Microsatellite markers-based characterisation of elephant grass (Pennisetum purpureum) harvested from selected locations in South-West Nigeria

This study was carried out to characterise Pennisetum purpureum harvested from some selected locations in S outh-W estern Nigeria using microsatellite markers. Leaf parts of growing young elephant grass (Pennisetum purpureum) were harvested and immediately preserved in ethanol solution before DNA extraction. Two (2) SSR primers (CTM59 and Xtxp278) were used to assess genetic diversity in Pennisetum purpureum. The result shows that 72% of the molecular variations in the elephant grass exists within the population with 28% among the population; there were no unique characteristics among the Nine (9) populations. Nei genetic index ranged from 0.067 (lowest) observed between Isokan and Odeda populations to 0.158 (highest), between Ifedore and Ikoyi Populations. Morphological characterization showed moderate diversity with two major clusters and one minor cluster. Keyword: Elephant grass; cultivars; locations; markers

Quantifying the individual impact of artificial barriers in freshwaters: A standardized and absolute genetic index of fragmentation

Fragmentation by artificial barriers is an important threat to freshwater biodiversity. Mitigating the negative aftermaths of fragmentation is of crucial importance, and it is now essential for environmental managers to benefit from a precise estimate of the individual impact of weirs and dams on river connectivity. Although the indirect monitoring of fragmentation using molecular data constitutes a promising approach, it is plagued with several constraints preventing a standardized and individual quantification of barrier effects. Indeed, observed levels of genetic differentiation depend on both the age of the obstacle and the effective size of the populations it separates, making difficult comparisons of the actual barrier effect of different obstacles. Here, we developed a standardized genetic index of fragmentation (FINDEX), allowing an absolute and independent assessment of the individual effects of obstacles on connectivity. The FINDEX is the standardized ratio (expressed as a percentage) between the observed genetic differentiation between pairs of populations located on either side of an obstacle and the genetic differentiation expected if this obstacle completely prevented gene flow. The expected genetic differentiation is calculated from simulations taking into account two nuisance parameters: the number of generations since barrier creation (the age of the obstacle) and the expected heterozygosity of the targeted populations, a proxy for effective population sizes. Using both simulated and published empirical datasets, we explored and discussed the validity and the limits of the FINDEX. We demonstrated that it allows quantifying genetic effects of fragmentation only from a few generations after barrier creation and provides valid comparisons among populations (or species) of different effective populations sizes and obstacles of different ages. The computation of the FINDEX requires a minimum amount of fieldwork and genotypic data, and solves some of the difficulties inherent to the study of artificial fragmentation in rivers and potentially in other ecosystems. This makes the FINDEX a promising and objective tool for managers aiming at at planning restoration programs and at evaluating the efficiency of these programs.

LYMPHOCYTE-PLATELET ADHESION IN PATIENTS WITH ISCHEMIC STROKE — CARRIERS OF GENETIC POLYMORPHISM OF SOME TOLL-LIKE RECEPTORS

Цель исследования: изучить феномен лимфоцитарно-тромбоцитарной адгезии и агрегационную активность тромбоцитов (спонтанную и индуцированную) у больных ишемическим инсультом (ИИ) в динамике заболевания с учетом носительства генетического полиморфизма некоторых толл-подобных рецепторов (TLRs) и генетического индекса. Материалы и методы. Обследовано 115 больных ИИ и 94 относительно здоровых резидента. Лимфоцитарно-тромбоцитарный индекс оценивали как среднее арифметическое количество тромбоцитов, присоединившихся к одному лимфоциту. Материалом для молекулярно-генетического анализа TLRs служили образцы ДНК, выделенные из лейкоцитов периферической крови. Результаты. Выявлено, что предикторами ИИ являются аллели -753Arg TLR2, -249Pro TLR6, -1237C TLR9 и генотипы -753Arg/Arg TLR2, -299Asp/Asp TLR4, -249Pro/Pro TLR6 с относительным риском от 1,49 до 3,35. В крови больных ИИ многократно увеличено число лимфоцитарно-тромбоцитарных агрегатов (ЛТА). Заключение. Для развития инсульта имеет значение не только качество полиморфных маркеров, но и количество предикторных аллельных вариантов. Чем выше индивидуальный генетический индекс, тем больше в острейший период острого нарушения мозгового кровообращения в кровотоке образуется ЛТА; их количество снижается до контрольных значений к 21 дню заболевания. Aim: to study the phenomenon of lymphocyte-platelet adhesion (LTA) and platelet aggregation activity (spontaneous and induced) in patients with ischemic stroke (IS) over time the disease taking into account the carriage of genetic polymorphism of some Toll-like receptors (TLRs) and genetic index. Materials and methods. We examined 115 patients with IS and 94 relatively healthy residents. The lymphocyte-platelet index was estimated as the arithmetic average of platelets number that joined one lymphocyte. DNA samples isolated from peripheral blood leukocytes were the material for molecular genetic analysis of TLRs. Results. We revealed that alleles -753Arg TLR2, -249Pro TLR6, -1237C TLR9 and genotypes -753Arg/Arg TLR2, -299Asp/Asp TLR4, -249Pro/Pro TLR6 with a relative risk 1,49–3,35 were predictors of IS. The number of blood lymphocyte-platelet aggregates (LTA) increased manyfold in patients with IS. Conclusion. The qualities of polymorphic markers as well as the number of predictor allelic variants are important for stroke development. In the sharpest period of acute stroke the greater number of LTA in circulation is formed in patients with higher individual genetic index. The number of LTA decreased to control values by 21 day of the disease.

Evaluation of production efficiencies among primiparous suckler cows of diverse genetic index at pasture

This study aimed to determine estimates of production efficiency among primiparous suckler cows of diverse genetic merit (GM) for the national Irish maternal index. Data from 82 heifers of diverse GM across two different replacement strategies (suckler (S) or dairy (D) sourced) were available. Milk yield, grass dry matter intake, cow BW and body condition score (BCS) were recorded. The maternal index had no significant effect on any parameters investigated, whereas S cows were 86 kg heavier in BW, had a 0.33 greater BCS and 0.6 UFL greater NEM requirement compared with D beef crossbred (F1) cows. The F1 produced 2.2 kg/day more milk and had greater lactation energy requirements (0.8 UFL) than S. The F1 produced 0.48 kg milk per 100 kg BW and 0.15 kg more milk per unit intake. An interaction between GM and cow origin (CO) showed that F1 low merit cows consumed an additional 1 kg DM than F1 high, and that S high merit cows produced 1.5 kg less milk than their S low counterparts resulting in a 0.5 UFL greater energy requirement for milk production for S low. The F1 high merit cows produced 0.12 kg more milk per unit intake than F1 low cows, whereas S low cows produced 0.12 kg less milk per unit intake than S high. The F1 low cows consumed 0.17 kg more DM per unit BW than F1 high. Thus, genetic selection for maternal traits has not resulted in differences in production efficiency traits, however CO differences were observed.