Cloning pets has pros and cons.
In this article we will learn about why it might be necessary to clone a dog and what does it mean to clone a dog (possible consequences).
Dogs are well-known companion animals but they really excel as working animals. You may already know they are widely used in different tasks to help and assist humans, such as supporting visually impaired people or detecting chemical molecules through their <powerful sense of smell>.
As an example of this impressive capability, a dog can detect molecules in concentrations measured in parts per million (ppm), equivalent to a single glass of water diluted in a medium size swimming pool.
This ability allows properly trained dogs to detect molecules of explosives, drugs, living or dead people as well as illegal products in customs and airports.
In addition to animals used for the detection of chemical molecules in field situations, cloned <dogs can also be used in the diagnosis of diseases such as cancer>, since tumors generate very specific organic molecules that dogs can detect. There is a lot of scientific evidence of this nowadays.
Dogs have a highly specialized and powerful olfactory nasal epithelium. The olfactory sensitivity of dogs is 100,000 times greater than that of humans, which is why dogs are placed within a group of mammals known as macrosmatics. In contrast and by comparison, human beings are considered microsmatic being our olfactory capacity obviously smaller.
This is evident from the high concentration of receptors located in the back of the nasal tissue of the olfactory organ in dogs.
The olfactory receptors are responsible for picking up chemical molecules that enter the nasal cavity dissolved in the air. When they come into contact with these receptors, they trigger nerve impulses that travel to the rhinencephalon (the area of the lower front brain responsible for processing olfactory information), which is stimulated during the training of dogs to detect molecules in the air. It should be noted that on average, a significant percentage of dogs fail to pass working dog training. Health conditions and temperament fall within the criteria used to approve this training. These two characteristics are considered to be inherited from one generation to another. Thus, through natural breeding, only about 50% of the dogs obtained this way, which are later trained to detect molecules through smell, will manage to qualify. Something similar occurs with guide dogs, trained to assist visually impaired people.
Eventually, those dogs that do not qualify as working dogs will be set aside and placed on a waiting list for adoption; therefore they suffer from different problems related to animal welfare. For instance, when they fail to get adopted, if you consider the life expectancy of these animals is in average 10 years, this is the time during which society will have to take care fof them, resulting in numerous economic and ethical consequences. This means, the raising of dogs intended for work assistance to humans leaves many dogs stranded and in need for foster families (if that is possible).
But, perhaps there is a solution.
Modern animal cloning techniques could help us in this situation.
High performance working dogs could be cloned with the intention of obtaining dogs with the same abilities as their genetic parents. Although contrary to popular belief, cloned dogs are not truly identical, but a dog cloned from an excellent working dog will very likely inherit most of the good working traits.
But, what happens when you clone a dog?
We normally use the word ‘cloning’; but to be more precise, the dog cloning process biotechnology is called <Somatic Cell Nuclear Transfer’ (SCNT)>. This name is derived from the fact that during the cloning technique, the nucleus of a somatic cell (like for instance a cell from the hair follicle) of the animal to be cloned is implanted into an egg of a donor female dog, from which the nucleus has been previously removed.
Remember that the nucleus of a cell is the place where the DNA carrying the individual’s genetic information is found, so when we take the nucleus of the animal to be cloned to an egg, an embryo is formed containing the genetic information of the donor animal, so the resultant embryo is a clone of the animal that donated the nuclear material. This embryo is placed in the uterus of a surrogate dog for her to carry out gestation.
This is all theory, but in practice, where were dogs cloned for the first time?
Most of the studies about cloning in dogs have been conducted in South Korea.
A cloned dog was first obtained from another dog in 2005 in that country.
Its name was Snuppy, obtained from the transfer of skin cells from the ear of a 3-year-old Afghan Hound using the <SCNT technique>.
The dog cloning process in dogs has been successful regardless of the gender of the animal donating genetic material (the cloned animal). It has also been successful in dogs of different breeds such as Poodle, Beagle, Labrador Retriever, Pekingese, German Shepherd, among others.
By the year 2020, dog cloning has been successfully performed to obtain elite animals destined to work more efficiently for humans, as clone dogs have received from their parents the necessary skills to qualify for the training to become working dogs.
This has reduced the costs associated with finding working dogs in which, as we mentioned, approximately 50% of them do not pass the training, while cloned dogs obtained from elite animals reproduce the skills of their parents almost entirely.
So far so good.
