Science. They discover the genes that make whales giant – Publimetro México

Madrid, 19 years old (Europe Press)

The results highlight the role of four genes (named GHSR, IGFBP7, NCAPG and PLAG1) and suggest that they promote large body sizes while mitigating potential negative effects, such as an increased risk of cancer.

Whales, dolphins, and porpoises (commonly known as cetaceans) evolved from tiny land ancestors about 50 million years ago, but some species are now among the largest animals that ever lived. However, gigantism can lead to biological negatives, such as decreased reproductive performance and increased chances of developing diseases such as cancer, and it is not clear what role different genes played in driving gigantism in whales.

Researcher Mariana Neri and colleagues from the University of Campinas, Brazil, conducted a molecular evolutionary analysis of nine candidate genes: five genes (GHSR, IGF2, IGFBP2, IGFBP7, and EGF) of the growth hormone/insulin-like growth factor axis, and four genes (NCAPG, LCORL, PLAG1, and ZFAT) associated with By increasing body size in hoofed animals such as cows and sheep, which are closely related to whales.

They tested these genes in 19 species of whales, including 7 species with a body length of more than 10 meters that are considered giants: sperm whale, bowhead whale, gray whale, humpback whale, North Pacific right whale, flipper and blue whale.

The authors found positive developmental selection for the GHSR and IGFBP7 genes on the growth hormone/insulin-like growth factor axis, and for the NCAPG and PLAG1 genes.

According to the authors, this indicates that these four genes may be involved in the increase in body size of giant whales. In addition, GHSR controls aspects of the cell cycle and IGFBP7 acts as an inhibitor of various types of cancer, which together can counteract some of the biological disadvantages associated with large body size.