Biotechnological
Communication
Biosci. Biotech. Res. Comm. 9(1):
Paleogeneticist view of leather: The role of mitochondrial DNA to uncover the mysteries of fake leather and its products
Rachel Matar1 and Maxime Merheb1,*
1Department of Biotechnology, American University of Ras Al Khaimah AURAK, Ras Al Khaimah, P.O Box 10021, United Arab Emirates
ABSTRACT
Currently,
KEY WORDS: MITOCHONDRIAL DNA; PALEOGENETICS; LEATHER; FORENSIC DNA; BIODIVERSITY
ARTICLE INFORMATION:
*Corresponding Author: maximemerheb@yahoo.fr Received 24th Feb, 2016
Accepted after revision 20th March, 2016 BBRC Print ISSN:
Online ISSN:
Thomson Reuters ISI SCI Indexed Journal NAAS Journal Score : 3.48
© A Society of Science and Nature Publication, 2016. All rights6 reserved.
Online Contents Available at: http//www.bbrc.in/
Molecular identification of species origin of leather would be particularly important, either concerning the commer- cial or other fundamental aspects. On the commercial aspect, leather manufactured products are very common and serious fraud situations exists due to the difficulty to recognize the species origin after the manufacturing process, and the value of products from different species may vary. In addition, a certain number of endangered protected wildlife species are fraudulently used in the leather market (Merheb et al., 2015) therefore; molecu- lar recognition of the species present in these substrates has an important impact in terms of protecting biodiver- sity. For this purpose, institutions are already promoting the development of detection methods for DNA testing of products related to leather. This study is presenting a general assessment of the chemical degradations of DNA extracted from manufactured leather concluding that due to the degradation that occurs during the tanning process, only mtDNA can be expected to survive.
INTRODUCTION
Nowadays, species identification is a critical issue to ensure and protect biodiversity and detect fraud in commercial food (Lefrançois et al., 1997, Lockley and Bardsley, 2000, Woolfe and Primrose, 2004, Merheb et al., 2015). The demand for species identification has increased due to the various food crises that occurred in the past 10 years (Bovine spongiform encephalop- athy BSE,
Each year, millions of animals are endangered by unlawful killing, captured for hunting games, collected for private zoos, decorative items (Elephant Ivory Com- stock et al., 2003), traditional medicine (The Tiger Wan and Fang, 2003, Wetton et al., 2004), Rhino (Hsieh et al., 2003), and human consumption (Sea Turtles and their eggs Moore et al., 2003). Therefore; identifying the species presented in the organic substrates (Fresh, Processed and Ancient) by reliable and quick methods is a matter of urgency. The case of traceability in food
Rachel Matar and Maxime Merheb
is often cited yet the application may also affect many other areas which should be considered. The range of substrates in which species are determined is very broad. It varies from a simple case such as a species found in a pure state in a fresh substrate to a complete situation of species found as mixtures and where product had been significantly altered (Teletchea et al., 2005).
Different species identification methods for processed organic products have been developed such as morpho- logical studies (Nunez, 1951, Tsuganezawa, 1965, Pray- son et al., 2008), protein analysis (Ashworth, 1987) and chemical analysis (Guy et al., 2000, Ozaki et al., 2004), yet these methods are outdated, as it is not very effective for the analysis of products which have been significantly altered (Teletchea et al., 2005, Merheb et al., 2016).
On the other hand, Molecular identification methods have been recently developed, including the use of DNA amplification using PCR and derived methods of molec- ular biology
DNA is a stable molecule, a very small amount is suffi- cient enough to undergo a complete analysis, which allows the study of highly degraded substrates possible (Paabo et al., 1989, Hänni et al., 1994, Paabo et al., 2004, Feuillie et al., 2011a, Feuillie et al., 2011b). Some specific substrates such as feces and hair are now important sources for genetic analyzes (Fabbri et al., 2007). Processed products such as leather, fur and all manufactured products made from animal hides are currently very reluctant to obtain reliable results in molecular traceability.
