Enables thioredoxin-disulfide reductase activity. Involved in circulatory system development; negative regulation of Wnt signaling pathway; and negative regulation of protein ubiquitination. Acts upstream of or within in utero embryonic development. Located in nucleus. Is expressed in several structures, including adipose tissue; alimentary system; genitourinary system; musculoskeletal system; and nervous system. Human ortholog(s) of this gene implicated in Robinow syndrome. Orthologous to human NXN (nucleoredoxin). [provided by Alliance of Genome Resources, Apr 2022]