarhizium flavoviride species complex. Phylogenetic analyses, based on sequence similarity analysis using internal transcribed spacer (ITS) and a set of four protein-coding marker sequences (EF1A, RPB1, RPB2 and BTUB), supported the status of this fungus as a new species. In addition, we tested the biological activity of the new species through assays against Blattella germanica nymphs and found that the two evaluated isolates were pathogenic. However, isolate CEP424 was more virulent and caused a confirmed mortality of 76 % with a median lethal time of 7.2 d. This study reports the southernmost worldwide location of a Metarhizium species that infects cockroaches and will help expand the knowledge of the biodiversity of pathogenic fungi of Argentine cockroaches.  相似文献   

9.
Behavioral studies indicate that adult mountain gorillas (Gorilla beringei) are the most terrestrial of all nonhuman hominoids, but that infant mountain gorillas are much more arboreal. Here we examine ontogenetic changes in diaphyseal strength and length of the femur, tibia, humerus, radius, and ulna in 30 Virunga mountain gorillas, including 18 immature specimens and 12 adults. Comparisons are also made with 14 adult western lowland gorillas (Gorilla gorilla gorilla), which are known to be more arboreal than adult mountain gorillas. Infant mountain gorillas have significantly stronger forelimbs relative to hind limbs than older juveniles and adults, but are nonsignificantly different from western lowland gorilla adults. The change in inter-limb strength proportions is abrupt at about two years of age, corresponding to the documented transition to committed terrestrial quadrupedalism in mountain gorillas. The one exception is the ulna, which shows a gradual increase in strength relative to the radius and other long bones during development, possibly corresponding to the gradual adoption of stereotypical fully pronated knuckle-walking in older juvenile gorillas. Inter-limb bone length proportions show a contrasting developmental pattern, with hind limb/forelimb length declining rapidly from birth to five months of age, and then showing no consistent change through adulthood. The very early change in length proportions, prior to significant independent locomotion, may be related to the need for relatively long forelimbs for climbing in a large-bodied hominoid. Virunga mountain gorilla older juveniles and adults have equal or longer forelimb relative to hind limb bones than western lowland adults. These findings indicate that both ontogenetically and among closely related species of Gorilla, long bone strength proportions better reflect actual locomotor behavior than bone length proportions.  相似文献   

10.
This study quantifies the metacarpal 1 (MC 1) proximal articular surface using three-dimensional morphometrics in extant hominids and fossil hominins (SK 84, cf. Paranthropus robustus/Homo erectus and StW 418, Australopithecus africanus) to understand which characteristics of the proximal metacarpal 1 are potentially correlated with human manipulative abilities and if they can be used in a paleoanthropological setting. A principal components (PC) analysis was used to compare MC 1 proximal articular surface shape and ANOVA and Tukey's HSD post-hoc tests were conducted to determine differences among groups. Homo is significantly different from nonhuman hominids having a less radioulnarly and dorsovolarly curved articular surface. All nonhuman hominids have more curved articular surface with Gorilla showing the most curved joint. Moreover, this study highlights the presence of a radially extended surface in Homo that may be related to the greater thumb abduction in human manipulation activities. Both fossils analyzed show a great ape-like MC 1 proximal articular surface which, associated with recent trabecular and archaeological evidence, may indicate that the ability to make/use stone tools preceded the morphological adaptations associated today with such behavior.  相似文献   

