In the latest Under the covers (Nature revealed) blog, Nature’s Art Director Kelly Krause discusses the inspiration behind this week’s front cover choice on the evolution of the Y Chromosome.
Caption:
Mammalian Y chromosomes, known for their roles in sex determination and male fertility, often contain repetitive sequences that make them harder to assemble than the rest of the genome. To counter this problem Henrik Kaessmann and colleagues have developed a new transcript assembly approach based on male-specific RNA/genomic sequencing data to explore Y evolution across 15 species representing all major mammalian lineages. They find evidence for two independent sex chromosome originations in mammals and one in birds. Their analysis of the Y/W gene repertoires suggests that although some genes evolved novel functions in sex determination/spermatogenesis as a result of temporal/spatial expression changes, most Y genes probably persisted, at least initially, as a result of dosage constraints.
In a parallel study, Daniel Bellott and colleagues reconstructed the evolution of the Y chromosome, using a comprehensive comparative analysis of the genomic sequence of X–Y gene pairs from seven placental mammals and one marsupial. They conclude that evolution streamlined the gene content of the human Y chromosome through selection to maintain the ancestral dosage of homologous X–Y gene pairs that regulate gene expression throughout the body. They propose that these genes make the Y chromosome essential for male viability and contribute to differences between the sexes in health and disease. Cover: Daren Newman
The evolution and multiple functions of the mammalian Y chromosome.
From the Art Desk:
Art Director, Kelly Krause, explains:
“The evolution of the Y chromosome, as a subject, is a perfect match for illustration. As both studies examined the Y chromosome by exploring sequences of other animals, it seemed obvious to me that we should somehow create a Y shape made of mammals from one of the studies (relevant mammals can be seen below).
“We gave this brief to artist Daren Newman, who came back to us with this stunning cover design. The flowing lines and organic composition give a sense of movement and evolution, as various mammals come together to form a whole.”
For additional behind the scenes commentary each week, check out Nature Graphics Tumblr and the previous Under the Covers on brain-wide axonal projection patterns.