Archaeologists find new evidence of animals being introduced to prehistoric Caribbean

ScienceDaily (Dec. 1, 2011) — An archaeological research team from North Carolina State University, the University of Washington and University of Florida has found one of the most diverse collections of prehistoric non-native animal remains in the Caribbean, on the tiny island of Carriacou. The find contributes to our understanding of culture in the region before the arrival of Columbus, and suggests Carriacou may have been more important than previously thought.

The researchers found evidence of five species that were introduced to Carriacou from South America between 1,000 and 1,400 years ago. Only one of these species, the opossum, can still be found on the island. The other species were pig-like peccaries, armadillos, guinea pigs and small rodents called agoutis.

Researchers think the animals were used as sources of food. The scarcity of the remains, and the few sites where they were found, indicate that the animals were not for daily consumption. "We suspect that they may have been foods eaten by people of high status, or used in ritual events," says Dr. Scott Fitzpatrick, an associate professor of anthropology at NC State and co-author of a paper describing the research.

"Looking for patterning in the distribution of animal remains in relation to where ritual artifacts and houses are found will help to test this idea," said Christina Giovas, lead author and a Ph.D. student at the University of Washington.

The team, which also included Ph.D. student Michelle LeFebvre of the University of Florida, found the animal remains at two different sites on the island, and used carbon dating techniques to determine their age. The opossum and agouti were the most common, with the latter remains reflecting the longest presence, running from A.D. 600 to 1400. The guinea pig remains had the shortest possible time-frame, running from A.D. 985 to 1030.

These dates are consistent with similar findings on other Caribbean islands. However, while these species have been found on other islands, it is incredibly rare for one island to have remains from all of these species. Guinea pigs, for example, were previously unknown in this part of the Caribbean. The diversity is particularly surprising, given that Carriacou is one of the smallest settled islands in the Caribbean, though the number of remains is still not that large -- a pattern seen on other islands as well.

This combination of small geographical area and robust prehistoric animal diversity, along with evidence for artifact trade with other islands and South America, suggests that Carriacou may have had some significance in the pre-Columbian Caribbean as a nexus of interaction between island communities.

The animal remains are also significant because they were found in archaeological digs at well-documented prehistoric villages -- and the remains themselves were dated, as opposed to just the materials (such as charcoal) found near the remains.

"The fact that the dates established by radiocarbon dating are consistent with the dates of associated materials from the villages means the chronology is well established," says Fitzpatrick, who has been doing research on Carriacou since 2003. "In the future we'd like to expand one of the lesser excavated sites to get more information on how common these species may have been, which could shed light on the ecological impact and social importance of these species prehistorically."

The paper, "New records for prehistoric introduction of Neotropical mammals to the West Indies: evidence from Carriacou, Lesser Antilles," is published online in the Journal of Biogeography and was co-authored by Fitzpatrick, Giovas and LeFebvre. The research was supported by the National Science Foundation, NC State, the University of Washington and the University of Florida.

NC State's Department of Sociology and Anthropology is part of the university's College of Humanities and Social Sciences.

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The above story is reprinted from materials provided by North Carolina State University.

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Journal Reference:

Christina M. Giovas, Michelle J. LeFebvre, Scott M. Fitzpatrick. New records for prehistoric introduction of Neotropical mammals to the West Indies: evidence from Carriacou, Lesser Antilles. Journal of Biogeography, 2011; DOI: 10.1111/j.1365-2699.2011.02630.x

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Progeria: Promising results from new gene therapy on animals

ScienceDaily (Oct. 27, 2011) — Huge progress has been made over the last few years in scientific research into progeria, a disease that leads to premature aging in children. In 2003, a team directed by Nicolas Lévy discovered the gene, and, in 2008, 12 children were able to begin clinical trials in which two molecules were combined to slow down the characteristic effects of the disease: premature aging. Researchers are continuing their efforts in an attempt to counter the consequences of the genetic defect that causes progeria.

