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1.
Zhen Ci Yan Jiu ; 47(9): 847-50, 2022 Sep 25.
Artigo em Chinês | MEDLINE | ID: mdl-36153462

RESUMO

Long snake moxibustion, a kind of indirect moxibustion therapy for stimulating the midline part of the back of the patient's body after playing a layer of ginger or garlic mud, is frequently used to treat spine disorders and deficiency-cold type syndromes. In the present paper, we introduced our newly made moxibustion box for applying long snake moxibustion which is safe and easy to operate and can be freely moved at any time in the treatment of vertebral diseases, and conveniently makes the ignited-moxa close to the locus. This newly-designed moxibustion box is made of two lines of paralleled flexible connection side plates hinged ends to ends and two U-like connection plates at the opposite two ends to construct a rectangular frame device. The hinged design makes the long snake moxibustion box conform to the physiological curvature of human body and its length can be adjusted according to the height of patients. When used in clinical practice, it can enhance the patients' safety and reduce the operator's working intensity, and may be helpful to the popularization and development of long snake moxibustion therapy.


Assuntos
Gengibre , Moxibustão , Pontos de Acupuntura , Animais , Humanos , Serpentes/genética
2.
J Infect Dev Ctries ; 16(8.1): 45S-51S, 2022 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-36156502

RESUMO

INTRODUCTION: In Sub-Saharan Africa, snakebites are a public health problem. In Ethiopia, clinical cases have been described, but little information exists on snakebites burden and its geographical distribution. The aim of this study was to document the spatial distribution of venomous snakes and snakebites in Ethiopia. METHODOLOGY: In a cross-sectional observational study, venomous snakes were collected during snake catching activities in six Ethiopian hotspot areas between April 2015 and September 2020. Species and habitat were described. In the hotspot areas, routine health information data on reported snakebites was collected in 78 districts and subsequently used to map annual incidence per district. RESULTS: A total of 333 snakes were collected and 14 species were identified. The most prevalent species were Bitis arietans, Bitis arietanus somalica, Echis pyramidum, known as vipers, and Naja pallida, known as cobra. The highest number of snakes (75) was observed in the Northwest and Eastern parts of Ethiopia, mostly in cultivation and man-made farm land, wooded and moist dry savanna. In each hotspot a wide variety of species was observed, although composition was different. The highest snakebite incidence overlapped with the high snakes densities in Northwest Ethiopia. The snakebite annual average incidence at district level was very heterogeneous and ranged from < 15 cases/100,000 inhabitants (44% of the districts) to 309.2 cases/100,000 inhabitants. CONCLUSIONS: Snake diversity and distribution, linked to high incidence of snakebites in the hotspots, suggests a close interconnection between human, animal and environmental systems and could inform the need for antivenoms per geographical locality.


Assuntos
Mordeduras de Serpentes , Animais , Antivenenos , Estudos Transversais , Etiópia/epidemiologia , Humanos , Mordeduras de Serpentes/epidemiologia , Serpentes
3.
An Acad Bras Cienc ; 94(suppl 3): e20210991, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36074426

RESUMO

Batesian mimicry may result in remarkable cases of phenotypic convergence that represent classic examples of evolution through natural selection. The existence of mimicry systems among coral snakes, however, remains controversial because of contradictions between the predictions of mimetic theory and the empirical patterns of co-occurrence and species abundance. Here, we analyze the geographic distribution of coral snake species of the genus Micrurus and populations of the false coral snake Atractus latifrons in Amazonia, and perform ecological niche modeling (ENM) analyzes to generate potential geographic distributions of species of Micrurus and A. latifrons, identify patterns of co-occurrence and assess whether the distribution of A. latifrons coincides with the distribution of Micrurus species, which could suggest the existence of a possible mimetic relationship between the species. We identified six Micrurus species that may represent mimetic models for A. latifrons. The results of the co-occurrence analysis corroborates the results from ENM, indicating that chromatic patterns of A. latifrons and their respective model species are aggregated. Our study suggests that all color patterns of A. latifrons - including the tricolor monads, and the more common tricolor dyads and tricolor tetrads - may benefit from the resemblance with other Micrurus species as perfect and imperfect mimics.


