Nature Genetics 15,[131][132][133][134][135][136].Editorial changes after the authors correction of the proofs resulted in the incorrect substitution of the word 'eutherian' for the word 'therian' throughout the text. We would like to clarify that the lnfraclass Eutheria refers to the 'placental' mammals only, whereas the Subclass Theria includes both the Infraclass Metatheria (marsupials) and the Infraclass Eutheria. Substitutions of'therian' for 'eutherian' should be made on: page 131, Abstract, line 7; page 134, column 2, line 3; page 135, column I, paragraph 3, line 3; page 135, column 2, paragraph 3, line 14.These alterations substantially change the conclusions of the article, which are as follows: the presence of a single copy RBM gene in American and Australian marsupials suggests that RBM was originally present as a single copy on the Y chromosome of an ancestral therian mammal. Following the divergence of marsupials and eutherians approximately 130 million years ago, RBM has been amplified independently in several marsupial and eutherian lineages. The conserved testis-specific expression of RBM in both marsupials and eutherians suggests that the selection for a critical male-specific function ensured the retention of RBM on the mammalian Y chromosome.Nature Genetics regrets any confusion this might have caused.Promoter swapping between the genes for a novel zinc finger protein and ~-catenin in pleiomorphic adenomas with t(3;8)(p21 ;q 12) translocations Nature Genetics 15, 170-174 (1997).Two lines of the Pl.AG I sequence (nt 5300-5621) in the 3' untranslated region were inadvertently deleted from Fig. 2 a. The complete sequence for this region can be obtained from GenBank accession nwnber U65002. We apologize for any inconvenience created by this error.

Ulnar-mammary syndrome is a rare pleiotropic disorder affecting limb, apocrine gland, tooth and genital development. We demonstrate that mutations in human TBX3, a member of the T-box gene family, cause ulnar-mammary syndrome in two families. Each mutation (a single nucleotide deletion and a splice-site mutation) is predicted to cause haploinsufficiency of TBX3, implying that critical levels of this transcription factor are required for morphogenesis of several organs. Limb abnormalities of ulnar-mammary syndrome involve posterior elements. Mutations in TBX5, a related and linked gene, cause anterior limb abnormalities in Holt-Oram syndrome. We suggest that during the evolution of TBX3 and TBX5 from a common ancestral gene, each has acquired specific yet complementary roles in patterning the mammalian upper limb.

To better understand the role of TBX5, a T-box containing transcription factor in forelimb and heart development, we have studied the clinical features of HoltOram syndrome caused by 10 different TBX5 mutations. Defects predicted to create null alleles caused substantial abnormalities both in limb and heart. In contrast, missense mutations produced distinct phenotypes: Gly80Arg caused significant cardiac malformations but only minor skeletal abnormalities; and Arg237Gln and Arg237Trp caused extensive upper limb malformations but less significant cardiac abnormalities. Amino acids altered by missense mutations were located on the three-dimensional structure of a related T-box transcription factor, Xbra, bound to DNA. Residue 80 is highly conserved within T-box sequences that interact with the major groove of target DNA; residue 237 is located in the T-box domain that selectively binds to the minor groove of DNA. These structural data, taken together with the predominant cardiac or skeletal phenotype produced by each missense mutation, suggest that organ-specific gene activation by TBX5 is predicated on biophysical interactions with different target DNA sequences.