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The full-length cDNA, encoding the orange-spotted grouper β-actin and spanning 1920 bp including a poly (A) tail, was cloned
from its brain cDNA library. The open reading frame encodes a protein of 375 amino acids. Sequence analysis indicated that
it contained the typical structural features of cytoplasmic actins, and showed higher homology with other vertebrate β-actin
than any other members of the actin family. The partial genomic sequence indicated that the organization of the β-actin gene
in the orange-spotted grouper might also be conserved. Northern blot analysis indicated that it was expressed at high levels
in the brain, spleen, adipose tissue, ovary, and liver, but at low levels in the gill filament and heart, and at a very low
level in the kidney. The expression of β-actin gene in the skeletal muscle was barely detectable. These results indicated
that the expression of the orange-spotted grouper β-actin gene showed significant variation in different tissues. Therefore,
caution should be taken when using β-actin gene as an internal control in the normalization of gene expression among tissues.
Whereas, semi-quantitative RT-PCR analysis indicated that treatment with 17α–methyltestosterone (MT) had little effect on
the mRNA expression of β-actin gene in the in vitro incubated hypothalamus, pituitary, and ovary fragments of the orange-spotted grouper, suggesting β-actin can be used as an
internal control for RT-PCR analysis of MT effects on gene expression in these tissues. 相似文献
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Larvae of jack mackerel Trachurus japonicus were sampled in seven depth layers (0–10 m, 10–20 m, 20–30 m, 30–40 m, 40–50 m, 50–70 m, and 70–100 m), with a closing-type
frame net, on 26th–27th February, 2003, at Sta. V (27°50′N, 126°00′E) continental shelf edge in the southern part of East
China Sea, to examine their vertical distribution. Most of the larvae (>90%) occurred in the upper 50 m layer during both
day and night. In the daytime, larvae of length from 3.0 mm to 4.5 mm were most abundant in the 10–20 m layer, those from
5.0 to 6.0 mm were most abundant in the 20–30 m layer, those from 6.0 to 8.0 mm occurred at greater depth, in the 30–40 m
layer, and those more than 9.0 mm were found in the 0–10 m layer and performed ontogenetic vertical migrations. Larvae from
6 mm to 8 mm length performed diurnal vertical migration, for the percentage (16.7%) of larval number in the 0–20 m layer
in the daytime increased to 42.1% at night and the percentage (78.1%) in the 20–50 m layer in the daytime decreased to 49.0%
at night. 相似文献
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Circe E. Badillo-Salas Enrique Valenzuela-Espinoza Marco A. González-Gómez Griselda Pares-Sierra Francisco Ley-Lou Zaul Garcia-Esquivel 《Aquaculture International》2009,17(2):173-186
Two trials were carried out in the laboratory in order to assess the effect of microparticulated feed (F) and live (Thalassiosira pseudonana, M) diets on the growth of recently set (396 ± 13 μm shell height) and 2 mm Crassostrea gigas postlarvae. Different proportions of M and F (100:0, 75:25, 50:50; 25:75, 0:100) were delivered in a single dose of 3 h d−1 in trial 1. Dietary M:F proportions of 100:0, 50:50, and 0:100 were delivered as a single pulse of 8 h d−1 (P1) or two pulses of 4 h−1 (P2) in trial 2. Maximal daily M ration was 296 cells μl−1 d−1 (trial 1), 150 M cells μl−1 d−1 (trial 2), or their equivalent F dry weight. Shell height (SH), dry (DW), and organic weight (AFDW) were evaluated weekly.
