Inbreeding in the jungle of Equatorial Guinea between two closely related gorillas — probably an uncle and a niece — caused the albinism of Snowflake, who remains the only white gorilla the world has ever seen.
That’s according to a recent study of the genome of the famous ape, who was the symbol of Barcelona Zoo for over 40 years until his death in 2003.
According to the investigation, which was published in the journal BMC Genetics and presented at Barcelona Zoo on Tuesday, the gene that made him white was SLC45A2 — the same gene that causes albinism in other species, including rats, horses and chickens.
Led by scientists from the Evolutionary Biology Institute (IBE) — joint-operated by Pompeu Fabra University and Spain’s National Research Council (CSIC) — the study opens the way to exploring new methodologies in the field of genetics related to the conservation of endangered species. It also makes it easier to potentially create a new albino gorilla, according to two of the study’s authors, Tomàs Marquès — who directed the project — and Javier Prado. “It is very simple and requires no genetic engineering or manipulation of any kind,” they said at the presentation. “All you need to do is detect the mutation in two gorillas and crossbreed them. You have a 25-percent chance of another albino coming out.” Another issue, of course, are the ethical implications of bringing an animal with a condition such as albinism into the world, they warn.
The project analyzed three billion DNA building blocks. The mutation was in just one
Snowflake, known in Spanish as Copito de Nieve, paid a high price for his fame — although his color initially saved his life, sparing him from the pot when he was captured in 1966 by Equatorial Guinean hunters, who subsequently sold him to Jordi Sabater Pi. Albinism causes serious problems, such as sensitivity to light, reduced visual acuity and a predisposition to skin cancer. It was the latter that finally did for Snowflake, who was put to sleep in 2003 when his disease was diagnosed as terminal.
Tissue samples were saved from his body, but it was a blood sample they already had in the laboratory that was used in the study, according to Jaume Bertranpetit, a population geneticist. “Twelve years ago I started to search Snowflake for the human albinism genes then known about and there wasn’t anything,” he explains. “Now with Marquès’s focus on the whole genome, the mutation of a gene associated with albinism, just one, has been found, which was not known about 12 years ago.”
The project analyzed three billion nucleotides (the building blocks of DNA) and the mutation was in just one of them, Bertranpetit adds.
In the child of two siblings, 25 percent of the two copies of the same chromosome will be identical. In Snowflake, 12.5 percent was identical. “The question was discovering what kind of kinship breeding generated the genetic pattern that we see in this individual,” explains Carles Lalueza-Fox, a CSIC scientist at the IBE and one of the authors of the study.
“Using models, we analyzed three possible types of kinship breeding: between first cousins, between uncle and niece and between grandfather and granddaughter, and the one that gives the closest-fitting distribution pattern to this specific gorilla is the second one, that of uncle and niece.”
Lalueza-Fox says such inbreeding is rare in the wild as they have habits that avoid it. “The normal thing is for the young male gorilla to abandon the group in which he was born, but in this case it is possible that he came back, he bred with a niece and Snowflake was born.”
Asked about the possibility of making another Snowflake, Lalueza-Fox offers an emphatic reply: “It would have no scientific use and ethically I think it is reprehensible.”