Zebras - Are They Black With White Stripes or White With Black Stripes?

The question of whether zebras are white with black stripes or black with white stripes may appear to be the setup for an old joke. But this isn't a joke because there is an answer ㅡ zebras are black with white stripes.

It has long been assumed that zebras were white animals with black stripes, but scientific evidence shows that this is not the case. According to embryological principles, the genuine/original color of zebras is black. The white color is a stripe around their body's main black background.

Most zebras have dark skin beneath their fur, but their stripes are not made of white fur with gaps in between – they have both black and white fur. Their fur color is determined by different developmental processes, just as a light-skinned person can have dark hair. 

At a first quick glimpse, it appears that zebras had white bodies with black stripes. The reason is that many zebras' black stripes end towards the belly, and the belly is mostly white.

Zebra embryos begin entirely black. Melanocytes are the cells that produce the black pigment melanin, which colors a zebra's hair and skin.

According to a 2005 study published in the Journal of Investigative Dermatology, every piece of hair, both light and dark, grows from a follicle filled with melanocyte cells. These cells secrete a pigment that determines the color of one's hair and skin. This pigment is called melanin; more melanin results in darker colors, while fewer melanin results in lighter colors. Zebras' black fur contains a lot of melanin, but melanin is missing from white fur. The follicles that form the white hair stripes have turned off melanocytes, which no longer produce pigment.

According to a study published in the journal Nature in 2016, the Alx3 gene is involved in stripe formation. Because zebras are challenging to keep in the laboratory, the researchers focused on the African striped mouse's stripe pattern.

Alx3 functions as a transcription factor. A transcription factor is a molecule, usually a protein, that can turn specific genes on or off. The cell maintains strict control over how and when the transcription factor can activate or deactivate its target gene. When the transcription factor has completed its task, the cell tells it to go back to sleep until needed again.

Alx3 It also suppresses the Mitf gene, which regulates the maturation of melanocytes. According to the findings, Alx3 is more active with light stripes in African striped mice than in dark stripes.

Researchers have also proposed various theories on why zebras have stripes, with explanations ranging from camouflage to predator protection to marks of uniqueness like a human fingerprint.

The exact biological processes underlying the zebra's stripes are unknown; however, in a study published in the online journal Nature Communications in 2014, Tim Caro, a UC Davis professor of wildlife biology and colleagues discovered that striping on animals is more common in areas rife with biting flies, which could mean that biting flies struggle to see a striped or black-and-white surface as a safe place to land.

To put this phenomenon to the test, researchers outfitted the horses in striped coats. Except for their uncovered heads, Surprisingly, the same animals became more resistant to flies when they were clad in stripes. And uniformly colored coats had no effect; the stripes, in particular, confused the flies.

More research is needed to examine which, if either, the theory is correct about why zebras have stripes, but for the time being, we know what color they are.