OBJECTIVES OF IDENTIFYING SPECIES ORIGIN OF LEATHER
FRAUD PREVENTION
Rachel Matar and Maxime Merheb
the misleading tag ‘leather’ or ‘real fur’. This is often a false description which induces, to a large extent, the consumer astray. To promote their sales, clothing acces- sories and fur from cats or dogs are labeled under other names. For example, fur traders explained to investiga- tors that labeling depended on the preferences of the buyer! Thus, we find the cat fur sold under the names “Lippi Cat”, “China Cat” or “Rabbit”. As for the dog fur, we find it under the fanciful name of “Asian Wolf” or “Chinese dog” etc. On 13 November 2008, the customs office of Villepinte announced a seize operation in a Paris warehouse of 4034 vests, jackets and coats with fur collars, declared as fake fur, but the inspections revealed that the fur came from dogs and cats. The National Museum of Natural History has confirmed the presence of raccoon dog fur among the documents seized, (www. douane.gouv.fr). This trade is not limited to Asia: Fur is used worldwide. In 1997,
PROTECTION OF BIODIVERSITY
Biodiversity is currently experiencing a major crisis, both in terms of numbers and the rate of population or species extinctions (Fonseca and Benson, 2003, DeSalle and Amato, 2004). Thus, since the seventeenth century, more than 250 species of birds, mammals, reptiles and amphibians were made extinct in the world because of human activities (Fonseca and Benson, 2003). The real crisis is in most cases extinction was the direct result of hunting, fishing, overfishing, poaching, and indirectly by the loss or damage of habitats, degradation of the natural environment: pollution, introduction of other species or other human activities (Leakey and Lewin, 1995). We realized in recent years that trading (legally and illegally) of species, including those endangered spe- cies has contributed a severe threat to global biodiver- sity. The wildlife trade and their products also represent the third largest trade after drugs and weapons (Manel et al., 2002). The luxury leather trade has pushed many species to extinction (www.endangeredspecieshandbook. org). Nearly a third of exotic leathers come from endan-
gered species, with impunity poached (snakes, lizards, crooked, crocodiles, ostriches, tigers, leopards, zebras, opossums, elephants, sharks, seals, walruses). This trade is cleverly concealed by the fur industry.
In Parallel, nongovernmental organizations also play a vital role in control of international trade of wild spe- cies by influencing decision makers with the help of their international conferences (Ringuet, 2004). Among these actions we cite the program TRAFFIC (www.traffic.org), created in 1976 by IUCN (International Union for Con- servation of Nature), (http://www.iucn.org) and the WWF (World Wild Fund). Currently, this international network coordinated by TRAFFIC has collaborators in more than 22 countries and projects in more than 10 countries. The famous “Red list” (http://www.iucnredlist.org) of the IUCN is estimating that more than 23,000 species are endangered as of 2015. Numbers of threatened species are listed by major groups of organisms since 1996.
LEATHER MANUFACTURING PROCESSES FROM ANIMAL SKINS
For thousands of years, humans have started to convert animal hides into resistant products which nowadays are referred to as “Leather”. The remains attributed to leather work are rare on prehistoric sites. However remnants related to this activity, as the OUI2 site in Siberia dated between 22,000 and 17,000 BP are exceptional (Vasil’ev, 1990 , Vasil’ev, 1994). A set of 21 ribs of sheep have been identified in the site. The ribs are introduced vertically into the ground forming an oval of 1.50 m of 0, 85 m. This set of rods has been interpreted as a tension structure of hides during the drying process (Beyries, 2008).
