UHRF1 plays a role in maintaining DNA methylation in mammalian cells

Epigenetic inheritance in mammals relies in part on robust propagation of DNA methylation patterns throughout development. We show that the protein UHRF1 (ubiquitin-like, containing PHD and RING finger domains 1), also known as NP95 in mouse and ICBP90 in human, is required for maintaining DNA methylation. UHRF1 colocalizes with the maintenance DNA methyltransferase protein DNMT1 throughout S phase. UHRF1 appears to tether DNMT1 to chromatin through its direct interaction with DNMT1. Furthermore UHRF1 contains a methyl DNA binding domain, the SRA (SET and RING associated) domain, that shows strong preferential binding to hemimethylated CG sites, the physiological substrate for DNMT1. These data suggest that UHRF1 may help recruit DNMT1 to hemimethylated DNA to facilitate faithful maintenance of DNA methylation.     

LAND USE/LAND COVER CHANGE ANALYSIS AND ITS IMPACT ON SOIL PROPERTIES IN THE NORTHERN PART OF GADARIF REGION,SUDAN

Several decades of intensive dry land farming in the Gadarif region, located in the Eastern part of Sudan, has led to rapid land use/land cover (LULC) changes mainly due to agricultural expansion, government policies and environmental calamities such as drought. In this paper, an attempt has been made to analyse and monitor the LULC changes using multi‐temporal Landsat data for the years 1979, 1989 and 1999 and ASTER data for the year 2009. In addition, efforts were made to discuss the impact of LULC changes on the selected soil properties. For this, a post‐classification comparison technique was used to detect LULC changes from satellite images. Primarily, three main LULC types were selected to investigate the properties of soil, namely, cultivated land, fallow land and woodland. Moreover, soil samples were also collected at two depths of surface soil from ten sample plots for each of the LULC type. For these soil samples, various soil properties such as texture, bulk density, organic matter, soil pH, electrical conductivity, sodium adsorption ratio, phosphorous and potassium were analysed. The results showed that a significant and extensive change of LULC patterns has occurred in the last three decades in the study area. Further, laboratory tests revealed that soil properties were significantly affected by these LULC changes. The change of the physical and chemical properties of the soil may have attributed to the changes in the LULC resulting in land degradation, which in turn has led to a decline in soil productivity. Copyright © 2011 John Wiley & Sons, Ltd.     

Immune complex-mediated glomerulopathy in Marek's disease

Chickens infected with Marek's disease (MD) virus developed immune complex (IC)-mediated glomerulopathy. Fluorescent antibody staining technique using antichicken globulin and antichicken complement was used to demonstrate IC in the kidney glomeruli. During the initial stages of MDV infection, IC deposits were seen on the glomerular basement membrane, but subsequently the entire glomerulus was involved. Mesangial cells also had IC deposits. Chicken complement was demonstrated in the glomeruli which had IC deposits. The number of glomeruli with IC deposition was higher in tumor-bearing birds than in non-tumor-bearing birds. Histologically, kidney lesion were characterized by thickening of basement membrane and proliferation of mesangial cells. It is suggested that IC-mediated glomerulopathy might be one of the major causes of death in MD.     

Isolation of useful variants in alloplasmic crop brassicas in the cytoplasmic background of Erucastrum gallicum

Alloplasmic Brassica juncea was synthesized by repeatedly backcrossing amphidiploid of Erucastrum gallicum × B. juncea with pollen of B. juncea. The E. gallicum cytoplasm was also transferred to B. napus and B. carinata through alloplasmic (E. gallicum) B. juncea. RFLP analyses of organelle DNA confirmed the presence of E. gallicum cytoplasm in all the alloplasmics. The cytoplasm of E. gallicum, though alien, did not induce stable cytoplasmic male sterility in any of the oilseed brassicas. Many useful variants such as early flowering and dwarf phenotypes were isolated in the alloplasmics of B. napus and B. carinata. These morphotypes provide useful genetic variability for the improvement of crop brassicas. This revised version was published online in July 2006 with corrections to the Cover Date.     

CYP19 (cytochrome P450 aromatase) gene polymorphism in murrah buffalo heifers of different fertility performance

The most common cause of infertility in buffaloes is anestrum. During late maturity the ovaries are in a state of true anestrum. One of the predominant causes of true anestrum is a low level of ovarian estrogens. The key enzyme in estrogen biosynthesis is cytochrome P450 aromatase, encoded by CYP19 gene. In the present study, CYP19 gene polymorphism was analyzed by Single Strand Conformational Polymorphism (SSCP) in buffaloes of different fertility performance. The SSCP and sequence analysis revealed 4 allelic variants in coding exons and introns which unaltered the protein sequence. However, a significant polymorphism (T/C heterozygote) was found near TATA binding protein region in regulatory part (a facet of promoter II) at position 23 of CYP19 exon 2, in all late matured and 50% of late maturing animals. Based on these observations and remarks of earlier workers, a hypothesis is proposed for the physiology of late maturity in buffaloes.     

