Minichromosome Maintenance 2 Bound with Retroviral Gp70 Is Localized to Cytoplasm and Enhances DNA-Damage-Induced Apoptosis

The interaction of viral proteins with host-cellular proteins elicits the activation of cellular signal transduction pathways and possibly leads to viral pathogenesis as well as cellular biological events. Apoptotic signals induced by DNA-damage are remarkably up-regulated by Friend leukemia virus (FLV) exclusively in C3H hosts; however, the mechanisms underlying the apoptosis enhancement and host-specificity are unknown. Here, we show that C3H mouse-derived hematopoietic cells originally express higher levels of the minichromosome maintenance (MCM) 2 protein than BALB/c- or C57BL/6-deriverd cells, and undergo more frequent apoptosis following doxorubicin-induced DNA-damage in the presence of the FLV envelope protein gp70. Dual transfection with gp70/Mcm2 reproduced doxorubicin-induced apoptosis even in BALB/c-derived 3T3 cells. Immunoprecipitation assays using various deletion mutants of MCM2 revealed that gp70 bound to the nuclear localization signal (NLS) 1 (amino acids 18–24) of MCM2, interfered with the function of NLS2 (amino acids 132–152), and suppressed the normal nuclear-import of MCM2. Cytoplasmic MCM2 reduced the activity of protein phosphatase 2A (PP2A) leading to the subsequent hyperphosphorylation of DNA-dependent protein kinase (DNA-PK). Phosphorylated DNA-PK exhibited elevated kinase activity to phosphorylate P53, thereby up-regulating p53-dependent apoptosis. An apoptosis-enhancing domain was identified in the C-terminal portion (amino acids 703–904) of MCM2. Furthermore, simultaneous treatment with FLV and doxorubicin extended the survival of SCID mice bearing 8047 leukemia cells expressing high levels of MCM2. Thus, depending on its subcellular localization, MCM2 plays different roles. It participates in DNA replication in the nucleus as shown previously, and enhances apoptosis in the cytoplasm

Aspects of language and cultural endangerment: Examples from Yoruba

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Feeding Rice Husk-Poultry Manure with and without Enzyme Supplementation on Performance and Carcass Profile of Rabbit

A total of thirty-six (36) rabbits of mixed sexes were used in a ten (10) week feeding trials to investigate the relative effect of dietary levels of rice husk poultry manure (RHPM) supplemented with or without β-xylanase. The rabbits were randomly allotted into six (6) dietary treatment groups of 0, 10 and 20% of RHPM with or without β-xylanase in a randomized complete block design experiment. Each treatment has three (3) replicates with two (2) rabbits in each. Analyzed data on daily weight gain, average daily feed intake, feed conversion efficiency, live shrunk weight, dressed carcass and dressing percentage were significantly (p0.05) in percentage primal cuts of rabbits. There was no mortality, however, the best performance was observed with rabbits fed 10% RHPM with enzyme supplementation.Key words: rabbits, nutrase XYLA, rice husk, poultry manure, Carcass characteristic

Performance and bone morphometry of two breeds of finishing broiler chickens reared on different housing systems

Adequate consideration of management systems is required to enhance the productivity of broiler chickens. This study was carried out to determine the effect of two housing systems on growth performance, carcass traits and bone morphometry of broiler chickens. A total of 180 unsexed one dayold Arbor Acre and Marshall breeds of broiler chickens were used for this study. The birds were brooded for 3 weeks and thereafter acclimatized for one week in their respective housing systems (deep litter and outdoor run). Each of the housing systems was allotted 90 chicks per breed with three replicates of 15 birds each. The birds were fed same quality and quantity of feed ad libitum and given water throughout the period of the experiment which lasted for four weeks. Data were collected weekly on weight gain and feed intake while feed conversion ratio was calculated. At the end of the study, 2 birds of representative weight in each replicate were selected for carcass analysis and bone strength determination. The experiment was arranged in a 2 x 2 factorial layout in a completely randomized design. The results of growth performance showed significantly (p<0.05) higher final weight (2,012.06g/b), weight gain (48.45g/b/d) and feed intake (151.74g/b/d) in Arbor Acre breed compared with the final weight (1,890.15g/b), weight gain (45.82g/b/d) and feed intake (144.60g/b/d) obtained in Marshall breed. Significantly (p<0.05) higher weight gain (49.70g/b/d) and better feed conversion ratio (2.92) was observed in broiler chickens reared on deep litter housing system while those reared on outdoor run had 49.11g/b/d and 3.01 for weight gain and feed conversion ratio, respectively. Birds managed on outdoor run consumed more feed compared to those kept on deep litter. Broiler chickens reared on deep litter were superior in retail cut (breast) and abdominal fat compared to those kept on outdoor run. Irrespective of breeds, birds reared on outdoor run had greater (p<0.05) bone strength (14.61N/mm2) compared to those on deep litter (10.68N/mm2). The study concluded that, Arbor Acre breed of broiler chickens could be reared on deep litter housing system for better performance. However, outdoor run could be adopted to enhance better bone strength in both breeds of broiler chickens.Keywords: Broiler chickens, breeds, performance, carcass traits, morphometry, housing system