Nowadays, the manufacturing of leather mainly consists of salting, desalting and tanning. Salting is designed to remove water from the tissues to slow the development of microorganisms and stop the putrefac- tion action. After 15 days, the skins are desalted; they are examined one by one and organized according to their thickness, weight or surface. The procedure of changing the skin into leather is called Tanning. This process is accomplished by tannins which are a variety of chemicals, the most
FROM PALEOGENETICS TO FORENSIC DNA
For over 25 years, many paleogenetic studies have shown that the DNA molecule remains very stable after the death of organisms, despite the time and environmental effects
(Higuchi et al., 1984). Since 1984, the first publication in this area was released (isolation of a few hundred base pairs of a mitochondrial gene from a tissue of a taxider- mied specimen, the quagga, died over a hundred and forty years ago (Higuchi et al., 1984)), numerous studies have shown that it is possible to retrieve and analyze a much older samples of DNA (Hänni et al., 1994, Loreille et al., 2001, Orlando et al., 2002, Poinar, 2002, Orlando et al., 2003, Salamon et al., 2005, Teletchea et al., 2005) such as samples of cave bear Ursus spelaeus dating back to 35,000 years ago (Hänni et al., 1994) and samples of woolly rhi- noceros dating back to 60000 years ago (Orlando et al., 2003). Hence the idea, by analogy, to use the stable and resistant DNA molecule, to identify species in processed or degraded products whilst undergone many chemical and physical treatments (Bartlett and Davidson, 1992, Ozaki et al., 1998, Etienne et al., 1999, Aguado et al., 2001, Hold et al., 2001, Urdiain et al., 2004, Teletchea et al., 2005, Lucey, 2006, Lema and Burachik, 2009, Botti and Giuffra, 2010). Moreover, even if the DNA molecule is degraded in this type of substrates (manufacturing processes, canning, smoking etc.) remains always possible to amplify it using Polymerase Chain Reaction (PCR) (Mullis and Faloona, 1987, Saiki et al., 1988, Saiki et al., 1985) small frag- ments of DNA with sufficient information to discriminate between closely related species (Kocher et al., 1989). Fur-
Rachel Matar and Maxime Merheb
thermore, since the DNA is present in all cells, it is poten- tially possible to identify a species from any type of sub- strate. However, the DNA molecule modified or degraded in these products has several characteristics that must be taken into consideration when developing new methods.
DNA CHARACTERISTICS IN LEATHER: A PROCESSED PRODUCT
The ancient DNA goes through several types of inflicting damage and changes that begins shortly after the death of the animal, especially the fragmentation of DNA into very small pieces and creation abasic sites,
The DNA molecule in this type of substrates are not only broken and deteriorated, but also present in very small quantities (Poinar, 2002, Hänni et al., 1994, Loreille et al., 2001), which further reduces the number of DNA fragments with a size sufficient enough for analysis (Tel- etchea, 2005). Therefore the paleogenetic studies and also
FIGURE 1: The various stages of preparation of the leather and consequences in terms of chemical lesions.
Rachel Matar and Maxime Merheb
tions or species from samples collected in the field and hairs (Fabbri et al., 2007, Debruyne et al., 2008, Schwarz et al., 2009), and feces (Taberlet and Bouvet, 1992), etc. showed that it was often necessary to increase the number of PCR cycles (up to 55 or 60 cycles) to have sufficient DNA to allow subsequent analyzes (Merheb et al., 2016).
Given i) the nature of degraded DNA in such sam- ples and ii) the fact that the PCR is an extremely sensi- tive method, it is possible that a single intact exogenous DNA molecule can be preferentially amplified instead of the degraded endogenous molecule (Merheb et al., 2016). Therefore, the samples must be handled (prior to PCR) in dedicated laboratories (physically isolated) (Loreille et al., 2001). In addition, it is essential to add «carrier effect» control (Cooper, 1992, Handt et al., 1994), which amplifies degraded DNA extracted from another species. The role of this control is to help trace amplified exoge- nous contaminant DNA, in the presence of ancient DNA.
Many factors from various sources are
At the amplification, the inhibitors can be directly neutralized by using BSA (Bovine Serum Albumin) to PCR reagents (Hagelberg et al., 1989, Hänni et al., 1994, Merheb, 2010). Indeed these proteins trap, by electro-
static interactions, a variety of inhibitors of Taq poly- merase (Pääbo, 1989).
