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1.
Zoo Biol ; 2024 Jun 27.
Article in English | MEDLINE | ID: mdl-38934616

ABSTRACT

Zoological institutions frequently engage in indirect conservation activities as global conservation targets suggest a need for raising public awareness and engagement in biodiversity conservation. However, research suggests that while members of the public are typically aware of general conservation issues, they are often uncertain of simple and practical actions they take that will be impactful. In light of current conservation goals and targets, and the need for social science research to address the environmental learning and behavior change gap, this study builds upon prior action-based environmental education research and tests the efficacy of ex situ environmental education in supporting in situ conservation. Zoos typically employ flagship species to center their conservation messaging due to the purported draw of charismatic species. Using outreach videos with a dialogic-based narrative approach, we evaluated the efficacy of different flagships for conservation, comparing both species-focused versus generic conservation messaging and charismatic versus less charismatic species ambassadors. We found that zoo conservation outreach videos using dialogic-based narrative approaches were equally impactful regardless of the level of focus (i.e., species vs. broader biodiversity) or charisma level of the focal taxa.

2.
Retina ; 43(1): 25-33, 2023 01 01.
Article in English | MEDLINE | ID: mdl-36542081

ABSTRACT

PURPOSE: AR-1105 is a novel biodegradable sustained-release dexamethasone implant designed to deliver 6-month durability. This Phase 2 study evaluated two AR-1105 formulations with different release profiles in patients with macular edema due to retinal vein occlusion. METHODS: Patients received a single intravitreal injection with 340 µg dexamethasone. In the initial phase, five patients received clinical formulation (CF) 1. In the randomized phase, 44 patients were randomized 1:1 to CF1 or CF2. The follow-up was 6 months. Patients had vision loss due to macular edema diagnosed ≥9 (central retinal vein occlusion) or ≥12 months (branch retinal vein occlusion) before screening, and could be treatment-naive or -experienced (if received prior steroids, must have demonstrated response). RESULTS: Both formulations improved vision and reduced retinal thickening from baseline across all visits. At Month 6, mean changes in best-corrected visual acuity were +4.3 and +8.0 letters, and mean changes in central subfield thickness were -93 µm and -211 µm in CF1 and CF2 randomized patients, respectively. Most common adverse events were reduced visual acuity, worsening macular edema, conjunctival hemorrhage, and increased intraocular pressure. No patients required surgery or laser for intraocular pressure control. CONCLUSION: Both formulations were well tolerated and demonstrated clinically meaningful and sustained improvements in vision and retinal thickening in patients with retinal vein occlusion with longstanding edema.


Subject(s)
Macular Edema , Retinal Vein Occlusion , Humans , Retinal Vein Occlusion/complications , Retinal Vein Occlusion/diagnosis , Retinal Vein Occlusion/drug therapy , Macular Edema/diagnosis , Macular Edema/drug therapy , Macular Edema/etiology , Dexamethasone , Glucocorticoids , Treatment Outcome , Drug Implants , Tomography, Optical Coherence , Intravitreal Injections
3.
Zoo Biol ; 40(1): 65-75, 2021 Jan.
Article in English | MEDLINE | ID: mdl-33043534

ABSTRACT

The vast number of species threatened with extinction, coupled with the limited resources to support them, results in the need to prioritize species for conservation action. Similarly, zoo collection managers must prioritize species for inclusion at their institutions, which are also limited by space and resources. While conservation status is one factor considered by zoos, weight is also given to qualitative features and practical considerations when evaluating the fit of different species. Resultantly, the species prioritized by zoos have limited overlap with those prioritized for conservation. Several recent studies have highlighted that the majority of species maintained in zoos are ranked globally as least concern. Given the centrality of conservation to the modern mission of zoos, there is value in identifying clear connections between non-threatened species in zoos and the roles they can play in conservation. Surrogate species approaches have been used in many instances to facilitate indirect conservation, and several distinctive types of surrogacy have been formally described. The aim of this study is to define a novel form of species surrogacy (i.e., "proxy species") that draws utility from non-threatened species maintained in zoos. A proxy species is here defined as a non-threatened species managed ex situ that can be used as a flagship for a related threatened species that is morphologically similar but not otherwise represented in zoos. The benefits of this approach and opportunities for its application are here reviewed. This concept will provide opportunities to enhance the value of pre-existing zoo collections, and ultimately, support conservation objectives.


