- •2) Objects and methods of animal biotechnology
- •3) Totipotent, multipotent, pluripotent animal cells
- •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
- •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
- •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
- •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
- •32) Main objects of animal biotechnology:
- •33) Morphological and functional features of gametes - eggs and sperm
- •39) Basic approaches and principles of gene therapy. Gene therapy ex vivo, in vivo, in situ.
- •35)The history of investigations of the genetic transformation of animal cells
- •53)Genetic engineering. Methods of genetic transformation
- •56) The vector systems used in the genetic engineering
- •62) Methods of producing chimeras
- •57) Methods of genetic engineering: agrobacterial genetic transformation
- •63) Collection and cultivation of oocytes in vivo and in vitro
- •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
- •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).
- •80) Methods of animal cloning, reproductive and therapeutic cloning
- •81) Microorganisms in water and wastewater treatment
- •86) Use of e.Coli for the biotechnological production
- •87) Microbes in milk and dairy products
26) Somaclonal and gametoclonal variation in plant cells culture.
Somaclonal variation is the variation seen in plants that have been produced by plant tissue culture. Chromosomal rearrangements are an important source of this variation.
Somaclonal variation is not restricted to, but is particularly common in, plants regenerated from callus. The variations can be genotypic or phenotypic, which in the latter case can be either genetic or epigenetic in origin. Typical genetic alterations are: changes in chromosome numbers (polyploidy and aneuploidy), chromosome structure (translocations, deletions, insertions and duplications) and DNA sequence (base mutations). Typical epigenetic related events are: gene amplification and gene methylation.
If no visual, morphogenic changes are apparent, other plant screening procedures must be applied. There are both benefits and disadvantages to somaclonal variation. The phenomenon of high variability in individuals from plant cell cultures or adventitious shoots has been named somaclonal variation.
When gametic cells are cultured under invitro conditions then variations observed in such culture are termed as gametoclonal variations. The products obtained from gametoclonal variations are regarded as gametoclones.
In gametoclonal variation, gametes being the products of meiotic division, possess only half of the parent cells. Gametoclones can be developed by culturing male or female gametic cells. The anthers or isolated microspores are widely used for developing gametoclones. A large number of plants have been regenerated from gametoclonal variations like Oryza sativa, Nicotiana tabacum, Brassica napus, Hordeum vulgare. Improvements have been made in several plant species through gametoclonal variation e.eg. rice, wheat & tobacco.
There are three major reasons which can cause genetic variation in the gametoclones:
-The techniques used in cell culture may induce genetic variations.
- The doubling of haploid chromosomes may generate variations.
-The heterozygocity of the diploids may induce genetic variations.
- Variations resulting from segregation and independent assortment.
-The gametoclones differ from somaclones by three distinct ways:
-Gametoclones regenerate into haploid plants in comparison to somaclones which develop into diploid plants.
- The recombination process occurs by meiotic crossing over in gametoclonal variation.
-The gametoclones can be stabilized by doubling the chromosome number.
Both gametoclonal and somaclonal variation have been detected in cultured cells and regenerated plants for morphological characteristics, biochemical characteristics, and chromosome number and structure.
27) Artificial seeds". Embryo culture in vitro
Artificial or synthetic or manufactured seed is encapsulated plant propagule (somatic embryo / shoot bud) in a suitable matrix, containing substances like nutrients, growth regulators, herbicides, insecticides, fungicides and mycorrhizae which will allow and help it to grow into a complete plantlet.
A typical synthetic seed has following parts
-plant propagule (somatic embryo or shoot bud)
-Matrix (synthetic gametophyte)
-Seed shell
The concept of artificial seed technology has been applied, commercially and successfully in crops like Azadirachta indica, some orchids (Dendrobium, Spathoglottis plicata, Cymbidium, Phalaenopsis ), Alfalfa, Gossypium hirsutum, and Santalum album.
There are many other things to know about this artificial seed technology. Those are as follows
Artificial Seed Production
The first one is how these seeds are manufactured? Visit Artificial Seed Production for the information on this topic. Here we will discuss desiccated and hydrated system and general procedure for artificial seed production.
Advantages of Synthetic Seed
To know what are the various uses and advantages of such seeds visit link advantages and uses of artificial seeds. This page contains sufficient information on the topic.
Embryo culture is a component of in vitro fertilisation wherein resultant embryos are allowed to grow for some time in an artificial medium before being inserted into the uterus.
Typically, embryos are cultured until having reached the 6–8 cell stage three days after retrieval. In many Canadian, American and Australian programmes[citation needed], however, embryos are placed into an extended culture system with a transfer done at the blastocyst stage at around five days after retrieval, especially if many good-quality embryos are still available on day 3. Blastocyst stage transfers have been shown to result in higher pregnancy rates.[1] In Europe, transfers after 2 days are common.
Techniques
Culture of embryos can either be performed in an artificial culture medium or in an autologous endometrial coculture (on top of a layer of cells from the woman's own uterine lining). With artificial culture medium, there can either be the same culture medium throughout the period, or a sequential system can be used, in which the embryo is sequentially placed in different media. For example, when culturing to the blastocyst stage, one medium may be used for culture to day 3, and a second medium is used for culture thereafter.[2] Single or sequential medium are equally effective for the culture of human embryos to the blastocyst stage.[3] Artificial embryo culture media basically contain glucose, pyruvate, and energy-providing components, but the addition of amino acids, nucleotides, vitamins, and cholesterol improve the performance of embryonic growth and development.[4] Methods to permit dynamic embryo culture with fluid flow and embryo movement are also available.[5] A new method in development uses the uterus as an incubator and the naturally occurring intrauterine fluids as culture medium by encapsulating the embryos in permeable intrauterine vessel.