Cryopreservation of In Vitro-Grown Shoot Tips of the Medicinal Species Cleome Spinosa (Cleomaceae) Applying Vitrification-Based Techniques

BACKGROUND

Few cryopreservation studies have been reported with the genus Cleome. Due to the use of C. spinosa in traditional medicine and its valuable pharmacological potential, the long-term conservation of the species will allow the safe maintenance of its germplasm.

OBJECTIVE

This study compares two vitrification-based techniques on the cryopreservation of shoot tips of C. spinosa.

MATERIALS AND METHODS

The effect of sucrose preculture and different vitrification solutions was evaluated using vitrification and V Cryo-plate techniques. The supplementation of recovery medium with BAP was also assessed.

RESULTS

The V Cryo-plate proved to be the most efficient technique. Treatment of shoot tips with PVS2 at 0°C resulted in a higher regeneration response after cryopreservation when compared to treatment with PVS2 and PVS3 at 25°C. The highest survival (83.3%) and recovery (76.6%) were achieved for shoot tips exposed to PVS2 for 90 min at 0°C and recovered on MS medium supplemented with 0.5 mg L^-1 BAP for 2 weeks.

CONCLUSION

Plants regenerated from cryopreserved shoot tips maintained their in vitro multiplication capacity and showed a normal phenotypic aspect, demonstrating the efficiency of the cryopreservation protocol.

Association of variant alleles of MBL2 gene with vasoocclusive crisis in children with sickle cell anemia

Vasoocclusive crisis (VOC) is the major cause of morbidity and mortality in sickle cell anemia (SCA), which is caused by the occlusion of blood vessels, followed by ischemia or infarct, resulting in progressive damage to organs. However, this clinical manifestation is variable, indicating that this process could be influenced by modifier genes. The gene MBL2 which codes for mannose-binding lectin (MBL) has been associated with modifications in the progression of infectious and inflammatory vascular diseases. The aim of this study was to determine the frequency of the polymorphisms of exon 1 (alleles A/O) and promoter region -221 (alleles Y/X) of MBL2 in children with SCA and to verify their association with VOC. The determination of the polymorphism of exon 1 and the promoter region of MBL2 was performed by SYBR GREEN((R)) and Taqman((R)) system, respectively. In the patients with SCA, the frequency of the genotype related to high production of MBL was 0.46 (YA/YA) and for intermediate/low production was 0.54 (YA/XA, XA/XA, YA/YO, XA/YO, YO/YO). The frequency of the genotypes and haplotypes of MBL2 in patients with SCA did not differ from control individuals. The populations were in Hardy-Weinberg equilibrium. The patients were divided into two groups. The groups were separated by the frequency of VOC, which was defined by the total of VOC episodes divided by the age of the children at the end of this study. Since, we choose a cut point in FVOC <1 (n=48) (which we considered of mild presentation of disease) and FVOC >or=1 (n=39) (higher severity). In children with SCA, the frequency of the genotypes of MBL2 of intermediate/low expression for MBL was associated with FVOC >or=1 (p=0.0188 OR=3.15 CI=1.19-8.50). The results suggest that MBL2 polymorphism at promoter and first exon of MBL2 associated with low serum levels and structural alterations of MBL could modify the phenotype of the child with SCA related to VOC.