Evolutionary Genomic Mechanisms and Adaptations of Osedax (Annelida: Siboglinidae) to Bone Consumption in the Deep Sea

• Grant number: 25/06854-9
• Support Opportunities: Scholarships in Brazil - Master
• Start date: August 01, 2025
• End date: July 31, 2027
• Field of knowledge: Physical Sciences and Mathematics - Oceanography - Biological Oceanography
• Principal Investigator: Paulo Yukio Gomes Sumida
• Grantee: Thammy Gularte Dias
• Host Institution: Instituto Oceanográfico (IO). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 19/12551-8 - Benthic connections of high Southern Latitudes: BECOOL, AP.PFPMCG.TEM

Abstract

The deep sea is one of the largest biomes on Earth, yet remains among the least explored. Within its specialized ecosystems, whale falls host remarkably diverse communities marked by unique evolutionary innovations. A prominent example is the genus Osedax, bone-eating annelids that lack a digestive system and rely exclusively on endosymbiotic bacteria to metabolize whale bones. To date, 34 species of Osedax have been described worldwide, occurring at depths between 20 and 4,200 meters. Studies involving natural whale falls, bone implant experiments, and fossil records have shown that different Osedax species can colonize bones from various vertebrates, suggesting potential preferences for distinct bone compositions.In this context, genomic adaptations related to nutrition in Osedax offer a valuable model for investigating genetic changes associated with the occupation of highly specialized niches. These insights can improve our understanding of Osedax diversification and substrate preference. Over the past three years, LAMP (IO-USP) has conducted experiments that led to the collection of Osedax species from the Antarctic Continental Shelf and South America. This project aims to sequence the transcriptomes of these specimens and compare them with available data from other species in the Atlantic, Pacific, Indian, Arctic, and Southern Oceans.The main objective is to identify potentially adaptive genomic regions associated with bone metabolism and compare their biological functions across species. The analysis will focus on gene families involved in bone-related processes such as amino acid biosynthesis, bone degradation, nutrient transport, gas exchange, and immune response. It will also assess gene family expansions or contractions, infer phylogenetic relationships based on orthologous genes, and detect signatures of natural selection throughout the group's evolutionary history. (AU)