Assuntos
Antozoários , Cobras Corais , Animais , Brasil , Seleção Genética , Serpentes
4.
Int J Mol Sci ; 23(17)2022 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-36077479

RESUMO

Anan's rock agama (Laudakia sacra) is a lizard species endemic to the harsh high-altitude environment of the Qinghai-Tibet Plateau, a region characterized by low oxygen tension and high ultraviolet (UV) radiation. To better understand the genetic mechanisms underlying highland adaptation of ectotherms, we assembled a 1.80-Gb L. sacra genome, which contained 284 contigs with an N50 of 20.19 Mb and a BUSCO score of 93.54%. Comparative genomic analysis indicated that mutations in certain genes, including HIF1A, TIE2, and NFAT family members and genes in the respiratory chain, may be common adaptations to hypoxia among high-altitude animals. Compared with lowland reptiles, MLIP showed a convergent mutation in L. sacra and the Tibetan hot-spring snake (Thermophis baileyi), which may affect their hypoxia adaptation. In L. sacra, several genes related to cardiovascular remodeling, erythropoiesis, oxidative phosphorylation, and DNA repair may also be tailored for adaptation to UV radiation and hypoxia. Of note, ERCC6 and MSH2, two genes associated with adaptation to UV radiation in T. baileyi, exhibited L. sacra-specific mutations that may affect peptide function. Thus, this study provides new insights into the potential mechanisms underpinning high-altitude adaptation in ectotherms and reveals certain genetic generalities for animals' survival on the plateau.


Assuntos
Altitude , Lagartos , Adaptação Fisiológica/genética , Animais , Hipóxia/genética , Sacro , Seleção Genética , Serpentes , Tibet
5.
Zootaxa ; 5128(1): 61-83, 2022 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-36101186

RESUMO

We performed a molecular phylogenetic analysis for the ground skink populations of the genus Scincella Mittleman, 1950 on Yonagunijima Island, Southern Ryukyus and representative samples of Scincella species known from other islands of the East Asian Archipelago. Partial mitochondrial cytochrome c oxidase subunit I and cytochrome b sequence data were used. Additionally, we examined the nuclear genetic variation between the Yonagunijima samples and those of closely related species. The genetic distances were largely equivalent between the Yonagunijima population and the two closest species, S. boettgeri from other southern Ryukyu Islands and S. formosensis from Taiwan. Moreover, there were nuclear haplotypes unique to the Yonagunijima population. We thus recognize the Yonagunijima population as a distinct species and describe it as Scincella dunan sp. nov. Morphologically, S. dunan sp. nov. is similar to S. boettgeri, but differs in some morphometric and meristic characters, and dorsolateral stripe pattern. These findings further support the biogeographically unique status of Yonagunijima Island among the southern Ryukyus islands.


Assuntos
Lagartos , Animais , Citocromos b/genética , Japão , Filogenia , Serpentes
6.
Zootaxa ; 5168(3): 375-387, 2022 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-36101279

RESUMO

A new snake of the genus Achalinus Peters, 1869 is described based on an adult male specimen from Son La Province, Vietnam. Achalinus vanhoensis sp. nov. can be distinguished from its congeners by a combination of the following characters: 1) maxillary teeth 32; 2) suture between the internasals distinctly longer than that between the prefrontals; 3) loreal fused with prefrontal, prefrontals stretch towards the supralabials; 4) dorsal scales in 252323 rows, keeled; 5) supralabials six (left) and seven (right); 6) infralabials six; 7) temporals 2+2, the two anterior temporals in broad contact with eye; 8) ventrals 176; 9) subcaudals 84, entire; 10) cloacal entire; 11) dorsum in preservative dark purple grey above; 12) venter somewhat lighter with yellow-edged scales in the chin region, including infralabials; 13) posterior edges of ventrals and subcaudals with yellow margin. In the molecular analysis, the new species is recovered as a sister taxon of Achalinus timi, a species endemic to Vietnam, and genetically the two species are around 5% divergent from each other based on a fragment of the mitochondrial COI gene. This discovery brings the number of Achalinus species known from Vietnam to nine.


Assuntos
Lagartos , Serpentes , Distribuição Animal , Estruturas Animais , Animais , Lagartos/genética , Masculino , Núcleo Familiar , Vietnã
7.
Toxins (Basel) ; 14(9)2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36136544

