Landscape of snake' sex chromosomes evolution spanning 85 MYR reveals ancestry of sequences despite distinct evolutionary trajectories

• Published in: Scientific reports Vol. 10; no. 1; p. 12499
• Main Authors: Viana, Patrik F, Ezaz, Tariq, de Bello Cioffi, Marcelo, Liehr, Thomas, Al-Rikabi, Ahmed, Goll, Leonardo G, Rocha, Anderson M, Feldberg, Eliana
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 27.07.2020; Nature Publishing Group UK
• Subjects: Animal behavior; Animals; Chromosome Painting; Chromosomes, Artificial, Bacterial - genetics; Comparative Genomic Hybridization; Cytogenetics; Degeneration; DNA - genetics; Evolution, Molecular; Evolutionary conservation; Female; Genome; Genomes; Heterochromatin - genetics; Male; Phylogeny; Sex chromosomes; Sex Chromosomes - genetics; Sex linkage; Snakes; Snakes - genetics; Species Specificity; Synteny
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-020-69349-5

Most of snakes exhibit a ZZ/ZW sex chromosome system, with different stages of degeneration. However, undifferentiated sex chromosomes and unique Y sex-linked markers, suggest that an XY system has also evolved in ancestral lineages. Comparative cytogenetic mappings revealed that several genes share ancestry among X, Y and Z chromosomes, implying that XY and ZW may have undergone transitions during serpent's evolution. In this study, we performed a comparative cytogenetic analysis to identify homologies of sex chromosomes across ancestral (Henophidia) and more recent (Caenophidia) snakes. Our analysis suggests that, despite ~ 85 myr of independent evolution, henophidians and caenophidians retained conserved synteny over much of their genomes. However, our findings allowed us to discover that ancestral and recent lineages of snakes do not share the same sex chromosome and followed distinct pathways for sex chromosomes evolution.