Содержание
- 2. A transgenic animal is one that carries a foreign gene that has been deliberately inserted into
- 3. Retroviridae is a family of enveloped viruses that replicate in a host cell through the process
- 4. А. Схема получения ретровирусного вектора. Для получения не способных к репродукции ретровирусных векторов используют специальные линии
- 5. The use of retroviral vectors. The advantage of the method based on the use of retroviral
- 6. Microinjection of DNA. Currently for the creation of transgenic mice microinjection of DNA are most commonly
- 7. In mammals, after the penetration of sperm into the oocyte nucleus of the sperm (male pronucleus)
- 8. Sterilization (vasoectomy) of males Vasectomy (lat. Vas - a vessel, duct + ectomy) - a surgical
- 9. For identification of transgenic animals DNA is isolated from a small piece of the tail and
- 10. Southern blot
- 11. Thus, from 1000 implanted fertilized oocytes 30 to 50 transgenic mice are developing. In addition, introduced
- 12. Using of the modified embryonic stem cells. Cells from mouse embryos at the blastocyst stage, can
- 13. Бластоци́ста (от др.-греч. — пузырь) — ранняя стадия развития зародыша млекопитающих (в том числе человека). Стадия
- 15. ES-cells, in which genome transgene is integrated in the right site, can be cultivated and injected
- 16. To create transgenic cows a modified scheme of mice transgenosis by microinjection of DNA are used.
- 17. e) microinjection of DNA into the male pronucleus; f) development of embryos in vitro; g) non-surgical
- 18. It was established that in transgenic pigs with growth hormone gene the final body weight was
- 20. Creation of transgenic animals opens real prospects for improving the quality or composition of animal products.
- 21. The presence in the milk of various microflora caused problems associated with the storage, processing, consumption
- 22. Institute of Cytology and Genetics of RAS (Novosibirsk) and the Institute of Molecular Genetics, RAS (Moscow)
- 23. By injection of recombinant DNA into zygotes pronuclei 4 transgenic mice were obtained. PCR shows the
- 24. The possibility of including in organism’s cells the genes responsible for synthesis of proteins of great
- 25. Foreign proteins can be synthesized by most tissues of the animal. Transgene expression in certain organs
- 26. The choice mammary gland as a site of production of foreign proteins justified by its huge
- 27. To date, a number of recombinant proteins is known, such as human protein C, antihemophilic factor
- 28. For this purpose the transgenic pigs were obtained carrying different human complement inhibitor genes. The cells
- 29. The first work on getting transgenic animals - producers of interleukin-2 turned out encouraging. Interleukin-2 being
- 31. Скачать презентацию
A transgenic animal is one that carries a foreign gene
A transgenic animal is one that carries a foreign gene
Transgenic technology developed and refined on laboratory mice. Since the early 1980's hundreds of genes were introduced to different strains of mice.
The introduction of foreign DNA into mice was carried out by different methods:
- by using retroviral vectors to infect embryo cells in the early stages of its development before implantation into a female recipient,
- by microinjection DNA into the sperm nucleus (male pronucleus) of fertilized egg,
- by introduction of genetically modified embryonic stem cells in pre-implanted embryo in its early stages of development.
Retroviridae is a family of enveloped viruses that replicate in a
Retroviridae is a family of enveloped viruses that replicate in a
In most viruses, DNA is transcribed into RNA, and then RNA is translated into protein. However, retroviruses function differently – their RNA is reverse-transcribed into DNA, which is integrated into the host cell's genome (when it becomes a provirus), and then undergoes the usual transcription and translational processes to express the genes carried by the virus. So, the information contained in a retroviral gene is used to generate the corresponding protein via the sequence: RNA → DNA → RNA → polypeptide.
А. Схема получения ретровирусного вектора. Для получения не способных к
А. Схема получения ретровирусного вектора. Для получения не способных к
Затем плазмиду, содержащую рекомбинантную ДНК провируса, в которой вместо генов gag, pol и env находится нужный трансген, используют для трансфекции упаковывающих клеток. ДНК провируса вводят в виде плазмиды, в которой между двумя длинными концевыми повторами заключены небольшой участок гена gag с сигналом сборки и чужеродные гены. Теперь клетки содержат все, что нужно для сборки вирусов, и ретровирусные векторы начинают накапливаться в культуральной среде. Эти векторы содержат трансген, но лишены вирусных генов gag, pol и env, а потому при заражении следующей клетки они не могут репродуцироваться. (gag—внутренние структурные белки, pol — обратная транскриптаза и env — белки вирусной оболочки)
Б. Экспрессия трансгена в клетке-мишени после внедрения РНК-содержащего ретровирусного вектора.
The use of retroviral vectors. The advantage of the method based
The use of retroviral vectors. The advantage of the method based
The use of retroviral vectors has is another great drawback. Although these vectors are created so that they were defective in replication, retroviruses can replicate in the body of the transgenic animal that is absolutely unacceptable, if these animals supposed to use as food or as a tool to get a commercial product. And because there are alternative methods of transgenic, retroviral vectors are rarely used to create transgenic animals that have commercial value.
