Shaochun Yuan

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It has been speculated that before vertebrates evolved somatic diversity-based adaptive immunity, the germline-encoded diversity of innate immunity may have been more developed. Amphioxus occupies the basal position of the chordate phylum and hence is an important reference to the evolution of vertebrate immunity. Here we report the first comprehensive(More)
In animals, the tetraspanins are a large superfamily of membrane proteins that play important roles in organizing various cell-cell and matrix-cell interactions and signal pathways based on such interactions. However, their origin and evolution largely remain elusive and most of the family's members are functionally unknown or less known due to difficulties(More)
To investigate the evolution and immune function of C-type lectin in amphioxus, the primitive representative of the chordate phylum, we identified three C-type lectins consisting solely of a carbohydrate recognition domain and N-terminal signal peptide and found that they had distinct express patterns in special tissues and immune response to stimulations(More)
A big bang expansion of the Vertebrate-type (V-type) TLRs was reported in amphioxus. To shed lights on its implications, a unique TLR which is reversely inserted into an intron of amphioxus PSMB7-10 by retrotransposition in the highly polymorphic proto-MHC region was cloned from Chinese amphioxus (Branchiostoma belcheri tsingtauense) and named as bbtTLR1.(More)
Vertebrates diverged from other chordates ~500 Myr ago and experienced successful innovations and adaptations, but the genomic basis underlying vertebrate origins are not fully understood. Here we suggest, through comparison with multiple lancelet (amphioxus) genomes, that ancient vertebrates experienced high rates of protein evolution, genome rearrangement(More)
C1q is the target recognition protein of the classical complement pathway and a major connecting link between innate and adaptive immunities. Its globular signature domain is also found in a variety of noncomplement protein that can be grouped together as a C1q family. In this study, we have cloned and identified a novel C1q family member in cephalochordate(More)
The TNF-associated factor (TRAF) family, the crucial adaptor group in innate immune signaling, increased to 24 in amphioxus, the oldest lineage of the Chordata. To address how these expanded molecules evolved to adapt to the changing TRAF mediated signaling pathways, here we conducted genomic and functional comparisons of four distinct amphioxus TRAF groups(More)
NF-κB transcription factors play important roles in immune responses and the development of the immune system. Many aspects of NF-κB signaling differ significantly among distinct species, although many similarities in signaling exist in flies and humans. Thus, to understand the functional refinement of the NF-κB cascade from invertebrates to vertebrates,(More)
Both amphioxus and the sea urchin encode a complex innate immune gene repertoire in their genomes, but the composition and mechanisms of their innate immune systems, as well as the fundamental differences between two systems, remain largely unexplored. In this study, we dissect the mucosal immune complexity of amphioxus into different(More)
Among five Toll/IL-1R resistance adaptors, sterile alpha and Toll/IL-1R resistance motif containing protein (SARM) is the only one conserved from Caenorhabditis elegans to human. However, its physiologic roles are hardly understood, and its involvement in TLR signaling remains debatable. In this study, we first demonstrated a predominant expression of(More)