Bioprospecting the American Alligator Peptidome for antiviral peptides against Venezuelan equine encephalitis virus.

The innate immune protection provided by cationic antimicrobial peptides (CAMPs) has been shown to extend to antiviral activity, with putative mechanisms of action including direct interaction with host cells or pathogen membranes. The lack of therapeutics available for the treatment of viruses such as Venezuelan equine encephalitis virus (VEEV) underscores the urgency of novel strategies for antiviral discovery. American alligator plasma has been shown to exhibit strong in vitro antibacterial activity, and functionalized hydrogel particles have been successfully employed for the identification of specific CAMPs from alligator plasma.

Developmental origins of the crocodylian skull table and platyrostral face.

The dorsoventrally flattened skull typifies extant Crocodylia perhaps more than any other anatomical feature and is generally considered an adaptation for semi-aquatic feeding. Although the evolutionary origins of caniofacial flattening have been extensively studied, the developmental origins have yet to be explored. To understand how the skull table and platyrostral snout develop, we quantified embryonic development and post-hatching growth (ontogeny) of the crocodylian skull in lateral view using geometric morphometrics.

Use of continuous cranial shape variation in the identification of divergent crocodile species of the genus Mecistops.

The discovery of cryptic biodiversity has blossomed under the advancements of genetic techniques, but species identification via morphology remains crucial to effective conservation efforts. In this study, we tested the use of continuous cranial shape variation in distinguishing the two living species of Mecistops: the West African slender-snouted crocodile (M. cataphractus) and the Central African slender-snouted crocodile (M.

High levels of population genetic differentiation in the American crocodile (Crocodylus acutus).

The American crocodile (Crocodylus acutus) is a widely distributed species across coastal and brackish areas of the Neotropical region of the Americas and the Greater Antilles. Available information on patterns of genetic differentiation in C. acutus shows a complex structuring influenced by interspecific interactions (mainly hybridization) and anthropogenic actions (mostly historical hunting, recent poaching, habitat loss and fragmentation, and unintentional translocation of individuals).

Divergent evolution of terrestrial locomotor abilities in extant Crocodylia.

Extant Crocodylia are exceptional because they employ almost the full range of quadrupedal footfall patterns ("gaits") used by mammals; including asymmetrical gaits such as galloping and bounding. Perhaps this capacity evolved in stem Crocodylomorpha, during the Triassic when taxa were smaller, terrestrial, and long-legged. However, confusion about which Crocodylia use asymmetrical gaits and why persists, impeding reconstructions of locomotor evolution.

The Komodo dragon (Varanus komodoensis) genome and identification of innate immunity genes and clusters.

Background: We report the sequencing, assembly and analysis of the genome of the Komodo dragon (Varanus komodoensis), the largest extant lizard, with a focus on antimicrobial host-defense peptides. The Komodo dragon diet includes carrion, and a complex milieu of bacteria, including potentially pathogenic strains, has been detected in the saliva of wild dragons. They appear to be unaffected, suggesting that dragons have robust defenses against infection.

The Frontoparietal Fossa and Dorsotemporal Fenestra of Archosaurs and Their Significance for Interpretations of Vascular and Muscular Anatomy in Dinosaurs.

The attachments of jaw muscles are typically implicated in the evolution and shape of the dorsotemporal fenestra on the skull roof of amniotes. However, the dorsotemporal fenestrae of many archosaurian reptiles possess smooth excavations rostral and dorsal to the dorsotemporal fossa which closely neighbors the dorsotemporal fenestra and jaw muscle attachments. Previous research has typically identified this region, here termed the frontoparietal fossa, to also have attachment surfaces for jaw-closing muscles.

Heterochronic shifts and conserved embryonic shape underlie crocodylian craniofacial disparity and convergence.

The distinctive anatomy of the crocodylian skull is intimately linked with dietary ecology, resulting in repeated convergence on blunt- and slender-snouted ecomorphs. These evolutionary shifts depend upon modifications of the developmental processes which direct growth and morphogenesis. Here we examine the evolution of cranial ontogenetic trajectories to shed light on the mechanisms underlying convergent snout evolution.

Crocodylian Head Width Allometry and Phylogenetic Prediction of Body Size in Extinct Crocodyliforms.

Body size and body-size shifts broadly impact life-history parameters of all animals, which has made accurate body-size estimates for extinct taxa an important component of understanding their paleobiology. Among extinct crocodylians and their precursors (e.g.

Systematic revision of the living African Slender-snouted Crocodiles (Mecistops Gray, 1844).

Molecular and morphological evidence has shown that the African slender-snouted, or sharp-nosed, crocodile Mecistops cataphractus (Cuvier, 1824) is comprised of two superficially cryptic species: one endemic to West Africa and the other endemic to Central Africa. Our ability to characterize the two species is compromised by the complicated taxonomic history of the lineage and overlapping ranges of variation in distinguishing morphological features. The name M.

Formants provide honest acoustic cues to body size in American alligators.

