J

Japan Bio-Industry Association An association of the largest Japanese companies that are engaged in at least some form of genetic engineering research or production. Similar to America’s Biotechnology Industry Organization (BIO), it is headquartered in Tokyo.

See also BIOTECHNOLOGY INDUSTRY ORGANIZATION (BIO), BIOTECHNOLOGY, GENETIC ENGINEER-

I N G , R E C O M B I N A N T D N A (r D N A ), S E N I O R

ADVISORY GROUP ON BIOTECHNOLOGY (SAGB),

INTERNATIONAL FOOD BIOTECHNOLOGY COUNCIL.

Jasmonic Acid Jasmonic Acid is a signaling molecule in Systemic Acquired Resistance (SAR) when SAR is triggered in plants (via spray application of harpin protein to various plants, via chewing of insects on the leaves of certain plants, and/or via the entry-into- plant of certain pathogenic bacteria/fungi,

etc.). See also SYSTEMIC ACQUIRED RESISTANCE

(SAR), SIGNALING MOLECULE, SOYBEAN PLANT,

FUNGUS, PATHOGEN, PROTEIN, PATHOGENESIS

RELATED PROTEINS, HARPIN, PHYTOALEXINS.

Jumping Genes Genes that move (change positions) within the genome. Genes associated

with transposable elements. A segment fragment of deoxyribonucleic acid (DNA) that can move from one position in the genome to another. See also GENE, GENOME, DEOXY-

RIBONUCLEIC ACID (DNA), GENETIC CODE, TRANS-

P O S I T I O N , T R A N S P O S O N , T R A N S L O C A T I O N ,

INTROGRESSION, HOT SPOTS.

Juncea Refers to a group of related plants; often commonly called “wild mustard.” See

also BRASSICA.

Junk DNA A term historically utilized by J some, to refer to portions of an organism’s

DNA that were not obviously genes (i.e., not transcribed into mRNA; thus not part of the DNA “tagged” with ESTs, etc.). However, it has recently been discovered that at least some of what was formerly called “junk DNA” (e.g., introns) helps enable more than one specific protein molecule to be expressed from certain genes. See also

DEOXYRIBONUCLEIC ACID (DNA), GENE, INTRON,

PROTEIN, EXPRESS, EXPRESSED SEQUENCE TAG

(EST), CENTRAL DOGMA (NEW).

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K

Karnal Bunt A plant disease that can be caused by the smut fungus Tilletia indica in wheat. See also FUNGUS, WHEAT.

Karyotype A size-order alignment of an organism’s chromosome pairs in the format of a chart. It enables the connecting of chromosomes to symptoms (e.g., of genetic diseases in the organism) and traits. See also

CHROMOSOMES, GENE, GENOTYPE, TRAIT, LINKAGE, LINKAGE GROUP, MUSCULAR DYSTROPHY

(MD), CHROMATIDS, CHROMATIN.

Karyotyper A scientist (or more frequently an automated analytical machine) that

•Takes a video picture of a given cell under a microscope

•Digitizes that picture within a computer

•“Cuts out” the individual chromosomes contained within that cell’s genome

•Arranges the cell’s chromosomes in pairs by size order into a chart (called a karyotype).

See also CHROMOSOMES, GENOME, KARYOTYPE.

Kb An abbreviation for 1,000 (kilo) base pairs of deoxyribonucleic acid (DNA). See also

DEOXYRIBONUCLEIC ACID (DNA), KILOBASE PAIRS

(Kbp).

Kd An abbreviation for kilodalton. See also

KILODALTON (Kd).

Kefauver Rule A 1962 U.S. law that mandates that the Food and Drug Administration (FDA) requires proof of pharmaceutical efficacy for drugs to be sold in the U.S.. See

also FOOD AND DRUG ADMINISTRATION (FDA).

Kenya Biosafety Council T h e c o u n t r y o f Kenya’s national regulatory body for granting approval to a new genetically engineered plant (e.g., a new genetically engineered crop to be planted). The Kenya Biosafety

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Council is analogous to Germany’s ZKBS (Central Commission on Biological Safety), Australia’s GMAC (Genetic Manipulation Advisory Committee), or Brazil’s CTNBio (National Biosafety Commission). See also

