Evolution of IZUMO1-JUNO proteins fusion pair in Carnivora

CAMPOS, MARÍA CLARA; PISCIOTTANO, FRANCISCO; BRUQUE, CARLOS DAVID; SARAGÜETA, PATRICIA

Mar del Plata

Congreso; Reunión Anual de Sociedades de Biociencias; 2023

SAIC

JUNO and IZUMO1 are the only gamete fusion pair identified toenable fertilization in mammal.Studying their evolution could leadto elucidate some aspects of oocyte-spermatozoa interaction spe-cies-specificity. In this work, IZUMO1-JUNO protein positive selec-tion signatures were studied in the context of Carnivora order, Can-iformia-Feliformia suborders and Pantherinae subfamily. Sequenceidentity analyses of a comprehensive and carefully curated alignedsequence collection was conducted to characterize and compareamino acids diversity within these proteins. Subsequently, site-lin-eage-specific positive selection analyses were run in order to detectsignals of molecular adaptation and diversifying evolution. Positiveselected sites were mapped onto protein jaguar structural models.IZUMO1 was higher significant variable than its counterpart JUNO.Both proteins exhibited a significantly lower diversity in Feliformiasuborder compared to Caniformia suborder. Signatures of adaptiveevolution were detected in IZUMO1, showing eight sites under pos-itive selection that are in the JUNO interaction region. On the con-trary, JUNO does not show positive selection signatures, indicatingneutral or negative evolution.IZUMO1-JUNO protein evolution pattern suggests that prezygoticisolation barrier could emerge due to gametic incompatibility, evenlacking positive selection driven solely by neutral changes.