11.
Strongyloidiasis is a human parasitosis that is considered a public health problem. Early diagnosis of this infection is extremely important in immunocompromised patients (i.e. subjects with alcoholism). This study aimed to evaluate anti-Strongyloides immunoglobulin G (IgG) and immunoglobulin A (IgA), assess levels of circulating immune complexes (IC) and determine IgG avidity in serum samples from alcoholic and nonalcoholic individuals. A total of 140 blood samples were collected from male individuals (70 alcoholic and 70 nonalcoholic subjects). Serum was obtained and analysed by enzyme-linked immunosorbent assay for IgG, IgA, IC detection and avidity determination. Anti-Strongyloides IgG was detected in 55.7% of alcoholic subjects and 32.8% nonalcoholics, while IC levels showed frequencies of 38.6% and 17.1% in these groups, respectively. Anti-Strongyloides IgA was lower among alcoholics (4.3%) than nonalcoholics (34.3%). Spearman's correlation coefficient reported a positive correlation between IgG, IC and IgA in alcoholic individuals and no correlation in nonalcoholics. The median avidity index was higher in alcoholics (83.8%) than nonalcoholic subjects (73.2%). In conclusion, this study shows that alcoholic subjects produced specific antibodies against S. stercoralis regardless of the possible immunosuppression caused by chronic alcoholism. Considering that alcoholics are more susceptible to the severe forms of strongyloidiasis, the implementation of immunological methods as a complementary approach to parasitological diagnostics (i.e. detection of IgG, IC and antibody avidity) appears to be an alternative method for early diagnosis in these individuals.  相似文献   

12.
As a process affecting animal communities, urbanization has been the subject of numerous studies. However, amphibians are still among the least studied vertebrate groups in urbanized landscapes. Generally, it has been found that the process of loss of amphibian diversity is nonrandom, with species from older evolutionary lines at greater risk. Regional data on amphibian assemblages in urban areas is a very useful tool for assessing how these assemblages react to changes.The aim of the present paper is to assess the diversity of amphibians in Polish cities based on data in the relevant literature, exploring different metrics (e.g., taxonomic, functional, and evolutionary diversity) calculated in amphibian species assemblages. We used data from 18 articles (including grey literature), characterized by comparable research methods and published between 1999 and 2017.Overall, amphibian species richness (ASR) amounted to an average of 9 species, ranging from 5 to 11 species per city. The higher species richness occurred in Białystok in North-west of Poland. Functional evenness (FEve), evolutionary distinctiveness (ED sum), and functional richness (FRic) were strongly positively correlated with ASR. However, ED mean was not significantly correlated with the total number of species in the community. Three taxa, the hybridogenetic water frogs Pelophylax esculentus complex, the common toad Bufo bufo, and the common frog Rana temporaria, occurred in all analyzed amphibian assemblages. Our study is one of the first attempts to compare urban amphibian assemblages, using different and complementary diversity metrics on a large spatial scale. In conclusion, we highlight that urban areas play an important role for conservation of amphibians, because they support amphibian assemblages characterized by a high level of overall diversity.  相似文献   

13.
  1. Animal movement is a key process that connects and maintains populations on the landscape, yet for most species, we do not understand how intrinsic and extrinsic factors interact to influence individual movement behavior.
  2. Land‐use/land‐cover changes highlight that connectivity among populations will depend upon an individual''s ability to traverse habitats, which may vary as a result of habitat permeability, individual condition, or a combination of these factors.
  3. We examined the effects of intrinsic (body size) and extrinsic (habitat type) factors on desiccation tolerance, movement, and orientation in three anuran species (American toads, Anaxyrus americanus; northern leopard frogs, Lithobates pipiens; and Blanchard''s cricket frogs, Acris blanchardi) using laboratory and field studies to connect the effects of susceptibility to desiccation, size, and movement behavior in single‐habitat types and at habitat edges.
  4. Smaller anurans were more vulnerable to desiccation, particularly for species that metamorphose at relatively small sizes. Habitat type had the strongest effect on movement, while body size had more situational and species‐specific effects on movement. We found that individuals moved the farthest in habitat types that, when given the choice, they oriented away from, suggesting that these habitats are less favorable and could represent barriers to movement.
  5. Overall, our work demonstrated that differences in habitat type had strong impacts on individual movement behavior and influenced choices at habitat edges. By integrating intrinsic and extrinsic factors into our study, we provided evidence that population connectivity may be influenced not only by the habitat matrix but also by the condition of the individuals leaving the habitat patch.
  相似文献   