Microinjection of DNA. Currently for the creation of transgenic mice microinjection
Microinjection of DNA. Currently for the creation of transgenic mice microinjection
The work begins with the stimulation of hyper ovulation in female donors to increase the number of eggs in which foreign DNA will be injected. At first Pregnant Mare Serum are injected to females and after about 48 hours Human Chorionic Gonadotropin is administrated. As a result of hyper ovulation about 35 eggs are formed instead of usual 5-10. Then females with hyper ovulation is crossing with males after which they were sacrificed, fertilized eggs are washed out from the oviduct, and immediately DNA is injected into fertilized eggs.
In mammals, after the penetration of sperm into the oocyte nucleus
In mammals, after the penetration of sperm into the oocyte nucleus
After the introduction of DNA 25 to 40 oocytes are implanted by microsurgical ways in "surrogate" mother whose in the false pregnancy state by mating with a sterile male. In mice, the pairing is the only known way to prepare the uterus for implantation.
Since sterile male does not produce sperm, no oocytes of "surrogate" mother is fertilized. Embryos are developed only from introduced oocytes and pups are born in 3 weeks after implantation
Sterilization (vasoectomy) of males
Vasectomy (lat. Vas - a vessel, duct +
Sterilization (vasoectomy) of males
Vasectomy (lat. Vas - a vessel, duct +
For identification of transgenic animals DNA is isolated from a small
For identification of transgenic animals DNA is isolated from a small
The described approach seems at first glance relatively simple, but it requires coordination of different stages. Even highly qualified specialist can obtain at the best only 5% of viable transgenic animals from the inoculated eggs.
None of the stages of the experiment is not effective at 100%, so for microinjection a large number of fertilized eggs should be used. For example, in obtaining transgenic mice after injection of DNA only 66% of fertilized eggs are survived; pups are developing from about 25% of implanted oocytes, and transgenic of them are only 25%.
Southern blot
Southern blot
Thus, from 1000 implanted fertilized oocytes 30 to 50 transgenic mice
Thus, from 1000 implanted fertilized oocytes 30 to 50 transgenic mice
Using of the modified embryonic stem cells. Cells from mouse embryos
Using of the modified embryonic stem cells. Cells from mouse embryos
Then it is possible to select the modified cells, cultivate them and use for the production of transgenic animals. This prevents accidental insertion characteristic by microinjection and retroviral vector systems.
Бластоци́ста (от др.-греч. — пузырь) — ранняя стадия развития зародыша млекопитающих (в том числе человека). Стадия бластоцисты следует
Бластоци́ста (от др.-греч. — пузырь) — ранняя стадия развития зародыша млекопитающих (в том числе человека). Стадия бластоцисты следует
ES-cells, in which genome transgene is integrated in the right site,
ES-cells, in which genome transgene is integrated in the right site,
Unfortunately, pluripotent ES-cells similar to those in mice that are not found in cattle, sheep, pigs and chickens, but the search continues.
To create transgenic cows a modified scheme of mice transgenosis
To create transgenic cows a modified scheme of mice transgenosis
a) collection of oocytes of cows slaughtered at the slaughterhouse;
b) oocytes maturation in vitro;
c) fertilization of oocytes with bovine sperm in vitro;
d) centrifugation of fertilized eggs to concentrate of yolks, which interferes with visualization of the male pronucleus in normal oocyte by sectional microscopy;
e) microinjection of DNA into the male pronucleus;
f) development of
e) microinjection of DNA into the male pronucleus;
f) development of
g) non-surgical implantation of a single embryo to recipient female during estrus;
h) screening of descendants DNA for the presence of transgene
Gene transfer in farm animals can be used in improving the productivity and quality of animal products, increasing resistance to disease and the creation of transgenic animals - bioreactors of valuable biologically active substances.
It was established that in transgenic pigs with growth hormone gene
It was established that in transgenic pigs with growth hormone gene
Unregulated expression of the growth hormone gene, as autologous or heterologous, can lead to a reduction life expectancy of transgenic animals due to pathological disorders of metabolism, development of acromegaly (excessive growth of certain parts of the face, limbs and internal organs), and exposure to various infectious diseases.
For example, diabetes - typical symptom of acromegaly was observed in transgenic sheep with high blood levels of growth hormone of cattle. Analysis of these experiments indicate that the use of transgenic technology to change the growth and composition of the tissue of domestic animals require further the understanding of the genetic regulation of growth.