GMAC, RECOMBINANT DNA ADVISORY COMMITTEE
(RAC), ZKBS (CENTRAL COMMISSION ON BIOLOG-
ICAL SAFETY), GENETIC ENGINEERING, CTNBio.
Keratins Insoluble protective or structural pro-
teins consisting of parallel polypeptide chains
arranged in an α-helical or β conformation.
Ketose A simple monosaccharide having its
carbonyl groups at other than a terminal	K
position. See also MONOSACCHARIDES.
Killer T Cell See CYTOTOXIC T CELLS.
Kilobase Pairs (Kbp) A unit of DNA equals
1,000 base pairs. See also BASE PAIR (bp),
DEOXYRIBONUCLEIC ACID (DNA).
Kilodalton (Kd) A unit of mass equal to 1,000
Daltons. See also DALTON.
Knockout (gene) See GENE SILENCING, GPA1,
NUCLEAR TRANSFER.
Konzo A term used in some countries to refer
to lathyrism. See also LATHYRISM, GLUCOSINO-
LATES.
Koseisho The Japanese government agency
that must approve new pharmaceutical prod-
ucts for sale with Japan. It is the equivalent
of the U.S. Food and Drug Administration.
See also NDA (TO KOSEISHO), FOOD AND DRUG
ADMINISTRATION (FDA), COMMITTEE FOR PROPRI-
ETARY MEDICINAL PRODUCTS (CPMP), COMMITTEE
ON SAFETY IN MEDICINES, MEDICINES CONTROL
AGENCY (MCA), EUROPEAN MEDICINES EVALUA-
TION AGENCY (EMEA), BUNDESGESUNDHEITSAMT
(BGA).
Krebs Cycle See CITRIC ACID CYCLE.
Kunitz Trypsin Inhibitor (TI) See T R Y P S I N
INHIBITORS.

© 2002 by CRC Press LLC

L

L-Selectin Also known as the homing recep-

tor. See also SELECTINS, LECTINS, ADHESION

MOLECULES.

Lab-On-A-Chip See BIOCHIP, NANOTECHNOLOGY,

MICROFLUIDICS, GENOSENSORS, GENE EXPRES-

SION, BIOSENSORS (ELECTRONIC), BIOSENSORS

(CHEMICAL), GENE EXPRESSION ANALYSIS.

Label (radioactive) A radioactive atom, introduced into molecule(s) in order to:

1.enable observation of that molecule’s metabolic transformation (within an organism). For example, if radioactive hydrogen in the form of water (known as deuterium) is supplied to a living cell, a series of “photographs” (e.g., taken via an electron microscope, which has photographic film in it that is sensitive to radiation) will reveal how rapidly that deuterium enters the cell, and into what structures within the cell that water is incorporated.

2.quantify the rate at which cetain (non-) radioactive atoms are being introduced into a polymer (e.g., DNA) that is being polymerized (manufactured) as part of a biological test or testing process (QPCR-Quantitative PCR, RT- PCR-Reverse Transcriptase PCR, etc.).

See also AUTORADIOGRAPHY, CELL, DEOXYRIBO-

NUCLEIC ACID (DNA), GENE EXPRESSION ANALY-

S I S , Q P C R , R T -P C R , R A D I O I M M U N O A S S A Y ,

RADIOIMMUNOTECHNIQUE.

Lac Operon An operon in Escherichia coli

(E. coli) that codes for three enzymes involved in the metabolism of lactose. See

also OPERON, CODING SEQUENCE, ESCHERICHIA

COLIFORM (E. COLI).

Lachrymal Fluid (tears) A salty solution produced by the tear glands to bathe and

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lubricate the eye. Possesses antimicrobial properties.

	Lactoferricin A protein compound that acts to
	inhibit pathogenic (disease-causing) bacteria
	and yeasts (e.g., in the human body). See
	also PROTEIN, PATHOGEN, BACTERIA, YEAST,
	LACTOFERRIN.
	Lactoferrin A protein compound that is natu-
	rally produced in human breast milk. Also
	produced in cow’s milk. Consumption of
	lactoferrin by infants (e.g., via nursing) helps
	strengthen their immune system. Consump-
	tion of lactoferrin by older humans helps
	their immune system to resist infectious dis-
		L
	eases. Lactoferrin binds free iron (e.g., in
	body fluids), thereby denying that iron to
	pathogenic baceria (which need that iron to
	grow/infect). Pepsin and some other pro-
	teases (enzymes) can convert lactoferrin to
	lactoferricin. See also PROTEIN, PATHOGEN,
	BACTERIA, GROWTH (MICROBIAL), LACTOFERRI-
	CIN, PEPSIN, PROTEASE, HIGH-LACTOFERRIN RICE,
	LACTOPEROXIDASE.
	Lactonase An enzyme that “breaks open” the
	lactone ring in (molecular structure of) the
	mycotoxin zearalenone. See also ENZYME,
	MYCOTOXIN, ZEARALENONE, TOXIN.
	Lactoperoxidase A p r o t e i n c o m p o u n d
	(enzyme) that acts to inhibit pathogenic bac-
	teria (e.g., in human body). See also PROTEIN,
	ENZYME, PATHOGEN, BACTERIA.
	Lambda Phage A bacteriophage that infects
	Escherichia coli (E. coli). It is commonly
	used as a vector in recombinant DNA
	(deoxyribonucleic acid) research. See also
	PHAGE, ESCHERICHIA COLIFORM (E. COLI).
	Langerhans Cells See DENDRITIC LANGERHANS
	CELLS, ISLETS OF LANGERHANS.
	Lathyrism See GLUCOSINOLATES.

