Comparative evaluation of fish protein concentrate and functional fish protein concentrate from cat fish

Fish protein concentrate and functional fish protein concentrate samples were prepared from eviscerated meat of cat fish (Tachysurus jella Day). Functional fish protein concentrate is found to be lighter, less gritty and rehydrates more rapidly than fish protein concentrate. Functional FPC is seen to have higher PER and biscuits containing it at levels of 5 and 7 percent are less hard compared to FPC.

Duplication and functional diversification of pancreatic ribonuclease (RNASE1) gene

Adaptation is one of the most fundamental issues in the studies of organismal evolution. Pancreatic ribonuclease is a very important digestive enzyme and secreted by the pancreas. Numerous studies have suggested that RNASE1 gene duplication is closely related to the functional adaptation of the digestive system in the intestinal fermentation herbivores. RNASE1 gene thus becomes one of the most important candidate genetic markers to study the molecular mechanism of adaptation of organisms to the feeding habit. Interestingly, RNASE1 gene duplication has also been found in some non-intestinal fermentation mammals, suggesting that RNASE1 gene may have produced novel tissue specificity or functions in these species. In this review, RNASE1 gene and its implications in adaptive evolution, especially in association with the feeding habit of organisms, are summarized.

Functional significance of stiffness in adaptation of multijoint arm movements to stable and unstable dynamics.

This study compared the mechanisms of adaptation to stable and unstable dynamics from the perspective of changes in joint mechanics. Subjects were instructed to make point to point movements in force fields generated by a robotic manipulandum which interacted with the arm in either a stable or an unstable manner. After subjects adjusted to the initial disturbing effects of the force fields they were able to produce normal straight movements to the target. In the case of the stable interaction, subjects modified the joint torques in order to appropriately compensate for the force field. No change in joint torque or endpoint force was required or observed in the case of the unstable interaction. After adaptation, the endpoint stiffness of the arm was measured by applying displacements to the hand in eight different directions midway through the movements. This was compared to the stiffness measured similarly during movements in a null force field. After adaptation, the endpoint stiffness under both the stable and unstable dynamics was modified relative to the null field. Adaptation to unstable dynamics was achieved by selective modification of endpoint stiffness in the direction of the instability. To investigate whether the change in endpoint stiffness could be accounted for by change in joint torque or endpoint force, we estimated the change in stiffness on each trial based on the change in joint torque relative to the null field. For stable dynamics the change in endpoint stiffness was accurately predicted. However, for unstable dynamics the change in endpoint stiffness could not be reproduced. In fact, the predicted endpoint stiffness was similar to that in the null force field. Thus, the change in endpoint stiffness seen after adaptation to stable dynamics was directly related to changes in net joint torque necessary to compensate for the dynamics in contrast to adaptation to unstable dynamics, where a selective change in endpoint stiffness occurred without any modification of net joint torque.

Structural and functional properties of the hemoglobin components from the Caspian Sea Acipenser persicus and Acipenser stellatus

Hemoglobin (Hb) variability is a commonly used index of phylogenetic differentiation and molecular adaptation in fish. In the current study, the structural and functional characteristics of Hbs from two Sturgeon species of the Southern Caspian Sea Basin were investigated. After extraction and separation of hemoglobin from whole blood , the polyacrylamide gel electrophoresis (SDSPAGE), native-PAGE and isoelectric focusing (IEF) were used to confirm Hb variability in these fishes. Ion-exchange on CM-cellulose chromatography was used for purification of the dominant Hbs from these fishes. The accuracy of the methods was confirmed by IEF and SDS-PAGE. Spectral studies using fluorescence spectrophotometery, circular dichroism spectropolarimetry (CD) analysis and UV–vis spectrophotometery. Oxygen affinities of these Hbs were compared using Hb-oxygen dissociation curves. Also, the dominant Hbs from these blood fishes were utilized for further experiments. The behavior of Hbs during the denaturation process by n-dodecyl trimethylammonium bromide (DTAB) is investigated by UV–vis spectrophotometer and circular dichroism spectropolarimetry. The thermal denaturation properties of the Hbs wereinvestigated by differential scanning calorimetry (DSC) and Hbs aggregation performed chemically in the presence of dithiotreitol (DTT) by UV–vis spectrophotometer and chemometric study. The results demonstrate a significant relationship between stability of fish hemoglobins and the ability of fish for entering to deeper depths. The UV–Vis absorption spectra identified species of hemoglobin and showed the concentration of oxyHb and metHb decreases and deoxyHb increases upon interaction with DTAB. Besides the UV–vis spectrophotometry, the interaction of DTAB with hemoglobins has been studied using circular dichroism spectropolarimetry analysis. This experiment was utilized to measure the unfolding mechanism and compared alpha-helix secondary structure under different conditions for Hbs. The results reveal that the Acipenser stellatus Hb in comparison with Acipenser persicus Hb has more stability and more structural compactness. Besides, the results confirm the hypothesis that there is a meaningful relation between average habitat depth, partial oxygen pressure, oxygen affinity, structural compactness of Hb, and its stability.

