Ethyl Methanesulfonate as Inductor of Somaclonal Variants in Different Crops

Ethyl methanesulfonate is a chemical mutagen,which is currently being used in plant breeding,to increase genetic variability in genes of agronomic interest,of species useful in agriculture.It primarily causes single base point mutations by inducing guanine alkylation,resulting in GC to AT transitions.Its effect is different between clones of a genotype and between genotypes of the same species.This review presents the results obtained in recent research,where its effect on plant tissues,callus,and cells in suspension has been evaluated.Changes in the phenotypic expression of somaclonal variants were reported,involving morphology,production of secondary metabolites,changes in metabolic routes of resistance,tolerance to stress,increased seed yield,among others.In addition,this review compiles the doses and guidelines to consider before using this mutagen,which can serve as a guide for future trials in deciding the response variables,the type of plant explants and the selection of the study model.Mutant lines have allowed plant breeders to have a collection of plants with different characteristics,in places where the cultivar does not have its center of origin.It is important to note that it is still necessary to continue evaluating the heritability of mutations and their behaviour in the environment where they will be established,in order to obtain new varieties of plants that can be cultivated with uniformity in their genetic response.

Characterization of a collection of Chinese fir elite genotypes using sequence.related amplified polymorphism markers

Chinese fir [Cunninghamia lanceolata （Lamb.） Hook] is a major timber tree species in China. In the pre- sent study, sequence-related amplified polymorphism （SRAP） markers were used to evaluate the polymorphisms, diversity, and relationships in a collection of Chinese fir elite genotypes （n = 103） from the Lechang provenance, an endangered provenance. Thirty-five SRAP primer combinations produced 620 bands among the tested 103 Lechang provenance genotypes and 17 nonSLechang provenance genotypes; 577 （93.1%） of these were polymorphic, yielding an average of 16.5 polymorphic bands per primer combination. Of the SRAP primer combinations （n = 35）, I4 ones identified 〉70.0 % of the 120 genotypes. The Mel2-Eml9 combination had the strongest discriminatory ability with 93.3 % of the genotypes iden- tified. An UPGMA dendrogram further showed that most of the Lechang provenance genotypes （87.4 %） grouped together （Cluster A）. The Lechang genotypes had a con- siderable amount of genetic variation with genetic simi- larity from 0.40 to 0.81. The current work may facilitate the management of the endangered Lechang Chinese fir provenance.

Genetic regulators of cytokine responses upon BCG vaccination in children from West Africa

Genetic variation is a key factor influencing cytokine production capacity,but which genetic loci regulate cytokine production before and after vaccination,particularly in African population is unknown.Here,we aimed to identify single-nucleotide polymorphisms(SNPs)controlling cytokine responses after microbial stimulation in infants of West-African ancestry,comprising of low-birth-weight neonates randomized to bacillus Calmette-Gue rin(BCG)vaccine-at-birth or to the usual delayed BCG.Genome-wide cytokine cytokine quantitative trait loci(cQTL)mapping revealed 12 independent loci,of which the LINC01082-LINC00917 locus influenced more than half of the cytokine-stimulation pairs assessed.Furthermore,nine distinct cQTLs were found among infants randomized to BCG.Functional validation confirmed that several complement genes affect cytokine response after BCG vaccination.We observed a limited overlap of common cQTLs between the West-African infants and cohorts of Western European individuals.These data reveal strong population-specific genetic effects on cytokine production and may indicate new opportunities for therapeutic intervention and vaccine development in African populations.