Subject(s)
Animals, Zoo , Conservation of Natural Resources/methods , Endangered Species , Animals
4.
Retina ; 41(1): 144-155, 2021 Jan 01.
Article in English | MEDLINE | ID: mdl-32134802

ABSTRACT

PURPOSE: To evaluate the safety and efficacy of Brimonidine Drug Delivery System (Brimo DDS), a biodegradable intravitreal implant, in the treatment of geographic atrophy (GA) secondary to age-related macular degeneration. METHODS: Phase 2, randomized, multicenter, double-masked, 24-month study. Study eyes were treated (Day 1; Month 6 retreatment) with Brimo DDS 132 µg (n = 49), Brimo DDS 264 µg (n = 41), or sham procedure (n = 23). The primary timepoint for efficacy analysis was Month 12. RESULTS: Mean GA area growth at Month 12 was 1.78 mm2, 1.59 mm2, and 2.19 mm2 in the Brimo DDS 132 µg, 264 µg, and sham groups, respectively. Geographic atrophy area growth was consistently smaller with Brimo DDS 132 and 264 µg than sham; between-group differences were significant (P ≤ 0.032) at Month 3. In patients with baseline lesion area ≥6 mm2 (two-thirds of patients), GA lesion area and effective radius growth was reduced with Brimo DDS 132 and 264 µg at Month 12 (P ≤ 0.050 vs. sham). Treatment-related adverse events were usually injection procedure-related. CONCLUSION: Brimo DDS demonstrated a favorable safety profile and reduced GA lesion area growth at Month 3. Lesion growth at Month 12 was reduced in patients with baseline GA lesion area ≥6 mm2. The results support Phase 3 development.


Subject(s)
Brimonidine Tartrate/administration & dosage , Geographic Atrophy/drug therapy , Macular Degeneration/drug therapy , Visual Acuity , Adrenergic alpha-2 Receptor Agonists/administration & dosage , Aged , Aged, 80 and over , Double-Blind Method , Drug Delivery Systems , Female , Fluorescein Angiography/methods , Follow-Up Studies , Fundus Oculi , Geographic Atrophy/diagnosis , Geographic Atrophy/etiology , Humans , Intravitreal Injections , Macular Degeneration/complications , Macular Degeneration/diagnosis , Male , Middle Aged , Treatment Outcome
5.
Zoo Biol ; 39(4): 257-262, 2020 Jul.
Article in English | MEDLINE | ID: mdl-32196733

ABSTRACT

Using molecular genetic information to guide population management can improve the sustainability of species in captivity. However, empirical population genetics has not been commonly applied to species management programs in zoos. One limitation may be the availability of genetic resources (e.g., markers, primers, etc.) for species held in zoos. To assess the extent to which species held in zoos have been studied using population genetics in the wild, we conducted a systematic literature review of close to 8,000 papers. We synthesized information on the availability and scale of population genetics studies across amphibian, bird, mammal, and reptile species held in zoos, and discussed their potential for informing ex situ management. We found that more than half of the species in zoos (52%) already have some genetic markers described in the literature specific for them, or a congeneric species, that could be further developed to aid the management of zoo populations, and the accumulation of these resources has been steady over the past decades. Furthermore, the proportion of species with genetic resources is even higher (62%) for species that are being managed through a formal breeding program in zoos. Our study provides encouraging results for captive program managers interested in integrating population genetics into ex situ management strategies.


Subject(s)
Amphibians/genetics , Birds/genetics , Mammals/genetics , Reptiles/genetics , Animals , Animals, Zoo , Conservation of Natural Resources/methods
6.
Annu Int Conf IEEE Eng Med Biol Soc ; 2017: 3561-3563, 2017 Jul.
Article in English | MEDLINE | ID: mdl-29060667

ABSTRACT

Speech is an important aspect of human communication; individuals with speech impairment are unable to communicate vocally in real time. Our team has developed the TongueToSpeech (TTS) device with the goal of augmenting speech communication for the vocally impaired. The proposed device is a wearable wireless assistive device that incorporates a capacitive touch keyboard interface embedded inside a discrete retainer. This device connects to a computer, tablet or a smartphone via Bluetooth connection. The developed TTS application converts text typed by the tongue into audible speech. Our studies have concluded that an 8-contact point configuration between the tongue and the TTS device would yield the best user precision and speed performance. On average using the TTS device inside the oral cavity takes 2.5 times longer than the pointer finger using a T9 (Text on 9 keys) keyboard configuration to type the same phrase. In conclusion, we have developed a discrete noninvasive wearable device that allows the vocally impaired individuals to communicate in real time.


