herbicides by the insertion (via genetic engi-	of different species. See also HETEROCYCLIC,
neering techniques) of the aroA transgene	HETERODUPLEX, HETEROGENEOUS (CATALYSIS),
(cassette) for CP4 EPSPS. Corn (maize) is	HETEROGENEOUS (CHEMICAL REACTION), HETERO-
made tolerant to glyphosate-containing herbi-	GENEOUS (MIXTURE), HETEROKARYON, HETEROLO-
cides by insertion (via genetic engineering	GOUS PROTEINS, HETEROLOGOUS DNA, HETEROLOGY,
techniques) of the mEPSPS or GA21 trans-	HETEROSIS, HETEROTROPH, HETEROZYGOTE.
gene (cassette). Some soybean varieties are	Heterocyclic See HETERO-.
made tolerant to sulfonylurea-based herbi-	Heteroduplex A DNA molecule, the two
cides by adding (via traditional breeding	strands of which come from different indi-
methods) the ALS gene (which confers the	viduals so that there may be some base pairs
sulfonylurea-tolerance trait). Corn (maize)	or blocks of base pairs that do not match.
and rice (Oryza sativa) are made tolerant to	Can arise from mutation, recombination, or
imidazolinone-containing herbicides by add-	by annealing DNA single strands in vitro.
ing (via traditional breeding techniques) the	See also DEOXYRIBONUCLEIC ACID (DNA).
imidazolinone-tolerance trait. That trait is	Heterogeneous (catalysis) Catalysis occur-	H
imparted by the T-Gene, IT-Gene, or the IR-	ring at a phase boundary, usually a solid-
Gene. See also GENE, GENETIC ENGINEERING, CAS-	fluid interface. See also HETERO- , HETEROGE-
SETTE, TRANSGENIC, DEOXYRIBONUCLEIC ACID	NEOUS (MIXTURE), CATALYST.
(DNA), rDNA, EPSP SYNTHASE, GLYPHOSATE OXI-	Heterogeneous (chemical reaction) A chem-
DASE, PAT GENE, BAR GENE, GENETICS, GLYPHO-	ical reaction in which the reactants are of
SATE, GA21, SULFOSATE, ALS GENE, EPSP SYNTHASE,	different phases: for example, gas with liq-
CP4 EPSPS, CHLOROPLAST TRANSIT PEPTIDE (CTP),	uid, liquid with solid, or a solid catalyst with
ACURON™ GENE, TRANSGENE, TRAIT, CANOLA,	liquid or gaseous reactants. See also HETERO- ,
SOYBEAN PLANT, CORN, MUTATION BREEDING, TRA-	HETEROGENEOUS (CATALYSIS), CATALYST.
DITIONAL BREEDING METHODS.	Heterogeneous (mixture) One that consists of
Heredity Transfer of genetic information from	two or more phases such as liquid-vapor, or
parent cells to progeny. See also INFORMA-	liquid-vapor-solid. See also HETERO- .
TIONAL MOLECULES, GENE, GENETIC CODE,	Heterokaryon A fused cell containing nuclei
GENOME, GENETICS, GENOTYPE, DEOXYRIBO-	of different species. See also NUCLEOID.
NUCLEIC ACID (DNA), HERITABILITY, QUANTITA-	Heterologous DNA Refers to a DNA mole-
TIVE TRAIT LOCI (QTL).	cule in which each of the (double) strands is
Heritability The fraction of variation (of an	from different sources (e.g., different spe-
individual’s given trait) that is due to genet-	cies). See also DEOXYRIBONUCLEIC ACID (DNA),
ics. For example, if a pig’s trait (e.g., weight	HETERO- , SPECIES.
at birth) is 30% heritable, that means that	Heterologous Proteins Those proteins pro-
30% of the (birthweight) difference between	duced by an organism that is not the wild
that individual pig and its (statistically rep-	type source of those proteins. For example,
resentative) group of contemporaries (pigs)	bacteria have been genetically engineered to
is due to genetics. The other 70% would be	produce human growth hormone and bovine
due to factors such as nutrition of the mother	(i.e., cow) somatotropin. See also PROTEIN,
during pregnancy, etc. See also HEREDITY,	WILD TYPE, GROWTH HORMONE (GH), BOVINE
TRAIT, GENETICS, INFORMATIONAL MOLECULES,	SOMATOTROPIN (BST), HOMOLOGOUS PROTEIN.
GENE, GENETIC CODE, GENOME, GENOTYPE,	Heterology A sequence of amino acids in two
DEOXYRIBONUCLEIC ACID (DNA), QUANTITATIVE	or more proteins that are not identical to each
TRAIT LOCI (QTL).	other. See also AMINO ACID, PROTEIN, HOMOLOGY.
Hetero- A chemical nomenclature prefix	Heterosis Also known as “hybrid vigor.” See
meaning “different.” For example, a hetero-	also F1 HYBRIDS.
cyclic compound is one with a (ring) structure	Heterotroph An organism that obtains nour-
made up of more than one kind of atom. A	ishment from the ingestion and breakdown
heterokaryon refers to a cell containing nuclei	of organic matter.

