Morphological and Isozyme Variation in Natural Populations of the Genus Medicago L. Prospected in Northern Algeria

As part of the evaluation and enhancement of genetic resources, morphological and isozyme variability within and among 169 accessions, representing 14 species of the genus Medicago L. collected in northern Algeria, was assessed using twelve quantitative traits and two enzymatic systems. Phenotype frequencies were scored in six enzyme zones to determine isozyme variability within and among populations. The data analysis resolved a high level of genetic diversity. Ten morphometric characteristics contributed to the discrimination of the species. The relationship between the collection site environment and phenotypic characteristics was also studied. Esterase (EST) enzyme system was more polymorphic than glutamate oxaloacetate transaminase (GOT) system. Were scored 2 zones with 10 bands and 21 phenotypes for GOT (glutamate oxaloacetate transaminase) and 4 zones with 22 bands and 71 phenotypes for EST (esterase) Polymorphism index and Jaccard’s genetic distances revealed the existence of a high genetic diversity within and among the studied populations. The annual species M. polymorpha presented an intraspecific polymorphism index of 0.57, which was higher than all other species indices. Clustering of the species based on isozyme markers was in agreement with taxonomic criteria and showed no significant correlation with morphological characteristics. Conservation programs should take into account the level of genetic diversity within and between populations revealed by isozyme markers

Genetic Variation and Geographical Diversity for Seed Storage Proteins of Seventeen Durum Wheat Populations Collected in Algeria

Variation in the HMW and LMW glutenin subunits of a collection of 856 accessions of botanic durum wheat collected in Algeria and divided a priori according to their agronomical and morphological traits in 17 populations were analyzed using SDS-PAGE. Among the 16 alleles identified at the Glu-1 loci, two were new. The first named Glu-B1i1 encoding for two bands located between 17 and 18 which was assigned the nomenclature 171 and 181. The other named Glu-B1e1 codes two bands similar to 20x and 20y but with faster mobility, which were named 20x1-20y1. At Glu-3 and Glu-2 loci, 19 alleles were identified, where the allele named Glu-B3ab (encoding for subunits 2-8-9-13-16) was considered as new. Global genetic diversity index (H) was relatively high (0.34). A final core collection of 21 accessions was selected. All the different geographical areas and the allelic diversity at the Glu-1, Glu-2 and Glu-3 polymorphic loci were represented in this core which represents a minimum of wheat Algerian genetic resources that could be used for dedicated breeding programs

Physical and chemical properties of the acid protease from Onopordum acanthium: Comparison between electrophoresis and HPLC of degradation casein profiles

A protease was extracted by grinding, precipitation and gel filtration from Onopordum acanthium flowers. The physicochemical study of the enzyme showed an optimum pH of 4, a temperature of 40°C and kinetic parameters of 12.25 mM-1 for KM and 1329.6 UmL-1 for Vmax. The inhibition by pepstatin indicated that it is an aspartyl-protease (APs). Zymogram showed that the protease has a monomeric structure and a molecular mass (MM) of 45 kDa. The hydrolysis of α, β and Κ- and whole casein by the protease was evaluated using electrophoresis and HPLC; the profiles showed many similarities between the vegetal protease action and that of industrial chymosin. So, the properties of the protease studied and the quality of its action showed its effectiveness and relevance of its use as a milk clotting enzyme which leads to a better use of extract of flowers O. acanthium as a locally substitute for rennet.Keywords: Aspartic protease, Onopordum acanthium, purification, characterization, casein hydrolysi