Subject(s)
Self-Help Devices , Humans , Speech , Tongue , User-Computer Interface , Wearable Electronic Devices
7.
Annu Int Conf IEEE Eng Med Biol Soc ; 2017: 3852-3855, 2017 Jul.
Article in English | MEDLINE | ID: mdl-29060738

ABSTRACT

Controlling a computer or a smartphone's cursor allows the user to access a world full of information. For millions of people with limited upper extremities motor function, controlling the cursor becomes profoundly difficult. Our team has developed the User Interface Cursor-Controller (UIC-C) to assist the impaired individuals in regaining control over the cursor. The UIC-C is a hands-free device that utilizes the tongue muscle to control the cursor movements. The entire device is housed inside a subject specific retainer. The user maneuvers the cursor by manipulating a joystick imbedded inside the retainer via their tongue. The joystick movement commands are sent to an electronic device via a Bluetooth connection. The device is readily recognizable as a cursor controller by any Bluetooth enabled electronic device. The device testing results have shown that the time it takes the user to control the cursor accurately via the UIC-C is about three times longer than a standard computer mouse controlled via the hand. The device does not require any permanent modifications to the body; therefore, it could be used during the period of acute rehabilitation of the hands. With the development of modern smart homes, and enhancement electronics controlled by the computer, UIC-C could be integrated into a system that enables individuals with permanent impairment, the ability to control the cursor. In conclusion, the UIC-C device is designed with the goal of allowing the user to accurately control a cursor during the periods of either acute or permanent upper extremities impairment.


Subject(s)
Wearable Electronic Devices , Hand , Humans , Self-Help Devices , Tongue , User-Computer Interface
8.
G3 (Bethesda) ; 7(2): 755-773, 2017 02 09.
Article in English | MEDLINE | ID: mdl-28087693

ABSTRACT

The Canadian beaver (Castor canadensis) is the largest indigenous rodent in North America. We report a draft annotated assembly of the beaver genome, the first for a large rodent and the first mammalian genome assembled directly from uncorrected and moderate coverage (< 30 ×) long reads generated by single-molecule sequencing. The genome size is 2.7 Gb estimated by k-mer analysis. We assembled the beaver genome using the new Canu assembler optimized for noisy reads. The resulting assembly was refined using Pilon supported by short reads (80 ×) and checked for accuracy by congruency against an independent short read assembly. We scaffolded the assembly using the exon-gene models derived from 9805 full-length open reading frames (FL-ORFs) constructed from the beaver leukocyte and muscle transcriptomes. The final assembly comprised 22,515 contigs with an N50 of 278,680 bp and an N50-scaffold of 317,558 bp. Maximum contig and scaffold lengths were 3.3 and 4.2 Mb, respectively, with a combined scaffold length representing 92% of the estimated genome size. The completeness and accuracy of the scaffold assembly was demonstrated by the precise exon placement for 91.1% of the 9805 assembled FL-ORFs and 83.1% of the BUSCO (Benchmarking Universal Single-Copy Orthologs) gene set used to assess the quality of genome assemblies. Well-represented were genes involved in dentition and enamel deposition, defining characteristics of rodents with which the beaver is well-endowed. The study provides insights for genome assembly and an important genomics resource for Castoridae and rodent evolutionary biology.


Subject(s)
Genome , Rodentia/genetics , Transcriptome/genetics , Animals , Genomics , Molecular Sequence Annotation , Open Reading Frames/genetics
9.
J Interpers Violence ; 31(20): 3464-3489, 2016 12.
Article in English | MEDLINE | ID: mdl-26045499

ABSTRACT

Using thematic analysis, this study explores the motivation to commit sexual homicide from the perspective of the perpetrator. In the process, it revisits motivational models and offender typologies that have been put forward to explain such offenses. From the homicide narratives of eight sexual homicide offenders detained in a high security hospital in the United Kingdom, four themes were found which appeared significant in terms of understanding the offenses committed. These themes were labeled as follows: (a) avenging sexual abuse, (b) events leading to a catathymic reaction, (c) homicidal impulse, and (d) emotional loneliness. Although these findings are not inconsistent with previous research, we argue that the current literature fails to capture the complexity associated with these offenses. We also argue that the context or situation in which sexual homicide occurs is a crucial feature of the offense, and one which has not been adequately taken into account by motivational models.