© 2002 by CRC Press LLC

Heterozygote An individual organism with different alleles at one or more particular loci. See also ALLELE.

Hexadecyltrimethylammonium Bromide (CTAB) A solvent that is widely utilized to dissolve plant DNA samples (e.g., when a scientist wants to sequence that sample of plant DNA). CTAB solvent helps the scientist to separate out contaminants that are commonly present in samples from plant tissues (polysaccharides, quinones, etc.) because DNA molecules are much more soluble in CTAB than are the contaminant mol-

ecules. See also DEOXYRIBONUCLEIC ACID (DNA),

HPOLYSACCHARIDES, SEQUENCING (OF DNA MOLECULES), SDS.

Hexose See GLUCOSE (GLc).

HF Cleavage A research process in which hydrofluoric acid is used to sequentially remove side-chain protective groups from peptide chains. Also used to remove the resin support from peptides that have been prepared via solid-phase peptide synthesis. The HF cleavage reaction is a temperaturedependent process. See also PROSTHETIC

GROUP, SYNTHESIZING (OF PROTEINS).

High-Amylose Corn Refers to those corn (maize) hybrids that produce kernels in which the starch that is contained within those kernels is at least 50% amylose, versus the average of 24–28% amylose in traditional corn starch. See also CORN, STARCH,

AMYLOSE.

High-Density Lipoproteins (HDLPs) Socalled “good” cholesterol, it consists of lipoproteins that can help move excess low-den- sity lipoproteins (“bad” cholesterol, which can clog arteries) out of the human body by binding to the low-density lipoproteins (also known as LDL cholesterol) in the blood and then attaching to special LDLP receptor molecules in the liver. The liver then clears those (bound) low-density lipoproteins out of the body as a part of regular liver functions.

Studies have shown that humans having high bloodstream levels of HDLPs will offset high levels of LDLPs (e.g., the HDLPs can still help lower the risk of developing coronary heart disease). Since cholesterol does not dissolve in water (which constitutes most of the volume of blood), the body

makes HDL cholesterol into little “packages” surrounded by a hydrophilic (“water loving”) protein. That protein “wrapper” is known as apolipoprotein A-1, or apo A-1, and it enables HDL cholesterol to be transported in the bloodstream because the apolipoprotein A-1 is attracted to water molecules in the blood. See also LOW-DENSITY

LIPOPROTEINS (LDLP), RECEPTORS, APOLIPOPRO-

TEINS, WATER SOLUBLE FIBER, CHOLESTEROL,

CORONARY HEART DISEASE (CHD).

High-Glutenin Wheat See GLUTEN. High-Isoflavone Soybeans Developed in the

U.S. in the 1990s, these are soybean varieties which contain greater content of isoflavones than do traditional soybean varieties (i.e., isoflavones constitute 0.15–0.3% of a traditional variety soybean’s dry weight). Consumption of isoflavones helps to reduce the blood level of low-density lipoproteins (“bad cholesterol”) in humans. A human diet containing a large amount of isoflavones helps prevent osteoporosis, causes reduced risk of certain cancers (breast cancer, prostate cancer, endometrial cancer, etc.), and decreases risk of prostate enlargement. See also ISOFLA-

VONES, SOYBEAN PLANT, CHOLESTEROL, CANCER,

PROSTATE-SPECIFIC ANTIGEN (PSA), LOW-DENSITY

LIPOPROTEINS (LDLP), OSTEOPOROSIS.

High-Lactoferrin Rice Refers to rice plants (Oryza sativa) which have been genetically engineered to produce substantial amounts of lactoferrin in the grain they yield. Lactoferrin is a compound that is naturally produced in human breast milk. Consumption of lactoferrin by infants helps to strengthen their immune system. Consumption of lactoferrin (e.g., from genetically engineered rice) by older humans helps their immune systems to resist some infectious diseases. Lactoferrin “binds” free iron (e.g., in body fluids), thereby denying that iron to pathogenic bacteria (which need free iron to grow/infect). Lactoferrin also promotes intestinal cell growth in humans. See also

GENETIC ENGINEERING, PATHOGEN, BACTERIA,

VALUE-ENHANCED GRAINS, GROWTH (MICRO-

BIAL), CELL.

High-Laurate Canola Refers to canola (Brassica napus/campesris) varieties genetically engineered (e.g., via insertion of gene for

© 2002 by CRC Press LLC

lauroyl-ACP thioesterase) to produce at least 40% laurate (lauric acid) in their oil (in

seed). See also LAURATE, CANOLA, GENETIC

ENGINEERING, FATTY ACID, LAUROYL-ACP

THIOESTERASE, VALUE-ENHANCED GRAINS.

