Genetic diversity assessment of the indigenous goat population of Benin using microsatellite markers.

Improved knowledge of the diversity within and among local animal populations is increasingly necessary for their sustainable management. Accordingly, this study assessed the genetic diversity and structure of the indigenous goat population of Benin. Nine hundred and fifty-four goats were sampled across the three vegetation zones of Benin [i.e., Guineo-Congolese zone (GCZ), Guineo-Sudanian zone (GSZ), and Sudanian zone (SZ)] and genotyped with 12 multiplexed microsatellite markers. The genetic diversity and structure of the indigenous goat population of Benin were examined using the usual genetic indices (number of alleles Na, expected and observed heterozygosities He and Ho, Fixation index FST, coefficient of genetic differentiation GST), and three different methods of structure assessment [Bayesian admixture model in STRUCTURE, self-organizing map (SOM), and discriminant analysis of principal components (DAPC)]. The mean values of Na (11.25), He (0.69), Ho (0.66), FST (0.012), and GST (0.012) estimated in the indigenous Beninese goat population highlighted great genetic diversity. STRUCTURE and SOM results showed the existence of two distinct goat groups (Djallonké and Sahelian) with high crossbreeding effects. Furthermore, DAPC distinguished four clusters within the goat population descending from the two ancestry groups. Clusters 1 and 3 (most individuals from GCZ) respectively showed a mean Djallonké ancestry proportion of 73.79% and 71.18%, whereas cluster 4 (mainly of goats from SZ and some goats of GSZ) showed a mean Sahelian ancestry proportion of 78.65%. Cluster 2, which grouped almost all animals from the three zones, was also of Sahelian ancestry but with a high level of interbreeding, as shown by the mean membership proportion of only 62.73%. It is therefore urgent to develop community management programs and selection schemes for the main goat types to ensure the sustainability of goat production in Benin.

Genetic Diversity Trends in the Cultivated Potato: A Spatiotemporal Overview.

We investigated the changes in genetic diversity over time and space of the cultivated potato (Solanum tuberosum L.) for the period pre-1800 to 2021. A substantial panel of 1219 potato varieties, belonging to different spatiotemporal groups, was examined using a set of 35 microsatellite markers (SSR). Genotypic data covering a total of 407 alleles was analyzed using both self-organizing map (SOM) and discriminant analysis of principal components (DAPC) de novo and a priori clustering methods, respectively. Data analysis based on different models of genetic structuring provided evidence of (1) at least two early lineages that have been maintained since their initial introduction from the Andes into Europe in the 16th century, followed by later ones coming from reintroduction events from the US in the mid-1800s; (2) a level of diversity that has gradually evolved throughout the studied time periods and areas, with the most modern variety groups encompassing most of the diversity found in earlier decades; (3) the emergence of new genetic groups within the current population due to increases in the use of germplasm enhancement practices using exotic germplasms. In addition, analysis revealed significant genetic differentiation both among and within the spatiotemporal groups of germplasm studied. Our results therefore highlight that no major genetic narrowing events have occurred within the cultivated potato over the past three centuries. On the contrary, the genetic base shows promising signs of improvement, thanks to extensive breeding work that is gaining momentum. This overview could be drawn on not only to understand better how past decisions have impacted the current genetic cultivated potato resources, but also to develop appropriate new strategies for breeding programs consistent with the socio-economic and sustainability challenges faced by agrifood systems.

Morphological variability within the indigenous sheep population of Benin.

Knowledge of both the genetic diversity and geographical distribution of animal genetic resources is a prerequisite for their sustainable utilization, improvement and conservation. The present study was undertaken to explore the current morphological variability within the sheep population in Benin as a prelude for their molecular characterization. From November 2018 to February 2020, 25 quantitative linear body measurements and 5 qualitative physical traits were recorded on 1240 adult ewes from the 10 phytogeographic zones that comprise the three vegetation zones of Benin. Fourteen morphological indices were calculated based on the linear body measurements. The collected data were first analyzed using multiple comparisons of least-square means (LSmeans), followed by generalized linear model (GLM) procedures, to explore the relationships among the measured morphometric traits and the 10 phytogeographic zones. Next, the presence of any genetic sub-populations was examined using multivariate analytical methods, including canonical discriminant analysis (CDA) and ascending hierarchical clustering (AHC). Univariate analyses indicated that all quantitative linear body measurements varied significantly (P<0.05) across the phytogeographic zones. The highest values (LSmean± standard error) of withers height (68.3±0.47 cm), sternum height (46.0±0.35 cm), and rump height (68.8±0.47 cm) were recorded in the Mekrou-Pendjari zone, the drier phytogeographic zone in the North, whereas the lowest values, 49.2±0.34, 25.9±0.26, and 52.0±0.35 cm, respectively, were recorded in the Pobe zone in the South. Multivariate analyses revealed the prevalence of four distinct sheep sub-populations in Benin. The sub-population from the South could be assimilated to the short-legged and that from the North to the West African long-legged sheep. The two other sub-populations were intermediate and closer to the crossbreeds or another short-legged sub-breed. The proportion of individuals correctly classified in their group of origin was approximately 74%. These results uncovered a spatial morphological variation in the Beninese sheep population along a South-North phytogeographic gradient.

Effects of Chemopreventive Natural Compounds on the Accuracy of 8-oxo-7,8-dihydro-2'-deoxyguanosine Translesion Synthesis.