Another advantage of these animal biotechnologies is the possibility of making gene banks from elite animals that have high performance as working dogs, for instance: from a minimal sample of tissue from a dog (obtained from a biopsy), a few thousand cells could be frozen, each of them with the potential to generate a cloned animal in the future. These cells could be frozen at about -196o Celsius (-321o F) for many years, or even decades.
Health of clone dogs
In general, clones can potentially present health problems unlike animals generated by natural breeding. For instance, working dogs that have been cloned are born slightly heavier than naturally selected dogs. This may be because pregnant substitute dogs that produce clone dogs have generally smaller litters (probably because some of the cloned embryos die in the womb). This can be due to the fact that nutritional resources are distributed within the uterus among a smaller number of dogs which are then born with a slightly higher weight (for yet unknown reasons, this is more critical in farm animals like cows and sheep). However, mildly overweight clone dogs at delivery develop well and have normal growth patterns comparable to other non-clone dogs.
Clone dogs have normal hematological and blood chemistry values. In addition, clone dogs have a normal nervous system. Thus, they have normal posture, correct walking position, and good reflexes, including spinal reflexes such as the knee-jerk reflex, palpebral reflex, corneal reflex, pupil reflex (to light), and threat response.
A dog destined to work for human assistance should have an excellent <cardiovascular system>. It is known that farm animal clones, such as calves, sheep and pigs, may have cardiovascular problems. It would be devastating for working dogs (and human owners!) if this were to happen. Fortunately, no cardiovascular problems have been found in cloned dogs. The results of studies carried out so far show the anatomy and functioning of dog clones cardiovascular system normal, so their performance is not compromised.
Personality and Behavior of Cloned Dogs
An animal’s temperament (sometimes called “personality”, although it should be “dogality”) determines its behavior. A dog’s personality can be observed at an early age during its <socialization period> which usually occurs between 1 and 3 months of age. At this stage, a dog’s temperament can be observed in order to predict its behavior as an adult or to detect possible behavior problems in the future. Several tests are used to predict this, such as the Campbell test, which allows assessing how dominant the dogs are at this age. A dog with high dominance during the socialization period may have aggressive behavior later in life (and therefore be aggressive or show other behavior problems). The ideal temperament in a dog during the socialization period is that of an active, outgoing dog, which is ideal for working dogs.
Do cloned dogs have the same personality? Clone dogs and genetics
It is generally said that two cloned animals are genetically identical, similar to what happens when two animals are identical twins. In reality, two animals that are clones of each other are not 100 percent genetically identical; they may even be slightly different in their physical appearance. However, let’s suppose the cloned animal is genetically identical to the animal that gave birth to it. This would indicate that certain characteristics of the original (“father”) working dog, such as memory, learning, and exploratory patterns, could be transmitted to its cloned offspring. In fact, personality in working dogs is strongly determined by genetic factors so they can easily be transmitted from working cloned to clone dogs.
Health Problems in Cloned Dogs
Health problems have been detected in farm animals in the past, such as large size and weight at birth, breathing difficulties, reluctance to breastfeed, sudden perinatal death, and increased prenatal losses. These conditions have been frequently reported in the cloned offspring of cattle and sheep. However, in dogs the perspective is different.
Cloned dogs generally do not have increased weights or dimensions at birth. In some individual cases, cloned dogs have had liver or gallbladder problems, cleft palate, and preputial abnormalities. There has also been no decrease in life expectancy of clone dogs, although there are not many studies done on this issue, but, anecdotally, we can mention that Snuppy had a life as long as other dogs of his breed.
So, there are many positive aspects and advantages to using the cloning process in dogs.
Are there any disadvantages, though?
The main limitation for dog cloning is its high cost and low efficiency.
What does this mean?
One measure of cloning efficiency is the number of animals born in relation to the number of embryos implanted in surrogate mothers. This efficiency in dog cloning varies from 1.7 to 3.8%. This means that approximately 33 embryos need to be used for a cloned dog to be born, in the best case.
Different protocols have been used to try to improve the <efficiency of the cloning process> (very geeky), such as:
- Nutritional treatment with minerals in oocyte-donor female dogs
- Modification of <acetylation patterns> of cloned cells (derived from the original animal)
- Cloned cell synchronization (derived from the original animal)
- Replacement of primary culture medium
- Replacement of the culture medium after activation of the new clone embryo
Despite all this, none of these methods have significantly increased the efficiency of dog cloning so far, thus there is still a long way to go on this field, so the <(SCNT)> procedure or cloning process is the bottleneck of this technology.
The good news is that cloned dogs seem to have a healthy life while being useful and having fun working among us, their human friends.