Growth response and nutrient digestibility of growing pigs to qualitative and quantitative feed restriction

Feed restriction is a relevant management tool use in modificationof livestock growth patterns by reducing their maintenance requirement, leading to improved feed efficiency and utilization. This study assessed the effect of qualitative and quantitative feed restriction on growth parameters and nutrients digestibility of growing pigs. Fifty four (54) mixed breed pigs with initial body weight of 6.72±0.38 kg were arranged in a 3x3 factorial arrangement for a 150-day study: Factor A consists of 3 levels of qualitative feed restriction (20%, 18% and 16% crude protein) and Factor B consists of 3 levels of quantitative feed restriction (adlibitum, 90% and 80% of ad-libitum feed offered). The experimental animals were grouped on weight equalization into 9 treatment groups of 3 replicates of 2 pigs per replicate. Growth performance data were collected on weekly basis and nutrient digestibility was carried out on the 11th week of the experiment. Data obtained were subjected to two-way analysis of variance. Final body weight, daily weight gain and daily feed intake were significantly (p<0.05) influenced by increment in dietary crude protein.The pigs fed 20% crude protein recorded the best FCR of 1.36. Quantitative feed restriction had no influence on the growth parameters studied. Feed quality and quantity offered had significant (P<0.05) influence on excreted faeces, faecal dry matter output, excreted faeces/dry matter intake, dry matter digestibility, crude protein digestibility, ether extract, crude fibre digestibility and ash. Similar (P>0.05) mean values of excreted faeces, faecal dry matter output, excreted faeces/ dry matter intake, crude protein digestibility, crude fibre digestibility, ash and ether extract were recorded for pigs fed 18% and 16% of crude protein respectively. It can be concluded from this study that a combination of qualitative and quantitative restriction (at 18% crude protein with 80% of ad libitum feed offered)can be used as management tool to improve feed utilization in growing pigs.Keywords: Qualitative, quantitative, restriction, growth, nutrients, pig

Effects of housing systems on behavioural assessment, bone morphometry and faecal egg counts of broiler chickens

Animals that are well-managed thrive and produce better than those kept under conditions which do not take full consideration of their behavioural and welfare needs. This experiment was conducted with one hundred and eighty unsexed one day-old Marshall and Arbor Acre breeds of broiler chickens to investigate the effects of housing systems on behavioural assessment, bone morphometry and faecal egg counts. The birds were brooded for three weeks and acclimatized for one week in their respective housing systems. Each of the housing systems (deep litter and outdoor run) was allotted 90 birds with 45 chicks per breed in three replicates of 15 birds each after balancing for body weights. The birds were fed same quality and quantity of feed and water ad libitum throughout the period of the experiment which lasted for four weeks. Data were collected on behavioural observations, bone morphometry and faecal samples were analyzed to determine the helminthes egg per gram. The experiment was arranged in a 2 x 2 factorial layout in a completely randomized design. The results of behavioural assessment showed that the two breeds of broiler chickens expressed more (p<0.05) of their natural instincts in the outdoor run compared with their counterparts on deep litter housing system. Irrespective of breeds, birds reared on outdoor run had higher (p<0.05) bone strength (14.61N/mm2) compared with those on deep litter (10.68N/mm2). Also, the result of faecal egg counts showed that broiler chickens reared on deep litter had a higher incidence of intestinal helminthes compared with those managed on outdoor run. It was concluded that outdoor run could be adopted to enhance more expression of natural behaviours, better bone strength and reduced incidence of intestinal helminthes in Marshall and Arbor Acre breeds of broiler chickens.Keywords: Behavioural assessment, bone morphometry, faecal egg counts, housing systems and broiler chicken