An improvised in vitro vegetative propagation technique for Bambusa tulda: influence of season,sterilization and hormones

Season and concentration of sterilizing agents play a significant role for establishment of aseptic in vitro shoot cultures and sprouting of nodal explants from field growing culms of bamboo species.In the present investigation the nodal segment explants of Bambusa tulda Roxb collected in different seasons and treated with various concentrations of HgCl_2 showed significant variation in aseptic culture establishment and bud break.The rainy season(July–August) recorded with highest of 78% aseptic culture establishment whereas autumn recorded with lowest 46%.Summer and winter seasons emerged to be the best period, registering60% in vitro bud break.On the other hand, the autumn season had the lowest value for bud break,i.e.42%.Among different doses of sterilizing agent tried,HgCl_2 0.1% found to be suitable for maximum aseptic culture establishment(66%) as well as bud break(59%).However, among the interactions, summer season and the dose of 0.1% HgCl_2 exhibited maximum of 73% response for both aseptic culture establishment and bud break.MS medium(liquid) enriched with 5.0 μM BA+5.0 μM Kn[Kinetin(N6-Furfuryladenine)] with additional supplementation of 100 μM glutamine+0.1 μM IAA supported a maximum in vitro shoot multiplication of 4.75 fold.The proliferated shoots were successfully rooted on MS medium(liquid) supplemented 40 μM coumarin.The plantlets transferred to the polythene bags showed 98% survival.     

Nitrogen Fixation Establishment during Initial Growth of Grain Legume Species

Atmospheric nitrogen fixation as a result of the symbiosis between bacteria and legume species, can result in major advantages in providing host plants with organic nitrogen. The objective of the present study was to evaluate the physiological potential during early seedling development for initiation of nodulation and nitrogen fixation activity of four grain legumes species: soybean [Glycine max (L.)], cowpea [Vigna unguiculate (L.) Walp], common bean [Phaseolus vulgaris (L.)], and peanut [Arachis hypogaea (L.)]. Seedlings were grown on a hydroponic solution so that nodule development could be readily observed until about 3 weeks after germination. Nodules developed in all cases. Acetylene reduction activity (ARA) by soybean and cowpea was also found early in seedling development. In contrast, peanut and common bean showed little or no development of ARA during seedling development. The results provided insight into differences in physiological potential among grain legumes in establishing symbiotic nitrogen fixation during crop establishment. These results indicate those species/cultivars that are candidates for readily establishing nitrogen fixation activity during the seedling stage of plant development.     

Protection against Plasmodium berghei yoelii in chloroquine- and pyrimethamine-treated mice

The antimalarial drugs chloroquine and pyrimethamine were observed to afford protection to mice treated with these agents. This protection was observed in mice when given a subsequent challenge infection after they had been radically cured of P. b. yoelii infection.     

Identifying the markers and tagging a leucine-rich repeat receptor-like kinase gene for resistance to anthracnose disease in vegetable cowpea [Vigna unguiculata (L.) Walp.]

Anthracnose caused by the fungus Colletotrichum lindemuthianum is the most destructive disease of cowpea. Field-type cowpeas show various levels of resistance, whereas pole-type vegetable cowpeas are highly susceptible. Transfer of resistance available in field types to vegetable types is a major breeding objective in cowpea. This paper details the development of an F₂ mapping population by crossing field-type cowpea variety Kanakamony (Vigna unguiculata ssp. cylindrica) with pole-type vegetable cowpea variety Sharika (Vigna unguiculata ssp. sesquipedalis), screening this population with artificial inoculation and Bulked Segregant Analysis (BSA) with random marker systems Random Amplified Polymorphic DNA (RAPD) and Inter-Simple Sequence Repeats (ISSR); the objective is to identify the markers linked with major resistance-contributing genes. RAPD primer OPA02 has yielded marker at 850 bp in susceptible genome, whereas ISSR primers UBC810 and UBC811 have yielded markers at 1.4 kb and 1.5 kb respectively in resistant genomes. These markers were reproducible and their linkage with resistance and suitability in marker assisted selection (MAS) were confirmed through co-segregation analysis in F₃ population. UBC811 marker was eluted, cloned on pGEM-T, and sequenced. The sequence had shown that this marker is anchored on LRR receptor-like serine/t\hreonine protein kinase gene which could be involved in the resistance mechanism.