14.
Composition and diversity in gut microbiota are impacted by a wide variety of factors. The similarity of gut microbiota in related or sympatric species has been gaining recent traction. Here, 16S rRNA gene sequencing technology was employed to study the gut microbiota of three sympatric frog species, namely Odorrana tormota, O. graminea, and Amolops wuyiensis. In these three frog species, the most abundant phylum was Proteobacteria, followed by Bacteroidetes, Verrucomicrobia, and Firmicutes. The most abundant family was Burkholderiaceae in three species. The most dominant genera were Burkholderia, Caballeronia, and Paraburkholderia with the highest relative abundance in O. tormota, O. graminea, and A. wuyiensis, respectively. No differences were observed in alpha diversity indexes among the three frog species. However, bacterial similarity of gut microbiota was significantly different between O. tormota and A. wuyiensis and between O. graminea and A. wuyiensis. Metabolism‐related gene function was predominantly enriched in the gut microbiota of the three evaluated frog species. From these findings, that the relative abundance of the gut microbiota and predicted gene functions differed in three species, we conclude that there were significant differences in the gut microbiota of the three species. Similar alpha diversity and interspecific bacterial similarity in the gut might be related to bacterial transmission among the three Anura frogs evaluated in this study.  相似文献   

15.
In the present study, we surveyed the distribution and diversity of fungal assemblages associated with 10 species of marine animals from Antarctica. The collections yielded 83 taxa from 27 distinct genera, which were identified using molecular biology methods. The most abundant taxa were Cladosporium sp. 1, Debaryomyces hansenii, Glaciozyma martinii, Metschnikowia australis, Pseudogymnoascus destructans, Thelebolus cf. globosus, Pseudogymnoascus pannorum, Tolypocladium tundrense, Metschnikowia australis, and different Penicillium species. The diversity, richness, and dominance of fungal assemblages ranged among the host; however, in general, the fungal community, which was composed of endemic and cold-adapted cosmopolitan taxa distributed across the different sites of Antarctic Peninsula, displayed high diversity, richness, and dominance indices. Our results contribute to knowledge about fungal diversity in the marine environment across the Antarctic Peninsula and their phylogenetic relationships with species that occur in other cold, temperate, and tropical regions of the World. Additionally, despite their extreme habitats, marine Antarctic animals shelter cryptic and complex fungal assemblages represented by endemic and cosmopolitan cold-adapted taxa, which may represent interesting models to study different symbiotic associations between fungi and their animal hosts in the extreme conditions of Antarctica.  相似文献   

16.
Remote populations are predicted to be vulnerable owing to their isolation from potential source reefs, and usually low population size and associated increased extinction risk. We investigated genetic diversity, population subdivision and connectivity in the brooding reef coral Seriatopora hystrix at the limits of its Eastern Australian (EA) distribution and three sites in the southern Great Barrier Reef (GBR). Over the approximately 1270 km survey range, high levels of population subdivision were detected (global FST = 0.224), with the greatest range in pairwise FST values observed among the three southernmost locations: Lord Howe Island, Elizabeth Reef and Middleton Reef. Flinders Reef, located between the GBR and the more southerly offshore reefs, was highly isolated and showed the signature of a recent bottleneck. High pairwise FST values and the presence of multiple genetic clusters indicate that EA subtropical coral populations have been historically isolated from each other and the GBR. One putative first-generation migrant was detected from the GBR into the EA subtropics. Occasional long-distance dispersal is supported by changes in species composition at these high-latitude reefs and the occurrence of new species records over the past three decades. While subtropical populations exhibited significantly lower allelic richness than their GBR counterparts, genetic diversity was still moderately high. Furthermore, subtropical populations were not inbred and had a considerable number of private alleles. The results suggest that these high-latitude S. hystrix populations are supplemented by infrequent long-distance migrants from the GBR and may have adequate population sizes to maintain viability and resist severe losses of genetic diversity.  相似文献   

17.
A new species of Tullbergia from Argentina is described and illustrated; it is differentiated from Tullbergia paranensis by the number of vesicles of postantennal organ, pseudocelli shape and its formulae and the number of dorsal sensilla on Ant. IV. In addition a key for the identification of the members of the family from Argentina is included.  相似文献   

