Calatayud S, Garcia-Risco M, Capdevila M, Cañestro C, Palacios Ò, Albalat R.

Front Cell Dev Biol. 2021 Jul 2;9:702688. doi:10.3389/fcell.2021.702688

Modular Evolution and Population Variability of Oikopleura dioica Metallothioneins.

“we concluded that the 11C/12C domain of OdiMTs formed stable clusters with four Cd(II) ions” “protein sequence comparisons reveal amino-acid identities ranging from 94.4% between Norway and Barcelona, up to 63.9% when compared with the sequence of Okinawa” “amino acid identities persistently were slightly lower than nucleotide identities [...] indicated that nucleotide substitutions are significantly affecting non-synonymous positions, which can be considered an indication [of] positive selection.” “The presence of [...] non-functional alleles for both MTs [...] opened the possibility that some O. dioica specimens might lack functional MTs” “The most conspicuous difference of OdiMT genes between O. dioica populations was the identification of OdiMT2 encoding proteins with variable number of RUs (i.e., t-12C/12 pairs). OdiMT2ORE with seven repeats (RU1–RU7) was the longest one, followed by OdiMT2NOR, with six repeats, OdiMT2OSA, with five repeats, OdiMT2CAT, with four repeats, and OdiMT2OKI, with three repeats.”