A computational approach to characterization of bovine sperm chromatin alterations

We describe here a computational morphology-based approach to the investigation of possible causes of chromatin alterations in sperm. A comprehensive set of state-of-the-art and geometric measures are computationally extracted from toluidine blue stained images and analyzed to infer the possible processes leading to normal and abnormal chromatin formation while seeking a possible taxonomy of chromatin alterations and their influence on sperm head morphology. Using this methodology, we have identified higher chromatin fragility at some specific points of the sperm head. Despite the lack of correlation between morphologies of sperm head and chromatin structure, four main morphological types of chromatin alterations in bull spermatozoa have been identified and their possible causes discussed.     

Influence of Different Rice Cultivars on <Emphasis Type="Italic">Schizotetranychus oryzae</Emphasis> Development

Schizotetranychus oryzae Rossi de Simons (Acari: Tetranychidae) is considered one of the most important phytophagous mite in rice cultivation in the Americas South, Central, and North. This study aimed to examine some biological aspects of S. oryzae developing on leaves of three different cultivars of rice [Oryza sativa (L.)—Poaceae] produced in the state of Rio Grande do Sul, Brasil. The plants were kept in a room at 25?±?1°C, with natural light (photophase of approximately 14 h) and 70?±?5% relative humidity. During the immature stages, observations were carried out daily at 7 am, 1 pm, and 7 pm. The results showed that the mean duration of the egg–adult period in days were similar between cultivars evaluated (Irga 424, 11.27?±?0.13; Taim, 11.21?±?0.14 and Sinuelo, 11.13?±?0.15). Egg–adult viability on Irga 424, Sinuelo, and Taim was 61.9, 85.71, and 90.48%, respectively, being lowest on Irga 424 (χ2?=?28.62, p?<?0.0001). The duration of the immature stages was not affected by cultivar, but on Irga 424, egg–adult viability and female longevity were lower. The results of this study can help select O. sativa cultivar resistant to S. oryzae. However, historically, the IRGA 424 has lower populations of S. oryzae in field conditions.     

Native or Exotic? Double or Single? Evaluating Plants for Pollinator-friendly Gardens

In a series of dawn-to-dusk studies, we examined the natureand accessibility of nectar rewards for pollinating insectsby monitoring insect visits and the secretion rate and standingcrop of nectar in the British native plant species Salvia pratensis,Stachys palustris, S. officinalis, Lythrum salicaria, Linariavulgaris, the non-native Calendula officinalis, Petunia x hybrida,Salvia splendens, and the possibly introduced Saponaria officinalis.We also compared single with double variants ofLotus corniculatus, Saponaria officinalis, Petunia x hybrida andCalendula officinalis. All the British species studied are nectar-rich and are recommendedfor pollinator-friendly gardens. They showed maximal secretionrates of about 10–90 µg sugar per flower h^-1, andmost had mean standing crops of about 5–60 µg sugarper flower. In all British species studied, the corolla wasdeep enough for the relatively long-tongued bumblebee Bombuspascuorum, but the shallower flowers of Lythrum salicaria werealso much visited by shorter-tongued bees and hoverflies, aswell as by butterflies. The exotic Salvia splendens, presumablycoevolved with hummingbirds in the Neotropics, has such deepflowers that British bees cannot reach the nectar except bycrawling down the corolla. With a secretion rate approaching300 µg sugar per flower h^-1and little depletion by insects,S. splendens accumulated high standing crops of nectar. S. splendens,and single and double flowers of the two probably moth-pollinatedspecies Petunia x hybrida and Saponaria officinalis, receivedfew daytime visits despite abundant nectar but Calendula waswell visited by hoverflies and bees. We compared single anddouble variants of Lotus corniculatus,Petunia x hybrida andCalendula officinalis, and also Saponaria officinalis, the lastbeing probably introduced in Britain (Stace, 1997 New floraof the British Isles. 2nd edn. Cambridge: Cambridge UniversityPress). In Petunia, Saponaria and Lotus, double flowers secretedlittle or no nectar. In Calendula, where doubling involved achange in the proportion of disc and ray florets rather thanmodification of individual flower structure, double and singlecapitula had similar standing crops of nectar. Except inCalendula, exotic or double flowers were little exploited by insect visitors.In the exotics, this was probably due to the absence or scarcityof coevolved pollinators, coupled, in double flowers, with theabsence of nectar. Copyright 2001 Annals of Botany Company Salvia pratensis, Salvia splendens, Stachys palustris, Stachys officinalis,Lythrum salicaria , Linaria vulgaris, Lotus corniculatus, Saponaria officinalis,Petunia x hybrida, Calendula officinalis, wild flowers, double flowers, gardens, nectar, secretion rate, standing crop, pollinators, bumblebees, Bombus, honeybees, Apis, hoverflies, butterflies,Anthidium manicatum     

Epigenetic regulation of insulin-like growth factor binding protein-3 (IGFBP-3) in cancer

Epigenetics refers to heritable changes in gene expression that are independent of alterations in DNA sequence. It is now accepted that disruption of epigenetic mechanisms plays a key role in the pathogenesis of cancer: culminating in altered gene function and malignant cellular transformation. DNA methylation and histone modifications are the most widely studied changes but non-coding RNAs such as miRNAs are also considered part of the epigenetic machinery. The insulin-like growth factor (IGF) axis is composed of two ligands, IGF-I and –II, their receptors and six high affinity IGF binding proteins (IGFBPs). The IGF axis plays a key role in cancer development and progression. As IGFBP genes have consistently been identified among the most common to be aberrantly altered in tumours, this review will focus on epigenetic regulation of IGFBP-3 in cancer for which the majority of evidence has been obtained.     

The usage of marker traits in plants for evaluation of resistance of the winter wheat to pest insects

A new method of selection of the winter wheat varieties has been tested for resistance to the pest insects' complex by the traits of plants that are the markers of plant resistance. It makes it possible to use this method from year to year independently of the pests' density.