Dahyun week5

interesting fact about animal genome

Are tortoiseshell cats always female?
-> Yes.  Tortoiseshell and calico cats are the result of a sex-linked gene and require two X chromosomes to appear. Generally, these colour patterns will only be seen in females.  Very rarely, these colour patterns may be seen in male cats, but these males are genetically abnormal and are almost always infertile.

What is a free-martin?
->A free-martin is a female calf that grew in the uterus with a male twin.  The twins exchange genetic material with each other through their placentas.  As a result, the female calf has some male cells.  She will look normal on the outside, but her internal reproductive organs are altered and she is infertile.  This phenomenon also occurs sometimes in other mammals, including sheep, goats and pigs.

detail about free-martin:
free-martin (sometimes martin heifer) is an infertile female cattle with masculinized behavior and non-functioning ovaries.^[1] Phenotypically, the animal appears female, but various aspects of female reproductive development are altered due to acquisition of anti-Müllerian hormone from the male twin.^[2] Genetically, the animal is chimeric: karyotypy of a sample of cells shows XX/XY chromosomes. The animal originates as a female (XX), but acquires the male (XY) component in utero by exchange of some cellular material from a male twin, via vascular connections between placentas: an example of microchimerism.^[3] The chimerism is mainly present in the hematopoietic stem cells.

does free-martin problem happen to human?
->

es, a phenomenon similar to the free-martin condition can occur in human twins, although in humans it's not referred to as "free-martin" but rather as "blood chimerism" or "microchimerism." This involves one twin acquiring genetically distinct cells from the other twin, resulting in both individuals having two different genetic codes present.

In humans, this condition usually does not significantly impact health, and many people may not even be aware that they have blood chimerism. However, under certain conditions, it can affect the function of the immune system and may increase or decrease the risk of certain diseases. The phenomenon of microchimerism in humans is of particular interest in research related to autoimmune diseases, pregnancy, and transplantation.

Unlike in animals where the free-martin phenomenon can lead to clear changes in sexual characteristics, in humans, the exchange of genetic material between twins does not typically result in visible gender changes. However, there can be cases where the two individuals share some genetic traits due to the exchange of genetic material, especially among identical twins.

does free-martin problem affect to male too?
->

The direct impact of the free-martin phenomenon is generally not reported in male twins. Male calves possess the normal male hormones necessary for their sexual development, so they are not affected in the same way as female calves. However, the phenomenon of microchimerism (the presence of cells with different genetic information in the blood) can also be found in males, resulting from the exchange of cells between twins. Nonetheless, this genetic exchange does not seem to have a noticeable effect on the health or reproductive capabilities of the male.

Therefore, the free-martin phenomenon is primarily observed in females and is understood to have little to no impact on the development of males.

microchimerisn:
Microchimerism is the presence of a small number of cells in an individual that have originated from another individual and are therefore genetically distinct. This phenomenon may be related to certain types of autoimmune diseases although the responsible mechanisms are unclear. The term comes from the prefix "micro" + "chimerism" based on the hybrid Chimera of Greek mythology.

ref: https://www.mitchellvets.ca/2014/02/06/some-fun-facts-about-animal-genetics-offered-by-mitchell-veterinary-services/