| 1. |
- Edwards, Robert A., et al.
(author)
-
Global phylogeography and ancient evolution of the widespread human gut virus crAssphage
- 2019
-
In: Nature Microbiology. - : Springer Science and Business Media LLC. - 2058-5276. ; 4:10, s. 1727-1736
-
Journal article (peer-reviewed)abstract
- Microbiomes are vast communities of microorganisms and viruses that populate all natural ecosystems. Viruses have been considered to be the most variable component of microbiomes, as supported by virome surveys and examples of high genomic mosaicism. However, recent evidence suggests that the human gut virome is remarkably stable compared with that of other environments. Here, we investigate the origin, evolution and epidemiology of crAssphage, a widespread human gut virus. Through a global collaboration, we obtained DNA sequences of crAssphage from more than one-third of the world's countries and showed that the phylogeography of crAssphage is locally clustered within countries, cities and individuals. We also found fully colinear crAssphage-like genomes in both Old-World and New-World primates, suggesting that the association of crAssphage with primates may be millions of years old. Finally, by exploiting a large cohort of more than 1,000 individuals, we tested whether crAssphage is associated with bacterial taxonomic groups of the gut microbiome, diverse human health parameters and a wide range of dietary factors. We identified strong correlations with different clades of bacteria that are related to Bacteroidetes and weak associations with several diet categories, but no significant association with health or disease. We conclude that crAssphage is a benign cosmopolitan virus that may have coevolved with the human lineage and is an integral part of the normal human gut virome.
|
|
| 2. |
- Moore, Bret A., et al.
(author)
-
A novel method for comparative analysis of retinal specialization traits from topographic maps
- 2012
-
In: Journal of Vision. - : Association for Research in Vision and Ophthalmology (ARVO). - 1534-7362. ; 12:12
-
Journal article (peer-reviewed)abstract
- Vertebrates possess different types of retinal specializations that vary in number, size, shape, and position in the retina. This diversity in retinal configuration has been revealed through topographic maps, which show variations in neuron density across the retina. Although topographic maps of about 300 vertebrates are available, there is no method for characterizing retinal traits quantitatively. Our goal is to present a novel method to standardize information on the position of the retinal specializations and changes in retinal ganglion cell (RGC) density across the retina from published topographic maps. We measured the position of the retinal specialization using two Cartesian coordinates and the gradient in cell density by sampling ganglion cell density values along four axes (nasal, temporal, ventral, and dorsal). Using this information, along with the peak and lowest RGC densities, we conducted discriminant function analyses (DFAs) to establish if this method is sensitive to distinguish three common types of retinal specializations (fovea, area, and visual streak). The discrimination ability of the model was higher when considering terrestrial (78%-80% correct classification) and aquatic (77%-86% correct classification) species separately than together. Our method can be used in the future to test specific hypotheses on the differences in retinal morphology between retinal specializations and the association between retinal morphology and behavioral and ecological traits using comparative methods controlling for phylogenetic effects.
|
|
| 3. |
- Hernández Salazar, Laura T., et al.
(author)
-
The Sensory Systems of Alouatta : Evolutionwith an Eye to Ecology
- 2015
-
In: Howler Monkeys. - New York : Springer Science+Business Media B.V.. - 9781493919567 ; , s. 317-336
-
Book chapter (peer-reviewed)abstract
- Our knowledge about the perceptual world of howler monkeys is unevenlydistributed between the fi ve senses. Whereas there is abundant knowledge about thesense of vision in the genus Alouatta , only limited data on the senses of hearing,smell, taste, and touch are available. The discovery that howler monkeys are theonly genus among the New World primates to possess routine trichromacy hasimportant implications for the evolution of color vision and therefore has been studiedintensively. Detailed information about the genetic mechanisms and physiologicalprocesses underlying color vision in howler monkeys are available. Although thesound production, vocal repertoire, and acoustic communication in the genusAlouatta have been well documented, basic physiological measures of hearing performancesuch as audiograms are missing. Similarly, despite an increasing numberof observational studies on olfactory communication in howler monkeys, there is acomplete lack of physiological studies on the effi ciency of their sense of smell.Information about the senses of taste and touch is even scarcer and mainly restrictedto a description of their anatomical basis. A goal of this chapter is to summarize ourcurrent knowledge of the anatomy, physiology, genetics, and behavioral relevanceof the different senses in howler monkeys in comparison to other platyrrhines.
|
|
