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Cell Jul 2023Snakes are a remarkable squamate lineage with unique morphological adaptations, especially those related to the evolution of vertebrate skeletons, organs, and sensory...
Snakes are a remarkable squamate lineage with unique morphological adaptations, especially those related to the evolution of vertebrate skeletons, organs, and sensory systems. To clarify the genetic underpinnings of snake phenotypes, we assembled and analyzed 14 de novo genomes from 12 snake families. We also investigated the genetic basis of the morphological characteristics of snakes using functional experiments. We identified genes, regulatory elements, and structural variations that have potentially contributed to the evolution of limb loss, an elongated body plan, asymmetrical lungs, sensory systems, and digestive adaptations in snakes. We identified some of the genes and regulatory elements that might have shaped the evolution of vision, the skeletal system and diet in blind snakes, and thermoreception in infrared-sensitive snakes. Our study provides insights into the evolution and development of snakes and vertebrates.
Topics: Animals; Snakes; Genome; Adaptation, Physiological; Acclimatization; Evolution, Molecular; Phylogeny; Biological Evolution
PubMed: 37339633
DOI: 10.1016/j.cell.2023.05.030 -
Toxins Dec 2023Venom components are invaluable in biomedical research owing to their specificity and potency. Many of these components exist in two genera of rattlesnakes, and , with... (Review)
Review
Venom components are invaluable in biomedical research owing to their specificity and potency. Many of these components exist in two genera of rattlesnakes, and , with high toxicity and proteolytic activity variation. This review focuses on venom components within rattlesnakes, and offers a comparison and itemized list of factors dictating venom composition, as well as presenting their known characteristics, activities, and significant applications in biosciences. There are 64 families and subfamilies of proteins present in and venom. Snake venom serine proteases (SVSP), snake venom metalloproteases (SVMP), and phospholipases A2 (PLA2) are the standard components in and venom. Through this review, we highlight gaps in the knowledge of rattlesnake venom; there needs to be more information on the venom composition of three species and one subspecies. We discuss the activity and importance of both major and minor components in biomedical research and drug development.
Topics: Humans; Animals; Crotalid Venoms; Snake Venoms; Serine Proteases; Serine Endopeptidases; Phospholipases A2; Crotalus; Crotalinae
PubMed: 38276526
DOI: 10.3390/toxins16010002 -
Viruses Oct 2023Tobamoviruses are plant-infecting viruses with an ancient lineage, understood to have arisen during the age of the dinosaurs in the Cretaceous period 145-66 million...
Tobamoviruses are plant-infecting viruses with an ancient lineage, understood to have arisen during the age of the dinosaurs in the Cretaceous period 145-66 million years ago [...].
Topics: Animals; Phylogeny; Tobamovirus; Plant Viruses; Dinosaurs
PubMed: 38005852
DOI: 10.3390/v15112174 -
Nature Communications Aug 2023Lizards cannot naturally regenerate limbs but are the closest known relatives of mammals capable of epimorphic tail regrowth. However, the mechanisms regulating lizard...
Lizards cannot naturally regenerate limbs but are the closest known relatives of mammals capable of epimorphic tail regrowth. However, the mechanisms regulating lizard blastema formation and chondrogenesis remain unclear. Here, single-cell RNA sequencing analysis of regenerating lizard tails identifies fibroblast and phagocyte populations linked to cartilage formation. Pseudotime trajectory analyses suggest spp1-activated fibroblasts as blastema cell sources, with subsets exhibiting sulf1 expression and chondrogenic potential. Tail blastema, but not limb, fibroblasts express sulf1 and form cartilage under Hedgehog signaling regulation. Depletion of phagocytes inhibits blastema formation, but treatment with pericytic phagocyte-conditioned media rescues blastema chondrogenesis and cartilage formation in amputated limbs. The results indicate a hierarchy of phagocyte-induced fibroblast gene activations during lizard blastema formation, culminating in sulf1 pro-chondrogenic populations singularly responsive to Hedgehog signaling. These properties distinguish lizard blastema cells from homeostatic and injury-stimulated fibroblasts and indicate potential actionable targets for inducing regeneration in other species, including humans.