In many vertebrates, acoustic cues to body size are encoded in resonance frequencies of the vocal tract ("formants"), rather than in the rate of tissue vibration in the sound source ("pitch"). Anatomical constraints on the vocal tract's size render formants honest cues to size in many bird and mammal species, but it is not clear whether this correlation evolved convergently in these two clades, or whether it is widespread among amniotes (mammals, birds, and non-avian reptiles). We investigated the potential for honest acoustic cues in the bellows of adult American alligators and found that formant spacing provided highly reliable cues to body size, while presumed correlates of the source signal did not.

Presence of Breeding Birds Improves Body Condition for a Crocodilian Nest Protector.

Ecological associations where one species enhances habitat for another nearby species (facilitations) shape fundamental community dynamics and can promote niche expansion, thereby influencing how and where species persist and coexist. For the many breeding birds facing high nest-predation pressure, enemy-free space can be gained by nesting near more formidable animals for physical protection. While the benefits to protected species seem well documented, very few studies have explored whether and how protector species are affected by nest protection associations.

Large Scale Discovery and De Novo-Assisted Sequencing of Cationic Antimicrobial Peptides (CAMPs) by Microparticle Capture and Electron-Transfer Dissociation (ETD) Mass Spectrometry.

The identification and sequencing of novel cationic antimicrobial peptides (CAMPs) have proven challenging due to the limitations associated with traditional proteomics methods and difficulties sequencing peptides present in complex biomolecular mixtures. We present here a process for large-scale identification and de novo-assisted sequencing of newly discovered CAMPs using microparticle capture followed by tandem mass spectrometry equipped with electron-transfer dissociation (ETD). This process was initially evaluated and verified using known CAMPs with varying physicochemical properties.

Bioprospecting the American alligator (Alligator mississippiensis) host defense peptidome.

Cationic antimicrobial peptides and their therapeutic potential have garnered growing interest because of the proliferation of bacterial resistance. However, the discovery of new antimicrobial peptides from animals has proven challenging due to the limitations associated with conventional biochemical purification and difficulties in predicting active peptides from genomic sequences, if known. As an example, no antimicrobial peptides have been identified from the American alligator, Alligator mississippiensis, although their serum is antimicrobial.

Multiple lineages of ancient CR1 retroposons shaped the early genome evolution of amniotes.

Chicken repeat 1 (CR1) retroposons are long interspersed elements (LINEs) that are ubiquitous within amniote genomes and constitute the most abundant family of transposed elements in birds, crocodilians, turtles, and snakes. They are also present in mammalian genomes, where they reside as numerous relics of ancient retroposition events. Yet, despite their relevance for understanding amniote genome evolution, the diversity and evolution of CR1 elements has never been studied on an amniote-wide level.

Rigorous approaches to species delimitation have significant implications for African crocodilian systematics and conservation.

Accurate species delimitation is a central assumption of biology that, in groups such as the Crocodylia, is often hindered by highly conserved morphology and frequent introgression. In Africa, crocodilian systematics has been hampered by complex regional biogeography and confounded taxonomic history. We used rigorous molecular and morphological species delimitation methods to test the hypothesis that the slender-snouted crocodile (Mecistops cataphractus) is composed of multiple species corresponding to the Congolian and Guinean biogeographic zones.

Insights into the ecology and evolutionary success of crocodilians revealed through bite-force and tooth-pressure experimentation.

Background: Crocodilians have dominated predatory niches at the water-land interface for over 85 million years. Like their ancestors, living species show substantial variation in their jaw proportions, dental form and body size. These differences are often assumed to reflect anatomical specialization related to feeding and niche occupation, but quantified data are scant.

An ancient icon reveals new mysteries: mummy DNA resurrects a cryptic species within the Nile crocodile.

The Nile crocodile (Crocodylus niloticus) is an ancient icon of both cultural and scientific interest. The species is emblematic of the great civilizations of the Nile River valley and serves as a model for international wildlife conservation. Despite its familiarity, a centuries-long dispute over the taxonomic status of the Nile crocodile remains unresolved.

Comparisons of innate immune activity of all known living crocodylian species.

Serum samples from all twenty-three known living members of the Crocodylia were tested for antibacterial activity against eight bacterial species. These data were used to generate an immune profile for each crocodylian species. Statistical analyses revealed that the three living lineages of crocodylians, Alligatoroidea, Crocodyloidea, and Gavialoidea, were distinguishable by their immunological activities.

Pharmacokinetic disposition of a long-acting oxytetracycline formulation after single-dose intravenous and intramuscular administrations in the American alligator (Alligator mississippiensis).

The pharmacokinetics of a long-acting oxytetracycline preparation administered i.v. and i.

Pharmacokinetics of enrofloxacin after single-dose oral and intravenous administration in the American alligator (Alligator mississippiensis).

The pharmacokinetics of enrofloxacin administered orally and i.v. to American alligators (Alligator mississippiensis) at 5 mg/kg was determined.