Analysis of susceptibility polymorphisms for nonsyndromic cleft lip with or without cleft palate in the Brazilian population

Background : Although genome‐wide association studies have identified several susceptibility loci for nonsyndromic cleft lip with or without cleft palate (NSCL/P) in populations around the world, the role of most loci is unknown in the highly heterogeneous Brazilian population. Methods : To determine the association of 7 markers that showed genome‐wide significant association in Brazilians with NSCL/P, we conducted a structured association study conditioned upon the individual ancestry proportions to evaluate markers at 1p36 (rs742071), 2p21 (rs7590268), 3p11.1 (rs7632427), 8q21.3 (rs12543318), 13q31.1 (rs8001641), 15q22.2 (rs1873147), and 17q22 (rs227731) in 505 patients with NSCL/P and 594 healthy controls recruited from 2 different geographical regions of Brazil. The polymorphisms were genotyped by TaqMan 5′‐exonuclease allelic discrimination assay, and each sample was independently typed for 40 biallelic short insertion/deletion markers to characterize the genomic ancestry. Results : After Bonferroni correction for multiple tests, significant associations with NSCL/P were observed for rs742071, rs1873147, and rs227731. However, the frequency of the risk alleles varied between the geographical regions, according to the proportions of European and African genomic ancestry. The group enriched by European ancestry showed significant association with rs227731 (p = 0.001), whereas the group with high African ancestry was significantly associated with rs1873147 polymorphism (p = 0.005). The significant association with rs742071 was only detected in the combined sample (p = 0.005). Conclusion : The findings of the present study revealed the associations of 1p36 (rs742071), 15q22 (rs1873147), and 17p22 (rs227731) with NSCL/P in the Brazilian population, and further confirmed that the genetic heterogeneity of NSCL/P may be related to the different ethnic background of the affected individuals. Birth Defects Research (Part A) 100:36–42, 2014. © 2013 Wiley Periodicals, Inc.     

Lenomyrmex, an enigmatic new ant genus from the Neotropical Region (Hymenoptera: Formicidae: Myrmicinae)

Abstract. We describe a new myrmicine ant genus, Lenomyrmex , with four new species: L. mandibularis (type species) and L. foveolatus from Colombia, L. wardi from Ecuador and Colombia, and L. costatus from Panama. The new taxon is clearly distinguished from other myrmicine ants by the following combination of characters: (1) mandibles elongate-triangular, with crenulate masticatory margin three times longer than basal margin, and bearing a series of ten to twenty minute peg-like denticles that arise along and immediately behind the masticatory margin; (2) frontal lobes poorly expanded laterally, partly covering the antennal fossae; (3) large and deep antennal fossae; (4) antennal scrobes absent; (5) eyes protuberant; (6) petiole pedunculate, with poorly defined node and with an anteroventral subpetiolar process pointed anteriorly. The affinities of this new taxon within Myrmicinae remain unclear and the observed characters do not permit it to be included satisfactorily in any of the known tribes or genus groups of the subfamily.     

Hydroxylation of 2-octaprenylphenol in Escherichia coli K 12

A membrane-bound pathway for the biosynthesis of ubiquinone 8 (UQ8) in $\text{Escherichia coli}$ has been identified from the analysis of the precursors accumulated by mutants blocked in the pathway. Ubiquinone 8 (UQ8) deficient mutant which accumulate 2 octaprenylphenol (2-OPP) allowed to show that two components are involved in the hydroxylating system of this compound: one membranous, is cytochrome $\text{o}$ and the second cytoplasmic, is an NADPH cytochrome $\text{c}$ reductase.     

Modulation of Escherichia coliN-acetylmuramoyl-l-alanine amidase activity by phosphatidylglycerol

The activity of pure Escherichia coli murein (peptidoglycan) amidase ($\text{N-}\text{acetylmuramoyl-}\text{l}\text{-alanine}$ amidase, EC 3.5.1.28) was measured after preincubation with E. coli phosphatidylglycerol microdispersions in final concentration ranging over micro- and millimolarities. The enzyme activity was increased up to 160% of the control for phosphatidylglycerol concentrations increasing from 2 to 50 μM. After a plateau extending from 0.05 to 0.3 mM, higher phosphatidylglycerol concentrations inactivated the enzyme down to 15% of initial activity for concentrations of 2 mM. Positive kinetic cooperativity was observed for the activation as well as for the inactivation processes. Cardiolipin (or diphosphatidylglycerol) from the same origin and under same conditions had no significant effect. Molecular sieving experiments have shown that, when inactivated, the enzyme remained firmly bound to the phosphatidylglycerol vesicles, whereas the activated phosphatidylglycerol-enzyme complex was totally dissociable by dilution. Activated phosphatidylglycerol complexes were recovered by gel exclusion chromatography at equilibrium in 40 μM phosphatidylglycerol. Possible physiological meaning of the results is briefly discussed in the context of our work and that done previously by others.