[Single chain DNA ]

Single chain DNA (single - stranded DNA) majority of DNA bydouble spiral structure existence, but as soon as passes through theheat or the alkali treatment can become the single chain condition.Single chain DNA is refers by this kind of condition existence DNA.Single chain DNA in the member hydromechanics nature, the absorptionspectrum, aspect and so on alkali base response nature is alldifferent with double strand DNA. Certain bacteriophage granulecontents has single chain ring-like DNA, such bacteriophage DNAmultiplies when the cell forms double strand DNA.

[ Closed loop DNA ]

Closed loop DNA (closed circular DNA) does not have thefracture double strand ring-like DNA, also is called ultra spiral DNA.Because has the spiral structure double strand each one closed,finally causes the entire DNA member further to turn on lathe the tuneto form three levels of structures. Moreover if or in two chainsdifferent spots produces a fracture, can become  the tunesplit-ring DNA member. The material particle or viral DNA withdrawswhich from the cell all include the closed loop and the split-ringthese two kind of members. May act according to two and the pigmentcombining capacity difference, but two separations.

[ Connects DNA ]

Connects DNA (Linker DNA): 核小体 center besides 146bp coreDNA all DNA.

[ Template DNA ]

Template DNA may be the single chain member, also may be thedouble strand member, may be the striation member, also may be thering-like member (striation molecular proportion ring-like memberexpands increases effect to be fairly good) Speaking of template DNA,affects PCR the primary factor is the template quantity and thepurity.

[ Supplementary DNA ]

Supplementary DNA (DNA, complementary DNA) constitutes thegene the double strand DNA member to take the template with a singlechain, copies produces if the sequence supplementary messenger RNAmember, then records the enzyme in the reverse under the function,take the mRNA member as the template, synthesizes with mRNA sequencesupplementary single chain DNA, finally again as the templatesynthesizes another take single chain DNA if supplementary singlechain DNA, two supplementary single chains DNA a molecular compositiondouble strand DNA member Therefore, the double strand DNA membersequence with copies the mRNA member gene which produces is sameTherefore a DNA member represents a gene But DNA was still differentwith the gene, because gene when copied produced mRNA, some notencoded sequence namely contains sub- was deleted, the retention onlycodes the sequence, namely apparent child Therefore the DNA sequenceall must be much shorter than the gene sequence, because in DNA notincluding gene non- code sequence --- content.


[ DNA restrictive piece length multi- state properties analysis ]

In the human gene group, equally approximately 200 pair ofalkali bases may have a pair of variation (to be called neutral suddenchange), the neutral sudden change causes the individual thenucleotide sequence difference, is called the DNA multi- stateproperties. The many DNA multi- state properties occur on therestrictive enzyme recognition position spot, the enzymolysisthis DNA fragment can produce the length different piece, is calledthe restrictive fragment length multi- state properties (RFLP). RFLRaccording to Mendel way heredity, in some specific family, if somepathogenesis gene and the special multi- state property pieces areclose chain-like, may use this more than 1 state property fragment isone kind "the heredity symbolizes", judges the family member or theembryo whether for pathogenesis gene . The armor hemophilia,the pouch textile fiber pathological change and the benzene oxonemiaand so on may draw support from this method to obtain the diagnosis

[ Gene treatment ]

The gene treatment is enters the cell with the normal geneconformity, adjusts and the replacement pathogenesis gene one methodof treatment. At present from generalized says, shifts some kind ofgenetic material to the patient cell in, causes its in vivo displayfunction, achieved treats the disease goal method, also says the genetreatment.

At present the gene treatment uses the method basically may divideinto following several kinds:

1 gene rectifies

The gene rectifies refers carries on the pathogenesis geneunusual alkali base the correction, but is normal partially retains.

2. genes replacement

The gene replacement is with the normal gene through in vivogene homology reorganization, in the home position replacepathological change cell pathogenesis gene, makes in the cell DNAcompletely to restore the normal state.