RESUMO

Snakebite envenomation is considered a neglected tropical disease, affecting tens of thousands of people each year. The recommended treatment is the use of antivenom, which is composed of immunoglobulins or immunoglobulin fragments obtained from the plasma of animals hyperimmunized with one (monospecific) or several (polyspecific) venoms. In this review, the efforts made in the improvement of the already available antivenoms and the development of new antivenoms, focusing on snakes of medical importance from sub-Saharan Africa and Latin America, are described. Some antivenoms currently used are composed of whole IgGs, whereas others use F(ab')2 fragments. The classic methods of attaining snake antivenoms are presented, in addition to new strategies to improve their effectiveness. Punctual changes in immunization protocols, in addition to the use of cross-reactivity between venoms from different snakes for the manufacture of more potent and widely used antivenoms, are presented. It is known that venoms are a complex mixture of components; however, advances in the field of antivenoms have shown that there are key toxins that, if effectively blocked, are capable of reversing the condition of in vivo envenomation. These studies provide an opportunity for the use of monoclonal antibodies in the development of new-generation antivenoms. Thus, monoclonal antibodies and their fragments are described as a possible alternative for the production of antivenoms, regardless of the venom. This review also highlights the challenges associated with their development.


Assuntos
Antivenenos , Mordeduras de Serpentes , Animais , Anticorpos Monoclonais , Antivenenos/uso terapêutico , Humanos , Fragmentos de Imunoglobulinas , Mordeduras de Serpentes/tratamento farmacológico , Serpentes
8.
Emerg Infect Dis ; 28(10): 2064-2068, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36148931

RESUMO

The fungus Ophiodimyces ophiodiicola is the etiologic agent of snake fungal disease. Recent findings date US occurrence at least as far back as 1945. We analyzed 22 free-ranging snakes with gross lesions consistent with snake fungal disease from museum collections from Europe. We found 5 positive samples, the oldest collected in 1959.


Assuntos
Micoses , Serpentes , Animais , Europa (Continente)/epidemiologia , Fungos , Micoses/epidemiologia , Micoses/microbiologia , Micoses/veterinária , Serpentes/microbiologia
9.
Curr Biol ; 32(18): R939-R940, 2022 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-36167038

RESUMO

Catania provides an introduction to tentacled snakes and their ingenious ability to capture fish.


Assuntos
Colubridae , Animais , Peixes , Serpentes
10.
PLoS Negl Trop Dis ; 16(9): e0010723, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36048902

RESUMO

The acute effects of snakebite are often emphasized, with less information on long-term effects. We aimed to describe the long-term health effects perceived by patients followed up after confirmed snakebites. Two groups of snakebite patients (>18y) from the Anuradhapura snakebite cohort were reviewed: Group I had a snakebite during August 2013-October 2014 and was reviewed after 4 years, and group II had a snakebite during May 2017-August 2018, and was reviewed after one year. Patients were invited by telephone, by sending letters, or doing home visits, including 199 of 736 patients (27%) discharged alive from group I and 168 of 438 patients (38%) from group II, a total of 367 followed up. Health effects were categorised as musculoskeletal, impact on daily life, and medically unexplained. Health issues were attributed to snakebite in 107/199 patients (54%) from group I and 55/168 patients (33%) from group II, suggesting the proportion with health issues increases with time. Sixteen patients (all viperine bites) had permanent musculoskeletal problems, none with a significant functional disability affecting daily routine. 217/367 reported being more vigilant about snakes while working outdoors, but only 21/367 were using protective footwear at review. Of 275 farmers reviewed, only six (2%) had restricted farming activities due to fear of snakebite, and only one stopped farming. 104/199 (52%) of group I and 42/168 (25%) of group II attributed non-specific symptoms (fatigue, body aches, pain, visual impairment) and/or oral cavity-related symptoms (avulsed teeth, loose teeth, receding gums) to the snakebite, which cannot be explained medically. In multivariate logistic regression, farming, type of snake, antivenom administration, and time since snakebite were associated with medically unexplained symptoms. The latter suggests medically unexplained effects increased with time. Based on two groups of snakebite patients reviewed one and four years post-bite, we show that long-term musculoskeletal disabilities are uncommon and not severe in snakebite survivors in rural Sri Lanka. However, a large portion of patients complain of various non-specific general and oral symptoms, not explainable based on the known pathophysiology of snakebite. These perceived effects of snakebite were more common in patients with systemic envenoming, and were more frequent the longer the time post-bite.