Chemical modifications are probably the less known characteristics of the DNA in the processed products, but paleogenetic and noninvasive ecology studies have shown that the environment (acidity, UV, humidity, etc.) could, in fact, induce chemical changes (oxidation or hydrolysis) of the DNA (Pääbo, 1989, Paabo et al., 1989, Hoss et al., 1996). In this case, the nucleic acids have modifications or artefactual mutations, which are changes in the nature of the nucleotide bases (Poinar, 2002). During PCR amplification, the Taq polymerase will mistakenly pair these modified bases.
Thus, opposite to the
A. The deamination of cytosine by hydrolysis forms Uracil.
FIGURE 2: The main consequences on PCR amplification of chemically modified DNA.
B. 8OHG:
C.
After drying, the skin undergoes two critical steps i) rehydration in warm water that contains boric acid (H3BO3) which promotes the hydrolysis of DNA. The hydrolysis promotes the two artifactual substitutions C to T and G to A and the creation of abasic sites which stop the elongation step of the Taq polymerase during the PCR ii) liming, immersion of the skin in the lime water (CaO + NaOH), which promotes the oxidation of DNA that pro- motes the artifactual substitution G to T and C to A. The final step of tanning consists of adding tannins which are polyphenols known for their inhibitory effect on PCR. In conclusion, one can make an analogy between all these leather processing conditions and the conditions affect- ing a fossil in its burial environment. For all mentioned reasons, it is essential that the DNA of leather must be considered and analyzed as ancient DNA.
FORENSIC DNA TECHNIQUES TO IDENTIFY SPECIES ORIGIN OF LEATHER
In a recent study, authors have focused on optimizing an ideal DNA extraction method for leathers (Merheb et al., 2014). Thus, 200 mg of modern chamois leather sample were extracted by the most used DNA extraction methods for degraded DNA,
CONCLUSION
Through an interesting study by Vuissoz et al. it was proven that “nuDNA” cannot be amplified from leather,
Rachel Matar and Maxime Merheb
due to the degradation that occurs during the tanning process. Immersion of the skin into liquids that are either acidic or basic occurs in many of the steps of the tan- ning process. Rates of DNA degradation increases quickly as pH varies from neutral (Lindahl et al., 1993) in solu- tions, such steps are expected to prompt the degradation of the DNA. Furthermore, Polyphenols have the ability to promptly
The extracted DNA is degraded and chemically altered during the process of leather manufacturing, therefore; utilizing tannins will enable the
Rachel Matar and Maxime Merheb
REFERENCES
Aguado, V., Vitas, A. I. &
Ashworth, R. B. (1987). Amino acid analysis for meat protein evaluation J Assoc Off Anal Chem Vol. 70 Issue 1:
Bartlett, S. E. & Davidson, W. S. (1992). FINS (forensically informative nucleotide sequencing): A procedure for identify- ing the animal origin of biological specimens Biotechniques Vol. 13 Issue 4: 518.
Beyries, S. (2008). Modélisation du travail du cuir en ethnolo- gie : proposition d’un système ouvert à l’archéologie Anthro- pozoologica Vol. 43. Issue 1:
Botti, S. & Giuffra, E. (2010). Oligonucleotide indexing of DNA barcodes: identification of tuna and other scombrid species in food products BMC Biotechnol Vol. 10 Issue: 60.
