Gene Expression and Polymorphism of Myostatin Gene and its Association with Growth Traits in Chicken.

Myostatin is a member of TGF-ß super family and is directly involved in regulation of body growth through limiting muscular growth. A study was carried out in three chicken lines to identify the polymorphism in the coding region of the myostatin gene through SSCP and DNA sequencing. A total of 12 haplotypes were observed in myostatin coding region of chicken. Significant associations between haplogroups with body weight at day 1, 14, 28, and 42 days, and carcass traits at 42 days were observed across the lines. It is concluded that the coding region of myostatin gene was polymorphic, with varied levels of expression among lines and had significant effects on growth traits. The expression of MSTN gene varied during embryonic and post hatch development stage.

Occurrence and expression of cspA, a cold shock gene, in Antarctic psychrotrophic bacteria.

The homologue of cold shock gene cspA of Escherichia coli was detected in various isolates of Antarctic psychrotrophs representing both Gram-positive and Gram-negative bacteria. The Northern hybridization study indicated that the transcript size of cspA in the psychrotrophic Gram-positive bacterium Arthrobacter protophormiae and Gram-negative Pseudomonas fluorescens was similar to that of E. coli and that the cspA homologues in these two psychrotrophs were expressed constitutively at a low level both at 4 degrees C and 22 degrees C. In P. fluorescens, the expression of cspA mRNA was inducible after shift of temperature from 22 to 4 degrees C and the maximum level of induction occurred after 1 h which correlated with the time-lag required for growth of the culture after temperature shift.

Effect of storage on protein concentration of tear samples.

PURPOSE: To determine the effect of storage on protein concentration of tear samples stored at room temperature (RT), 4 degrees C, -20 degrees C and -70 degrees C. METHODS: Total protein concentration of closed, open (basal tears) and reflex tears (stimulated tears) was measured by modified Bradford's method. SDS-PAGE gel electrophoresis was used to determine the intensity of protein bands. Quantity of various tear proteins was determined by HPLC analysis. RESULTS: Compared to control samples (0 h) protein concentrations decreased significantly in tear samples stored beyond 4 h (for closed) and 8 h (for open and reflex) at RT. However, no significant change in protein concentrations was observed in closed and reflex tears when stored up to 1 week at 4 degrees C, up to 2 months at -20 degrees C; and up to 4 months at -70 degrees C. Multiple freeze-thaw procedures (6 x per day at 2 h intervals) resulted in 8% decrease (at -20 degrees C) and 10% decrease (at -70 degrees C) of protein concentrations in closed eye tears. SDS-PAGE analysis of tear samples stored at -20 degrees C and -70 degrees C for 4 months greatly affected the intensity of the protein bands. HPLC analysis of tear samples stored at these conditions showed the significant reduction in the peak corresponding to secretory IgA in closed eye tears and a split in the peak corresponding to lysozyme in case of reflex tears. CONCLUSIONS: Reduction in the total protein concentration, intensity of the protein bands as well as changes in the quantity of tear proteins were observed in the tear samples stored for longer duration of time at various temperatures.

HPLC analysis of closed, open, and reflex eye tear proteins.

Changes in the closed, open and reflex eye tear proteins of normal subjects were compared and analysed. Tear proteins were resolved by high-performance liquid chromatography (HPLC) utilising both gel filtration (P-300 SW) and reverse-phase (C-18) columns and the HPLC fractions were further analysed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) under reducing and non-reducing conditions. The protein composition of the closed-eye tear was significantly different from that of the open and reflex-eye tear. Secretory IgA (sIgA) was the predominant protein in closed eye tears constituting 49% of the total protein compared to 11% in reflex tears, whereas lysozyme was the predominant protein (53%) in reflex tears. Levels of lactoferrin, lipocalin and lysozyme were relatively constant in both open and reflex tears. HPLC profiles of the closed-eye tears, upon continuous stimulation of lacrimal glands indicated that sIgA was significantly reduced whereas lactoferrin, lipocalin, and lysozyme were significantly increased. These results indicate that the tear composition upon waking attains that of the open eye within 4 to 5 minutes, and upon continuous stimulation this reflects the reflex-eye tear composition. It also indicates that mechanisms responsible for changes in concentration of constitutive and regulated tear protein with stimulus can be studied successfully using non-invasive methods to collect human tears.

Transcriptional activity at supraoptimal temperature of growth in the antarctic psychrotrophic bacterium Pseudomonas syringae.

Transcriptional activity was monitored in cells of the Antarctic psychrotrophic bacterium Pseudomonas syringae (Lz4W), which does not grow above 30 degrees C. It was observed that the bacterium was capable of synthesising RNA at a temperature range of 0-37 degrees C, both in vitro and in vivo. The net incorporation of the radioactive precursor, [3H]uridine, into RNA was found to be affected at 37 degrees C. A pulse-chase experiment following a 32P labeling of RNA in vivo indicated that the ribosomal RNAs (rRNAs) degrade faster at and above 30 degrees C. It was also found that the increased ribonuclease (RNase) activity at high temperature might be responsible for this degradation. The attack on ribosomal RNAs by RNase took place after their assembly into ribosomal particles. It is suggested that the degradation of rRNAs at supraoptimal temperatures might be a detrimental factor for growth above 30 degrees C.