Subject(s)
Criminals/psychology , Homicide/psychology , Motivation , Rape/psychology , Adult , Criminals/statistics & numerical data , Homicide/statistics & numerical data , Humans , Impulsive Behavior , Loneliness , Male , Middle Aged , Rape/statistics & numerical data , Sex Offenses/psychology , Sex Offenses/statistics & numerical data
10.
Bioorg Med Chem ; 22(16): 4499-505, 2014 Aug 15.
Article in English | MEDLINE | ID: mdl-24794750

ABSTRACT

A series of structurally related citric acid-ciprofloxacin conjugates was synthesised to investigate the influence of the linker between citric acid and ciprofloxacin on antibacterial activities. Minimum inhibitory concentrations (MICs) were determined against a panel of reference strains and clinical isolates of bacteria associated with infection in humans and correlated with the DNA gyrase inhibitory activity. The observed trend was rationalised by computational modelling.


Subject(s)
Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Ciprofloxacin/chemistry , Ciprofloxacin/pharmacology , Citric Acid/chemistry , Drug Design , Topoisomerase II Inhibitors/pharmacology , Anti-Bacterial Agents/chemical synthesis , Bacteria/drug effects , Citric Acid/pharmacology , DNA Gyrase/metabolism , Dose-Response Relationship, Drug , Humans , Microbial Sensitivity Tests , Models, Molecular , Molecular Structure , Structure-Activity Relationship , Topoisomerase II Inhibitors/chemical synthesis , Topoisomerase II Inhibitors/chemistry
11.
Chembiochem ; 15(3): 466-71, 2014 Feb 10.
Article in English | MEDLINE | ID: mdl-24449436

ABSTRACT

Mono- and disaccharide-functionalised conjugates of the fluoroquinolone antibiotic ciprofloxacin have been synthesised and used as chemical probes of the bacterial uptake of glycosylated ciprofloxacin. Their antimicrobial activities against a panel of clinically relevant bacteria were determined: the ability of these conjugates to inhibit their target DNA gyrase and to be transported into the bacteria was assessed by using in vivo and in vitro assays. The data suggest a lack of active uptake through sugar transporters and that although the addition of monosaccharides is compatible with the inhibition of DNA gyrase, the addition of a disaccharide results in a significant decrease in antimicrobial activity.


Subject(s)
Anti-Bacterial Agents/chemistry , Ciprofloxacin/chemistry , Glycoconjugates/chemistry , Anti-Bacterial Agents/pharmacology , Bacterial Proteins/antagonists & inhibitors , Bacterial Proteins/metabolism , DNA Gyrase/chemistry , DNA Gyrase/metabolism , Disaccharides/chemistry , Disk Diffusion Antimicrobial Tests , Glycoconjugates/chemical synthesis , Glycoconjugates/pharmacology , Glycosylation , Gram-Negative Bacteria/drug effects , Gram-Positive Bacteria/drug effects , Monosaccharides/chemistry
12.
Ecol Evol ; 3(7): 1915-30, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23919139

ABSTRACT

The Northern Fulmar (Fulmarus glacialis) is a common tube-nosed seabird with a disjunct Holarctic range. Taxonomic divisions within the Northern Fulmar have historically been muddled by geographical variation notably including highly polymorphic plumage. Recent molecular analyses (i.e., DNA barcoding) have suggested that genetic divergence between Atlantic and Pacific populations could be on par with those typically observed between species. We employ a multigene phylogenetic analysis to better explore the level of genetic divergence between these populations and to test an old hypothesis on the origin of the modern distribution of color morphs across their range. Additionally, we test whether mutations in the melanocortin-1 receptor gene (MC1R) are associated with dark plumage in the Northern Fulmar. We confirmed that mitochondrial lineages in the Atlantic and Pacific populations are highly divergent, but nuclear markers revealed incomplete lineage sorting. Genetic divergence between these populations is consistent with that observed between many species of Procellariiformes and we recommend elevating these two forms to separate species. We also find that MC1R variation is not associated with color morph but rather is better explained by geographical divergence.

13.
Am J Pharm Educ ; 77(5): 100, 2013 Jun 12.
Article in English | MEDLINE | ID: mdl-23788811

ABSTRACT

OBJECTIVES: To implement and evaluate a 3-year reflective writing program incorporated into introductory pharmacy practice experiences (IPPEs) in the first- through third-year of a doctor of pharmacy (PharmD) program. DESIGN: Reflective writing was integrated into 6 IPPE courses to develop students' lifelong learning skills. In their writing, students were required to self-assess their performance in patient care activities, identify and describe how they would incorporate learning opportunities, and then evaluate their progress. Practitioners, faculty members, and fourth-year PharmD students served as writing preceptors. ASSESSMENT: The success of the writing program was assessed by reviewing class performance and surveying writing preceptor's opinions regarding the student's achievement of program objectives. Class pass rates averaged greater than 99% over the 8 years of the program and the large majority of the writing preceptors reported that student learning objectives were met. A support pool of 99 writing preceptors was created. CONCLUSIONS: A 3-year reflective writing program improved pharmacy students' reflection and reflective writing skills.


