- •2) Objects and methods of animal biotechnology
- •3) Totipotent, multipotent, pluripotent animal cells
- •4.Allophenic animals. Genetic chimers
- •5)The principles of genetic cloning
- •6.Allophenic animals. Genetic chimers
- •8) Methods for introducing foreign dna into animal cells
- •9)Cryopreservation of reproductive and germ cells of animals and humans
- •11)The principles and methods of plant cells cultivation in vitro
- •12. The types of medium. Physiological means of compounds medium (as an example you can use the composition of Murashige-Skug medium)
- •14)Differentiation and dedifferentiation in plant cell culture. The obtaining callus mass and cultivation of callus tissue .
- •15)The influence of phytohormons on morphogenesis and regeneration in plant cells culture
- •16.The main path of morphogenesis processes in plant cells culture
- •18.The growth stages in suspension culture
- •20) The factors influenced on microclonal propagation in plant cell culture.
- •21) What is Biotechnology? Various definitions of “Biotechnology”. History of Biotechnology
- •22.Microbial Biotechnology: fundamentals of applied microbiology
- •24.Sterilization in Biotechnology: Methods and principles
- •26) Somaclonal and gametoclonal variation in plant cells culture.
- •27) Artificial seeds". Embryo culture in vitro
- •28. Culture of apical meristem cells
- •29)Cell reconstruction. Theoretical means of cell reconstruction
- •30.Basics of phytopathology. The main diagnostics methods of plant diseases
- •32) Main objects of animal biotechnology:
- •33) Morphological and functional features of gametes - eggs and sperm
- •34Hormonal regulation of mammalian reproduction
- •35)The history of investigations of the genetic transformation of animal cells
- •36.The principles of genetic engineering in animal biotechnology
- •53)Genetic engineering. Methods of genetic transformation
- •54. Methods of receiving plant materials without viruses
- •56) The vector systems used in the genetic engineering
- •57) Methods of genetic engineering: agrobacterial genetic transformation
- •58)Methods of genetic engineering: bioballistics methods
- •60.Apply cell technology and cryopreservation technology for safe gene bank
- •62) Methods of producing chimeras
- •63) Collection and cultivation of oocytes in vivo and in vitro
- •64 Collection and cultivation of embryos in vivo and in vitro
- •66.Fertilization of oocytes in vitro, environment and conditions
- •68) Draw a diagram of the structure of plasmid pBr322
- •69) Draw a diagram of an experiment in genetic engineering (design recDna) and give a description of the main stages
- •70)Describe the calcium-phosphate method for introducing foreign dna into mammalian cells.
- •72 Methods of cryopreservation of sperm and oocytes of mammals
- •74) Modes of freezing and thawing of gametes and embryos
- •75) Methods of artificial fertilization: gamete insemination fallopian tube (gift), zygosity insemination fallopian tubes (zift).
- •76) Stem cells and prospects for their use in practice
- •78.Technical equipment of experiments on artificial insemination
- •80) Methods of animal cloning, reproductive and therapeutic cloning
- •81) Microorganisms in water and wastewater treatment
- •82 Microbial fermentations in food products
- •84.Bacterial examination of water and standard water analysis
- •86) Use of e.Coli for the biotechnological production
- •87) Microbes in milk and dairy products
- •88) What is the benefit of microorganisms in industry
- •90. Algae, their applications
74) Modes of freezing and thawing of gametes and embryos
Cryopreservation of gametes
Spermatozoa
Typically the process of preserving male gametes is more straightforward than that of preserving female gametes, partly because a single semen sample typically contains millions of sperm, so even modest cryosurvival rates result in large quantities of sperm.
There are however a number of factors which influence the effectiveness of sperm cryopreservation including:
Quality of the semen sample - The proportion of live sperm which survive the freezing and thawing process is higher in a normozoospermic sample (24.9% survival) than in a oligoozoospermic sample (11.9% survival).