High-Lysine Corn Developed in the U.S. in the mid-1960s, these were initially corn (maize) varieties possessing the opague-2 gene. The opague-2 gene causes such corn to contain 0.30–0.55% lysine (i.e., 50–80% more than traditional No. 2 yellow corn). Other genes have subsequently been discovered that, when inserted into the corn/maize genome (e.g., via genetic engineering techniques), cause production of larger amounts of lysine than in traditional corn/maize varieties. High-lysine corn is particularly useful for feeding of swine, since traditional No. 2 yellow corn does not contain enough lysine for optimal swine growth. See also CORN,

LYSINE (lys), GENE, OPAGUE-2, GENETIC ENGI-

NEERING, GENOME, VALUE-ENHANCED GRAINS,

“IDEAL PROTEIN” CONCEPT, MAL (MULTIPLE

ALEURONE LAYER) GENE.

High-Methionine Corn Developed in the U.S. in the mid-1960s, these were initially corn (maize) varieties possessing the floury- 2 gene. The floury-2 gene causes such corn to contain slightly higher levels of methionine than traditional No. 2 yellow corn. Other genes have subsequently been discovered that, when inserted into corn/maize genome (e.g., via genetic engineering techniques), cause production of larger amounts of methionine than in traditional corn/maize varieties. High-methionine corn is particularly useful for feeding of poultry, since traditional No. 2 yellow corn does not contain enough methionine for optimal poultry (especially feather) growth. See also

METHIONINE (met), CORN, FLOURY-2, GENE,

G E N O M E , G E N E T I C E N G I N E E R I N G , V A L U E -

ENHANCED GRAINS, OPAGUE-2, “IDEAL PROTEIN”

CONCEPT, MAL (MULTIPLE ALEURONE LAYER)

GENE.

High-Oil Corn Conceived in 1896 at the University of Illinois in the U.S., high-oil corn (HOC) is defined to be corn (maize) possessing a kernel oil content of 5.8% or greater. Traditional No. 2 yellow corn varieties tend

to contain 4.5% or less oil content. See also

VALUE-ENHANCED GRAINS, CORN, CHEMOMETRICS.
High-Oleic Oil Soybeans S o y b e a n s f r o m
plants which have been genetically engi-
neered to produce soybeans bearing oil that
contains more than 70% oleic acid, instead
of the typical 24% oleic acid content of soy-
bean oil produced from traditional varieties
of soybeans. Cosuppression, via inserted
gene for ∆ 12 desaturase (an enzyme that
normally converts oleic acid to linoleic acid
as part of the oil creation process in tradi-
tional varieties of soybean plants), causes the
higher than traditional amount of oleic acid
in the soybean oil. High-oleic soybean oil	H
would tend to have greater oxidative stability
(especially at elevated temperatures) than
soybean oil from traditional varieties of soy-
beans. Because of that, nuts that were fried
in high-oleic oil have been shown to possess
a longer shelf life than nuts fried in tradi-
tional oils. A human diet containing a large
amount of oleic acid causes lower blood cho-
lesterol level, and thus lower risk of coronary
heart disease (CHD). See also SOYBEAN
PLANT, SOYBEAN OIL, FATTY ACID, OLEIC ACID,
MONOUNSATURATED FATS, GENETIC ENGINEER-
ING, DELTA 12 DESATURASE, CHOLESTEROL, COR-
ONARY HEART DISEASE (CHD), PALMITIC ACID,
COSUPPRESSION, ENZYME, LINOLEIC ACID.
High-Phytase Corn and Soybeans Crop plants
that have been genetically engineered to con-
tain in their grain/seed high(er) levels of the
enzyme phytase (which aids digestion and
absorption of phosphate in that grain/seed).
High-phytase grains or oilseeds are particu-
larly useful for the feeding of swine and
poultry, since traditional No. 2 yellow corn
(maize) or traditional soybean varieties do
not contain phytase in amounts needed for
complete digestion/absorption of phosphate
naturally contained in those traditional
soybeans and corn (maize) in the form of
phytate. See also PHYTASE, ENZYME, PHYTATE,
VALUE-ENHANCED GRAINS, LOW-PHYTATE CORN,
LOW-PHYTATE SOYBEANS.
High-Stearate Canola Canola varieties which
have been genetically engineered so their
seeds contain a higher percentage of stearate
(also called stearic acid) in the canola oil
than the typical stearate content in canola oil

© 2002 by CRC Press LLC

(C. ELEGANS),

TODES,

produced from traditional canola varieties. Cosuppression, via inserted gene for D-stearoyl-ACP desaturase (i.e., enzyme that normally converts stearic acid to to oleic acid in the oil creation process in traditional varieties of canola), causes the higher than traditional amount of stearic acid in the canola

oil. See also CANOLA, STEARATE, SATURATED FATTY ACIDS (SAFA), GENE, GENETIC ENGINEERING,

VALUE-ENHANCED GRAINS, FATTY ACID, COSUP-

PRESSION, ENZYME, OLEIC ACID, STEAROYL-ACP

DESATURASE, CHOLESTEROL, CORONARY HEART

DISEASE (CHD).

