A High Polymorphism Level in Rhinopithecus roxellana

The Sichuan golden monkey (Rhinopithecus roxellana) is a famous and beautiful endangered primate. Owing to the dearth of samples and technical limitations, previous studies could not adequately assess the levels of genetic polymorphisms in the species. To

Is there a genetic relationship between mRNA and the encoded protein at three-dimensional level?

A comparative study on the structures of some mRNAs and their encoded proteins shows an intriguing correlation between the two foldings. Non-random distribution of codons in the secondary structures of mRNAs is also shown, which appears to be in accordance with the conformational properties of amino acids in protein structures to some extent. These results seem to suggest that there may be a kind of genetic relationship between mRNA and protein at three-dimensional level.

An Evaluation of Four Phylogenetic Markers in Nostoc: Implications for Cyanobacterial Phylogenetic Studies at the Intrageneric Level

The success of some phylogenetic markers in cyanobacteria owes to the design of cyanobacteria-specific primers, but a few studies have directly investigated the evolution "behavior" of the loci. In this study, we performed a case study in Nostoc to evaluate rpoC1, hetR, rbcLX, and 16S rRNA-tRNA(Ile)-tRNA(Ala)-23S rRNA internal transcribed spacer (ITS) as phylogenetic markers. The results indicated that the gene trees of these loci are not congruent with the phylogeny based on 16S rRNA gene. The mechanisms contributing to the incongruence include randomized variation and recombination. As the results suggested, one should be careful to choose the molecular markers for phylogenetic reconstruction at the intrageneric level in cyanobacteria.

Phylogeography of the freshwater catfish Hemibagrus guttatus (Siluriformes, Bagridae): Implications for South China biogeography and influence of sea-level changes

National Natural Science Foundation of China (NSFC) ; [2007CB411600]; [30530120]

Effects of age and dietary protein level on digestive enzyme activity and gene expression of Pelteobagrus fulvidraco larvae

The present research studied the effects of age and dietary protein level on pepsin, trypsin and amylase activity and their mRNA level in Petteobagrus fulvidraco larvae from 3 to 26 days after hatch (DAH). Three DAH larvae were fed three isoenergetic diets, containing 42.8% (CP 43), 47.3% (CP 47) and 52.8% (CP 53) crude protein. Live food (newly hatched Artemia, unenriched) was included as a control. The effects of age on enzyme activity and mRNA were as follows: pepsin and trypsin activity in all treatment groups showed a significant (P < 0.05) increase at the beginning and decrease later although the timing of decrease was not the same among treatment groups and between the digestive enzymes. Pepsin and trypsin mRNA level followed the pattern of their respective enzyme changes. Age significantly affected amylase activity (P < 0.05) while age had no effect on amylase mRNA during the experimental period. The four diets significantly (P < 0.05) affected activity and mRNA level of pepsin and trypsin. Diets did not affect amylase activity or mRNA level. These results suggest that the effects of age on pepsin and trypsin gene expressions are at the transcriptional level. Dietary protein level does affect pepsin and trypsin gene expression in the early life of P. fulvidraco. There were no transcriptional effects on amylase gene expression. (c) 2005 Elsevier B.V. All rights reserved.

Comparative study on the effect of dietary lipid level on growth and feed utilization for gibel carp (Carassius auratus gibelio) and Chinese longsnout catfish (Leiocassis longirostris Gunther)

An 8-week growth trial investigated the effect of dietary lipid level on growth performance of a carnivorous fish, Chinese longsnout catfish (Leiocassis longirostris Gunther) and an omnivorous fish, gibel carp (Carassius auratus gibelio). For each species, seven isonitrogenous semi-purified diets (455 g kg(-1) crude protein for Chinese longsnout catfish and 385 g kg(-1) crude protein for gibel carp) were formulated to contain 30, 60, 90, 120, 150, 180 or 210 g kg(-1) lipid. For Chinese longsnout catfish, feed intake (FI) decreased with increasing dietary lipid and there was no significant difference in feed intake from 90 to 210 g kg(-1) lipid. Specific growth rate (SGR) increased with dietary lipid level (P < 0.05) and the 150 and 180 g kg(-1) groups were the best. Feed conversion efficiency (FCE), protein retention efficiency (PRE) and energy retention efficiency (ERE) were higher at 180 g kg(-1) lipid. For gibel carp, FI decreased with increased dietary lipid and 180 and 210 g kg(-1) lipid groups showed lower values. SGR increased with dietary lipid level and the 150 and 180 g kg(-1) were the best. FCE was higher at 180 g kg(-1) lipid level. PRE increased with dietary lipid level and there was no significant difference in groups from 120 to 210 g kg(-1) dietary lipid. ERE increased with increasing dietary lipid level, and groups fed 120, 150 and 180 g kg(-1) lipid showed the highest values. In Chinese longsnout catfish, increase in dietary lipid level, resulted in increased carcass dry matter, crude protein, crude lipid and gross energy. In gibel carp, dry matter, crude protein, and crude lipid increased with dietary lipid level. Based on regression between SGR and dietary lipid, dietary lipid requirements for Chinese longsnout catfish and gibel carp were 142.6 and 140.5 g kg(-1), respectively.