Subject(s)
Education, Pharmacy/methods , Students, Pharmacy/psychology , Teaching/methods , Writing , Curriculum , Humans , Learning , Preceptorship , Program Development , Program Evaluation , Time Factors
14.
Org Biomol Chem ; 11(21): 3461-8, 2013 Jun 07.
Article in English | MEDLINE | ID: mdl-23575952

ABSTRACT

A series of fluoroquinolone conjugates was synthesised by linking the carboxylic acid functionality of the carboxylate-type siderophore staphyloferrin A and its derivatives to the piperazinyl nitrogen of ciprofloxacin and norfloxacin via amide bond formation. Four siderophore-drug conjugates were screened against a panel of bacteria associated with infection in humans. Whilst no activity was found against ciprofloxacin- or norfloxacin-resistant bacteria, one of the conjugates retained antibacterial activity against fluoroquinolone-susceptible strains although the structure of its lysine-based siderophore component differs from that of the natural siderophore staphyloferrin A. In contrast, three ornithine-based siderophore conjugates showed significantly reduced activity against strains that are susceptible to their respective parent fluoroquinolones, regardless of the type of fluoroquinolone attached or chirality at the ornithine Cα-atom. The loss of potency observed for the (R)- and (S)-ornithine-based ciprofloxacin conjugates correlates with their reduced inhibitory activity against the target enzyme DNA gyrase.


Subject(s)
Anti-Bacterial Agents/chemistry , Citrates/chemistry , Fluoroquinolones/chemistry , Ornithine/analogs & derivatives , Siderophores/chemistry , Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/pharmacology , Bacteria/drug effects , Carboxylic Acids/chemistry , Fluoroquinolones/chemical synthesis , Fluoroquinolones/pharmacology , Humans , Models, Molecular , Ornithine/chemistry
16.
PLoS One ; 7(8): e43992, 2012.
Article in English | MEDLINE | ID: mdl-22952842

ABSTRACT

The accuracy of DNA barcode databases is critical for research and practical applications. Here we apply a frequency matrix to assess sequencing errors in a very large set of avian BARCODEs. Using 11,000 sequences from 2,700 bird species, we show most avian cytochrome c oxidase I (COI) nucleotide and amino acid sequences vary within a narrow range. Except for third codon positions, nearly all (96%) sites were highly conserved or limited to two nucleotides or two amino acids. A large number of positions had very low frequency variants present in single individuals of a species; these were strongly concentrated at the ends of the barcode segment, consistent with sequencing error. In addition, a small fraction (0.1%) of BARCODEs had multiple very low frequency variants shared among individuals of a species; these were found to represent overlooked cryptic pseudogenes lacking stop codons. The calculated upper limit of sequencing error was 8 × 10(-5) errors/nucleotide, which was relatively high for direct Sanger sequencing of amplified DNA, but unlikely to compromise species identification. Our results confirm the high quality of the avian BARCODE database and demonstrate significant quality improvement in avian COI records deposited in GenBank over the past decade. This approach has potential application for genetic database quality control, discovery of cryptic pseudogenes, and studies of low-level genetic variation.


Subject(s)
Birds/genetics , DNA Barcoding, Taxonomic/standards , Pseudogenes/genetics , Sequence Analysis, DNA/standards , Animals , Base Sequence , Birds/classification , Databases, Genetic , Polymorphism, Single Nucleotide/genetics , Quality Control
17.
Methods Mol Biol ; 858: 127-52, 2012.
Article in English | MEDLINE | ID: mdl-22684955

ABSTRACT

As of February 2011, COI DNA barcode sequences (a 648-bp segment of the 5' end of the mitochondrial gene cytochrome c oxidase I, the standard DNA barcode for animals) have been collected from over 23,000 avian specimens representing 3,800 species, more than one-third of the world's avifauna. Here, we detail the methodology for obtaining DNA barcodes from birds, covering the entire process from field collection to data analysis. We emphasize key aspects of the process and describe in more detail those that are particularly relevant in the case of birds. We provide elemental information about collection of specimens, detailed protocols for DNA extraction and PCR, and basic aspects of sequencing methodology. In particular, we highlight the primer pairs and thermal cycling profiles associated with successful amplification and sequencing from a broad range of avian species. Finally, we succinctly review the methodology for data analysis, including the detection of errors (such as contamination, misidentifications, or amplification of pseudogenes), assessment of species resolution, detection of divergent intraspecific lineages, and identification of unknown specimens.