Oysters from trial 1 significantly increased their size after 28 days, and exhibited no significant dietary differences in
terms of DW (1.21 ± 0.15 to 2.01 ± 0.28 mg) or AFDW (0.091 ± 0.022 to 0.166 ± 0.029 mg). Newly set postlarvae (trial 2) also
exhibited significant growth after 25 days. No dietary differences were observed in trial 2, yet P2 oysters attained significantly
higher shell heights (825–912 μm) than P1 oysters (730–766 μm) after 25 d. Pulse effects were marginally not significant in
terms of AFDW and growth rate. Together, these findings showed that balanced microfeeds have a practical potential for the
culture of early C. gigas postlarvae, when they are delivered in pulse-feeding schemes 相似文献
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The growth hormone (GH) gene isolated and cloned from various Labeo species (L. rohita, L. calbasu, L. fimbriatus, L. gonius, L. bata, and L. kontius) is shown to contain a single copy in the haploid genome, with an overall size of ∼2.5 kb. The GH gene in all the Labeo species studied has five exons and four introns of various sizes with the exon/intron boundary sequence of GT/AG. The length
variation of the GH gene between the species is found to be due to length variation in the form of several deletions in the
third intron. The length of individual exons is the same in all the species with an open reading frame (ORF) of 630 bp (210
amino acids) except in L. rohita, which has a 9 bp deletion in the fourth exon, resulting in a shorter GH of 621 bp (207 amino acids). The similarity in the
nucleotide and amino acid sequences between the different Labeo species is greater than 97%, in spite of eight amino acids being altered in the GH protein of Labeo that reside outside the conserved domain sequence required for its function. Nucleotide substitutions are seen in the form
of 20 transitions and three transversions in the ORF of the GH gene. Both types of transitions (A–G; T–C) and only one type
of transversion (A–C) are detected in the GH gene. Codon preference in GH gene shows a strong preference for G and C in the
wobble position of the codons. Genetic interrelationships determined between Labeo and other species of fishes using nucleotide sequence of GH cDNA supports the overall teleost classification of Nelson (Fishes
of the World. Wiley, New York, 1984) with separate clades for Ostariophysi, Protacanthopterygii, and Acanthopterygii. Besides, the unweighted pair group method
with arithmetic means (UPGMA) analysis clearly distinguishes between the species having five exons and four introns in the
GH gene from the species having six exons and five introns in the same gene. The Labeo species analyzed in the present study could be clustered into two groups using the maximum-parsimony method on the intron
sequences data of the GH gene. 相似文献
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《Aquaculture (Amsterdam, Netherlands)》2007,262(2-4):504-513
The objective of this study was to determine whether metallothionein (MT) expression was related to Cd accumulation in hard clams (Meretrix lusoria). We cloned clam MT. Then a specific primer for the hard clam was designed for MT mRNA measurements using real-time PCR. The hard clams were exposed to 50, 200, and 1000 μg/L cadmium (Cd) for 1, 3, 5, and 7 days, to determine the relationship between MT mRNA relative quantity (RQ) levels and Cd accumulation. The following results were obtained: (1) the cloned MT, consisting of 228 bp encoding a protein of 76 amino acids showed higher than 55% identity with the deduced amino acid sequence previously published for another bivalve. (2) Both MT mRNA expression and Cd accumulation appeared to be dose-responsive following cadmium treatment for 1, 3 and 5 days, respectively; however, no time-dependent responses were found. According to these results, MT mRNA expression levels can be used as an indicator to monitor the concentrations of Cd in aquaculture farms. 相似文献
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The present study examines the pattern of accumulation of cadmium (Cd) and its biochemical effects on selected tissues of
a variety of African catfish (Clarias gariepinus), after exposure to various doses of Cd. The results obtained indicate that at the end of 21 days of exposure, the total
tissue organ cadmium concentration followed the pattern kidney > gill > liver > muscle for each of the exposure concentrations.