© 2002 by CRC Press LLC

Laurate A medium chain length (i.e., C12) fatty acid that is naturally produced by coconut trees, oil palm trees, and certain species of wild plants. In 1992, some canola varieties were genetically engineered so that they could also produce (desirable) laurate in their seeds. See also FATTY ACID, FATS, CANOLA,

GENETIC ENGINEERING, GENETIC CODE, LPAAT

PROTEIN, ACP, LAUROYL-ACP THIOESTERASE,

HIGH-LAURATE CANOLA.

Lauric Acid See LAURATE.

Lauroyl-ACP Thioesterase The enzyme that is required for the synthesis (manufacturing) of laurate in plants. For example, the presence of this enzyme in the California bay tree (Umbellularia californica) causes its seed oil to contain as much as 45% laurate.

See also LAURATE, ENZYME, LPAAT PROTEIN,

HIGH-LAURATE CANOLA.

Lazaroids A class of drugs being developed to “bring back from the dead” tissues that have been (almost) killed due to a lack of oxygen

L(e.g., Krebs Cycle L caused by a clot blocking a vital artery). See also HUMAN SUPER-

OXIDE DISMUTASE (hSOD), FIBRIN, REPERFUSION.

LDL See LOW-DENSITY LIPOPROTEINS (LDLP).

LDLP See LOW-DENSITY LIPOPROTEINS.

LDLP Receptors See LOW-DENSITY LIPOPRO-

TEINS (LDLP).

Leader See LEADER SEQUENCE.

Leader Sequence The nontranslated sequence at the 5′ end of mRNA that precedes the initiation codon. See also MESSENGER RNA

(mRNA), CODON.

Leaky Mutants A mutant in which the mutated gene product, such as an enzyme, still possesses a fraction of its normal biological activity. See also MUTATION, GENE,

PROTEIN, BIOLOGICAL ACTIVITY, ENZYME.

Lear See CANOLA.

Lecithin See LECITHIN (crude, mixture), LECITHIN

(refined, specific).

Lecithin (crude, mixture) A mixture of phospholipids (i.e., lecithin-phosphatidylcholine, cephalin, inositol phosphatides, glycerides, tocopherols, glucosides, and certain pigments). Historically, crude (mixture) lecithin has often been utilized commercially in food processing as an emulsifier, instantizing agent, and lubricating agent. Because leci- thin-phosphatidylcholine naturally contains

a high content of linoleic acid, consumption by humans of lecithin-phosphatidylcholine results in similar impact (e.g., lowered cholesterol levels in blood) as consumption of linoleic acid. Because dietary fats are generally not absorbed directly through the intestinal wall (when eaten), they must first be emulsified, to form micelles that can pass through the intestinal wall and thus be absorbed by the body. That emulsifica- tion/micelle-formation is aided by lecithin, since it is an emulsifier. See also LECITHIN

(refined, specific), LIPOPROTEIN, LIPIDS, CONJUGATED PROTEIN, HIGH-DENSITY LIPOPROTEINS

(HDLP), LOW-DENSITY LIPOPROTEINS (LDLP),

SOYBEAN PLANT, SOYBEAN OIL, CHOLINE, SIGNAL

TRANSDUCTION, LINOLEIC ACID, ACETYLCHOLINE,

FATS, MICELLE, DIGESTION (WITHIN ORGANISMS),

BILE ACIDS.

Lecithin (refined, specific) A by-product of the refining process for soybean oil (deoiled lecithin from processed soybeans is composed of approximately 20–25% phosphatidyl choline by weight). The lecithin molecule (i.e., phosphatidyl choline) naturally contains a high content of linoleic acid, so consumption of lecithin by humans results in similar impact (e.g., lowered cholesterol levels in blood) as consumption of linoleic acid. Because dietary fats are generally not absorbed directly through the intestinal wall (when eaten), they must first be emulsified to form micelles that can pass through the intestinal wall and be absorbed by the body. That emulsification/micelle-for- mation is aided by lecithin, since it is an emulsifier.

Lecithin (also known as phosphatidylcholine) is a source of choline when digested, and is a critical component of the lipoproteins that transport fat and cholesterol molecules in the bloodstream (e.g., from the digestive system, to body cells, to the liver, etc.). Lecithin (phosphatidylcholine) promotes synthesis of high-density lipoproteins (HDLP, also known as “good” cholesterol) by the liver, when it is consumed by humans. Phosphatidyl choline (PC) is involved in cell signal transduction (e.g., via which a cell reacts to an external chemical “signal”). Some other common dietary sources of

© 2002 by CRC Press LLC