Cano, R. J., Borucki, M. K.,
Cano, R. J. & Poinar, H. N. (1993). Rapid isolation of DNA from fossil and museum specimens suitable for PCR Biotechniques Vol. 15 Issue 3:
Capelli, C., Tschentscher, F. & Pascali, V. L. (2003). Ancient protocols for the crime scene? Similarities and differences between forensic genetics and ancient DNA analysis Forensic Sci Int Vol. 131 Issue 1:
Champlot, S., Berthelot, C., Pruvost, M., Bennett, E. A., Grange, T. & Geigl, E. M. An efficient multistrategy DNA decontamina- tion procedure of PCR reagents for hypersensitive PCR applica- tions PLoS One Vol. 5 Issue 9:
Comstock, K. E., Ostrander, E. A. & Wasser, S. K. (2003). Ampli- fying Nuclear and Mitochondrial DNA from African Elephant Ivory: a Tool for Monitoring the Ivory Trade Conservation Biology Vol. 17 Issue 6:
Cooper, A. (1992). Removal of colourings, inhibitors of PCR, and the carrier effect of PCR contamination from ancient DNA samples Anc. DNA Newslett. Vol. Issue 1:
Debruyne, R., Schwarz, C. & Poinar, H. (2008). Comment on
Desalle, R. & Amato, G. (2004). The expansion of conservation genetics Nat Rev Genet Vol. 5 Issue 9:
Eloit, M., Adjou, K., Coulpier, M., Fontaine, J. J., Hamel, R., Lilin, T., Messiaen, S., Andreoletti, O., Baron, T., Bencsik, A., Biacabe, A. G., Beringue, V., Laude, H., Le Dur, A., Vilotte, J. L., Comoy, E., Deslys, J. P., Grassi, J., Simon, S., Lantier, F. & Sarradin, P. (2005). BSE agent signatures in a goat Vet Rec Vol. 156 Issue 16:
Etienne, M., Jerome, M., Fleurence, J., Rehbein, H., Kundi- ger, R., Yman, I. M., Ferm, M., Craig, A., Mackie, I., Jessen, F., Smelt, A. & Luten, J. (1999). A standardized method of iden-
tification of raw and
Fabbri, E., Miquel, C., Lucchini, V., Santini, A., Caniglia, R., Duchamp, C., Weber, J. M., Lequette, B., Marucco, F., Boitani, L., Fumagalli, L., Taberlet, P. & Randi, E. (2007). From the Apennines to the Alps: colonization genetics of the naturally expanding Italian wolf (Canis lupus) population Mol Ecol Vol. 16 Issue 8:
Feuillie, Merheb, Gillet, Montagnac, Daniel & Hänni. Specific DNA detection by SERRS: toward older biosignatures. Origins 2011, The International Astrobiology Society and Bioastron- omy, 2011a.
Feuillie, C., Merheb, M., Gillet, B., Montagnac, G., Michot, L., Daniel, I. & Hänni, C. Adsorption of DNA on
Feuillie, C., Merheb, M. M., Gillet, B., Montagnac, G., Daniel, I. & Hänni, C. (2011c). A novel SERRS
Feuillie, C., Merheb, M. M., Gillet, B., Montagnac, G., Daniel, I. & Hänni, C. (2014). Detection of DNA Sequences Refractory to PCR Amplification Using a Biophysical SERRS Assay (Sur- face Enhanced Resonant Raman Spectroscopy) PloS one Vol. 9 Issue 12: e114148.
Feuillie, C., Merheb, M. M., Gillet, B., Montagnac, G., Hänni, C.
&Daniel, I. (2012).
Fonseca, G. & Benson, P. J. (2003). Biodiversity conservation demands open access PLoS Biol Vol. 1 Issue 2: E46.
Gilbert, M. T., Hansen, A. J., Willerslev, E., Rudbeck, L., Barnes, I., Lynnerup, N. & Cooper, A. (2003a). Characterization of genetic miscoding lesions caused by postmortem damage Am J Hum Genet Vol. 72 Issue 1:
Gilbert, M. T., Willerslev, E., Hansen, A. J., Barnes, I., Rudbeck, L., Lynnerup, N. & Cooper, A. (2003b). Distribution patterns of postmortem damage in human mitochondrial DNA Am J Hum Genet Vol. 72 Issue 1:
Golenberg, E. M. (1991). Amplification and analysis of Mio- cene plant fossil DNA Philos Trans R Soc Lond B Biol Sci Vol. 333 Issue 1268:
Guy, P. A., Gremaud, E., Richoz, J. & Turesky, R. J. (2000). Quantitative analysis of mutagenic heterocyclic aromatic amines in cooked meat using liquid
Hagelberg, E., Sykes, B. & Hedges, R. (1989). Ancient bone DNA amplified Nature Vol. 342 Issue 6249: 485.
