Naslov
The pleiotropic effects of melanin loss in cave snails Physella sp.

Autori
Grgić, Magdalena ; Weck, Robert G. ; Keresteš, Gaj ; Bilandžija, Helena

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Proceedings of the 25th International Conference on Subterranean Biology : ARPHA Conference Abstracts / Moldovan, Teodora Oana - Cluj - Napoca : Pensoft Publishers, 2022

Skup
25th International Conference on Subterranean Biology

Mjesto i datum
Cluj-Napoca, Rumunjska, 18.07.2022. - 22.07.2022

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
cave adaptation ; albinism ; loss of pigmentation ; melanin ; pleiotropy ; adaptive evolution

Sažetak
A traditional explanation for the loss of pigmentation in cave dwellers is the absence of negative selection acting on surface species to remove all albinos from the population. Recently, however, evidence has been accumulating that albinism in the cavefish Astyanax mexicanus has several beneficial pleiotropic effects. Albino cavefish have higher catecholamine levels due to a loss-of-function mutation in the oca2 gene, higher resistance to anesthesia, and sleep less than their pigmented, surface-dwelling conspecifics. All of these traits are beneficial to cavefish, given the scarcity of food and the availability of mates in caves. To understand whether pleiotropy might be a general mechanism for the loss of melanin pigmentation in cave animals, we use Physella sp., a freshwater snail from SW Illinois, USA. Within one cave Physella sp. occurs in several different morphs, ranging from completely albino to fully pigmented individuals. Using melanogenic substrate assay, we demonstrated that the first step of melanin synthesis is blocked in Physella sp. To investigate the pleiotropic effects of this blockade, we tested anesthesia resistance (AR). Similar to A. mexicanus, albino morphs of Physella sp. exhibited higher AR levels compared to pigmented morphs, with AR being controlled by the noradrenergic system in both morphs. AR and the noradrenergic system are linked to melanin synthesis via a common precursor L- tyrosine, which can be redirected between melanin and catecholamine pathways. Using RNA sequencing of albino and pigmented morphs of Physella sp. we aim to gain further insight into other pleiotropic effects of melanin loss. Our results suggest that pleiotropy may be involved in the evolution of albinism in both cave vertebrates and invertebrates.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

POVEZANOST RADA