Subject(s)
Birds/genetics , DNA Barcoding, Taxonomic/methods , DNA/genetics , Electron Transport Complex IV/genetics , Animals , DNA/isolation & purification , Electron Transport Complex IV/isolation & purification , Mitochondria/enzymology , Polymerase Chain Reaction
18.
PLoS One ; 6(7): e20744, 2011.
Article in English | MEDLINE | ID: mdl-21818252

ABSTRACT

BACKGROUND: The causes for the higher biodiversity in the Neotropics as compared to the Nearctic and the factors promoting species diversification in each region have been much debated. The refuge hypothesis posits that high tropical diversity reflects high speciation rates during the Pleistocene, but this conclusion has been challenged. The present study investigates this matter by examining continental patterns of avian diversification through the analysis of large-scale DNA barcode libraries. METHODOLOGY AND PRINCIPAL FINDINGS: Standardized COI datasets from the avifaunas of Argentina, the Nearctic, and the Palearctic were analyzed. Average genetic distances between closest congeners and sister species were higher in Argentina than in North America reflecting a much higher percentage of recently diverged species in the latter region. In the Palearctic genetic distances between closely related species appeared to be more similar to those of the southern Neotropics. Average intraspecific variation was similar in Argentina and North America, while the Palearctic fauna had a higher value due to a higher percentage of variable species. Geographic patterning of intraspecific structure was more complex in the southern Neotropics than in the Nearctic, while the Palearctic showed an intermediate level of complexity. CONCLUSIONS AND SIGNIFICANCE: DNA barcodes can reveal continental patterns of diversification. Our analysis suggests that avian species are older in Argentina than in the Nearctic, supporting the idea that the greater diversity of the Neotropical avifauna is not caused by higher recent speciation rates. Species in the Palearctic also appear to be older than those in the Nearctic. These results, combined with the patterns of geographic structuring found in each region, suggest a major impact of Pleistocene glaciations in the Nearctic, a lesser effect in the Palearctic and a mild effect in the southern Neotropics.


Subject(s)
Biodiversity , Birds/genetics , DNA Barcoding, Taxonomic , Gene Library , Animals , Arctic Regions , Argentina , Electron Transport Complex IV/genetics , Haplotypes/genetics , Phylogeography , Species Specificity
19.
Mol Ecol Resour ; 11(6): 1045-55, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21777399

ABSTRACT

The barcode of life project has assembled a tremendous number of mitochondrial cytochrome c oxidase I (COI) sequences. Although these sequences were gathered to develop a DNA-based system for species identification, it has been suggested that further biological inferences may also be derived from this wealth of data. Recurrent selective sweeps have been invoked as an evolutionary mechanism to explain limited intraspecific COI diversity, particularly in birds, but this hypothesis has not been formally tested. In this study, I collated COI sequences from previous barcoding studies on birds and tested them for evidence of selection. Using this expanded data set, I re-examined the relationships between intraspecific diversity and interspecific divergence and sampling effort, respectively. I employed the McDonald-Kreitman test to test for neutrality in sequence evolution between closely related pairs of species. Because amino acid sequences were generally constrained between closely related pairs, I also included broader intra-order comparisons to quantify patterns of protein variation in avian COI sequences. Lastly, using 22 published whole mitochondrial genomes, I compared the evolutionary rate of COI against the other 12 protein-coding mitochondrial genes to assess intragenomic variability. I found no conclusive evidence of selective sweeps. Most evidence pointed to an overall trend of strong purifying selection and functional constraint. The COI protein did vary across the class Aves, but to a very limited extent. COI was the least variable gene in the mitochondrial genome, suggesting that other genes might be more informative for probing factors constraining mitochondrial variation within species.


Subject(s)
Birds/genetics , DNA Barcoding, Taxonomic/methods , Evolution, Molecular , Genetic Variation , Selection, Genetic , Amino Acid Sequence , Animals , Base Sequence , Databases, Genetic , Electron Transport Complex IV/genetics , Molecular Sequence Data , Sequence Analysis, DNA , Species Specificity
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