Handt, O., Hoss, M., Krings, M. & Paabo, S. (1994). Ancient DNA: methodological challenges Experientia Vol. 50 Issue 6:
Hänni, C., Laudet, V., Stehelin, D. & Taberlet, P. (1994). Track- ing the origins of the cave bear (Ursus spelaeus) by mitochon- drial DNA sequencing Proc Natl Acad Sci U S A Vol. 91 Issue 25:
Higuchi, R., Bowman, B., Freiberger, M., Ryder, O. A. & Wil- son, A. C. (1984). DNA sequences from the quagga, an extinct member of the horse family Nature Vol. 312 Issue 5991: 282- 284.
Hoffmann, B., Harder, T., Lange, E., Kalthoff, D., Reimann, I., Grund, C., Oehme, R., Vahlenkamp, T. W. & Beer, M. New real- time reverse transcriptase polymerase chain reactions facilitate detection and differentiation of novel A/H1N1 influenza virus in porcine and human samples Berl Munch Tierarztl Wochen- schr Vol. 123 Issue
Hofreiter, M., Jaenicke, V., Serre, D., Haeseler Av, A. & Paabo, S. (2001). DNA sequences from multiple amplifications reveal artifacts induced by cytosine deamination in ancient DNA Nucleic Acids Res Vol. 29 Issue 23:
Hold, G. L., Russell, V. J., Pryde, S. E., Rehbein, H., Quinteiro, J., Vidal, R.,
Hoss, M., Jaruga, P., Zastawny, T. H., Dizdaroglu, M. & Paabo, S. (1996). DNA damage and DNA sequence retrieval from ancient tissues Nucleic Acids Research Vol. 24 Issue:
Hsieh, H. M., Huang, L. H., Tsai, L. C., Kuo, Y. C., Meng, H. H., Linacre, A. & Lee, J. C. (2003). Species identification of rhinoc- eros horns using the cytochrome b gene Forensic Sci Int Vol. 136 Issue
Kocher, T. D., Thomas, W. K., Meyer, A., Edwards, S. V., Paabo, S., Villablanca, F. X. & Wilson, A. C. (1989). Dynamics of mitochondrial DNA evolution in animals: amplification and sequencing with conserved primers Proc Natl Acad Sci U S A Vol. 86 Issue 16:
Leakey, R. & Lewin, R. 1995. The Sixth Extinction: Biodiversity and its Survival London, Phoenix.
Lefrançois, C., Hänni, C. & Lange, M. (1997). L’ADN anti- fraudes Biofutur Vol. 1997 Issue 165:
Lema, M. A. & Burachik, M. (2009). Safety assessment of food products from
Leonard, J. A., Shanks, O., Hofreiter, M., Kreuz, E., Hodges, L., Ream, W., Wayne, R. K. & Fleischer, R. C. (2007). Animal DNA in PCR reagents plagues ancient DNA research Journal of Archaeological Science Vol. 34 Issue 9:
Lindahl, T. (2000). Fossil DNA Curr Biol Vol. 10 Issue 17: R616.