Assuntos
Mordeduras de Serpentes , Animais , Antivenenos/efeitos adversos , Estudos de Coortes , Humanos , Mordeduras de Serpentes/complicações , Mordeduras de Serpentes/epidemiologia , Serpentes , Sri Lanka/epidemiologia
12.
J Exp Biol ; 225(17)2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-35946379

RESUMO

Sublethal dehydration can cause negative physiological effects, but recent studies investigating the sub-lethal effects of dehydration on innate immune performance in reptiles have found a positive correlation between innate immune response and plasma osmolality. To investigate whether this is an adaptive trait that evolved in response to dehydration in populations inhabiting water-scarce environments, we sampled free-ranging cottonmouth snakes (n=26 adult cottonmouths) from two populations inhabiting contrasting environments in terms of water availability: Snake Key (n=12), an island with no permanent sources of fresh water, and Paynes Prairie (n=14), a flooded freshwater prairie. In addition to field surveys, we manipulated the hydration state of 17 cottonmouths (Paynes Prairie n=9, Snake Key n=8) in a laboratory setting and measured the response of corticosterone and innate immune performance to dehydration with the aim of identifying any correlation or trade-offs between them. We measured corticosterone of cottonmouths at a baseline level and then again following a 60 min stress test when at three hydration states: hydrated, dehydrated and rehydrated. We found that innate immune performance improved with dehydration and then returned to baseline levels within 48 h of rehydration, which agrees with previous research in reptiles. Despite the frequent exposure of cottonmouths on Snake Key to dehydrating conditions, we did not find cottonmouths inhabiting the island to show a greater magnitude or more prolonged immune response compared with cottonmouths from Paynes Prairie. We also found a positive association between dehydration and corticosterone values.


Assuntos
Agkistrodon , Crotalinae , Agkistrodon/fisiologia , Animais , Corticosterona , Desidratação/veterinária , Imunidade Inata/fisiologia , Serpentes/fisiologia , Água
13.
Toxins (Basel) ; 14(8)2022 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-36006232

RESUMO

We aimed to make an exhaustive assessment of circumstances of bites by exotic reptiles bred in France. A retrospective observational study was conducted in all the reported cases from 2000 to 2020 in French poison control centers (PCCs). Two hundred and eighteen cases of bites were recorded. The sex ratio (M/F) of the patients was 1.79 and the mean age of the patients was 29.0 ± 15.8 years. Twenty-two cases (10.1%) occurred during the deep night. One hundred and eighty-six bites (85.7%) occurred in a private context; however, there were more cases of high severity when it occurred in a professional setting (60.0% vs. 11.2%, p < 0.01). The feeding/nursing activity accounted for 54.7% cases. Forty-three species of snake were identified; 28 were considered venomous. There were no deaths among the patients in the study. Most of the cases (85.8%) were of mild severity. All of the patients bitten by a venomous reptile were hospitalized: 10 patients received an antivenom; and 2 required surgery. Bites occurred at home and by a small number of popular non-venomous reptile species (pythons and boas, colubrids). These occurred mainly when handling the animals. The rare envenomations were mainly by Asian and American crotalids, followed by elapids. One-third of them were treated with antivenom when available.


Assuntos
Antivenenos , Mordeduras de Serpentes , Animais , Centros de Controle de Intoxicações , Répteis , Mordeduras de Serpentes/epidemiologia , Serpentes , Estados Unidos , Peçonhas
14.
PLoS Negl Trop Dis ; 16(8): e0010647, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35969634

RESUMO

BACKGROUND: Snakebite envenoming is a neglected tropical disease that kills an estimated 81,000 to 138,000 people and disables another 400,000 globally every year. The World Health Organization aims to halve this burden by 2030. To achieve this ambitious goal, we need to close the data gap in snake ecology and snakebite epidemiology and give healthcare providers up-to-date knowledge and access to better diagnostic tools. An essential first step is to improve the capacity to identify biting snakes taxonomically. The existence of AI-based identification tools for other animals offers an innovative opportunity to apply machine learning to snake identification and snakebite envenoming, a life-threatening situation. METHODOLOGY: We developed an AI model based on Vision Transformer, a recent neural network architecture, and a comprehensive snake photo dataset of 386,006 training photos covering 198 venomous and 574 non-venomous snake species from 188 countries. We gathered photos from online biodiversity platforms (iNaturalist and HerpMapper) and a photo-sharing site (Flickr). PRINCIPAL FINDINGS: The model macro-averaged F1 score, which reflects the species-wise performance as averaging performance for each species, is 92.2%. The accuracy on a species and genus level is 96.0% and 99.0%, respectively. The average accuracy per country is 94.2%. The model accurately classifies selected venomous and non-venomous lookalike species from Southeast Asia and sub-Saharan Africa. CONCLUSIONS: To our knowledge, this model's taxonomic and geographic coverage and performance are unprecedented. This model could provide high-speed and low-cost snake identification to support snakebite victims and healthcare providers in low-resource settings, as well as zoologists, conservationists, and nature lovers from across the world.


