Friday 11 January 2013

Mules Are Rh Negative!!

OK, so you know how these memes start. Some ill-informed person decides to start a rumour without checking the facts and then posts it up on the internet. Soon it is all over, and people copy and paste is everywhere and the source of the disinformation is soon lost.

However, being as this blog deals in facts only I thought I would put to bed the idea that mules have Rh-negative blood once and for all.

Animals have different blood and antigens to humans. Animals do get Hemolytic disease which can be caused when human Rh negatives and positives have children together. However, that does not mean to say it is the same antigen that causes it in animals too.

Neonatal isoerythrolysis (NI) is an immune-mediated hemolytic disease seen in newborn horses, mules, cattle, pigs, cats, and, rarely, in dogs. NI is caused by ingestion of maternal colostrum containing antibodies to one of the neonate’s blood group antigens. The maternal antibodies develop to specific foreign blood group antigens during previous pregnancies, unmatched transfusions, and from Babesia and Anaplasma vaccinations in cattle. Cats are unique in that blood type B cats have naturally occurring anti-A antibodies without prior exposure, and their kittens that are type A develop hemolysis after nursing. In horses, the antigens usually involved are A, C, and Q; NI is most commonly seen in Thoroughbreds and mules. Neonates with NI are normal at birth but develop severe hemolytic anemia within 2-3 days and become weak and icteric. Diagnosis is confirmed by screening maternal serum, plasma, or colostrum against the paternal or neonatal RBC. Treatment consists of stopping any colostrum while giving supportive care with transfusions. If necessary, neonates can be transfused with triple-washed maternal RBC. NI can be avoided by withholding maternal colostrum and giving colostrum from a maternal source free of the antibodies. The newborn’s RBC can be mixed with maternal serum to look for agglutination before the newborn is allowed to receive maternal colostrum.

On these fantasy sites, they also use the fact mules are sterile as a way of comparing it to Rh-neg women having trouble having babies with Rh positives.

A mule is the product of two different species (a horse and a donkey) mating with each other. Mules are always sterile because horses and donkeys have different chromosome numbers.

For the mule, having parents with different chromosome numbers isn't a problem. During mitotic cell division, each of the chromosomes copies itself and then distributes these two copies to the two daughter cells. In contrast, when the mule is producing sperm or egg cells during meiosis, each pair of chromosomes (one from Mum and one from Dad) needs to pair up with each other. Since the mule doesn't have an even number of homologous pairs (his parents had different chromosome numbers), meiosis is disrupted and viable sperm and eggs are not formed.

Neanderthals and the simians they mixed genes with did have different amounts of chromosomes, but the two smallest ape chromosomes were combined into a single, larger human chromosome.

Most ape and human chromosomes are identical. The 9th and the 14th ape chromosomes, when combined, are like a palindrome of the human 12th chromosome. That is, when viewed on a chromatic scale if the ape chromosomes (9 + 14) are joined and flipped over, the result would look just like the human #12 chromosome.

That's what makes apes so genetically close to human beings, despite the difference in the number of chromosomes, and once the chromosomes had been joined and Sapiens were created it was possible for them to breed with Neanderthals. Some of the Neanderthals did breed with the new Sapiens, and that produced the Cro-Magnons. It was harder for them to reproduce this way, but it was possible, even though the Rh factor was different.

Even though Neanderthals and the Simians started out not being able to breed with each other, after genetic engineering it was possible. The Sapiens could of course breed very easily between themselves. 

Two people with Rh-negative blood can have children normally, as can two Rh-positive. The only problems occur when the parents are incompatible and it doesn't matter which way round it is.

Like so:

Father Mother Result
Rh Negative Rh Negative Normal
Rh Positive Rh Positive Normal
Rh Positive Rh Negative Problems
Rh Negative Rh Positive Problems

By Tia L Douglass of NATA


  1. I really do not understand why they never taught us in school something as critical as blood type compatibility between spouses. Sounds pretty important to me, I mean, being that we all want healthy kids and what not..

    That said..common mainstream knowledge is that mules are sterile, this is however not always entirely true.

  2. iam A-Rh Negative and my husband is RH Positive and we had normal childern
    with the same rare blood

    1. You are lucky that the baby had your blood and not your husbands, otherwise there would have been problems. They probably gave you the anti D injection anyway, which could be bad news for both you and your baby long term.

    2. What do you mean bad news for you and your baby long term???

    3. The Rhogam shot is said to cause autoimmune diseases in both mother and baby, and sometimes autism in the baby.

    4. I am Rh negative and my daughter of 8years old is Rh positive thanks to her father....I have had no issues with her and is faily healthy...she gets cold and flu just ad regular as other children, no learning disabilities or any other problems, depicted thr fact I'm rh negative and her a positive and after having the antigen shot

    5. Tau Tia L Douglass,
      I am Rh negative and so are all of my children, when I was pregnant with my first, the idiot dr gave me a Rhogam shot while pregnant, my first born has autism. He was born and is Rh negative which means the shot was unnecessary.
      I never let them give me the shot again.

  3. I was given the shot once. What does it do exactly?

    1. The Rhogam shot is said to cause autoimmune diseases in both mother and baby, and sometimes autism in the baby.

  4. My mother has rh- blood, my father has rh+. I was born healthy with rh- blood. My brother rh+ was a blue baby and required medical assistance after birth. He now has autoimmune issues, although this could be down to my mother developing auto immune issues after his birth (so genetically passed down from her) rather than the rhogam shot. My sister rh+ did not have any complications at birth, but does have a mild form of autism and ADHD and has had other medical problems since puberty. But again, it is impossible to know whether this was simply an inherited problem and I was just lucky.

  5. My mom is a negative and my father was a positive(hybrid). My oldest sister is a positive and my 2 brothers and I are negatives. My mom had six miscarriages in between us.