18.
After treatment with d-galactose oxidase to form an aldehyde group, d-galactose or 2-acetamido-2-deoxy-d-galactose reacted with indole-hydrochloric acid to give a colored compound having a spectrum very similar to that of d-galacturonic acid, but with a maximum at 500 nm and a shoulder at 480 nm. The reaction is linear between 16.6 and 83 nmol of sugar per mL of final solution. 2-Amino-2-deoxy-d-galactose gave no reaction, even when 5 μmol were used, and 2-deoxy-d-lyxo-hexose did not interfere either.  相似文献   

19.
Glutathione (GSH) is an antioxidant synthesized from three constitutive amino acids (CAA): cysteine (Cys), glycine (Gly) and glutamate (Glu). Glutathione plays an important role in oocyte maturation, fertilization and early embryo development. This study aimed to investigate the effect of Cys (0.6 mM), Gly (0.6 mM) and Glu (0.9 mM) supplementation during in vitro fertilization (IVF) of cattle oocytes. In a Pilot Experiment, de novo synthesis of GSH in bovine zygote was evaluated using a modified TALP medium prepared without MEM-essential and MEM-non-essential amino acids (mTALP): mTALP + CAA (constitutive amino acids); mTALP + CAA+5 mMBSO (buthionine sulfoximide); mTALP + Cys + Gly; mTALP + Cys + Glu and mTALP + Gly + Glu. This evidence led us to investigate the impact of CAA supplementation to TALP medium (with essential and non-essential amino acids) on zygote viability, lipid peroxidation, total intracellular GSH content (include reduced and oxidized form; GSH-GSSG), pronuclear formation in zygotes and subsequent embryo development. IVF media contained a) TALP; b) TALP + Cys + Gly + Glu (TALP + CAA); c) TALP + Cys + Gly; d) TALP + Cys + Glu; e) TALP + Gly + Glu, were used. Total GSH-GSSG concentration was increased in TALP, TALP + CAA, and TALP + Cys + Gly. The viability of zygote was similar among treatments. Lipid peroxidation was increased in zygote fertilized with TALP + Cys + Gly; TALP + Cys + Glu; TALP + Gly + Glu and TALP + CAA. The percentage of penetrated oocytes decreased in TALP + CAA and TALP + Cys + Gly. The cleavage rate was lower in TALP + CAA and TALP + Gly + Glu. The percentage of embryos developing to the blastocyst stage was lower in TALP + Cys + Glu and TALP + CAA. In conclusion, we have demonstrated the synthesis of GSH during IVF. However, Cys, Gly and Glu supplementation to TALP medium had negative effects on embryonic development.  相似文献   

20.
Miocene scleractinian corals were documented for the first time in the Fırat Formation of Sarıca village, Eğil district of Diyarbakır, SE Turkey. The fauna consists of four hermatypic species belonging to three families: Diploastrea taurinensis (d’Achiardi, 1868), Tarbellastraea reussiana (Milne-Edwards and Haime, 1850), Echinopora gemmacea (Lamarck, 1816) and Montastraea pelouaensis (Chevalier, 1954). The morphospecies described here are typical of the early Miocene (Aquitanian-Burdigalian) and show that the Fırat Formation coral community was composed of shallow and subtropical reefs of Mediterranean Tethys palaeobiogeographical affinity. The examined species are reef components found in tropical and subtropical oceans, as are the majority of zooxanthellae. The species were upper photic zone related, had massive colonial growth morphology, and lived in a shallow tropical-subtropical marine palaeoenvironment at a depth of up to 50 m. They grew on hard ground, clean water, and normal salinity and required a minimum seawater temperature of 18 ̊C; however, they were most abundant at water temperatures ranging from 22 to 26 ̊C in high-moderate water energy. Consequently, this fossil assemblage will not only improve our knowledge of scleractinian coral diversity and morphological variation in SE Turkey but will also provide an important background for future studies of coral taxonomy, diversity and biogeography of the region.  相似文献   

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