Fossils of an extinct, armored fish challenge current understanding of when copulation and internal fertilization evolved in jawed vertebrates.
Cloning and in vitro culture of sheep embryos have been associated with bigger livestock and 'large offspring syndrome' (LOS). In the February Nature Genetics Young et al. provide a molecular explanation for the observed fetal overgrowth (Nat Genet 2001, 27:153-154). They developed a culture system that consistently results in large offspring (LO) in 25% of births. Young et al. measured the levels of several imprinted genes that are associated with fetal overgrowth syndromes in man. The levels o
February 21, 2001|