High-Stearate Soybeans Soybean plant vari-

Heties which have been bred or genetically engineered so their beans contain at least 12% stearate (also known as stearic acid) within their soybean oil (i.e., more than four times the typical 3% stearic acid content in the soybean oil produced from traditional soybean varieties). Some high-stearate soybeans contain more than 20% stearate. Cosuppression, via inserted gene for

D-stearoyl-ACP desaturase (i.e., enzyme that normally converts stearic acid to oleic acid in the oil creation process in traditional varieties of soybeans), is the primary way to cause the higher than traditional amount of stearic acid in the resultant soybean oil. A human diet containing stearate instead of alternative saturated fatty acids, does not cause an increase in blood cholesterol levels (whereas human consumption of the other saturated fatty acids causes bloodstream cholesterol levels to increase, which increases risk of coronary heart disease). See

also STEARATE, VALUE-ENHANCED GRAINS, SOY-

BEAN PLANT, SOYBEAN OIL, GENE, GENETIC ENGI-

NEERING, FATTY ACID, COSUPPRESSION, ENZYME,

OLEIC ACID, CHOLESTEROL, SATURATED FATTY

ACIDS (SAFA), CORONARY HEART DISEASE (CHD),

STEAROYL-ACP DESATURASE.

High-Sucrose Soybeans Another name for low-stachyose soybeans because the soybeans replace the (reduced) stachyose with (additional) sucrose. See also LOW-STACHYOSE

SOYBEANS, STACHYOSE, VALUE-ENHANCED GRAINS,

SOYBEAN PLANT, SUGAR MOLECULES.

High-Throughput Identification Determination of the identification of a given chemical compound (e.g., within a mixture), the

desired impact (cell apoptosis, etc.), a specific segment (sequence) of DNA (i.e., a specific gene), a specific ligand or receptor (e.g., “attaching” itself to a given molecule), etc. within the overall process known as highthroughput screening. See also H I G H-

THROUGHPUT SCREENING (HTS), COMBINATORIAL

CHEMISTRY, BIOCHIPS, CELL, APOPTOSIS, GENE,

DEOXYRIBONUCLEIC ACID (DNA), GENE EXPRES-

SION, TARGET-LIGAND INTERACTION SCREENING,

R E C E P T O R S , C H A R A C T E R I Z A T I O N A S S A Y,

SEQUENCE (OF A DNA MOLECULE), GENE EXPRES-

SION ANALYSIS, CAENORHABDITIS ELEGANS

(C. ELEGANS), MOLECULAR BEACON.

High-Throughput Screening (HTS) A methodology utilized to quickly screen large numbers of compounds for use as pharmaceuticals or agrochemicals (e.g., herbicides). For example, when screening chemical compounds for potential use as a pharmaceutical, the goal often is to assess differences between diseased and treated cells; enabling identification of a pharmaceutical candidate that favorably impacts change in protein level (i.e., gene expression) which characterizes a diseased state, or some other gene expression marker (e.g., apoptosis).

When screening compounds for potential use as herbicide active ingredients, the goal is to assess differences between normal and treated weed plant cells; enabling identification of a potential herbicide candidate that imparts desired (fatal) change. Although whole living cells or whole microscopic animals such as nematodes could be utilized in HTS, it is more common to use a proxy (e.g., receptors, enzymes, or STATs from applicable cells) whose interaction with candidate compounds can be inferred to cell (and/or organism) effects. See also COMBINATORIAL

CHEMISTRY, BIOCHIP, TARGET-LIGAND INTERACTION SCREENING, CELL, ORGANISM, CHARACTER- I Z A T I O N A S S A Y, P R O T E I N , G E N E , G E N E EXPRESSION, HIGH-THROUGHPUT IDENTIFICATION,

RECEPTORS, GENE EXPRESSION ANALYSIS, BIOASSAY, GENE EXPRESSION MARKERS, SIGNAL TRANSDUCERS AND ACTIVATORS OF TRANSCRIPTION

(STATs), APOPTOSIS, IN SILICO SCREENING, NEMA-

CAENORHABDITIS ELEGANS

ENZYME, NORTHERN BLOT ANALYSIS, MOLECULAR BEACON.

© 2002 by CRC Press LLC