Gene Loss

Publication Details

Identifier: JB_C0DTWC

Curator: M. Lopes-Marques

Title:

Transition to an Aquatic Habitat Permitted the Repeated Loss of the Pleiotropic KLK8 Gene in Mammals.

Abstract:

Kallikrein related peptidase 8 (KLK8; also called neuropsin) is a serine protease that plays distinct roles in the skin and hippocampus. In the skin, KLK8 influences keratinocyte proliferation and desquamation, and activates antimicrobial peptides in sweat. In the hippocampus, KLK8 affects memory acquisition. Here, we examined the evolution of KLK8 in mammals and discovered that, out of 70 placental mammals, KLK8 is exclusively lost in three independent fully-aquatic lineages, comprising dolphin, killer whale, minke whale, and manatee. In addition, while the sperm whale has an intact KLK8 reading frame, the gene evolves neutrally in this species. We suggest that the distinct functions of KLK8 likely became obsolete in the aquatic environment, leading to the subsequent loss of KLK8 in several fully-aquatic mammalian lineages. First, the cetacean and manatee skin lacks sweat glands as an adaptation to the aquatic environment, which likely made the epidermal function of KLK8 obsolete. Second, cetaceans and manatees exhibit a proportionally small hippocampus, which may have rendered the hippocampal functions of KLK8 obsolete. Together, our results shed light on the genomic changes that correlate with skin and neuroanatomical differences of aquatic mammals, and show that even pleiotropic genes can be lost during evolution if an environmental change nullifies the need for the different functions of such genes.

Last update:

30-08-2024

Associated Glosses (9 results)

GlossID	Species	Symbol	Gene Loss Mechanism	Loss Type	Lineage Specific	Citation
GL_3ZCLG5	Tursiops truncatus	KLK11	LOF (frameshift, premature stop, ss)	Full	Cetacea	10.1093/gbe/evx239
GL_6NZSBB	Physeter catodon	KLK11	LOF (frameshift, premature stop, ss)	Full	Cetacea	10.1093/gbe/evx239
GL_6ZECGV	Trichechus manatus	KLK8	LOF (frameshift, premature stop, ss)	Full		10.1093/gbe/evx239
GL_HCRWZZ	Physeter catodon	KLK8	LOF (frameshift, premature stop, ss)	Full		10.1093/gbe/evx239
GL_LATCIF	Balaenoptera acutorostrata	KLK11	LOF (frameshift, premature stop, ss)	Full	Cetacea	10.1093/gbe/evx239
GL_LSBN1F	Orcinus orca	KLK11	LOF (frameshift, premature stop, ss)	Full	Cetacea	10.1093/gbe/evx239
GL_QI0IK7	Orcinus orca	KLK8	LOF (frameshift, premature stop, ss)	Full		10.1093/gbe/evx239
GL_TPZKDX	Tursiops truncatus	KLK8	LOF (frameshift, premature stop, ss)	Full		10.1093/gbe/evx239
GL_YWZWN7	Balaenoptera acutorostrata	KLK8	LOF (frameshift, premature stop, ss)	Full		10.1093/gbe/evx239