Variogram investigation of covariance shape within longitudinal data with possible use of a krigeage technique as an interpolation tool: Sheep growth data as an example

peer-reviewedMost quantitative traits considered in livestock evolve over time and several continuous functions have been proposed to model this change. For individual records (longitudinal data), it is evident that measures taken at close dates are generally more related than these further apart in time. Since milk production involves several parities, the covariance structure within this trait has been analysed by time series methodology. However, the covariance structure within traits that are not repeated during life, such as those linked to growth, has not yet been formally modelled by considering time lags as is done in time series analysis. We propose an adaptation of the variogram concept to shape this structure; which gives the possibility of kriging missing data at any particular time. A new parameter, the halftime variogram, has been proposed to characterise the growing potential of a given population. The weight records of a Barbarine male lamb population were used to illustrate the methodology. The variogram covering the whole growth process in this population could be modelled by a logistic equation. To estimate the missing data from birth to 105 days of age, a simple linear interpolation was sufficient since kriging on a linear model basis gives a relatively more accurate estimation than kriging on a logistic model basis. Nevertheless, when both known records around the missing data are distant, a krigeage on the basis of the logistic model provides a more accurate estimation

Analyse de la variabilité germinative de la vesce commune sous l’impact d’un stress Ferrique-Cadmique-Salin

Ce travail a pour but de voir l’impact de l’application d’une combinaison de stress abiotique sur la germination des graines de vesce commune ainsi que de visualiser les modifications physiologiques et histologiques au niveau des tissus racinaires sous l’influence de ces contraintes. De ce fait, une conduite de germination a été réalisée avec des graines de vesce commune dans différentes situations de combinaisons entre trois types de stress métallique-cadmique-salin et un suivi a été fait en se basant sur des caractères végétatifs bien déterminés. Les résultats montrent bien une nette différence entre les réponses des graines à l’application de stress séparément et entre les combinaisons de stress ainsi qu’une variabilité intra-espèce énorme vis-à-vis de différentes types de contraintes.Mots-clés : vesce commune, stress métallique-cadmique-salin, caractères végétatifs, modifications physiologiques et histologiques

The use of reproductive vigor descriptors in studying genetic variability in nine Tunisian faba bean (Vicia faba L.) populations

A collection of nine Tunisian faba bean (Vicia faba) populations belonging to three botanical classes (Var. minor, var. equina and var. major) was evaluated using twenty seven agro-morphological traits. Analysis of variance, correlation coefficients and principal components analysis (PCA) were performed based on MVSP 3.13 program. Significant differences between populations were noted for most agromorphological traits in four main groups. The first group, positively correlated to the two axes, isrepresented by ‘Bachaar’ belonging to V. faba. var. minor, the second group, including V. faba. var. minor population (‘Massri’ and ‘Badï’), is positively correlated to the PC1 and negatively correlated to the PC2 while the third group, is composed of two V. faba var. major (‘Malti’ and ‘Batata’) and were positively and negatively correlated to the PC2 and PC1, respectively. Finally, the fourth group negatively correlated to the two axes, gathers the remaining population (‘Chahbi’, ‘Chemlali’, ‘Aguadulce’ and ‘Super Aguadulce’). The dendrogram based on Nei's genetic distance of the 9 populations using UPGMA method, show some genetic drift between populations.Key words: Faba bean, agromorphological traits, principal components analysis, UPGMA method

Variation of gene effects of six agronomic traits with water regimes in durum wheat

This study was carried out to determine the relative importance of additive, dominance and epistatic effects of six agronomic traits evaluated in two crosses under irrigated and rainfed conditions. Separate generations mean analyses revealed that gene effects were dependent upon water regime. Under irrigated regime, only additive and dominance effects were implicated in inheritance of all traits, except plant height in the two crosses and grains per spike in the cross Razzek × Chili. However, under rainfed condition, additive, dominance and epistasis effects were induced in the genetic control of these traits. Thus, epistasis effect was water regime depended and seems to play a significant role in the genetic adaptability of populations. The variation of inheritance and the presence of genetic interactions complicate the procedure of breeding. Under irrigated regime, selection would be simpler because only additive and dominance effects were implicated in the genetic control of all traits. Consequently, the genetic mechanism would not be stable when plants are grown in environment with lower water availability. However, for the stability of suitable cultivars, selection under rainfed condition (lower water availability) was suggested. The moderate to high narrow-sense heritability estimates for the majority of traits indicate that selection would be efficient.Keywords: Durum wheat, epistatic effect, genetic adaptability, heritability, water regimeAfrican Journal of Biotechnology Vol. 12(15), pp. 1769-177

