This document discusses genetic manipulation of carotenoid biosynthesis. It defines genetic engineering as the direct manipulation of an organism's genes using techniques like recombinant DNA and gene splicing. It explains that genetic manipulation can be used to alter existing species' characteristics or induce mutations to produce desirable traits. Specific techniques discussed include site-directed mutagenesis, protoplast fusion, and using shuttle and expression vectors. Carotenoids are described as pigments that protect plant structures and have health benefits when consumed by humans as antioxidants and for vitamin A activity. The locations and functions of carotenoid pigments are summarized.

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2. GENETIC MANIPULATION OF CAROTENOID BIOSYNTHESIS
by:abbas Morovvati
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4. What is genetic engineering?
• Genetic engineering,
technology, genetic modification/manipulation (GM)
and gene splicing are terms that apply to the direct
manipulation of an 's
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6. Genetic manipulation
– Altering the characteristics of existing known
species to produce new and desirable
characteristics
– Mutations can be induced with mutagenic
agents or UV irradiation
• Example: Development of high-yield cultures of
Penicillium for penicillin production
– Protoplast fusion can be used to fuse cells of
eukaryotic microbes and microbes that are
not phylogenetically related; used especially
for genetic manipulation in yeasts & molds
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7. Genetic manipulation
– Site-directed mutagenesis is the insertion of short
segments of DNA (using recombinant DNA
technology) into a gene to lead to desired changes in
its protein product
– Recombinant DNA can be transferred between
different organisms, creating combinations of genes
with exhibit desired characteristics
• Shuttle vectors: Vectors (such as bacterial
plasmids) that can replicate in more than one
species
• Expression vectors: Vectors that have
transcriptional promoters capable of mediating
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9. Different between Genetic Engineering and traditional
• , where the organism's genes are manipulated indirectly;
genetic engineering uses the techniques of
and to alter the structure and
characteristics of genes directly. Genetic engineering
techniques have found some successes in numerous
applications. Some examples are in improving crop
technology, the manufacture of synthetic human
through the use of modified , the manufacture of
in hamster cells, and the production
of new types of experimental mice such as the
(cancer mouse) for research.
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10. pigments protect photosynthetic plant structures by
dissipating excess light energy and binding singlet oxygen to inhibit
oxidative damage . Examples of include lutein and -
carotene.
• Dietary intake of lutein, -carotene, and other has been
associated with reduced risk of lung cancer and chronic eye
diseases, including cataract and age-related macular degeneration
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11. Definition
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13. Copyright restrictions may apply.

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18. What do carotenoids do?
• In human beings, carotenoids can serve several important functions. The most widely studied and
well-understood nutritional role for carotenoids is their provitamin A activity. Deficiency of vitamin
A is a major cause of premature death in developing nations, particularly among children. Vitamin
A, which has many vital systemic functions in humans, can be produced within the body from
certain carotenoids, notably beta-carotene (Britton et al. 1995). Dietary beta-carotene is obtained
from a number of fruits and vegetables, such as carrots, spinach, peaches, apricots, and sweet
potatoes (Mangels et al. 1993). Other provitamin A carotenoids include alpha-carotene (found in
carrots, pumpkin, and red and yellow peppers) and cryptoxanthin (from
oranges, tangerines, peaches, nectarines, and papayas).
• Carotenoids also play an important potential role in human health by acting as biological
antioxidants, protecting cells and tissues from the damaging effects of free radicals and singlet
oxygen. Lycopene, the hydrocarbon carotenoid that gives tomatoes their red color, is particularly
effective at quenching the destructive potential of singlet oxygen (Di Mascio et al. 1989). Lutein
and zeaxanthin, xanthophylls found in corn and in leafy greens such as kale and spinach, are
believed to function as protective antioxidants in the macular region of the human retina
(Snodderly 1995). Astaxanthin, a xanthophyll found in salmon, shrimp, and other seafoods, is
another naturally occurring xanthophyll with potent antioxidant properties (Di Mascio et al. 1991).
Other health benefits of carotenoids that may be related to their antioxidative potential include
enhancement of immune system function (Bendich 1989), protection from sunburn (Matthews-
Roth, 1990), and inhibition of the development of certain types of cancers (Nishino 1998)
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19. Where are Carotenoid Pigments?
• Carotenoid pigments These pigments are also found in plastids.
The carotenoids occur, along with the chlorophyll pigments, in tiny
structures - called plastids - within the cells of leaves. Sometimes
they are in such abundance in the leaf that they give a plant a
yellow-green color, even during the summer. But usually we become
aware of their presence for the first time in autumn, when the leaves
begin to lose their chlorophyll.
Carotenoid yellow and orange color is in many living things, giving
characteristic color to carrots, corn, canaries, and daffodils, as well
as egg yolks, rutabagas, buttercups, and bananas. Their brilliant
yellows and oranges tint the leaves of such hardwood species as
hickories, ash, maple, yellow-poplar, aspen, birch, black
cherry, sycamore, cottonwood, sassafras, and alder.
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21. References
• Bendich, A. (1989). Carotenoids and the immune response. J. Nutr., 119:112-115.
• Britton, G. (1995). Structure and properties of carotenoids in relation to function.
FASEB J., 9:1551-1558.
• Britton, G., S. Liaaen-Jensen, and H. Pfander. (1995). Carotenoids today and
challenges for the future. In: Britton, G., S. Liaaen-Jensen, and H. Pfander
[eds], Carotenoids vol. 1A: Isolation and Analysis. Basel: Birkh user.
• Di Mascio, P., Kaiser, S., and Sies, H. (1989) Lycopene as the most efficient
biological carotenoid singlet oxygen quencher. Arch. Biochem. Biophys., 274:532-
538.
• Di Mascio, P., M. E. Murphy, and H. Sies. (1991) Antioxidant defense systems: the
role of carotenoids, tocopherols, and thiols. Am. J. Clin. Nutr., 53:194S-200S.
• ^ Armstrong GA, Hearst JE (1996). "Carotenoids 2: Genetics and molecular biology
of carotenoid pigment biosynthesis". FASEB J. 10 (2): 228–37. PMID 8641556.
• ^ Bjelakovic G, et al (2007). "Mortality in randomized trials of antioxidant supplements
for primary and secondary prevention: systematic review and meta-analysis". JAMA
297 (8): 842–57. doi:10.1001/jama.297.8.842. PMID 17327526.
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22. References
• Mangels, A.R., J.M. Holden, G.R. Beecher, M.R. Forman, and E. Lanza.
(1993). Carotenoid content of fruits and vegetables: an evaluation of
analytic data. J. Am. Diet. Assoc., 93:284-296.
• Mathews-Roth, MM. (1990) Plasma concentration of carotenoids after large
doses of beta-carotene. Am. J. Clin. Nutr., Sep 52:3, 500-1
• Mercadante, A. (1999) New carotenoids: recent progress. Invited Lecture 2.
Abstracts of the 12th International Carotenoid
Symposium, Cairns, Australia, July 1999.
• Nishino, H. (1998) Cancer prevention by carotenoids. Mutat. Res., 402:159-
163.
• Ong, A.S.H., and E.S. Tee. (1992) Natural sources of carotenoids from
plants and oils. Meth. Enzymol., 213: 142-167.
• Pfander, H. (1992) Carotenoids: an overview. Meth. Enzymol., 213: 3-13.
• Snodderly, D.M. (1995) Evidence for protection against age-related macular
degeneration by carotenoids and antioxidant vitamins. Am. J. Clin.
Nutr., 62(suppl):1448S-1461S.
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