Gene Loss

Publication Details

Identifier: JB_YLLOZG

Curator: M. Lopes-Marques

DOI: 10.1371/journal.pgen.1000634

PMID: 19730686

Title:

Molecular decay of the tooth gene Enamelin (ENAM) mirrors the loss of enamel in the fossil record of placental mammals.

Abstract:

Vestigial structures occur at both the anatomical and molecular levels, but studies documenting the co-occurrence of morphological degeneration in the fossil record and molecular decay in the genome are rare. Here, we use morphology, the fossil record, and phylogenetics to predict the occurrence of "molecular fossils" of the enamelin (ENAM) gene in four different orders of placental mammals (Tubulidentata, Pholidota, Cetacea, Xenarthra) with toothless and/or enamelless taxa. Our results support the "molecular fossil" hypothesis and demonstrate the occurrence of frameshift mutations and/or stop codons in all toothless and enamelless taxa. We then use a novel method based on selection intensity estimates for codons (omega) to calculate the timing of iterated enamel loss in the fossil record of aardvarks and pangolins, and further show that the molecular evolutionary history of ENAM predicts the occurrence of enamel in basal representatives of Xenarthra (sloths, anteaters, armadillos) even though frameshift mutations are ubiquitous in ENAM sequences of living xenarthrans. The molecular decay of ENAM parallels the morphological degeneration of enamel in the fossil record of placental mammals and provides manifest evidence for the predictive power of Darwin's theory.

Last update:

30-08-2024

Associated Glosses (20 results)

GlossID	Species	Symbol	Gene Loss Mechanism	Loss Type	Lineage Specific	Citation
GL_2C8CYG	Bradypus tridactylus	ENAM	LOF (frameshift, premature stop, ss)	Full	No	10.1371/journal.pgen.1000634
GL_2V2Z1H	Caperea marginata	ENAM	LOF (frameshift, premature stop, ss)	Full	No	10.1371/journal.pgen.1000634
GL_3L8GKQ	Kogia sima	ENAM	LOF (frameshift, premature stop, ss)	Full	No	10.1371/journal.pgen.1000634
GL_4GOBO4	Orycteropus afer	ENAM	LOF (frameshift, premature stop, ss)	Full	No	10.1371/journal.pgen.1000634
GL_4JDXHW	Eschrichtius robustus	ENAM	LOF (frameshift, premature stop, ss)	Full	No	10.1371/journal.pgen.1000634
GL_5TDV36	Choloepus didactylus	ENAM	LOF (frameshift, premature stop, ss)	Full	No	10.1371/journal.pgen.1000634
GL_6R7Q1L	Tolypeutes matacus	ENAM	LOF (frameshift, premature stop, ss)	Full	No	10.1371/journal.pgen.1000634
GL_9MINOE	Eubalaena glacialis	ENAM	LOF (frameshift, premature stop, ss)	Full	Eubalaena	10.1371/journal.pgen.1000634
GL_AJDDHM	Kogia breviceps	ENAM	LOF (frameshift, premature stop, ss)	Full	No	10.1371/journal.pgen.1000634
GL_BEDX6K	Dasypus novemcinctus	ENAM	LOF (frameshift, premature stop, ss)	Full	No	10.1371/journal.pgen.1000634