Topics: Humans; Animals; Hedgehog Proteins; Chondrogenesis; Lizards; Fibroblasts; Single-Cell Analysis; Tail; Mammals
PubMed: 37563130
DOI: 10.1038/s41467-023-40206-z -
Biology Open Aug 2023This review highlights the largely understudied behavior of gliding locomotion, which is exhibited by a diverse range of animals spanning vertebrates and invertebrates,... (Review)
Review
This review highlights the largely understudied behavior of gliding locomotion, which is exhibited by a diverse range of animals spanning vertebrates and invertebrates, in air and in water. The insights in the literature gained from January 2022 to December 2022 continue to challenge the previously held notion of gliding as a relatively simple form of locomotion. Using advances in field/lab data collection and computation, the highlighted studies cover gliding in animals including seabirds, flying lizards, flying snakes, geckos, dragonflies, damselflies, and dolphins. Altogether, these studies present gliding as a sophisticated behavior resulting from the interdependent aspects of morphology, sensing, environment, and likely selective pressures. This review uses these insights as inspiration to encourage researchers to revisit gliding locomotion, both in the animal's natural habitat and in the laboratory, and to investigate questions spanning gliding biomechanics, ecology, sensing, and the evolution of animal flight.
Topics: Animals; Odonata; Wings, Animal; Locomotion; Flight, Animal; Biomechanical Phenomena; Lizards
PubMed: 37581305
DOI: 10.1242/bio.059973 -
Seminars in Nuclear Medicine Sep 2023The bulk of biomedical positron emission tomography (PET)-scanning experiments are performed on mammals (ie, rodents, pigs, and dogs), and the technique is only... (Review)
Review
The bulk of biomedical positron emission tomography (PET)-scanning experiments are performed on mammals (ie, rodents, pigs, and dogs), and the technique is only infrequently applied to answer research questions in ectothermic vertebrates such as fish, amphibians, and reptiles. Nevertheless, many unique and interesting physiological characteristics in these ectothermic vertebrates could be addressed in detail through PET. The low metabolic rate of ectothermic animals, however, may compromise the validity of physiological and biochemical parameters derived from the images created by PET and other scanning modalities. Here, we review some of the considerations that should be taken into account when PET scanning fish, amphibians, and reptiles. We present specific results from our own experiments, many of which remain previously unpublished, and we draw on examples from the literature. We conclude that knowledge on the natural history and physiology of the species studied and an understanding of the limitations of the PET scanning techniques are necessary to avoid the design of faulty experiments and erroneous conclusions.
Topics: Animals; Swine; Dogs; Vertebrates; Reptiles; Amphibians; Fishes; Positron-Emission Tomography; Mammals
PubMed: 37438172
DOI: 10.1053/j.semnuclmed.2023.06.006 -
PLoS Neglected Tropical Diseases Jul 2023The world-famous markets of Marrakech, also known in Arabic as souks, harbor a vast diversity of reptiles that are sold for medicinal/magic/pet purposes or used for...
The world-famous markets of Marrakech, also known in Arabic as souks, harbor a vast diversity of reptiles that are sold for medicinal/magic/pet purposes or used for snake charming. This unique epidemiological context has never been studied considering the interactions of humans, reptiles, and zoonotic pathogens. Thus, the aim of this study was to identify the parasites and pathogens present in blood and feces associated with handled reptiles in the markets of Marrakech to assess the risk of zoonotic transmission within the reptile-human interface. Privately owned reptiles (n = 118), coming from vendors or snake charmers, were examined and blood and feces sampled. DNA was extracted and molecular screening (cPCR, nPCR, qPCR, dqPCR) was performed aiming to identify potentially zoonotic pathogens (i.e., Anaplasma/Ehrlichia spp., Rickettsia spp., Borrelia burgdorferi sensu lato, Coxiella burnetii, Babesia/Theileria spp., Cryptosporidium spp., Giardia spp., Leishmania spp., Cestoda). Overall, 28.9% (34/118) of reptiles were positive for at least one pathogen. In blood, Anaplasma spp. were detected in four snakes, with two Montpellier snakes positive for Anaplasma phagocytophilum, while Rickettsia spp. were detected in one Mediterranean chameleon and four puff adders. Leishmania tarentolae was molecularly detected in a Mediterranean chameleon and a Montpellier snake. In feces, the cox1 gene generated a myriad of sequences for nematodes, cestodes, fungi and bacteria. Importantly, Proteus vulgaris was identified from a Mediterranean chameleon. Cryptosporidium spp. nPCR yielded a positive sample (i.e., Cryptosporidium sp. apodemus genotype I) from a Moroccan worm lizard, as well as for bacteria such as Pseudomonas aeruginosa in an Egyptian cobra, and Morganella morganii from a puff adder. Results from this study demonstrated the risk of zoonotic transmission of microorganisms and parasites present in blood and feces from reptiles that are brought to the souks in Marrakech, Morocco, to be sold for medicinal purposes or used for snake charming, being in direct and straight contact with humans.
