2p24.2 (rs7552) is a susceptibility locus for nonsyndromic cleft lip with or without cleft palate in the Brazilian population.

The population of Brazil is highly admixed, with each individual showing variable levels of Amerindian, European and African ancestry, which may interfere in the genetic susceptibility of known risk loci to nonsyndromic cleft lip with or without cleft palate (NSCL±P). Here, we investigated 5 reported genome-wide loci for NSCL±P in an ancestry-structured case-control study containing 1697 Brazilian participants (831 NSCL±P and 866 healthy controls). SNPs rs7552 in 2q24.2, rs8049367 in 16p13.3, rs1880646, rs7406226, rs9891446 in 17p13, rs1588366 in 17q23.2 and rs73039426 in 19q13.11 were genotyped using TaqMan allelic discrimination assays and genomic ancestry was estimated using a panel of 40 biallelic short insertion/deletion polymorphic markers informative of the Brazilian population. Logistic regression analysis of the single-markers revealed rs7552 in 2p24.2 as a susceptibility risk marker for NSCL±P, yielding an odds ratio (OR) of 1.71 (95% confidence interval (CI): 1.31-2.24, P = 9 × 10-6 ) in the homozygous state. Several SNP-SNP interactions containing rs7552 reached significance after adjustment for multiple tests (both Bonferroni assumption and 1000 permutation test), with the most significant interaction involving the 3-loci among rs7552, rs9891446 and rs73039426 (P = 6.1 × 10-9 and p1000 permutation = 0.001). Our study is the first to support the association of rs7552 in 2p24.2 with NSCL±P in the highly admixed Brazilian population.

The transcriptional activator NtrC controls the expression and activity of glutamine synthetase in Herbaspirillum seropedicae.

The role of the Ntr system in Herbaspirillum seropedicae was determined via ntrB and ntrC mutants. Three phenotypes were identified in these mutants: Nif(-), deficiency in growth using nitrate, and low glutamine synthetase (GS) activity. All phenotypes were restored by the plasmid pKRT1 containing the intact glnA, ntrB and ntrC genes of H. seropedicae. The promoter region of glnA was subcloned into a beta-galactosidase fusion vector and the results suggested that NtrC positively regulates the glnA promoter in response to low nitrogen. The H. seropedicae ntrC and ntrB mutant strains showed a deficiency of adenylylation/deadenylylation of GS, indicating that NtrC and NtrB are involved in both transcription and activity control of GS in this organism.