AFM study of strawberry pectin nanostructure and its relevance on fruit texture

Atomic force microscopy (AFM) has been used to characterize the nanostructure of cell wall pectins during strawberry fruit growth and ripening, as well as in transgenic fruits with pectinase genes downregulated. This technique allows the imaging of individual polymers at high magnification with minimal sample preparation. AFM studies during fruit development show that pectin size, ramification and aggregation is reduced in ripe fruits. Additionally, transgenic lines with different pectinase genes downregulated (polygalacturonase, pectate lyase and B-galactosidase) also show a more complex pectin nanostructure, including longer chains, higher branching degree and larger presence of aggregates. In all those cases the higher pectin complexity at nanoscale correlates with a reduced softening in strawberry fruits at macroscale level. Globally, our results support the key role of pectins in fruit structure and highlights the use of AFM as a powerful tool to gain insights about the bases of textural fruit quality not only in strawberry, but also in other commercial crops.AGL2017-86531-C2-1-R, Ministerio de Economía, Industria y Competitividad of Spain and FEDER EU funds. Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Genomic analysis of a novel pathogenic variant in the gene LMNA associated with cardiac laminopathies found in Ecuadorian siblings: A case report

IntroductionCardiac laminopathies are caused by mutations in the LMNA gene and include a wide range of clinical manifestations involving electrical and mechanical changes in cardiomyocytes. In Ecuador, cardiovascular diseases were the primary cause of death in 2019, accounting for 26.5% of total deaths. Cardiac laminopathy-associated mutations involve genes coding for structural proteins with functions related to heart development and physiology.Family descriptionTwo Ecuadorian siblings, self-identified as mestizos, were diagnosed with cardiac laminopathies and suffered embolic strokes. Moreover, by performing Next-Generation Sequencing, a pathogenic variant (NM_170707.3:c.1526del) was found in the gene LMNA.Discussion and conclusionCurrently, genetic tests are an essential step for disease genetic counseling, including cardiovascular disease diagnosis. Identification of a genetic cause that may explain the risk of cardiac laminopathies in a family can help the post-test counseling and recommendations from the cardiologist. In the present report, a pathogenic variant ((NM_170707.3:c.1526del) has been identified in two Ecuadorian siblings with cardiac laminopathies. The LMNA gene codes for A-type laminar proteins that are associated with gene transcription regulation. Mutations in the LMNA gene cause laminopathies, disorders with diverse phenotypic manifestations. Moreover, understanding the molecular biology of the disease-causing mutations is essential in deciding the correct type of treatment

Yield of fractions after sequential extraction of the cell wall material (CW) isolated from fruits of control (C) and transgenic Apel lines

<p><b>Copyright information:</b></p><p>Taken from "Antisense inhibition of a pectate lyase gene supports a role for pectin depolymerization in strawberry fruit softening"</p><p></p><p>Journal of Experimental Botany 2008;59(10):2769-2779.</p><p>Published online 2 Jun 2008</p><p>PMCID:PMC2486476.</p><p></p

Molecular mass profiles of polyuronides extractable by sodium carbonate from cell walls of control and transgenic green fruits

Profiles were obtained by size exclusion chromatography on Sepharose CL-2B. Fractions were assayed for uronic acid content. Uronic content of the fractions was normalized to the maximum absorbance value obtained in each profile. The elution volume for the blue dextran standard (2000 kDa) is shown on the figure.<p><b>Copyright information:</b></p><p>Taken from "Antisense inhibition of a pectate lyase gene supports a role for pectin depolymerization in strawberry fruit softening"</p><p></p><p>Journal of Experimental Botany 2008;59(10):2769-2779.</p><p>Published online 2 Jun 2008</p><p>PMCID:PMC2486476.</p><p></p

Fruit weight and firmness of control and transgenic lines during fruit development