Assuntos
Mordeduras de Serpentes , África ao Sul do Saara , Animais , Antivenenos/uso terapêutico , Inteligência Artificial , Saúde Global , Humanos , Doenças Negligenciadas/diagnóstico , Doenças Negligenciadas/epidemiologia , Mordeduras de Serpentes/diagnóstico , Mordeduras de Serpentes/epidemiologia , Mordeduras de Serpentes/terapia , Serpentes
15.
Proc Biol Sci ; 289(1981): 20220841, 2022 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-35975445

RESUMO

Developmental pathways encompass transcription factors and cis-regulatory elements that interact as transcription factor-regulatory element (TF-RE) units. Independent origins of similar phenotypes likely involve changes in different parts of these units, a hypothesis promisingly tested addressing the evolution of the rib-associated lumbar (RAL) morphotype that characterizes emblematic animals such as snakes and elephants. Previous investigation in these lineages identified a polymorphism in the Homology region 1 [H1] enhancer of the Myogenic factor-5 [Myf5], which interacts with HOX10 proteins to modulate rib development. Here we address the evolution of TF-RE units focusing on independent origins of RAL morphotypes. We compiled an extensive database for H1-Myf5 and HOX10 sequences with two goals: (i) evaluate if the enhancer polymorphism is present in amphibians exhibiting the RAL morphotype and (ii) test a hypothesis of enhanced evolutionary flexibility mediated by TF-RE units, according to which independent origins of the RAL morphotype might involve changes in either component of the interaction unit. We identified the H1-Myf5 polymorphism in lineages that diverged around 340 Ma, including Lissamphibia. Independent origins of the RAL morphotype in Tetrapoda involved sequence variation in either component of the TF-RE unit, confirming that different changes may similarly affect the phenotypic outcome of a given developmental pathway.


Assuntos
Sequências Reguladoras de Ácido Nucleico , Fatores de Transcrição , Anfíbios/metabolismo , Animais , Fator Regulador Miogênico 5/genética , Fator Regulador Miogênico 5/metabolismo , Serpentes/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
16.
PLoS Negl Trop Dis ; 16(8): e0010643, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35960772

RESUMO

BACKGROUND: Snakebite envenomation exerts a heavy toll in sub-Saharan Africa. The design and production of effective polyspecific antivenoms for this region demand a better understanding of the immunological characteristics of the different venoms from the most medically important snakes, to select the most appropriate venom combinations for generating antivenoms of wide neutralizing scope. Bitis spp. and Echis spp. represent the most important viperid snake genera in Africa. METHODOLOGY/PRINCIPAL FINDINGS: Eight rabbit-derived monospecific antisera were raised against the venoms of four species of Bitis spp. and four species of Echis spp. The effects of immunization in the rabbits were assessed, as well as the development of antibody titers, as judged by immunochemical assays and neutralization of lethal, hemorrhagic, and in vitro coagulant effects. At the end of immunizations, local and pulmonary hemorrhage, together with slight increments in the plasma activity of creatine kinase (CK), were observed owing to the action of hemorrhagic and myotoxic venom components. Immunologic analyses revealed a considerable extent of cross-reactivity of monospecific antisera against heterologous venoms within each genus, although some antisera provided a more extensive cross-reactivity than others. The venoms that generated antisera with the broadest coverage were those of Bitis gabonica and B. rhinoceros within Bitis spp. and Echis leucogaster within Echis spp. CONCLUSIONS/SIGNIFICANCE: The methodology followed in this study provides a rational basis for the selection of the best combination of venoms for generating antivenoms of high cross-reactivity against viperid venoms in sub-Saharan Africa. Results suggest that the venoms of B. gabonica, B. rhinoceros, and E. leucogaster generate antisera with the broadest cross-reactivity within their genera. These experimental results in rabbits need to be translated to large animals used in antivenom production to assess whether these predictions are reproduced in horses or sheep.


