This is sweet
little Jimmy a year-old calf. He was
born on 2001 in Texas. He is a healthy calf who loves to play with his tail. There
is something special about Jimmy. He is not naturally born. Once upon a time, a
male bull named Brad died at the farm. Before he died, the owner farm Mr
Clinton retrieved some of his samples of sperm. Brad had never successfully
bred in his lifetime. Due to the good genetic, Brad’s sperm sample were stored
and preserved by using cryopreservation method. Jimmy is the product from Brad’s
frozen sperm.
Cryopreservation
is process by which any living cell, tissue, organ or entire bodies are protected
from decay by storing them at extremely low temperature. This method of
preservation helps Brad’s sperm protected from decay by storing them at
extremely low temperature. His sperm was stored at very low temperature which
is at -195°C in CryoBioBank. At low enough temperature, any enzymatic or
chemical activity which might cause damage to Brad’s sperm is effectively
stopped.
There
are several types of method cryopreservation such as slow programmable freezing
and vitrification (Lecchi et al., 2016). Brad’s sperm was cryopreserved by
using vitrification method. Semen from all mammalian livestock species as well
as poultry species can be successfully frozen. Freezing procedure for semen
cryopreservation are species-specific, but the general procedures are as
follows:
- Following collection, semen is diluted in a suitable
ionic (salt) or non-ionic (sugar) solution adjusted to near physiological
osmolarity.
- Suitable cryoprotectant is added, glycerol is mostly
used, but dimethyl sulfoxide (DMSO), dimethylacetamide (DMA) or
dimethylformamide (DMF) are also used especially in avian species.
- Diluted semen is cooled, sampled and then frozen in liquid
nitrogen (-196 °C).
- Individual semen doses are generally frozen in straws
rather than pellets to guarantee optimal sanitary conditions and permanent
identification of each dose.
 |
| Mechanism of cryopreservation process |
Since the useful and successful of
this method in preserving various type of foods, so there are many applications
have been practiced in food industry. Cryopreservation protocols have been
established for root and tubers, fruit, forest trees, ornamentals and
plantation crops and often applied to large numbers of accessions within
species. Example of cryopreservation of
pollen and seeds. Cryopreservation of pollen is preserving the pollen and it is
useful for cross-pollination of cultivars differing in flowering period.
In agricultural and horticultural
cryopreservation of seeds, the species are tolerant to desiccation and exposure
to liquid nitrogen. This method also as an alternative to the traditional
storage. Celery is an example of orthodox seed cryopreservation. The number of
genebanks and botanic gardens where cryopreservation is employed on large scale
to different types materials is keep growing. Here some examples of cryopreserved
collections of tropical plant species which are coffee, musa and cassava.
Cryopreservation
is considered as sort of miracle in science world. Throughout the 1940s,
researchers worked to determine a process for safely freezing cells that would
be viable for use after thawing (Bailey, 2017). The first successful story of
cryopreservation of mammalian cells was performed by Christopher Polge and his colleagues
in 1949. They found that the frozen fowl spermatozoa had resumed motility on thawing
and was capable of effecting fertilization on the egg, though no live chicks
were produced. This had spark large interest amongst scientists on the
potential of cryopreservation in cells preservation to produce living
organisms.
Subsequent studies resulted in key
milestones to the enhancement of the technology. Smith and Polge (1950) had successfully
cryopreserved bull spermatozoa; Stewart’s (1951) research resulted in the first
live birth of calves after insemination using frozen spermatozoa; Latta (1971) involved
in cryopreservation of plant cell cultures; both Whittingham and Wilmut (1972)
had successfully recovered frozen mouse embryos; and Cohen and colleagues
(1985) had stored human embryos using cryopreservation for use in in vitro
fertilization. Thus, cryopreservation has become widely accepted as the optimal
method for the preservation of microorganisms.
Recently,
Malaysia had imported about RM5.5 billion of processed food, RM4.0 billion of
sugar and sugar confectionary, RM3.0 billion of dairy products, RM1.8 billion
of preserved vegetables and fruits and RM1.5 billion of cocoa (Mida.gov.my,
2017) due to lack source of food. Cryopreservation may assist to ensure the
sustainability of food source by preserving the seeds of those species as they
are unable to withstand dehydration process and sensitive to chilling (Engelmann
& Dussert, 2013). As the source of food is sufficient,
prices of food can be controlled during different season.