Lindahl, T., Prigent, C., Barnes, D. E., Lehmann, A. R., Satoh, M. S., Roberts, E., Nash, R. A., Robins, P. & Daly, G. (1993). DNA joining in mammalian cells Cold Spring Harb Symp Quant Biol Vol. 58 Issue:
Rachel Matar and Maxime Merheb
Lockley, A. K. & Bardsley, R. G. (2000). Novel method for the discrimination of tuna (Thunnus thynnus) and bonito (Sarda sarda) DNA J Agric Food Chem Vol. 48 Issue 10:
Loreille, O., Orlando, L.,
Lucey, C. (2006). Brief report on the United States Food and Drug Administration Blood Products Advisory Committee rec- ommendations for management of donors and units testing positive for hepatitis B virus DNA Vox Sang Vol. 91 Issue 4:
Mafra, I., Ferreira, I. & Oliveira, M. (2008). Food authentication by
Manel, S., Berthier, P. & Luikart, G. (2002). Detecting Wildlife Poaching: Identifying the Origin of Individuals with Bayesian Assignment Tests and Multilocus Genotypes Conservation Biology Vol. 16 Issue 3:
Manel, S., Gaggiotti, O. E. & Waples, R. S. (2005). Assignment methods: matching biological questions with appropriate tech- niques Trends Ecol Evol Vol. 20 Issue 3:
Merheb, M., Vaiedelich, S., Maniguet, T. & Hänni, C. (2016). Mitochondrial DNA, restoring Beethovens music Mitochon- drial DNA Vol. 27 Issue 1:
Merheb, M., Vaiedelich, S., Maniguet, T. & Hänni, C. (2014). Molecular Species Identification in Processed Animal Hides for Biodiversity Protection Int’l Journal of Advances in Chemical Engg., & Biological Sciences (IJACEBS) Vol. 1 Issue 1(2014):
Merheb, M., Vaiedelich, S., Maniguet, T. & Hänni, C. (2015). DNA for Species Identification in Leather: Fraud detection and endangered species protection Research Journal Of Biotech- nology Vol. 10 Issue 9:
Merheb, M. (2010). Détection et identification de l’ADN dégradé: nouvelles approches moléculaires et biophysiques. Lyon, École normale supérieure (Sciences).
Moore, M. K., Bemmiss, J. A., Rice, S. M., Quattro, J. M. & Woodley, C. M. (2003). Use of restriction fragment length poly- morphisms to identify sea turtle eggs and cooked meats to spe- cies Conservation Genetics Vol. 4 Issue 1:
Mullis, K. B. & Faloona, F. A. (1987). Specific synthesis of DNA in vitro via a
Nicholson, E. M., Brunelle, B. W., Richt, J. A., Kehrli, M. E., Jr.
&Greenlee, J. J. (2008). Identification of a heritable polymor- phism in bovine PRNP associated with genetic transmissible spongiform encephalopathy: evidence of heritable BSE PLoS One Vol. 3 Issue 8: e2912.
Nunez, O. (1951). Morphologic interpretation of rice spicule. Cienc Invest Vol. 7 Issue 5:
Orlando, L., Bonjean, D., Bocherens, H., Thenot, A., Argant, A., Otte, M. & Hänni, C. (2002). Ancient DNA and the population genetics of cave bears (Ursus spelaeus) through space and time Mol Biol Evol Vol. 19 Issue 11:
Rachel Matar and Maxime Merheb
Orlando, L., Leonard, J. A., Thenot, A., Laudet, V., Guerin, C. & Hänni, C. (2003). Ancient DNA analysis reveals woolly rhino evolutionary relationships Mol Phylogenet Evol Vol. 28 Issue 3:
Ozaki, A., Kitano, M., Itoh, N., Kuroda, K., Furusawa, N., Mas- uda, T. & Yamaguchi, H. (1998). Mutagenicity and
Ozaki, A., Yamaguchi, Y., Fujita, T., Kuroda, K. & Endo, G. (2004). Chemical analysis and genotoxicological safety assess- ment of paper and paperboard used for food packaging Food Chem Toxicol Vol. 42 Issue 8:
Pääbo, S. (1989). Ancient DNA: Extraction, characterization, molecular cloning, and enzymatic amplification Proc. Natl. Acad. Sci. USA Vol. 86 Issue:
Paabo, S., Higuchi, R. G. & Wilson, A. C. (1989). Ancient DNA and the polymerase chain reaction. The emerging field of molecular archeology The Journal Of Biological Chemistry Vol. 264 Issue 17:
