RESUMO
SUMMARY: Combined factor V (FV) and factor VIII (FVIII) deficiency (F5F8D) is a rare autosomal recessive disorder caused by mutations in LMAN1 or MCFD2 genes which encode proteins that form a complex involved in the transport of FV and FVIII from the endoplasmic reticulum to Golgi apparatus. We report two novel mutations in MCFD2 gene and one recurrent mutation in LMAN1 gene that caused combined FV and FVIII deficiency in two unrelated Tunisian Muslim families. For the first family two patients were homozygous for a new missense mutation Asp81His in exon 3 of MCFD2 and heterozygous for a second new missense mutation Val100Asp in the same exon. Replacement respectively of the hydrophilic Asp residue with hydrophobic positively charged His and of the hydrophobic neutral Val residue with the Asp residue most likely disrupts the MCFD2-LMAN1 interaction, thus leading to the disease phenotype. For the second family a reported Arg202X mutation in exon 5 in the LMAN1 gene was identified in the homozygous state.
Assuntos
Deficiência do Fator V/genética , Hemofilia A/genética , Lectinas de Ligação a Manose/genética , Proteínas de Membrana/genética , Mutação de Sentido Incorreto , Proteínas de Transporte Vesicular/genética , Análise Mutacional de DNA , Éxons/genética , Família , Feminino , Humanos , Masculino , Análise de Sequência de DNA , TunísiaAssuntos
Deficiência do Fator XIII/genética , Efeito Fundador , Hemorragia Pós-Parto/prevenção & controle , Adulto , Feminino , Genótipo , Humanos , Masculino , Fenótipo , Gravidez , TunísiaRESUMO
The role of ethylene in shoot regeneration was investigated using transgenic Cucumis melo plants expressing an antisense 1-aminocyclopropane-1-carboxylate (ACC) oxidase gene. ACC oxidase catalyses the last step of ethylene biosynthesis. Leaf and cotyledon explants from the transgenic plants exhibited low ACC oxidase activity and ethylene production, whereas the regeneration capacity of the tissues was greatly enhanced (3.5- and 2.8-fold, respectively) compared to untransformed control tissues. Addition of ethylene released by 50 or 100 µM 2-chloroethylphosphonic acid dramatically reduced the shoot regeneration rate of the transgenic tissues. The results clearly demonstrate that ethylene plays an important role in C. melo morphogenesis in vitro.