3. genes supplement

The gene supplements refers inducts the goal gene thepathological change cell or other cells, does not remove the unusualgene, but is through the goal gene non- fixed-point conformity, causesit to express the product to compensate the flaw gene the function orenable the original function to obtain strengthens. At present thegene treatment selects this method.

4. genes deactivation

The early time generally refers to the counter- righteousnessnucleic acid technology. It is the specific counter- righteousnessnucleic acid, including counter- righteousness RNA, counter-righteousness DNA and the nuclear enzyme inducts the cell, istranslating and copies the level to block certain genes theexceptionally expression. In recent years also had the counter- genestrategy, the peptide nucleic acid, the gene removes with the RNAdisturbance technology.
[ DNA is all biological genetic material foundation ]
DNA (deoxyribonucleic acid) is a nucleic acid kind, because inthe member includes the ribodesose to acquire fame.
The DNA member is extremely huge (molecular weight generally at leastabove millions), the main component is the adenine deaerationnucleotide, the guanine deaeration nucleotide, the cytosine deaerationnucleotide and the thymine deaeration nucleotide. DNA exists in thecell nucleus, a line grain of body, the chloroplast, also may the freestate exist to in certain cells cytoplasm. In the majority knownbacteriophage, the partial animals virus and the minority plant virusalso include DNA.
Besides RNA (ribonucleic acid (RNA)) and the bacteriophage, DNA is allbiological genetic material foundation. The organism kisses betweenchild's similarity and inherits the nature namely so-called geneticinformation, all stores in the DNA member. In 1953, the James watsonand Francis Krick described the DNA structure: Mutually coils aroundby pair of multi- nucleotides chains the group to form a pair thescrew. They therefore  shared 1962 Nobel physiology or themedicine prize with London country engineering institute's physicistFrederick.

[ Obese gene ]

The English London imperial family hospital scientistsdiscovered that, in obesity in vivo, all has one kind of functionunique gene, this kind of gene concerns with human body in 3chromosomes. Because this gene only exists to obesity in vivo,therefore, the scientist calls it "the obese gene".
After the research discovery, the obese gene can press to embark on anofficial career the system to compose one kind to transport the fat inthe blood the protein - "APO - D" the gene. This gene more, bloodtransportation fat smoother, in vivo agglomeration fat also more, theperson is more obese. The scientists have done following interestingexperiment: Lets the mouse which a pair carries has the obese genecarry on the copulation, finally the descendants all roll the meloncircle to slide, shape with meat ball; But lets a pair of not obesegene the mouse carries on the copulation, gives birth the mouse invivo fat are few, each one all very much becomes emaciated. Scientistsaccording to this kind of heredity pattern, but also may cultivate thebody content fat 20 ~ 50% size degree different mouse at will. Furtherdiscovered that, human's obese gene heredity situation and the mouseclass slightly has the difference, belongs separates a generation ofheredity. Namely, the people can observe, in quite many families, thefat grandmother generally cannot bequeath the obese gene own children,but bequeaths her Sun Beimen.
The scientists also discovered that, continues one kind with the obeserelated gene. For example an American New York Rockefelleruniversity's research team recently announced that, they pass through8 year long research, had discovered one kind can control the appetiteand the energy metabolism gene. It is said that, this kind of gene cantransmit the signal to the cerebrum which one kind stops eating food,causes the cerebrum the master at the right moment weakens theappetite, avoids in vivo energy too much; If this gene has thevariation, the master can the appetite greatly increase,  eats,ends in a big fat person. Further studies promulgates, this kind ofgene is composed by 4,500 alkali bases, part can produce the proteinwhich is composed by 167 amino acids. If this protein synthesis isnormal, can send out the signal to the cerebrum which stops eatingfood; If codes this protein in the amino acid composition to code the105th amino acid remnant base the alkali base to appear exceptionally,stops the signal which eats food being able to malfunction, thuscauses obese.

（转自网络，仅供参考，感谢原作者！）