Creation of transgenic animals opens real prospects for improving the quality
Creation of transgenic animals opens real prospects for improving the quality
(Promoter - region of DNA to which RNA polymerase binds to start the synthesis of mRNA)
The presence in the milk of various microflora caused problems associated
The presence in the milk of various microflora caused problems associated
Institute of Cytology and Genetics of RAS (Novosibirsk) and the Institute
Institute of Cytology and Genetics of RAS (Novosibirsk) and the Institute
Ген регулятор - Ген, кодирующий белок репрессор, взаимодействующий с геном оператором и таким образом регулирующий транскрипцию “своего” транскриптона;
By injection of recombinant DNA into zygotes pronuclei 4 transgenic
By injection of recombinant DNA into zygotes pronuclei 4 transgenic
PCR shows the tissue specificity of expression of human GM-CSF only in the mammary gland of lactating females. Because mentioned construction is tissue-specific, it falls under the regulation of physiological signals of pregnancy and lactation.
The possibility of including in organism’s cells the genes responsible
The possibility of including in organism’s cells the genes responsible
Transgenic animals used for the production of valuable biological products have several advantages over microorganisms-producers, as well as cellular systems. In simple recombinant systems, of microorganisms glycosylation, B-hydroxylation or carboxylation of mammalian proteins in most cases it is impossible or possible, but with insufficient accuracy. This changes the structure of proteins, which reflect on their biological activity. Along with this, in drugs which are used by humans for therapeutic agents admixture of bacterial proteins is undesirable. The main disadvantage of genetically engineered cell culture is the low yield of protein. Industrial reactors used for the cultivation of producer cells, are expensive, both in terms of their value, and in respect of their service. Creation of transgenic animals also requires more resources and moreover it is not easy, but once bred line of such animals can produce a large number of proteins with low cost, which will pay back all the expenses for a short time.
Production of biologically active human proteins from transgenic agricultural animals guarantee their environmental cleanliness, which practically comes to exploitation of animals-producers.
Foreign proteins can be synthesized by most tissues of the animal.
Foreign proteins can be synthesized by most tissues of the animal.
Structural gene linked to a promoter milk protein gene (casein, laktoalbumin, lactoglobulin), in the first place will be expressed in the cells of mammary gland. It allows to receive useful products with milk.
Альфа-1-антитрипсин – белок, который вырабатывается печенью. Он помогает организму в инактивации ферментов, при этом основная его функция состоит в защите лёгких от эластазы – она производится нейтрофилами в ответ на повреждения и воспаления. Эластаза расщепляет белки, которые затем перерабатываются организмом и удаляются. Если ее активность не контролируется альфа-1-антитрипсином, она начинает разрушать ткани легких.
The choice mammary gland as a site of production of foreign
The choice mammary gland as a site of production of foreign
To date, a number of recombinant proteins is known, such
To date, a number of recombinant proteins is known, such
Recently, much attention is paid to the use of animal organs for transplantation to man. The main problem of interspecies transplantation is hyperacute rejection. Hyperacute rejection involves the binding of antibodies of the host to carbohydrate antigenic determinant on the surface of cells of transplanted organ. Antibodies cause acute inflammatory response (activation of the complement cascade) that is why mass death of cells bearing antibodies is occured and rapid loss of the transplanted organ is observed. In natural conditions inflammatory response is blocked by special proteins. These proteins - complement inhibitors are species specific. It has been suggested that if the donor animals carried one or more genes of the human protein that inhibits the complement, the transplanted organ would have been protected from the primary inflammatory response.
For this purpose the transgenic pigs were obtained carrying different human
For this purpose the transgenic pigs were obtained carrying different human
Galactose-alpha-1,3-galactose, commonly known as alpha gal, is a carbohydrate found in most mammalian cell membranes. It is not found in primates, including humans, whose immune systems recognize it as a foreign body and produce xenoreactive immunoglobulin M antibodies, leading to organ rejection after transplantation.
Anti-alpha gal immunoglobulin G antibodies are some of the most common in humans. Regular stimulation from gut flora, typically initiated within the first six months of life, leads to an exceptionally high titre of around 1% of all circulating IgG. Alpha gal has also been suggested to play a role in an IgE-specific allergic response to some meats.
Perhaps transgenic pigs carrying the human complement inhibitor gene and deprived of basic pig cell surface protein, which causes acute rejection, provide a source of organs for transplantation to man.
The first work on getting transgenic animals - producers of
The first work on getting transgenic animals - producers of
Thus, integration of one or more genes in mammalian embryos is achieved and their expression as well as the transmission to the offspring is proved. However, the difficulties and uncertainties should be emphasized with which still related technique for producing transgenic animals. Mechanism of integration of the gene in mammalian cells is still poorly understood. A)This integration occurs randomly and not connected with a specific region of a chromosome. B) Another difficulty is due to the instability of the cells in which gene (s) is introduced: it may be lost or modified as a result becomes inactive. C) Finally, the activity of genes is determined not only by sequences of nucleotides that provide gene transcription with the formation of mRNA, but as well as other sequences of nucleotides, which are often far from their own gene. These sequences are administered with a gene to achieve full expression of the it.
The results achieved in the field of genetic engineering on getting transgenic mammals allow to deepen our knowledge about gene expression that in the future facilitate gene transfer and identification of factors that contribute to a more complete expression of the genetic information stored in transgene.