Biomonitoring of polycyclic aromatic hydrocarbons (PAH) and heavy metals Ni, V in sediments and anodonts of the Anzali Lagoon and applicability of netural red retention assay (NRR) as biomarkers of these pollutants

Biochemical ecotoxicology and biomarkers using are a new sciences that are used for biomonitoring in aquatic environment. Biomonitoring plays a vital role in strategies to identify, assess, and control contaminants. On the other hands in recent year's attention to polycyclic Aromatic Hydrocarbons (PAHs) and heavy metals increased in aquatic environments because of their carcinogenic and mutagenic properties combined with their nearly ubiquitous distribution in depositional environments by oil pollution or industrial waste waters. The present research aimed to assess PAHs and Ni, V levels in surface sediments and bivalves (Anodonta cygnea)and the effects of PAHs and heavy metals (Ni,V) on the hemocyte of the Anodonta cygnea were investigated in 2 stations (Mahrozeh, Selke in Anzali Lagoon, North of Iran). Samples were collected during at 2 different periods of the year, Dry and rain seasons, (June & September) and to confirm our first observations, Cage station is added. The bivalves hemocytes were monitored for membrane injury by NRR methods (neutral red retention assay). Heavy metal (Ni, V) concentrations were determined by Atomic Absorption in Anodonta cygnea and the sediments in Anzali Lagoon. The vanadium concentration in bivalves and sediments was ND(not detect )-0.4231 μg/g and 1.4381-306.9603 μg/g dry weight respectively. Nickel concentration in bivalves and sediments was 0.0231-1.3351, 0.4024-19.3561 μg/g dry weight respectively. PAHs concentrations were determined by GC-Mass in Anodonta cygnea and the sediments. Average concentration of PAHs is 115-373.788 ng/g dry weight in bivalves and average concentration of PAHs is 34.85-1339.839 ng/g dry weight in sediments. Bioaccumulation sediments factor(BASF) is high about PAHs (>1) and BASF is low for Ni, V (<1) . Internal Damage mechanisms of bivalves hemocytes (cell mortality, dye leakage, decreased membrane stability, are observed (Lowe Methods). Statistical analysis was used to explore the relationship between altered cellular and above contaminants. There are power and negative correlations between PAHs and NRR method for hemocytes in Anodonta cygnea (P<0.0005), but good correlation is not observed between Ni, V and NRR method for hemocytes in every time. This research indicates that the NRR assay is a useful screening technique able to discriminate polluted sites and at first we announce that Anodonta cygnea hemocytes are efficient biomarker for PAHs pollutants in fresh water.

CORRELATION OF ZONA-BINDING WITH OOCYTE MATURATION AND SPERM MOTILITY IN RHESUS-MONKEYS BY HEMIZONA ASSAY

The hemizona assay (HZA) in Rhesus monkeys was employed to study the correlation of zona-binding ability with sperm motility or with naturally developing oocytes at various maturational stages. Oocytes from unstimulated ovaries were retrieved within 2 hr from monkeys sacrificed for vaccine production (in reproductive season, but with their menstrual cycles not determined). Oocytes were divided into four groups based on their morphological maturation: 1) Oocytes surrounded by more than one cumulus layer (MC); 2) Oocytes retaining intact germinal vesicle nuclei (GV); 3) Oocytes with germinal vesicle breakdown showing distinct perivitelline space (PVS); and 4) Oocytes extruding the first polar body (PB1). The mean numbers of sperm bound to hemizona for PBI, PVS, GV, and MC groups were 132.9 +/- 12.0, 71.5 +/- 10.1, 36.1 +/- 4.0, and 20.1 +/- 2.9 (Mean +/- SE), respectively. The four groups showed significant differences from each other in sperm/egg binding ability (P < 0.01). The number of bound sperm significantly increased with oocyte maturation. The present study also showed that zona-binding ability was also affected by sperm motility. For sperm with 67.7% motility and sperm with 31.2% motility, the average numbers of bound sperm were 43.5 +/- 2.2 and 25.3 +/- 2.9 (Mean +/- SE), respectively. There was significantly higher binding ability for sperm with higher motility (P < 0.01). The results suggest that: 1)The rhesus monkey model can serve as a very sensitive model for studying sperm/egg interaction by HZA; 2) Sperm motility positively correlated with sperm/egg binding; and 3) Sperm/egg binding ability increases with oocyte maturation. The binding ability is highest when oocytes matured to the PB1 stage, which is also the best opportunity for fertilization. This is strong evidence for the ''zona maturation'' hypothesis. (C) 1994 Wiley-Liss, Inc.