Translesion synthesis is a DNA damage tolerance mechanism that relies on a series of specialized DNA polymerases able to bypass a lesion on a DNA template strand during replication or post-repair synthesis. Specialized translesion synthesis DNA polymerases pursue replication by inserting a base opposite to this lesion, correctly or incorrectly depending on the lesion nature, involved DNA polymerase(s), sequence context, and still unknown factors. To measure the correct or mutagenic outcome of 8-oxo-7,8-dihydro-2'-deoxyguanosine bypass by translesion synthesis, a primer-extension assay was performed in vitro on a template DNA bearing this lesion in the presence of nuclear proteins extracted from human intestinal epithelial cells (FHs 74 Int cell line); the reaction products were analyzed by both denaturing capillary electrophoresis (to measure the yield of translesion elongation) and pyrosequencing (to determine the identity of the nucleotide inserted in front of the lesion). The influence of 14 natural polyphenols on the correct or mutagenic outcome of translesion synthesis through 8-oxo-7,8-dihydro-2'-deoxyguanosine was then evaluated in 2 experimental conditions by adding the polyphenol either (i) to the reaction mix during the primer extension assay; or (ii) to the culture medium, 24 h before cell harvest and nuclear proteins extraction. Most of the tested polyphenols significantly influenced the outcome of translesion synthesis, either through an error-free (apigenin, baicalein, sakuranetin, and myricetin) or a mutagenic pathway (epicatechin, chalcone, genistein, magnolol, and honokiol).

Root Morphological Traits of Seedlings Are Predictors of Seed Yield and Quality in Winter Oilseed Rape Hybrid Cultivars.

The root system is responsible for soil resources acquisition. Hence, optimizing crop root characteristics has considerable implications for agricultural production. This study evaluated a panel of twenty-eight European modern cultivars of oilseed rape (Brassica napus L.) cultivated in laboratory and field environments. Root morphology was screened using a high-throughput hydroponic growth system with two divergent nitrogen supplies. The panel showed an important diversity for biomass production and root morphological traits. Differences in root and shoot dry biomasses and lateral root length were mainly explained by the genotype, and differences in primary root length by nitrogen nutrition. The cultivars were tested in a pluriannual field trial. The field variation for yield and seed quality traits attributed to the genotype was more important than the year or the genotype × year interaction effects. The total root length measured at the seedling stage could predict the proportion of nitrogen taken up from the field and reallocated to seed organs, a component of the nitrogen use efficiency. The genetic interrelationship between cultivars, established with simple sequence repeat markers, indicated a very narrow genetic base. Positive correlations were found between the genetic distance measures, root morphological traits during nitrogen depletion and yield components. This study illustrates a root phenotyping screen in the laboratory with a proof of concept evaluation in the field. The results could assist future genetic improvements in oilseed rape for desirable root characteristics to reduce nutrient losses in the environment.

Development and application of a quantitative real-time PCR assay for rapid detection of the multifaceted yeast Kazachstania servazzii in food.

The beneficial contributions of Kazachstania servazzii are well-established in various food processes. This yeast also contributes in the spoilage of finished packaged food due to abundant gas production. In particular, an occurrence of K. servazzii was recently positively correlated with the formation of severe package swelling of some prepared fresh pizzas. To circumscribe this concern, a quantitative SYBR green real-time PCR assay based on a newly designed specific primer pair targeting the ribosomal ITS1-5.8S-ITS2 region of K. servazzii was developed. The quantification was enabled using a standard curve created from serially diluted plasmids containing the target sequence of the K. servazzii strain. A validation of the assay was achieved by enumeration of K. servazzii DNA copies from artificially infected culture broths containing non-contaminated pizza substrates. The newly developed method was then tested on total DNA extracted from packaged fresh pizzas, in which certain lots were swollen and thus suspected of containing K. servazzii. This study highlights that this newly developed quantitative assay is not only sufficiently sensitive, specific and reliable to be functionally used in food control as a routine method of detection, but also promising in specific studies that seek to further characterize the dynamic of this yeast in some increasingly popular food processes.

Measurement of translesion synthesis by fluorescent capillary electrophoresis: 7,8-dihydro-8-oxodeoxyguanosine bypass modulation by natural products.

Translesion synthesis (TLS) relies on a series of specialized DNA polymerases able to insert a base either correctly or incorrectly opposite a lesion on a DNA template strand during replication or post-repair synthesis. To measure the correct or mutagenic outcome of 7,8-dihydro-8-oxodeoxyguanosine (8-oxodG) bypass by TLS DNA polymerases, a capillary electrophoresis (CE) method with fluorescent label has been developed. Two oligonucleotides were designed and hybridized: (i) a 72-mer oligonucleotide framing one 8-oxodG at position 40 and (ii) the 39-mer oligonucleotide complementary to the first strand from the 3' end to the lesion and labeled at the 5' end with a fluorochrome. After incubation with FHs 74 Int human intestinal epithelial cell nuclear proteins, in the presence of either deoxyadenosine triphosphate (dATP) or deoxycytidine triphosphate (dCTP), and denaturation, the resulting elongated oligomers were analyzed by fluorescent capillary electrophoresis. This primer extension assay was then validated in terms of linearity (linear range=0.5-2.5 nM), detectability (limits of detection and quantification=0.023 and 0.091 nM, respectively), and precision (total precisions=8.1% and 3.7% for dATP and dCTP, respectively, n=9). The addition of some natural phytochemicals to the reaction mix significantly influences the outcome of TLS either in an error-free way or in a mutagenic way.

Use of Self-Organizing Map to Analyze Images of Fungi Colonies Grown from Triticum aestivum Seeds Disinfected by Ozone Treatment.

We submitted to ozone treatment Triticum aestivum (common wheat) seeds severely contaminated by fungi. Fungi colonies developed when seeds were placed over malt agar medium in Petri dishes; Fusarium sp. and Alternaria sp. were identified. However, conventional colonies counting did not allow a clear assessment of the effect of ozone disinfection. We thus used self-organizing maps (SOMs) to perform an image analysis of colonies surface area that clearly showed a significant disinfection effect on Fusarium sp.