The first Intersex Southern Right is to explore Balina

IN 2022 analyzed the genes of the southern right whales when Carla Crossman encountered something unexpected.

In 1989, decades, researchers used special cross springs to collect smaller skin samples from 10 southern right whales in the Calfah areas of the Argentine Valdés Peninsula as part of the effort to evaluate the genetic diversity of species. Nova Scotia, a master student at the University of Saint Mary’s in Halifax, worked with these historical examples, especially when she was stuck in DNA results for a whale: EAU10b.

Scientists studying wild animals need several number of keys to measure the health of a population. For example, how many people are there? And how many people are there against men? This gender ratio reveals whether a population will grow.

After lining DNA for each whale, Crossman quickly scanned the chromosomes of animals to estimate their gender. With whales, people and other mammals – with plants such as some fish and even plants such as ginkgos and kiwis – there is a y gender chromosome and an x ​​chromosome, while women have two X chromosomes. Crossman’s data showed that EAU10B is two XS. “I was quite trusting myself [Eau10b] He was a woman ..

Intersex whales float under the radar, so to speak, because the marine mammals have internal genital organs.

However, when it checked the Crossman forecast with a routine sex identification technique called the Sry test, the answer was not logical.

Scientists use this test to determine whether an animal carries the Sry (or “Gender Determination Zone Y”) that helps to trigger male development. Since the Sry gene exists only in Y chromosome, the test for its presence is an easy way to remove the gender of an animal.

The EAU10B test showed the SRY gene. Whale was a man.

Confused, crossman is back A third technique– A test for a series of genes called ZFX and ZFY in X and Y chromosomes. In EAU10B, Crossman found both gene and confirmed that the animal was Y chromosome. But the DNA of the whale Moreover The gene carried on the X chromosome contained a dual dose of ZFX. The result revealed that EAU10B has a Y chromosome And Two x chromosomes, that is, the animal was neither male nor female. EAU10B was an intersex whale –The first of the species known by scientists.

The combination of this gender chromosomes occurs when a cell takes an extra copy of the X chromosome during cell division. A similar event can lead to female cubs with chromosomes or men with two y chromosomes.

Crossman does not know how many southern right whale with XXY sex chromosome can be there. Even the fate of EAU10B is unknown, because the researchers did not define the whale when they received DNA sample in 1989. But the southern right whales can live up to 70 years, so EAU10B may still visit the oceans of the world and winter from the Valdés Peninsula.

Although intersex animals generally cannot produce puppies to help infertile and a population growth, bean Velocci, a historian who examines gender classification at the University of Pennsylvania, says that intersex animals are probably playing important non -reproductive roles in social species such as whales.

Examining the intersex animals helped scientists better understand how genes and hormones shape as individuals developed. With the domestication process of home animals, people know intersex cows for thousands of years. In Vanuatu, the islanders in the South Pacific feed a unique intersex pork strain rewarded for their sensitive spiral teeth. More recently, researchers also documented intersex horses, dogs, deer, sheep, fish, and many different invertebrate species. Crossman, intersex animals are rare among species, but he says, “Historically, it is more common than we think.”

In humans, the XXY chromosome configuration is called Klinefelter syndrome And most of them may not even notice that they have unusual chromosomes defined as men.

Terminology and definitions used to talk about Intersex individuals Changed over timeEspecially when referring to people. However, according to Velocci, scientists use the intersex term to identify bodies that cannot be easily categorized as male or female, regardless of species.

In social species, intersex animals probably play important roles that are not important to benefit the population.

All intersex individuals do not have XXY chromosomes – this term includes individuals with various characteristics caused by differences in genetics, hormones and anatomy. An inter -individual individual may have a physical appearance that separates the sex organs or the norm. For example, some individuals have a Y chromosome and testicles, but cells do not respond to male sex hormones, so external anatomies are more feminine.

Intersex whales are especially floating under the radar, because there are mammal inner genital organs. “You often don’t take good care of the genitals of a whale, Cross says Crossman. “Everything is inside.” Nevertheless, scientists had previously found Intersex fins whales, Belugas, Bowhead whales, short -gag -shared dolphins and True’s beak whales.

“Always [researchers] They look at the field or examples, they just continue to find these exceptions, Vel Velocci. Scientists said, “This gender is not clearly dual. “

However, Velocci says that scientific education is not adapted. “Xx and xy [taught as] Rather than a possible variation among many. “

For some well-studied relatives of the North Atlantic Right Whale-South Right whale, which is extinct, researchers estimate the gender of an individual by observing behaviors such as swimming or obvious external characteristics such as swimming or genital slits. However, DNA tests for most whales offer a single answer.

Nevertheless, the story of EAU10B shows that even the most routine sex tests are not perfect. By reducing the gender to the presence or absence of a single gene, Sry is the risks looking at animals that do not smoothly fall into the male-female duo. In genetic research, it is now easier to describe intersex animals by comparing the recent splashes with the results obtained from different tests. “We can just start looking, Cross says Crossman.

When scientists define the next intersex animal, this does not change how the types of information are managed or understood. However, this individual will offer another difficulty to the solid definitions of sex, whether a guppy or whale. What society sees normally is a box that is carefully drawn to a wild and messy world, and every individual that cannot be included offers a fascinating look at the real diversity of nature.

A version of this story It appeared initially biographicalAn independent magazine about nature and renewal supported by the Academy of Sciences of California.

Lead Image: Tomas Kotouc / Shutterstock

• Vanessa Minke-Martin

  Published April 1, 2025

  Vanessa Minke-Martin is a scientific writer and old fish biologist in Vancouver Island, British Kolumbiyası.

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