Semen preparation - The method by which semen is washed prior to freezing also influences post-thaw vitality. In normozoospermic semen samples, the proportion of sperm which survive cryopreservation increases from 24.9% with no preparation, to 35.6% if sperm are washed using a ‘swim up' technique prior to cryopreservation. Both the swim up and density gradient centrifugation techniques also significantly improve the survival rate of spermatozoa in oligozoospermic samples (from 11.9% when not washed to 27.7% using swim up and 22.4% using centrifugation).
Oocytes
The cryopreservation of oocytes has proven more challenging than the cryopresevation of sperm, in particular because many regimens cause damage to an egg's zona pellucida (i.e. shell). However there are now a range of cryopreservation protocols which can be used to preserve mature or immature oocytes. While survival rates for immature oocytes have reached 60%, the freezing process often alters the oocyte development process and fertilisation and live birth rates for surviving oocytes, are consistently lower than those achieved using fresh oocytes.
Cryopreservation of embryos
Overall cryopreservation of embryos results in about 5% chance of live birth, while for blastocysts the rate is around 10%. It is considerably more efficient than the cryopreservation of oocytes and it is therefore most common for oocytes to be fertilised in vitro prior to cryopreservation.
Reproductive outcomes following embryo cryopreservation depend on the stage of embryo development, both at the time of freezing and at the time of implantation. Embryos which have recommenced mitosis (division and replication which leads to the growth of the embryo) post-thaw but pre-implantation have a higher chance of implantation.
Cryopreservation of ovarian and testicular tissues
The cryopreservation of gonadal tissues is most commonly performed when a patient must immediately undergo toxic treatment which threatens their fertility. As the urgency of such treatment may not allow time for the collection of mature gametes (e.g. because there is no time to perform ovarian stimulation or because they have not yet gone through puberty), removal and storage of gonadal tissues which contain immature gametes is sometimes the only option for fertility preservation.
75) Methods of artificial fertilization: gamete insemination fallopian tube (gift), zygosity insemination fallopian tubes (zift).
GIFT (gamete intrafallopian transfer) and ZIFT (zygote intrafallopian transfer) are modified versions of in vitro fertilization. Like IVF, these procedures involve retrieving an egg from the woman and re-implanting it after manipulation. Unlike IVF, the timing between mixing the sperm and eggs and the transfer is faster.
In GIFT, the sperm and eggs are mixed together and immediately inserted. On the other hand, with ZIFT, the fertilized eggs --”zygotes”-- are inserted within 24 hours of the mixing.
What are the advantages to these procedures?
While the success rates are similar to IVF, the processes used in GIFT and ZIFT are closer to natural conception. In ZIFT, the eggs are placed in the fallopian tubes rather than directly in the uterus. With GIFT, fertilization actually takes place in the body rather than in a petri dish.
As in vitro fertilization techniques have become more refined, GIFT and ZIFT have become less relied upon. Additionally, as GIFT and ZIFT require surgery while IVF does not, IVF is the preferred choice in clinics. In vitro fertilization accounts for at least 98% of all assisted reproductive technology procedures performed in the U.S., while GIFT and ZIFT make up less than 2%.
What Types of Infertility Are Addressed By Gift and Zift?
GIFT and ZIFT can be used to treat many types of infertility, except cases caused by damage or abnormalities of the fallopian tubes. These techniques can also be used in cases of mild male infertility, as long as the sperm is capable of fertilizing an egg.
GIFT: What You Can Expect
Eggs and sperm are collected just as they would be in an IVF procedure, but after that, the two techniques differ. Unlike IVF, GIFT requires an incision be made in the abdomen and the eggs and sperm placed in the fallopian tubes using a laparoscope.
Because the eggs and sperm are placed into the fallopian tubes before conception, there's no way to know if fertilization has taken place prior to transfer. Typically, more eggs will be used in GIFT to ensure pregnancy, which has the side effect of increased multiple births.
ZIFT: What You can Expect
Unlike GIFT, with ZIFT the sperm and egg are mixed together in the laboratory, and given time to fertilize before being transferred to the fallopian tubes thus lowering the number of eggs used and correspondingly the chances for multiple pregnancy. As this is a post-fertilization technique, ZIFT is closer to in vitro fertilization. ZIFT, like GIFT, requires the procedure be performed by laparoscopy.