Genetic differentiation of the Capparis spinosa group in the Mediterranean area

The Capparis spinosa group is represented in the Mediterranean by a complex of taxa widespread in North Africa, the Middle East, and southern Europe. The taxonomy of this group used to be based on morphological characters with little work on the genetics of the group, and there is still much to be learned about its evolutionary history and diversification. We sampled 431 individuals of two subspecies and five varieties of C. spinosa and analysed them using highly informative EST-SSR markers to evaluate the population genetic diversity, structure and differentiation of the species in the Mediterranean. In addition, comparisons with the genetic profiles of C. spinosa subsp. cartilaginea, the putative ancestral taxon were made to investigate the phylogeographic history and possible gene flow across taxa. Integrated Bayesian approaches showed: i) a high divergence among C. spinosa subsp. spinosa var. canescens, C. spinosa subsp. spinosa var. aegyptia and the three varieties belonging to C. spinosa subsp. rupestris (var. rupestris, var. ovata and var. myrtifolia), with a clear separation between var. aegyptia and var. canescens which allows to consider var. aegyptia as a subspecies of C. spinosa; ii) a significant correlation between genetic divergence and geographic distance between the five varieties studied; iii) that the different varieties in the Mediterranean may have been derived from C. spinosa subsp. cartilaginea. Further genomic investigations are required to confirm our results. However, the findings presented allows us to suggest the genus Capparis can be considered a model for the study of the gene flow and differentiation in species occurring in a wide range of habitats

Diversity of Seven Glutenin and Secalin Loci within Triticale Cultivars Grown in France

Although the endosperm storage protein of hexaploid triticale have already been analysed, the allelic diversity of glutenins and secalins remains to be described. Analysis by SDS-PAGE of the majority of hexaploid triticales (69 cultivars) grown in France allowed to identify 36 alleles at seven loci: Glu-A1, Glu-B1, Glu-R1, Gli-R2, Glu-B2, Glu-A3 and Glu-B3. Glu-B1 and Glu-B3 loci were the most polymorphic with 9 alleles each. On the basis of allelic frequencies at the seven loci, genetic distances between hexaploid triticales grouped according to their origins revealed two groups: winter triticales mostly originating from European germplasm and spring triticales essentially of CIMMYT origin. Comparison of allele frequencies between hexaploid triticale cultivars and a world collection of bread (Triticum aestivum) and durum (Triticum durum) wheat was investigated at Glu-A1 and Glu-B1: only a significant association was found for Glu-A1 alleles (?2 = 2.26, p =0.36) between triticale and bread wheat

Ecogeographic variability and genetic diversity associated with seed albumins, globulins and prolamins patterns in Vicia taxa from Algeria

Abstract Genetic variability was studied in 78 populations of locally collected Vicia L. taxa for seed albumins, globulins and prolamins patterns by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) along with an ecogeographic characterization of sites investigated. 131, 119 and 98 bands were respectively used for albumin, globulin and prolamin cluster analysis. Dendrograms based on the Jaccard index and the UPGMA method were generated and the degree of genetic diversity between and within taxa was evaluated. Five clusters were generated from albumins, six from globulins and four from prolamins patterns. The results reflect the great diversity of storage proteins and a high correlation was obtained between the three studied fractions. Several accessions present specific bands which could be used as a discriminatory marker both on intra and interspecific levels. No clear relationships were seen between the groups according to their geographical origin. Data obtained from ecogeographic investigation can be used for future collecting missions

Genetic Diversity of High and Low Molecular Weight Glutenin Subunits in Algerian <i>Aegilops geniculata</i>

Aegilops geniculata Roth is an annual grass relative to cultivated wheat and is widely distributed in North Algeria. Endosperm storage proteins of wheat and its relatives, namely glutenins and gliadins, play an important role in dough properties and bread making quality. In the present study, the different alleles encoded at the four glutenin loci (Glu-M1, Glu-U1, Glu-M3 and Glu-U3) were identified from thirty five accessions of the tetraploid wild wheat A. geniculata collected in Algeria using Sodium dodecyl Sulfate - Polyacrylamide Gel Electrophoresis (SDS-PAGE). At Glu-M1 and Glu-U1 loci, encoding high molecular weight glutenin subunits (HMW-GS) or A-subunits, 15 and 12 alleles were observed respectively, including one new subunit. B-Low molecular weight glutenin subunits zone (B-LMW-GS) displayed a far greater variation, as 28 and 25 alleles were identified at loci Glu-M3 and Glu-U3 respectively. Thirty two subunits patterns were revealed at the C subunits- zone and a total of thirty four patterns resulted from the genetic combination of the two zones (B- and C-zone). The wide range of glutenin subunits variation (high molecular weight glutenin subunits and low molecular weight glutenin subunits) in this species has the potential to enhance the genetic variability for improving the quality of wheat

ERK1 and ERK2 activation modulates diet-induced obesity in mice.