AKT/mTOR Signaling Modulates Resistance to Endocrine Therapy and CDK4/6 Inhibition in Metastatic Breast Cancers

Endocrine therapy (ET) in combination with CDK4/6 inhibition is routinely used as first-line treatment for HR+/HER2− metastatic breast cancer (MBC) patients. However, 30–40% of patients quickly develop disease progression. In this open-label multicenter clinical trial, we utilized a hypothesis-driven protein/phosphoprotein-based approach to identify predictive markers of response to ET plus CDK4/6 inhibition in pre-treatment tissue biopsies. Pathway-centered signaling profiles were generated from microdissected tumor epithelia and surrounding stroma/immune cells using the reverse phase protein microarray. Phosphorylation levels of the CDK4/6 downstream substrates Rb (S780) and FoxM1 (T600) were higher in patients with progressive disease (PD) compared to responders (p = 0.02). Systemic PI3K/AKT/mTOR activation in tumor epithelia and stroma/immune cells was detected in patients with PD. This activation was not explained by underpinning genomic alterations alone. As the number of FDA-approved targeted compounds increases, functional protein-based signaling analyses may become a critical component of response prediction and treatment selection for MBC patients

Impact of intercurrent introduction of steroids on clinical outcomes in advanced non-small-cell lung cancer (Nsclc) patients under immune-checkpoint inhibitors (ici)

Background: Baseline steroids before ICI have been associated with poor outcomes, particularly when introduced due to cancer symptoms. Methods: Retrospective analysis of advanced NSCLC patients treated with ICI. We collected the use of intercurrent steroids (≥10 mg of prednisone-equivalent) within the first eight weeks of ICI. We correlated steroid use with patient outcomes according to the indications. Results: 413 patients received ICI, 299 were steroids-naïve at baseline. A total of 49 patients received intercurrent steroids (16%), of whom 38 for cancer-related symptoms and 11 for other indications, such as immune-related events. Overall, median (m) progression-free survival (PFS) was 1.9 months (mo.) [95% CI, 1.8-2.4] and overall survival (OS) 10 mo. [95% CI, 8.1–12.9]. Intercurrent steroids under ICI correlated with a shorter PFS/OS (1.3 and 2.3 mo. respectively, both p < 0.0001). Intercurrent steroids for cancer-related symptoms correlated with poorest mPFS [1.1 mo.; 95% CI, 0.9–1.5] and mOS [1.9 mo.; 95%CI, 1.5–2.4; p < 0.0001)]. No mOS and mPFS differences were found between cancer-unrelated-steroid group and no-steroid group. Steroid use for cancer-related symptoms was an independent prognostic factor for poor PFS [HR 2.64; 95% CI, 1.2–5.6] and OS [HR 4.53; 95% CI, 1.8–11.1], both p < 0.0001. Conclusion: Intercurrent steroids during ICI had no detrimental prognostic impact if the indication was unrelated to cancer symptoms

Relationship between epistasis and aggressiveness in resistance of pepper (Capsicum annuum L.) to Phytophthora nicotianae