Assuntos
Viperidae , África ao Sul do Saara , Animais , Antivenenos , Hemorragia , Cavalos , Soros Imunes , Coelhos , Ovinos , Venenos de Serpentes , Serpentes
17.
Sci Rep ; 12(1): 14469, 2022 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-36008512

RESUMO

Traditionally considered the earliest-diverging group of snakes, scolecophidians are central to major evolutionary paradigms regarding squamate feeding mechanisms and the ecological origins of snakes. However, quantitative analyses of these phenomena remain scarce. Herein, we therefore assess skull modularity in squamates via anatomical network analysis, focusing on the interplay between 'microstomy' (small-gaped feeding), fossoriality, and miniaturization in scolecophidians. Our analyses reveal distinctive patterns of jaw connectivity across purported 'microstomatans', thus supporting a more complex scenario of jaw evolution than traditionally portrayed. We also find that fossoriality and miniaturization each define a similar region of topospace (i.e., connectivity-based morphospace), with their combined influence imposing further evolutionary constraint on skull architecture. These results ultimately indicate convergence among scolecophidians, refuting widespread perspectives of these snakes as fundamentally plesiomorphic and morphologically homogeneous. This network-based examination of skull modularity-the first of its kind for snakes, and one of the first to analyze squamates-thus provides key insights into macroevolutionary trends among squamates, with particular implications for snake origins and evolution.


Assuntos
Evolução Biológica , Serpentes , Animais , Cabeça , Filogenia , Crânio/anatomia & histologia , Serpentes/anatomia & histologia
18.
Biological sciences ; 289(1981)Aug. 2022.
Artigo em Inglês | Sec. Est. Saúde SP, CONASS, SESSP-IDPCPROD, Sec. Est. Saúde SP | ID: biblio-1393200

RESUMO

ABSTRACT: Developmental pathways encompass transcription factors and cis-regulatory elements that interact as transcription factor-regulatory element (TF-RE) units. Independent origins of similar phenotypes likely involve changes in different parts of these units, a hypothesis promisingly tested addressing the evolution of the rib-associated lumbar (RAL) morphotype that characterizes emblematic animals such as snakes and elephants. Previous investigation in these lineages identified a polymorphism in the Homology region 1 [H1] enhancer of the Myogenic factor-5 [Myf5], which interacts with HOX10 proteins to modulate rib development. Here we address the evolution of TF-RE units focusing on independent origins of RAL morphotypes. We compiled an extensive database for H1-Myf5 and HOX10 sequences with two goals: (i) evaluate if the enhancer polymorphism is present in amphibians exhibiting the RAL morphotype and (ii) test a hypothesis of enhanced evolutionary flexibility mediated by TF-RE units, according to which independent origins of the RAL morphotype might involve changes in either component of the interaction unit. We identified the H1-Myf5 polymorphism in lineages that diverged around 340 Ma, including Lissamphibia. Independent origins of the RAL morphotype in Tetrapoda involved sequence variation in either component of the TF-RE unit, confirming that different changes may similarly affect the phenotypic outcome of a given developmental pathway.


Assuntos
Animais , Serpentes/genética , Sequências Reguladoras de Ácido Nucleico , Fator Regulador Miogênico 5/genética , Fator Regulador Miogênico 5/metabolismo , Anfíbios/metabolismo
19.
Eur J Neurosci ; 56(6): 4788-4802, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35971965

RESUMO

We examined the behavioural responses and Fos expression pattern of rats that were exposed to snake threats from shed snakeskin and a live snake. We differentiated the behavioural responses and the pattern of Fos expression in response to the odour cues and mild threat from a live snake. Animals exposed to the snake odour alone or to the confined snake showed a great deal of risk assessment. Conversely, the intensification of odour during exposure to the live snake decreased the threat ambiguity, and the animals froze for a significantly longer period. Our Fos analysis showed that a pathway formed by the posteroventral part of the medial amygdalar nucleus to the central part of the ventromedial hypothalamic nucleus appeared to be solely responsive to odour cues. In addition, we showed increased Fos expression in a parallel circuit comprising the lateral amygdalar nucleus, ventral subiculum, lateral septum, and juxtadorsomedial region of the lateral hypothalamic area that is responsive to both the odour and mild threat from a live snake. This path is likely to process the environmental boundaries of the threat to be avoided. Both paths merge into the dorsal premammillary nucleus and periaqueductal grey sites, which all increase Fos expression in response to the snake threats and are likely to organize the defensive responses. Moreover, we found that the snake threat mobilized the Edinger-Westphal and supraoculomotor nuclei, which are involved in stress adaptation and attentional mechanisms.


Assuntos
Complexo Nuclear Basolateral da Amígdala , Comportamento Animal , Animais , Complexo Nuclear Basolateral da Amígdala/metabolismo , Comportamento Animal/fisiologia , Medo/fisiologia , Substância Cinzenta Periaquedutal/fisiologia , Proteínas Proto-Oncogênicas c-fos/metabolismo , Ratos , Serpentes/metabolismo
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