A testis‐specific gene within a widely expressed gene: Contrasting evolutionary patterns of two differentially expressed mammalian proteins encoded by a single gene,CAMK4

Understanding the patterns of genetic variations within fertility‐related genes and the evolutionary forces that shape such variations is crucial in predicting the fitness landscapes of subsequent generations. This study reports distinct evolutionary features of two differentially expressed mammalian proteins [CaMKIV (Ca²⁺/calmodulin‐dependent protein kinase IV) and CaS (calspermin)] that are encoded by a single gene, CAMK4. The multifunctional CaMKIV, which is expressed in multiple tissues including testis and ovary, is evolving at a relatively low rate (0.46–0.64 × 10^?9 nucleotide substitutions/site/year), whereas the testis‐specific CaS gene, which is predominantly expressed in post‐meiotic cells, evolves at least three to four times faster (1.48–1.98 × 10^?9 substitutions/site/year). Concomitantly, maximum‐likelihood‐based selection analyses revealed that the ubiquitously expressed CaMKIV is constrained by intense purifying selection and, therefore, remained functionally highly conserved throughout the mammalian evolution, whereas the testis‐specific CaS gene is under strong positive selection. The substitution rates of different mammalian lineages within both genes are positively correlated with GC content, indicating the possible influence of GC‐biased gene conversion on the estimated substitution rates. The observation of such unusually high GC content of the CaS gene (≈74%), particularly in the lineage that comprises the bovine species, suggests the possible role of GC‐biased gene conversion in the evolution of CaS that mimics positive selection.     

A spatial panel statistical analysis on cultivated land conversion and chinese economic growth

The conflict between cultivated land protection and economic development has become increasingly acute in recent years. Despite, intensive researches made on this conflict, little attention has been paid to the spatial correlation of variables. In view of this, the paper introduces the spatial panel regression model to estimate, and test whether the relationship between economic growth and cultivated land conversion conforms to Kuznets curve. Research results show that the area of converted cultivated land in China exhibits strong spatial auto-correlation; the spatial panel model with time effect and fixed effect is more stable and significant than conventional panel mode, and that the relationship between economic growth and cultivated land conversion agrees with the inverted U-shape of Kuznets curve, with inflection point occurring when average per capita GDP reaches ¥31330.93 (calculated at comparable price of 1999). On the basis of analysis, it is suggested that the government, with a view to developing economy alongside protecting cultivated land, should attach more importance to land use and planning in the future, pay more attention to the spatial correlation of cultivated land planning in adjacent areas and make greater efforts to increase the input–output ratio of land.     

Metabolism of maltose and sucrose by microspores isolated from barley (Hordeum vulgare L.)

The aim of this work was to discover why barley (Hordeum vulgare L.) microspores die when cultured on media containing 40 mM sucrose but undergo embryogenesis on 40 mM maltose. Freshly isolated microspores were cultured for 6–24 h on media containing either [U-¹⁴C]maltose or [U-¹⁴C]sucrose at 40 mM, and the detailed distribution of ¹⁴C was determined. The amounts of glycolytic intermediates, ATP, ADP and AMP, in microspores were also measured. Cultures on sucrose differed from those on maltose in that the initial rate of metabolism was faster but declined rapidly, less ¹⁴C was recovered in polymers and more in alanine, there was extensive leakage of assimilated carbon, significant accumulation of ethanol and a lower adenylate energy charge. It is argued that microspores cultured on 40 mM sucrose die because they metabolize the sugar rapidly, become hypoxic and, as a result, accumulate large quantities of ethanol within the cells. Metabolism of maltose is slower and there is sufficient oxygen available to allow cells to survive in culture. Consequently some of the cultured cells undergo embryogenesis.P.S. thanks the Science and Engineering Research Council and Shell Research Ltd., Sittingbourne, for a Cooperative Award in Science and Engineering studentship.     