IF 3.112International audienceObesity is a worldwide problem, and dietary lipids play an important role in its pathogenesis. Recently, Erk1 knock-out (ERK1(-/-)) mice have been shown to exhibit low preference for dietary fatty acids. Hence, we maintained Erk1(-/-) mice on a high-fat diet (HFD) to assess the implication of this mitogen-activated protein (MAP) kinase in obesity. The Erk1(-/-) mice, fed the HFD, were more obese than wild-type (WT) animals, fed the same diet. Erk1(-/-) obese mice gained more fat and liver mass than WT obese animals. No difference was observed in daily food and energy intake in HFD-fed both group of animals. However, feed efficiency was higher in Erk1(-/-) than WT animals. Blood cholesterol, triglyceride and insulin concentrations were higher in Erk1(-/-) obese mice compared to WT obese animals. Accordingly, homeostatic model assessment of insulin resistance (HOMA-IR) value was higher in Erk1(-/-) obese mice compared to WT obese animals. Interestingly, only Erk1(-/-) obese mice, but not WT-obese animals, exhibited high degree of phosphorylation of liver MEK, the upstream regulator of ERK1/2. This phenomenon was associated with high liver ERK2 phosphorylation in Erk1(-/-) obese mice which also had high liver acetyl-CoA carboxylase 1 (ACC1) and fatty acid synthase (FAS) mRNA expression, suggesting high lipogenesis in these animals. The Erk1(-/-) obese mice also had low PPAR-α and CPT1β mRNA, indicating low fatty acid oxidation. Our observations suggest that ERK1 and ERK2 might play key roles in the regulation of obesity

Characterization of fatty acid and carotenoid production in an Acutodesmus microalga isolated from the Algerian Sahara

An Acutodesmus microalga of the Scenedesmaceae family isolated from the Algerian Sahara was characterized for its ability to produce lipids, fatty acids (FA) and carotenoids under nitrate starvation, osmotic stress and a varying level of oxidative stress. The FA produced by this strain isolated from an environment typified by extreme heat showed a lower degree of unsaturation than those of other Scenedesmus which have been isolated from cold or temperate water environments, with no unsaturated C16 FA and more than 92% of the FA profile being comprised of FA with less than three unsaturated bonds. According to the degree of unsaturation and the cetane number, the FA profile from this strain is highly favorable for biofuel production. Lipogenesis and carotenogenesis were easily reversible upon removal of the stress. These results constitute an advance in developing strains suitable for industrial-scale production of biofuels

Morphological and Eco-Geographic Variation in Algerian Wild Olives

Algerian wild olives can represent an important resource for cultivated olive breeding, since they are characterized by great morphological variability. Moreover, they grow in different bioclimatic environments, including dry and hot climates, making the collections of wild olives a good source of abiotic stress resistance traits. Our study aimed to investigate the morphological diversity of 175 wild olive trees collected in North Algeria along with a wide range of different bioclimatic habitats for studying traits of olive accessions in relation to their different ecogeographical parameters. Wild olive trees were found in five different bioclimates areas spanning from humid to Saharan areas. They showed high variation in all traits, in particular fruit and stone weight, which expressed the highest coefficient of variation, and a high positive correlation between fruit weight/width. Cluster analysis separated the samples into two groups mostly based on fruit and stone size, while no relationship was observed with the area of sampling. Only the Saharan samples showed significantly different foliar and fruit characteristics compared to samples from other bioclimatic areas