While the Y chromosome is important in differentiating males from females during fertilization, scientists previously believed it didn't do anything else. With new research on the functions of the Y chromosome, scientists finally give the chromosome the credit it deserves.
Two new studies have shed new light on both the history and function of the Y chromosome. Researchers have found that this chromosome actually controls a number of other functions and phenotypic expressions found in males. In fact, the researchers were also surprised to find that the newfound genetic control mechanisms found in the Y chromosome are not related to either sperm production of the differentiation between males and females.
Previously held beliefs indicated that the Y chromosome functioned as a regulator of certain male phenotypic expressions such as muscle mass, the production of male gametes and the development of the male voice. However, the new findings have expanded the Y chromosome's repertoire extensively.
The new studies were conducted by two unrelated research teams. The first study was conducted by researchers from the Swiss University of Laussane. To conduct their study, the team headed by Swiss researcher Henrik Kaessman sequenced a number of Y chromosomes from a variety of mammals. In total, the team analyzed genetic material from 15 different species. Their findings were used to create a genetic roadmap of the Y chromosome's evolution over the past 180 million years. The Swiss team published their findings in the online journal Nature.
The second study was conducted by a differed research team based in the Massachusetts Institute of Technology (MIT). The MIT team found that the Y chromosome is a necessity for the continued survival of many species, humans included. The team's findings were also published in Nature.
"The human X and Y chromosomes evolved from an ordinary pair of autosomes, but millions of years ago genetic decay ravaged the Y chromosome, and only three per cent of its ancestral genes survived," says the study conducted by the MIT team. "We reconstructed the evolution of the Y chromosome across eight mammals to identify biases in gene content and the selective pressures that preserved the surviving ancestral genes. "
New scientific evidence also supports the theories that the Y chromosome serves an important role in determining the susceptibility of males to certain diseases. These differences in disease susceptibility provide another clear demarcation between males and females.
The researchers also found that the Y chromosome also had an effect on many different organs and bodily functions throughout the human body.
"Beyond its roles in testis determination and spermatogenesis, the Y chromosome is essential for male viability, and has unappreciated roles in Turner's syndrome and in phenotypic differences between the sexes in health and disease," the MIT team said.