The effect of age and castration on the growth rate,blood lipid profile,liver histology and feed conversion in Green-legged Partridge cockerels and capons

The surgical castration of male chickens induces hormonal changes, which permanently influence metabolic processes in birds. The aim of this study was to determine the effect of age and castration on the growth rate, feed conversion, lipid profile and histopathological changes in the livers of cockerels and capons. The experimental materials comprised male chickens of the Green-legged Partridge breed (old traditional Polish chicken breed), raised to 28 weeks of age. At 8 weeks of age, 100 birds were castrated. Caponization had a significant effect on the plasma concentrations of total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and triacylglycerols (P<0.05). Fatty degeneration and lymphoid cell infiltration were observed more frequently in the livers of capons than cockerels. Capon carcasses were characterized by increased deposition of abdominal and subcutaneous fat (P<0.05). Total meat weight in the carcasses of cockerels and capons was similar, but the proportions of muscles were different. From 20 weeks of age, the weight of breast muscles was higher, and the weight of leg muscles was lower in capons than in cockerels (P<0.05). Capons were characterized by higher liver weight, higher gizzard weight and lower heart weight than cockerels (P<0.05). The feed conversion ratio (kg/kg BW) was similar in intact cockerels and capons. The values of carcass quality parameters and feed conversion ratio as well as histopathological changes in the liver indicate that Green-legged Partridge capons should be slaughtered at 20 to 24 weeks of age.     

Acute effects of Amomum villosum Lour. fruit extract on postprandial glycemia and insulin secretion: A single-blind,placebo-controlled,crossover study in healthy subjects

BackgroundAmomum villosum Lour., (Zingiberaceae) an herbaceous plant in the ginger family, has been used to treat various diseases. In a single-blind, randomized, crossover study, we assessed the postprandial blood insulin and blood glucose responses in healthy subjects (n = 40) after the Amomum villosum water extract (AVE) (5 g/person) or a placebo (5 g/person) consumption.MethodsDuring each treatment course, the healthy subject consumed a regular late afternoon meal, followed by fasting for 12 h, and arrived at the clinical study center the next morning. Blood insulin and blood glucose levels were assessed at 0, 30, 60, 90, and 120 min after AVE consumption. Between each treatment, the subjects accomplished one week of a washout period.ResultsThe AVE intake demonstrated a significant (67.26%) decline in postprandial blood glucose AUC_{0–120 min} (incremental area under the curve from 0 to 120 min) versus the placebo (P = 0.011). Furthermore, AVE reduced postprandial blood insulin AUC_{0–120 min} by 59.95% compared to the placebo group (P < 0.003), supporting the blood glucose results.ConclusionThis study revealed that AVE consumption significantly reduced postprandial insulin and glucose levels in healthy individuals, due in part to inhibition of α-glucosidase, and glucose transport.     

Sucrose phosphorylase as cross-linked enzyme aggregate: Improved thermal stability for industrial applications

Sucrose phosphorylase is an interesting biocatalyst that can glycosylate a variety of small molecules using sucrose as a cheap but efficient donor substrate. The low thermostability of the enzyme, however, limits its industrial applications, as these are preferably performed at 60°C to avoid microbial contamination. Cross-linked enzyme aggregates (CLEAs) of the sucrose phosphorylase from Bifidobacterium adolescentis were found to have a temperature optimum that is 17°C higher than that of the soluble enzyme. Furthermore, the immobilized enzyme displays an exceptional thermostability, retaining all of its activity after 1 week incubation at 60°C. Recycling of the biocatalyst allows its use in at least ten consecutive reactions, which should dramatically increase the commercial potential of its glycosylating activity.     

Sucrose utilization during ovule and seed development ofGasteria verrucosa (Mill.) H. Duval as monitored by sucrose synthase and invertase localization

Summary The development ofGasteria verrucosa ovules and seeds seems to follow a pattern of growth in which the majority of carbohydrates is first used in the sporophytic tissue (nucellus, integuments, and arillus) around the gametophyte-derived cells. After fertilization the carbohydrates are used for further development of the arillus and seed coat. During the next stage carbohydrates are directed to develop the endosperm, followed by carbohydrate investment in the developing embryo and in storage products. This utilization pattern is deducted from a localization study on sucrose synthase and invertase. These two enzymes break down imported sucrose and are in that perspective used as markers for carbohydrate transport since diffusion is expected to be induced towards cells and tissues with high sucrose-hydrolyzing activities.