CRYSTAL STRUCTURE OF A BONY FISH 2-MICROGLOBULIN: INSIGHTS INTO THE EVOLUTIONARY ORIGIN OF IGSF CONSTANT MOLECULES Weihong Chen, Feng Gao, Fuliang Chu, Jianhua Zhang, George F. Gao and Chun Xia From Department of Microbiology and Immunology, College of Veterinary Medicine, China Agricultural University, Beijing 100094, The People’s Republic of China, CAS Key Laboratory of Pathogenic Microbiolo...

The present study analysed the relationship between morphology and trophic structure of Siluriformes (Pisces, Osteichthyes) from the Caracu Stream (22º 45' S and 53º 15' W), a tributary of the Paraná River (Brazil). Sampling was carried out at three sites using electrofishing, and two species of Loricariidae and four of Heptapteridae were obtained. A cluster analysis revealed the presence of th...

Although lymphocyte-like cells secreting somatically-recombining receptors have been identified in the jawless fishes (hagfish and lamprey), the cartilaginous fishes (sharks, skates, rays and chimaera) are the most phylogenetically distant group relative to mammals in which bona fide immunoglobulins (Igs) have been found. Studies of the antibodies and humoral immune responses of cartilaginous f...

Caves and other subterranean habitats represent one of the most challenging environments on the planet. Other than salamanders, bony fishes are the only vertebrate group that has successfully colonized and are completely restricted to those habitats. Despite being known to science for over 150 years, only recently have cavefishes become model systems for evolutionary studies. Several cavefishes...

It has long been believed that fish lack antibody affinity maturation, in part because they were thought to lack germinal centers. Recent research done on sharks and bony fishes indicates that these early vertebrates are able to affinity mature their antibodies. This article reviews the functionality of the fish homologue of the immunoglobulin (Ig) mutator enzyme activation-induced cytidine dea...

Despite being one of the richest Neogene deposits marine fossil vertebrates along Pacific coast South America, no detailed study bony fishes from Bahía Inglesa Formation has been carried out. Through revision historical collections Caldera Paleontological Museum, we describe 27 remains fishes. Fossils described here are distributed in 13 taxa. Among these, Sardinops sp. cf. S. sagax (Clupeidae)...

Extant vertebrates are divided into three major groups: hagfishes (Hyperotreti, myxinoids), lampreys (Hyperoartia, petromyzontids), and jawed vertebrates (Gnathostomata). The phylogenetic relationships among the groups and within the jawed vertebrates are controversial, for both morphological and molecular studies have rendered themselves to conflicting interpretations. Here, we use the sequenc...