This study evaluated the types of gene action governing the inheritance of resistance to Phytophthora nicotianae necrosis in populations derived from two crosses involving two susceptible (Beldi and Nabeul II) and one resistant (CM334) cultivars of pepper (Capsicum annuum L.). Populations, composed of Pr, Ps, F1 , F 2 , BC 1 Pr, and BC 1 Ps generations, were inoculated with six P. nicotianae isolates. Generation means analysis indicated that an additive-dominance model was appropriate for P. nicotianae isolates Pn Ko1 , Pn Ko2 and Pn Kr1 , which showed low aggressiveness in the two crosses. For the more aggressive isolates Pn Bz1 , Pn Bz2 and Pn Kr2 , epistasis was an integral component of resistance in the two crosses. The presence of epistasis in the resistance of pepper to P. nicotianae was dependent on the level of aggressiveness of the isolates. Selection in pepper with less aggressive isolates was efficient, but not with more aggressive isolates; on the other hand, selection with more aggressive isolates was more stable. The minimum number of genes controlling resistance was estimated at up to 2.71. In the majority of cases, the additive variance was significant and greater than the environmental and dominance variance

Epistasis and genotype-by-environment interaction of grain protein content in durum wheat

Parental, F1 , F 2 , BC 1 and BC 2 generations of four crosses involving four cultivars of durum wheat (Triticum durum Desf.) were evaluated at two sites in Tunisia. A three-parameter model was found inadequate for all cases except crosses Chili x Cocorit 71 at site Sidi Thabet and Inrat 69 x Karim at both sites. In most cases a digenic epistatic model was sufficient to explain variation in generation means. Dominance effects (h) and additive x additive epistasis (i) (when significant) were more important than additive (d) effects and other epistatic components. Considering the genotype-by-environment interaction, the non-interactive model (m, d, h, e) was found adequate. Additive variance was higher than environmental variance in three crosses at both sites. The estimated values of narrow-sense heritability were dependent upon the cross and the sites and were 0%-85%. The results indicate that appropriate choice of environment and selection in later generations would increase grain protein content in durum wheat

Molecular characterization of new oat crown rust resistant sources

383-386Crown rust, caused by the fungus Puccinia coronata f. sp. avenae, is a widespread and damaging disease of oat. Spontaneous oat species are an important and abundant source of new rust resistance genes. Two Tunisian resistant spontaneous oat accession JT0 and JT5 (Avena sterilis) was characterized using 21 RAPD primers and compared to the differential lines Pc38, Pc39 and Pc68 (Avena sativa L.), which showed previously a high resistance level to the local population of crown rust. The effectiveness of molecular markers could be evaluated through such parameters as the polymorphic information content (PIC), marker index (MI), heterozygosity (H) and the resolving power (Rp). Banding patterns obtained by RAPD analysis revealed polymorphism between accessions & RAPD profiles showed 33 common bands, 4 markers specific to A. sterilis accessions and 3 markers specific to A. sativa species. JT0 showed the lowest RAPDs number (61) among oat accessions. The Neighbor-Joining dendrogram inferred from the Slatkin’s pair wise distances (FST) showed that JT0 accession was clearly separated from the other accessions. JT5, Pc68, Pc38 and Pc39 were clustered in one group. It’s interesting to state that an A. sterilis line (JT5) would be more closely related to 3 A. sativa lines than a fellow an A. sterlis line. JT0 and JT5 could be an interesting provider of a genetic control of the resistance to oat crown rust. A crossing between the spontaneous accessions and the differential lines needs to be done to conclude about the originality of the resistance genetic control in JT0 and JT5

Etat des ressources génétiques de la population locale du poulet de Tunisie

Genetic Resources of the Local Chickens in Tunisia. The opportunity to develop rural livestock and poultry genetic resources in Tunisia has been discussed by giving historical rural poultry origins and structures through trials and sample surveys on their performances and polymorphism. The poultry phenotypes observed in the north-east rural area of Tunisia (i.e. Ariana and Bizerte) are various and their performances were low and vary a lot. Local rural hen can produce an average of 127 eggs per year and its weight reaches 1.206 kg at age 18 weeks. While the cocks have a body weight of 1.620 kg at the same age. Despite the genetic erosion which they have endured over the centuries, the local chicken populations in Tunisia succeeded in preserving a sufficiently significant variability; this allows them to guaranty not only a minimum egg production level and a first choice quality meet, but also to preserve a unique gene reserves of various types and characteristics (i.e. colour, form, rusticity, etc.). The wealth of the genetic resources of the poultry rural population in Tunisia, well identified in this work, makes us believe that a gene conservation program is highly recommended to promote Tunisian rural poultry