Association between promoter -1607 polymorphism of MMP1 and Lumbar Disc Disease in Southern Chinese

<p>Abstract</p> <p>Background</p> <p>Matrix metalloproteinases (MMPs) are involved in the degradation of the extracellular matrix of the intervertebral disc. A SNP for guanine insertion/deletion (G/D), the -1607 promoter polymorphism, of the <it>MMP1 </it>gene was found significantly affecting promoter activity and corresponding transcription level. Hence it is a good candidate for genetic studies in DDD.</p> <p>Methods</p> <p>Southern Chinese volunteers between 18 and 55 years were recruited from the population. DDD in the lumbar spine was defined by MRI using Schneiderman's classification. Genomic DNA was isolated from the leukocytes and genotyping was performed using the Sequenom^®platform. Association and Hardy-Weinberg equilibrium checking were assessed by Chi-square test and Mann-Whitney U test.</p> <p>Results</p> <p>Our results showed substantial evidence of association between -1607 promoter polymorphism of <it>MMP1 </it>and DDD in the Southern Chinese subjects. D allelic was significantly associated with DDD (p value = 0.027, odds ratio = 1.41 with 95% CI = 1.04–1.90) while Genotypic association on the presence of D allele was also significantly associated with DDD (p value = 0.046, odds ratio = 1.50 with 95% CI = 1.01–2.24). Further age stratification showed significant genotypic as well as allelic association in the group of over 40 years (genotypic: p value = 0.035, odds ratio = 1.617 with 95% CI = 1.033–2.529; allelic: p value = 0.033, odds ratio = 1.445 with 95% CI = 1.029–2.029). Disc bulge, annular tears and the Schmorl's nodes were not associated with the D allele.</p> <p>Conclusion</p> <p>We demonstrated that individuals with the presence of D allele for the -1607 promoter polymorphism of <it>MMP1 </it>are about 1.5 times more susceptible to develop DDD when compared with those having G allele only. Further association was identified in individuals over 40 years of age. Disc bulge, annular tear as well as Schmorl's nodes were not associated with this polymorphism.</p

Transmission efficiency of Grapevine leafroll-associated virus 3 (GLRaV-3) by the mealybugs Planococcus ficus and Pseudococcus longispinus (Hemiptera: Pseudococcidae)

Grapevine leafroll-associated virus 3 (GLRaV-3) is transmitted from grapevine to grapevine through grafting infected material, as well as mealybug and soft scale insect vectors. We determined the transmission efficiency of GLRaV-3 by two mealybug vectors, Planococcus ficus and Pseudococcus longispinus, by examining the relationship between the number of nymphs per plant, using groups of 1, 5, 10, 20 and 40 first- to second-instar nymphs, and the infection rate of healthy grapevine plants. Plants and single nymphs were tested for GLRaV-3 with nested reverse transcription polymerase chain reaction (nested RT-PCR). The results of this study showed the infection rate of P. ficus and P. longispinus nymphs with GLRaV-3 after acquisition access and inoculation access periods of 5 days each to be similar between intra- and interspecific groups, ranging from 5% to 19%, except for the ‘40-nymph group’ of P. longispinus, which had a higher number of infected nymphs (63%). The number of nymphs used per group did not influence the infection rate of plants, which ranged from 11% to 80% and 20% to 70% for P. ficus and P. longispinus, respectively. Transmission of GLRaV-3 with single P. ficus and P. longispinus nymphs resulted in 70% GLRaV-3 positive plants in both cases. This study has shown both species to be equally efficient as vectors of GLRaV-3. We have further shown for the first time that a single individual of either P. ficus or P. longispinus is capable of transmitting GLRaV-3 and infecting a healthy grapevine plant. The results of the study highlight the importance of implementing vector control measures