Genetic heterogeneity and ploidy level analysis among different gynogenetic clones of the polyploid gibel carp

Background: Some triploid and tetraploid clones have been identified in the gynogenetic gibel carp, Carassius auratus gibelio Bloch, by karyotypic and cytologic analyses over many years. Further, 5-20% males and karyotypic diversity have been found among their natural and artificial populations. However, the DNA contents and the relation to their ploidy level and chromosome numbers have not been ascertained, and whether normal meiosis occurs in spermatogenesis needs to be determined in the different clones. Methods: The sampled blood cells or sperms were mixed with blood cells from chicken or individual gibel carp and fixed in 70% pre-cooled ethanol overnight at 4degreesC. The mixed cell pellets were washed 2-3 times in 1x phosphate buffered saline and then resuspended in the solution containing 0.5% pepsin and 0.1 M HCl. DNA was stained with propidium iodide solution (40 mug/mL) containing 4 kU/ml RNase. The measurements of DNA contents were performed with Phoenix Flow Systems. Results: Triploid clones A, E, F, and P had almost equal DNA content, but triploid clone D had greater DNA content than did the other four triploid clones. DNA content of clone M (7.01 +/- 0.15 pg/nucleus) was almost equal to the DNA content of clone D (5-38 +/- 0.06 pg/nucleus) plus the DNA content of common carp sperm (1.64 +/- 0.02 pg/nucleus). The DNA contents of sperms from clones A, P, and D were half of their blood cells, suggesting that normal meiosis occurs in spermatogenesis. Conclusions: Flow cytometry is a powerful method to analyze genetic heterogeneity and ploidy level among different gynogenetic clones of polyploid gibel carp. Through this study, four questions have been answered. (a) The DNA content correlation among the five triploid clones and one multiple tetraploid clone was revealed in the gibel carp, and the contents increased with not only the ploidy level but also the chromosome number. (b) Mean DNA content was 0.052 pg in six extra chromosomes of clone D, which was higher than that of each chromosome in clones A, E, F, and P (about 0.032 pg/ chromosome). This means that the six extra chromosomes are larger chromosomes. (c) Normal meiosis occurred during spermatogenesis of the gibel carp, because DNA contents of the sperms from clones A, P, and D were almost half of that in their blood cells. (d) Multiple tetraploid clone M (7.01 +/- 0.15 pg/nucleus) contained the complete genome of clone D (5.38 +/- 0.06 pg/nucleus) and the genome of common carp sperm (1.64 +/- 0.02 pg/nucleus). Cytometry Part A 56A:46-52, 2003. (C) 2003 Wiley-Liss, Inc.

Determination of trace level microcystins in water using solid-phase extraction and high performance liquid chromatography

This paper presents a method for trace level analysis of microcystins in water using solid-phase extraction and high performance liquid chromatography. The optimized condition enabled the determination of common microcystins at levels as low as 0.02 similar to 0.05 mug/L, and the liner range is from 0.1 mug/L to 50 mug/L. The method has been applied to the analysis of field sample from Dianchi lake.

Wafer-Level Testable High-Speed Silicon Microring Modulator Integrated with Grating Couplers

A wafer-level testable silicon-on-insulator-based microring modulator is demonstrated with high modulation speed, to which the grating couplers are integrated as the fiber-to-chip interfaces. Cost-efficient fabrications are realized with the help of optical structure and etching depth designs. Grating couplers and waveguides are patterned and etched together with the same slab thickness. Finally we obtain a 3-dB coupling bandwidth of about 60nm and 10 Gb/s nonreturn-to-zero modulation by wafer-level optical and electrical measurements.

Annihilation of deep level defects in InP through high temperature annealing

Deep level transient spectroscopy (DLTS) and thermally stimulated current spectroscopy (TSC) have been used to investigate defects in semi-conducting and semi-insulating (SI) InP after high temperature annealing, respectively. The results indicate that the annealing in iron phosphide ambient has an obvious suppression effect of deep defects, when compared with the annealing in phosphorus ambient. A defect annihilation phenomenon has also been observed in Fe-doped SI-InP materials after annealing. Mechanism of defect formation and annihilation related to in-diffusion of iron and phosphorus is discussed. Nature of the thermally induced defects has been discussed based on the results. (c) 2007 Elsevier Ltd. All rights reserved.