image: An ornate burrowing frog (Platyplectrum ornatum). Photo by Stephen Mahony. view more
Credit: Stephen Mahony
A study uncovers potential drivers and mechanisms of genome reduction in frogs with small genomes. Genome size varies across the tree of life, with frogs and birds possessing relatively large and small genomes, respectively. The mechanisms by which genomes shrink are poorly understood. Scott Edwards, Tariq Ezaz, and colleagues sequenced the genome of the ornate burrowing frog (Platyplectrum ornatum), whose genome is smaller than that of many birds and exhibits bird-like characteristics, including reduced repetitive DNA content and reduced distances between genes. The sequences suggest several mechanisms that may be responsible for genome size reduction, including reduced abundance of transposable elements, increased deletion bias for transposable elements, reduction in the length of introns within genes, and expansion of the repertoire of genes that suppress transposable elements. Comparison with two other frog genera with small and large genomes suggests that reduction in genome size may occur in independent, convergent events and may be related to life history, given that tadpole development and diet are similar among frog genera with reduced genome size. According to the authors, the study provides a framework for comparing genome reduction processes in other amphibians and vertebrates.
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Article #20-11649:
"A bird-like genome from a frog: mechanisms of genome size reduction in the ornate burrowing frog, Platyplectrum ornatum," by Sangeet Lamichhaney et al.
MEDIA CONTACT:
Scott V. Edwards,
Harvard University, Cambridge MA;
tel: 617-384-8082;
email: <sedwards@fas.harvard.edu>