Scientists have found that deer also have sickle cells

red blood cells in patients with sickle cell anemia, red blood cells in the body can be distorted into abnormal shapes.
picture Source: P. D. Butcher
have something in common with deer and sickle cell anemia patients: their red blood cells are distorted into abnormal forms. Now, researchers have shed light on the cells in deer's blood cells that cause this distortion. The discovery solves a puzzle that has puzzled scientists since the 1840s and may help scientists understand how deformed blood cells can make some people fight malaria.
patients with sickle cell anemia carry a mutation that distorts the structure of hemolybin, a molecule that carries oxygen in the blood. This DNA "failure" makes β-globulin, one of the two proteins that produce hemoglobin, more viscous, causing hemoglobin molecules to stick together and form stiff fibers. In turn, these fibers twist usually disc-shaped red blood cells into a new moon or other abnormal shape. When twisted and fragile red blood cells clog small blood vessels or rupture, people with the disease suffer from pain, fatigue, and organ damage.
blood cells from several species of deer also show sickle shapes, but scientists don't know what contributed to the change. To that end, Tobias Warnecke, an evolutionary biologist at the British Medical Research Council in London, and colleagues collected blood, muscle and DNA samples from 15 species of deer around the world. Warnecke said most of the samples came from zoo animals, but to get tissue from two species of deer, moose and reindeer, they had to buy minced meat from companies that sell rare meats.
the two species, as well as the North American horse deer, did not exhibit sickle-shaped red blood cells. When the scientists compared their β-globulin amino acid sequence with that from a deer with a sickle-like cell, they found a key difference: in sickle-shaped red blood cells, an amino acid changed from glutamate to proline. The same amino acid exchange occurs in the wrong form of hemolybin, which causes sickle cell anemia, but in a different position in the molecule.
in deer's red blood cells appears to cause their hemolubin molecules to congreose into fibers. The researchers reported the
in the Journal of Science and Technology. However, in humans, deer with sickle-like cells appear to be perfectly healthy. "I'm sure there must be a price in it, but I don't know what the price is." Warnecke said.
for humans, the cost of turning red blood cells into sickles is clear. In the United States, people with the disease usually do not live past the age of 50. However, the β-globulin gene seems surprisingly common where malaria is prevalent. That's because people who have only one defective copy of this version of the gene get some protection against malaria, although researchers aren't sure how the altered protein fights the parasites that cause the disease. (Source: Science Network Zonghua)