My answer to the question “Can Rh negative blood be cloned?”

Years ago someone made the following claim:

“Rh negative blood cannot be cloned”

It sometimes changed to

“O negative blood cannot be cloned”.

To this day, a number of searches leading to this blog stems from the term

“Can Rh negative blood be cloned?”

That is primarily due to this previous post:

Can Rh Negative Blood be Cloned?

In order to answer the question properly, one must understand what exactly cloning is.

Cloning is the process of producing individual organisms with identical or virtually identical DNA, either by natural or artificial means. In nature, some organisms produce clones through asexual reproduction. 

When we refer to the term “cloning”, we are talking about the cloning of Nucleic acid segments or genes or possibly the expression of proteins. If it was monetarily manageable to produce blood in a bioreactor, rh negative stem cells would be used and with that rh negative blood would be produced.

The following study is from 1990:

Molecular cloning and protein structure of a human blood group Rh polypeptide

Here is the interesting part:

cDNA clones encoding a human blood group Rh polypeptide were isolated from a human bone marrow cDNA library by using a polymerase chain reaction-amplified DNA fragment encoding the known common N-terminal region of the Rh proteins. The entire primary structure of the Rh polypeptide has been deduced from the nucleotide sequence of a 1384-base-pair-long cDNA clone. Translation of the open reading frame indicates that the Rh protein is composed of 417 amino acids, including the initiator methionine, which is removed in the mature protein, lacks a cleavable N-terminal sequence, and has no consensus site for potential N-glycosylation. The predicted molecular mass of the protein is 45,500, while that estimated for the Rh protein analyzed in NaDodSO4/polyacrylamide gels is in the range of 30,000-32,000. These findings suggest either that the hydrophobic Rh protein behaves abnormally on NaDodSO4 gels or that the Rh mRNA may encode a precursor protein, which is further matured by a proteolytic cleavage of the C-terminal region of the polypeptide. Hydropathy analysis and secondary structure predictions suggest the presence of 13 membrane-spanning domains, indicating that the Rh polypeptide is highly hydrophobic and deeply buried within the phospholipid bilayer. In RNA blot-hybridization (Northern) analysis, the Rh cDNA probe detects a major 1.7-kilobase and a minor 3.5-kilobase mRNA species in adult erythroblasts, fetal liver, and erythroid (K562, HEL) and megakaryocytic (MEG01) leukemic cell lines, but not in adult liver and kidney tissues or lymphoid (Jurkat) and promyelocytic (HL60) cell lines. These results suggest that the expression of the Rh gene(s) might be restricted to tissues or cell lines expressing erythroid characters.

Remember:

Because of the lack of nuclei and organelles, mature red blood cells do not contain DNA and cannot synthesize any RNA, and consequently cannot divide and have limited repair capabilities. The inability to carry out protein synthesis means that no virus can evolve to target mammalian red blood cells. However, infection with parvoviruses (such as human parvovirus B19) can affect erythroid precursors while they still have DNA, as recognized by the presence of giant pronormoblasts with viral particles and inclusion bodies, thus temporarily depleting the blood of reticulocytes and causing anemia.

Are you surprised?