In
addition, cryopreservation may assist in import export activity as it will
guarantee a better quality of product. For example, conventional freezing of
food may cause freezer burn, dehydration, colour changing, ice-crystallization,
drip loss and lipid oxidation. Cryopreservation may assist to protect the
physical and chemical properties of food. Transporting of food in long distance
may affect the safety of food. This can be related to the experience where
spices from India had been banned by certain country due to contamination and
quality issue (Edison, 1995). As solution, extremely low temperature had been
used during grinding to gain better quality of product and less risk of food
contamination. Last but not least, every preservation methods may help in
increasing the shelf life of product but in limiting time. Rapid cooling may
assist to decrease the respiration rate of and retard the physiological changes
of products thus increasing the storage life of food (Goswami, 2010).
As
cryopreservation is the optimum method of preserving microorganisms, its
potential has been studied and proven to be beneficial in food preservation. The
technology of cattle breeding through insemination of frozen sperm by cryopreservation
has been applied in the past 50 years ago and will continue so. Jimmy is not
alone, he had, has and will be joined by his brothers and sisters through this
technology.
References
Lecchi, L., Giovanelli, S., Gagliardi, B., Pezzali, I., Ratti, I., & Marconi, M. (2016). An
update on methods for cryopreservation and thawing of hemopoietic stem cells. Transfusion
and Apheresis Science, 54(3), 324–336.
http://doi.org/10.1016/j.transci.2016.05.009
Bailey, R. (2017, 5
October). “Revival of Spermatozoa after Dehydration and Vitrification at Low
Temperatures” (1949), by Christopher Polge, Audrey Ursula Smith, and Alan
Sterling Parkes. The Embryo Project Encyclopedia. Retrieved from http://embryo.asu.edu/pages/revival-spermatozoa-after-dehydration-and-vitrification-low-temperatures-1949-christopher
Polge, C., Smith, A.
U. & Parkes, A. S. (1949). Revival of spermatozoa after vitrification and
dehydration at low temperature. Nature 164, 666.
Smith , A. U. &
Polge, C. (1950). Storage of bull spermatozoa at low temperatures. Vet. Rec.
62, 115-117.
Stewart, D. L.
(1951). Storage of bull spermatozoa at low temperatures. Vet. Rec. 63,
65, 66.
Latta, R. (1971).
Preservation of suspension cultures of plant cells by freezing. Can. J. Bot.
49, 1253, 1254.
Whittingham, D. G.,
Leibo, S. P. & Mazur, P. (1972). Survival of mouse embryos frozen to -196
and -296°C. Science 178, 411-414.
Wilmut, I. (1972).
The effects of cooling rate, cryoprotectant agent and stage of development on
survival of mouse embryos during freezing and thawing. Life Sci 11,
1071-1079.
Cohen, J., Simons,
R., Fehilly, C. B., Fishel, S. B., Edwards, R. G., Hewitt, J., Rowland, G. F.,
Steptoe, P. C. & Webster, J. M. (1985). Birth after replacement of hatching
blastocyst cryopreserved at expanded blastocyst stage. Lancet I, 647.
Mida.gov.my.
(2017). MIDA | Malaysian Investment Development Authority:. Food Technology
and Sustainable Resources. [online] Available at:
http://www.mida.gov.my/home/food-technology-and-sustainable-resources/posts/
[Accessed 19 Dec. 2017].
Engelmann, F., & Dussert, S. (2013). Cryopreservation. In
M. N. Normah, H. F. Chin, & B. M. Reed (Eds.), Conservation of Tropical Plant Species (pp. 107-119). New York, NY:
Springer New York.
Goswami, T.
(2010). Role of Cryogenics in Food Processing and Preservation. International
Journal of Food Engineering, 6(1).
Edison,
S. (1995). Spices: Research Support to Productivity. Survey of Indian Agriculture.