Paabo, S., Poinar, H., Serre, D.,
Poinar, H. N. (2002). The genetic secrets some fossils hold Acc Chem Res Vol. 35 Issue 8:
Prayson, B. E., Mcmahon, J. T. & Prayson, R. A. (2008). Apply- ing morphologic techniques to evaluate hotdogs: what is in the hotdogs we eat? Ann Diagn Pathol Vol. 12 Issue 2:
Ringuet, S. (2004). Les ONG et le commerce international des espèces sauvages : L’exemple de TRAFFIC Bull. Soc. Zool. Fr. Vol. 129 Issue:
Saiki, R. K., Gelfand, D. H., Stoffel, S., Scharf, S. J., Higuchi, R., Horn, G. T., Mullis, K. B. & Erlich, H. A. (1988). Primer- directed enzymatic amplification of DNA with a thermostable DNA polymerase Science Vol. 239 Issue 4839:
Saiki, R. K., Scharf, S., Faloona, F., Mullis, K. B., Horn, G. T., Erlich, H. A. & Arnheim, N. (1985). Enzymatic amplification of
Salamon, M., Tuross, N., Arensburg, B. & Weiner, S. (2005). Relatively well preserved DNA is present in the crystal aggre- gates of fossil bones Proc Natl Acad Sci U S A Vol. 102 Issue 39:
Schwarz, C., Debruyne, R., Kuch, M., Mcnally, E., Schwarcz, H., Aubrey, A. D., Bada, J. & Poinar, H. (2009). New insights from old bones: DNA preservation and degradation in permafrost preserved mammoth remains Nucleic Acids Research Vol. 37 Issue 10:
Sharphouse, J. H. 1983. Leather technician’s handbook, Leather Producers’ Association.
Shutler, G. G., Gagnon, P., Verret, G., Kalyn, H., Korkosh, S., Johnston, E. & Halverson, J. (1999). Removal of a PCR inhibi-
tor and resolution of DNA STR types in mixed
Taberlet, P. & Bouvet, J. (1992). Bear conservation genetics Nature Vol. 358 Issue 6383: 197.
Teletchea, F. 2005. Révision taxonomique des Gadidae et Puce
àADN pour l’identification d’espèces: De l’intérêt de la Systé- matique. Universite Claude Bernard – Lyon I.
Teletchea, F., Maudet, C. & Hänni, C. (2005). Food and forensic molecular identification: update and challenges Trends Bio- technol Vol. 23 Issue 7:
Tsuganezawa, O. (1965). [Morphological studies on the ingested food. Identification of the species of the ingested fish] Nihon Hoigaku Zasshi Vol. 19 Issue 5:
Urdiain, M.,
&Rossello, J. A. (2004). Identification of two additives, locust bean gum
Vasil’ev, S. A. (1990 ). Le Paléolithique final du bassin supérieur de l’Iénisseï d’après les fouilles près du
Vasil’ev, S. A. (1994). Oui2 : Un site préhistorique à riche strati- graphie des Sayans occidentaux (Sibérie du sud) Anthropolo- gie Vol. 98 Issue
Vassioukovitch, O., Orsini, M., Paparini, A., Gianfranceschi, G., Cattarini, O., Di Michele, P., Montuori, E., Vanini, G. C. & Romano Spica, V. (2005). Detection of metazoan species as a public health issue: simple methods for the validation of food safety and quality Biotechnol Annu Rev Vol. 11 Issue: 335- 354.
Vuissoz, A., Worobey, M., Odegaard, N., Bunce, M., Machado, C. A., Lynnerup, N., Peacock, E. E. & Gilbert, M. T. P. (2007). The survival of
Wan, Q. H. & Fang, S. G. (2003). Application of
Wan, X. F., Ren, T., Luo, K. J., Liao, M., Zhang, G. H., Chen, J. D., Cao, W. S., Li, Y., Jin, N. Y., Xu, D. & Xin, C. A. (2005). Genetic characterization of H5N1 avian influenza viruses iso- lated in southern China during the
Wetton, J. H., Tsang, C. S., Roney, C. A. & Spriggs, A. C. (2004). An extremely sensitive
Wilson, I. G. (1997). Inhibition and facilitation of nucleic acid amplification Appl Environ Microbiol Vol. 63 Issue 10: 3741- 3751.
Woolfe, M. & Primrose, S. (2004). Food forensics: using DNA technology to combat misdescription and fraud Trends Bio- technol Vol. 22 Issue 5:
ConvertedByBCLTechnologies