The transmission of genes, the functional unit for the genetic information, from one generation to another.
生殖細胞(せいしょくさいぼう) - germ cell
A reproductive cell; a cell specially differentiated for
reproduction such as an ovum(egg) and a spermatozoon(sperm).
体細胞(たいさいぼう) - somatic cell
General term for the cells of which a multicellular organism
is constructed, other than the mature gametes and the germ cells from which they develop.
免疫(めんえき) - immunity
The cellular and humoral reaction of a living organism to eliminate "non-self" by distinguishing "self" from "non-self." The state of an animal that has an enhanced ability, greater than a nonimmune state, to respond to some specific antigen in which the antigen is bound and rendered inactive or eliminated from the body.
抗体(こうたい) - antibody
Any protein which is produced in a living organism in response to stimulation by an antigen and that is capable of combining in a specific manner with a corresponding antigen.
重鎖(じゅうさ) - heavy chain
One of two identical polypeptide chains that are linked to two
light, likewise identical polypeptide chains to form an
immunoglobulin molecule. The molecular weight of a heavy chain
is about 50,000 - 70,000. The heavy chain in each different
immunoglobulin has a differenct structure, and the heavy chains
of the IgA, IgD, IgE, IgG, and IgM immunoglobulins are denoted
α, δ, ε, γ, and μ, respectively.
軽鎖(けいさ) - light chain
One of two identical polypeptide chains that are linked to two
heavy, likewise identical polypeptide chains to form an
immunoglobulin molecule. The molecular weight of a light chain
is about 23,000. Two different types of light chains, K and L,
are know and they are denoted κ and λ.
不変領域(ふへんりょういき) - constant region
A part of a polypeptide chain in immunoglobulin, in which
the sequence of amino acids is the same as in the
immunoglobulins from the same class. The constant region
comprises portions of both the light and heavy chains
and does not constitute an antigen binding site.
可変領域/可変部(かへんりょういき/かへんぶ) - variable region
A part of a polypeptide chain in immunoglobulin, in which
the sequence of amino acids is different in the
immunoglobulins from the same class. The variable region
comprises portions of both the light and the heavy chains
and constitutes the two antigen biding sites.
Bリンパ球(Bりんぱきゅう) - B lymphocyte (B cell)
A bone marrow-derived cell producing antibodies.
B cells function in humoral immunity in which
antibodies are circulated in the blood and secreted
onto mucous surfaces.
制限酵素(せいげんこうそ) - restriction enzyme
Enzymes which recognize specific base sequences
in DNA and hence cut a DNA molecule into a relatively
small number of fragments. They are often used
in recombinant DNA experiments and gene analysis.
DNA
Deoxyribonucleic acid; a polynucleotide which consists of
D-2-deoxyribose as a sugar and adenine, guanine, cytosine
and thymine as a base composition. DNA is famous for its
double helix structure in which two chains are bonded by
Watson-Crick base pairing. DNA constitutes the genetic
materials in most organisms and is composed of genes.
組み換えDNA手法(くみかえDNAしゅほう) - recombinant DNA technology
A technique in which genetic recombination is used in vitro.
It involves (1) breaking DNA using restriction enzymes
to produce DNA fragments, (2)joining these DNA fragments
to other DNA molecules from differnet organisms (splicing)
and (3)inserting the resultant recombinant DNA into host cells
where they self-replicate to produce multiple copies of the
inserted DNA fragments (cloning). For example, a human
gene coding for insulin is inserted into the DNA of a bacterial
plasmid and the latter is cloned to produce many identical
copies of the inserted gene.
RNA
Ribonucleic acid; a polynucleotide which consists of
D-ribose as a sugar and adenine, guanine, cytosine
and uracil as a base composition. There are three
major forms - ribosomal, transfer, and messenger
RNA. All of them function in biosysnthesis of proteins.
核(かく) - nucleus
The most conspicuous and usually spheroidal cell organelle of a
eukaryotic cell, and which contains the chromosomes. It is the site
where DNA is replicated and RNA is synthesized.
Any intragenic region of DNA in an eukaryote that does not contain
any genetic (amino acid sequence) information.
リボゾーム - ribosome
An intracellular organelle, consisting of RNA and protein. It is
the site where protein is synthsized.
細胞分化(さいぼうぶんか) - differentiation, development
The process whereby relatively unspecialized cells, e.g. embryonic
or regenerative cells, acquire specialized structural and/or
functional features to attain mature state during development.