(A) Fruit weight and firmness of control fruits at different stages: small green, G1; large green, G2; white, W; turning (meaning at least 25% surface red), T; totally red ripe fruit, R; and overripe fruit (ripe fruits stored 3 d at 25 °C in a growth chamber, OR. (B) Effect of antisense down-regulation of pectate lyase on fruit firmness during these developmental stages. In this case, the values of firmness are expressed as a percentage of control untransformed fruits. The arrow indicates the stage after which differences between control fruits and the two transgenic lines become significant.<p><b>Copyright information:</b></p><p>Taken from "Antisense inhibition of a pectate lyase gene supports a role for pectin depolymerization in strawberry fruit softening"</p><p></p><p>Journal of Experimental Botany 2008;59(10):2769-2779.</p><p>Published online 2 Jun 2008</p><p>PMCID:PMC2486476.</p><p></p

(A) Uronic acid (UA) contents in PAW and other sequentially extracted fractions of the cell wall material (CW) isolated from control (C) and three independent transgenic Apel lines

(B) Ratio of UA relative to total sugar contents in these fractions.<p><b>Copyright information:</b></p><p>Taken from "Antisense inhibition of a pectate lyase gene supports a role for pectin depolymerization in strawberry fruit softening"</p><p></p><p>Journal of Experimental Botany 2008;59(10):2769-2779.</p><p>Published online 2 Jun 2008</p><p>PMCID:PMC2486476.</p><p></p

Molecular mass profiles of polyuronides extractable by 1 M and 4 M KOH from fruit cell walls of control and three independent Apel transgenic lines

Profiles were obtained by size exclusion chromatography on Sepharose CL-2B. Fractions were assayed for uronic acid content and presented as optical density values at 515 nm. The elution volume for the blue dextran standard (2000 kDa) is shown on the figure.<p><b>Copyright information:</b></p><p>Taken from "Antisense inhibition of a pectate lyase gene supports a role for pectin depolymerization in strawberry fruit softening"</p><p></p><p>Journal of Experimental Botany 2008;59(10):2769-2779.</p><p>Published online 2 Jun 2008</p><p>PMCID:PMC2486476.</p><p></p

Image_1_Case report: Genomic screening for inherited cardiac conditions in Ecuadorian mestizo relatives: Improving familial diagnose.PNG

IntroductionGenomic screening is an informative and helpful tool for the clinical management of inherited conditions such as cardiac diseases. Cardiac-inherited diseases are a group of disorders affecting the heart, its system, function, and vasculature. Among the cardiac inherited abnormalities, one of the most common is Wolff-Parkinson-White syndrome. Similarly, hypertrophic cardiomyopathy is another common autosomal dominant inherited cardiac disease. Hypertrophic cardiomyopathy is associated with an increased incidence of Wolff-Parkinson-White syndrome; reports have suggested that it could be caused by a mutation in the protein-coding gene PRKAG2, which encodes a subunit of the AMP-activated protein kinase.Case presentationA 37-year-old Ecuadorian male (Subject A) with familiar history of bradycardia, cardiac pacemaker implantation, and undiagnosed cardiac conditions began with episodes of tachycardia, dizziness, shortness of breath, and a feeling of fainting. He was diagnosed with hypertrophic myocardiopathy and Wolff Parkinson White preexcitation syndrome. Furthermore, his cousin's son, an 18-year-old Ecuadorian male (Subject B), started suffering from migraine and tachycardia at any time of the day. He was diagnosed with hypertrophic myocardiopathy; his electrocardiogram showed a systolic overload. Next-generation sequencing and ancestry analyses were performed. A c.905G>A p.(Arg302Gln) mutation in the gene PRKAG2 and a mainly European composition were identified in both subjects.ConclusionGenetic testing is a valuable tool as it can provide important information regarding a disease, including its cause and consequences, not only for single individuals but to identify at-risk relatives. Furthermore, NGS results could guide the physician into targeted therapy. In the present case report, a missense pathogenic Arg302Gln mutation in the PRKAG2 gene has been identified in two related Ecuadorian Subjects diagnosed with hypertrophic myocardiopathy and Wolff-Parkinson-White. The variant has not been reported in Latin America; hence, this is the first report of the Arg302Gln mutation in the PRKAG2 gene in mestizo Ecuadorian subjects with mainly European ancestry components.</p