Until now, no model had been able to accurately imitate the effects of the disease in humans. For several years, research has been conducted in close collaboration from teams led by Nicolas Lévy and Annachiara De Sandre-Giovannoli at Inserm/Université de la Méditerranée and from a team led by Carlos López-Otín (University of Oviedo) and has succeeded in making such a model possible. The lifespan of mice treated through gene therapy is significantly extended and several other parameters related to them are improved. The research, published Oct. 26, 2011 in Science Translational Medicine, received backing from the AFM thanks to donations from a Telethon.

Progeria is a rare genetic disease. Children suffering from it seem to experience accelerated aging (chronic hair loss, joint pains, thin and hairless skin, cardiovascular problems). In 2003, Nicolas Lévy and his team identified the cause of the disease when they discovered the involvement of the LMNA (nuclear protein-coding) gene, lamin A/C. The mutation causes the production of a truncated protein, progerin, which accumulates in the nuclei of cells and its toxic effects cause their deformation and various other malfunctions. It has since been proven that progerin progressively accumulates in normal cells, thus establishing a link between the disease and physiological aging.

In 2008, European clinical trials began on twelve children suffering from progeria. The treatment is based on a combination of two existing molecules: statins (prescribed in the treatment and prevention of atherosclerosis and cardiovascular risks) and aminobisphosphonates (prescribed in to treat osteoporosis and to prevent complications in some forms of cancer). The use of both these molecules aims to chemically alter progerin to reduce its toxicity. However, although this treatment aimed to slow down the development of the disease, it did not reduce the quantities of progerin. To study this aspect, researchers needed to obtain a relevant animal model.

An "authentic" progeria model…

To generate a model of this kind, Spanish and French researchers decided to introduce a gene mutation (G609G), equivalent to that identified in humans (G608G), in mice to reproduce the exact pathological mechanism found in the children, with a view to then blocking it. The mice models were created under the supervision of Bernard Malissen using the IBISA platform located at the Marseille-Luminy Centre of Immunology. This approach made it possible to obtain young mice that produced progerin, characteristic of the disease in humans. After three weeks alive, the mutated mice displayed growth defects, weight loss caused by bone deformation and cardiovascular and metabolic anomalies mirroring the human phenotype and considerably reducing their lifespan (an average of 103 days compared with two years for wild mice). The progerin thus produced accumulates in mouse cells via genetic mechanisms (abnormal splicing) identical to those observed in humans, i.e. the source of anomalies characteristic of the disease.

… for a targeted gene therapy

Using this unique progeria animal model, the researchers focussed their efforts on implementing a mutation-targeted treatment, with a view to reducing, and, if possible, preventing the production of progerin. To this end, they used "vivo-morpholino" antisense oligonucleotide technology. "This technology, explains Nicolas Lévy, is based on introducing a synthetic antisense aglionecleotide into mice. As is the case with progeria, this sequence is applied to block (or facilitate) the production of a functional protein using a gene. In this case, the production of progerin, as well as lamin A from the gene, were reduced."

There was a highly significant increase in life expectancy of mice treated using this new technology, from an average of 155 days to a maximum of 190 days.

Nicolas Levy's team, with continued collaboration with Carlos López-Otín, now intend to translate this preclinical research into a new therapeutic trial for children, possibly combined with other pharmacological molecules. Other research is being conducted in parallel to find alternative administration channels for antisense oligonucleotides.

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The above story is reprinted from materials provided by INSERM (Institut national de la santé et de la recherche médicale).

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Journal Reference:

Fernando G. Osorio, Claire L. Navarro, Juan Cadiñanos, Isabel C. López-Mejía, Pedro M. Quirós, Catherine Bartoli, José Rivera, Jamal Tazi, Gabriela Guzmán, Ignacio Varela, Danielle Depetris, Félix De Carlos, Juan Cobo, Vicente Andrés, Annachiara De Sandre-Giovannoli, José M. P. Freije, Nicolas Lévy, Carlos López-Otín. Splicing-Directed Therapy in a New Mouse Model of Human Accelerated Aging. Science Translational Medicine, 2011; 3 (106): 106ra107 DOI: 10.1126/scitranslmed.3002847

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Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

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