Topics: Animals; Humans; Cryptosporidiosis; Morocco; Cryptosporidium; Rickettsia; Parasites; Anaplasma; Snakes; Reptiles
PubMed: 37467211
DOI: 10.1371/journal.pntd.0011431 -
European Journal of Protistology Apr 2024The zoonotic potential of the protist parasites Cryptosporidium spp. and Giardia duodenalis in amphibians and reptiles raises public health concerns due to their growing... (Review)
Review
The zoonotic potential of the protist parasites Cryptosporidium spp. and Giardia duodenalis in amphibians and reptiles raises public health concerns due to their growing popularity as pets. This review examines the prevalence and diversity of these parasites in wild and captive amphibians and reptiles to better understand the zoonotic risk. Research on Giardia in both groups is limited, and zoonotic forms of Cryptosporidium or Giardia have not been reported in amphibians. Host-adapted Cryptosporidium species dominate in reptiles, albeit some reptiles have been found to carry zoonotic (C. hominis and C. parvum) and rodent-associated (C. tyzzeri, C. muris and C. andersoni) species, primarily through mechanical carriage. Similarly, the limited reports of Giardia duodenalis (assemblages A, B and E) in reptiles may also be due to mechanical carriage. Thus, the available evidence indicates minimal zoonotic risk associated with these organisms in wild and captive frogs and reptiles. The exact transmission routes for these infections within reptile populations remain poorly understood, particularly regarding the importance of mechanical carriage. Although the risk appears minimal, continued research and surveillance efforts are necessary to gain a more comprehensive understanding of the transmission dynamics and ultimately improve our ability to safeguard human and animal health.
Topics: Animals; Humans; Giardiasis; Cryptosporidiosis; Cryptosporidium; Zoonoses; Giardia lamblia; Anura; Reptiles; Prevalence; Feces
PubMed: 38442435
DOI: 10.1016/j.ejop.2024.126066 -
Gesundheitswesen (Bundesverband Der... Feb 2024
Topics: Animals; Dinosaurs; Germany
PubMed: 38378012
DOI: 10.1055/a-2220-7799 -
ELife Mar 2024Gasdermins oligomerize to form pores in the cell membrane, causing regulated lytic cell death called pyroptosis. Mammals encode five gasdermins that can trigger...
Gasdermins oligomerize to form pores in the cell membrane, causing regulated lytic cell death called pyroptosis. Mammals encode five gasdermins that can trigger pyroptosis: GSDMA, B, C, D, and E. Caspase and granzyme proteases cleave the linker regions of and activate GSDMB, C, D, and E, but no endogenous activation pathways are yet known for GSDMA. Here, we perform a comprehensive evolutionary analysis of the gasdermin family. A gene duplication of GSDMA in the common ancestor of caecilian amphibians, reptiles, and birds gave rise to GSDMA-D in mammals. Uniquely in our tree, amphibian, reptile, and bird GSDMA group in a separate clade than mammal GSDMA. Remarkably, GSDMA in numerous bird species contain caspase-1 cleavage sites like YVAD or FASD in the linker. We show that GSDMA from birds, amphibians, and reptiles are all cleaved by caspase-1. Thus, GSDMA was originally cleaved by the host-encoded protease caspase-1. In mammals the caspase-1 cleavage site in GSDMA is disrupted; instead, a new protein, GSDMD, is the target of caspase-1. Mammal caspase-1 uses exosite interactions with the GSDMD C-terminal domain to confer the specificity of this interaction, whereas we show that bird caspase-1 uses a stereotypical tetrapeptide sequence to confer specificity for bird GSDMA. Our results reveal an evolutionarily stable association between caspase-1 and the gasdermin family, albeit a shifting one. Caspase-1 repeatedly changes its target gasdermin over evolutionary time at speciation junctures, initially cleaving GSDME in fish, then GSDMA in amphibians/reptiles/birds, and finally GSDMD in mammals.
Topics: Animals; Caspase 1; Caspases; Gasdermins; Inflammasomes; Amphibians; Reptiles; Birds
PubMed: 38497531
DOI: 10.7554/eLife.92362