The levels of Cd in these organs were higher than those in ambient water. Moreover, while the rate of uptake of Cd increased
with time in the kidney, liver and muscle, it decreased in the gill. Superoxide dismutase (SOD) was significantly elevated
only in the kidney of catfish treated with 0.2 and 0.4 ppm of Cd for 7 days compared with the control. Conversely, gill SOD
was significantly decreased in the same concentrations of Cd-treated catfish relative to the control. Statistically similar
levels of SOD were observed in the liver, brain and muscle with all the treatments after the same duration of treatment. In
the fish exposed for 21 days, SOD activity was significantly decreased in the kidney with a corresponding increase in lipid
peroxidation (LPO), but it manifested only with the 0.2- and 0.4-ppm Cd treatment relative to the control. In the liver, however,
Cd exposure significantly increased SOD in the 0.2- and 0.4-ppm treatments of the same duration. In conclusion, the present
study indicates that the accumulation of Cd and its effect on SOD and LPO in C. gariepinus is dependent on concentration, tissue and time 相似文献
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Dabas A Nagpure NS Kumar R Kushwaha B Kumar P Lakra WS 《Fish physiology and biochemistry》2012,38(2):469-482
The effects of different concentrations of cadmium chloride on the extent of lipid peroxidation (LPO) and alterations in the
antioxidant enzyme activities were studied in liver, kidney and gill tissues of freshwater murrel, Channa punctatus. The fish specimens were exposed to 6.7, 13.4 and 20.1 mg l−1 sublethal concentrations of cadmium chloride and the oxidative stress was assessed after 24, 48, 72 and 96 h post-exposure.
The biomarkers selected for the study were thiobarbituric acid reactive substances for assessing the extent of lipid peroxidation
and antioxidant defense system such as reduced glutathione (GSH), glutathione reductase (GR), glutathione peroxidase (GPX), glutathione-S-transferase (GST), catalase (CAT) and superoxide dismutase (SOD) activities. In general, the cadmium exposure
elevated the LPO in subject tissues of treated group and modulated the activities of GPx, GST, SOD, CAT, GR and level of GSH
after given exposure as compared to the control. All enzymes activities, except CAT (in kidney and gills), and amount of LPO
elevated significantly (P < 0.05) in treated group with respect to control in all tissues, while significant difference was not observed between the
exposed concentrations and within exposure duration. The results indicated that increase in LPO level and the fluctuation
in antioxidant defense system in fish could be due to cadmium-induced increase in the production of reactive oxygen species
(ROS). The potential role of these parameters as biomarkers of heavy metal pollution in aquatic system is discussed. 相似文献
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Amin Oujifard Jafar Seyfabadi Abdolmohammad Abedian Kenari Masood Rezaei 《Aquaculture International》2012,20(1):117-129
Replacement of fish meal (FM) with rice protein concentrate (RPC) as a practical diet for the Pacific white shrimp, Litopenaeus vannamei, was evaluated. Five isonitrogenous (36.6% protein) diets, formulated by replacing 0, 25, 50, 75, and 100% of FM by RPC,
were fed to shrimp (initial weight of 6.99 ± 0.08 g) five times daily to satiation for 60 days. Relatively high final weight
(FW 17.64–18.25 g) and weight gain (WG 10.81–11.39 g) were obtained in treatments up to 50% of the plant protein inclusion.
Above this inclusion level, FW (14.93–14.35 g) and WG (7.68–7.23 g) were reduced. Survival was high (≥95%) and similar for
all diets. There were no significant differences (P > 0.05) in tail-muscle composition (moisture, protein, lipid, and ash) among different dietary treatments. Dispensable and
indispensable amino acids of the tail muscle of shrimp fed with 25, 50, and 75% RPC were significantly higher than the FM
(0%) and 100% RPC diets. A decreasing trend in apparent digestibility coefficient (excluding dry matter) for crude protein
(90.52–52.41), ether extract (94.11–80.03), organic matter (87.25–50.16), and gross energy (89.41–55.24) was observed at higher
RPC inclusion rates. The results suggest that RPC meal can be a potential candidate for FM replacement up to 50% of the protein
in shrimp diets. 相似文献
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Hung-Yueh Yeh Craig A. Shoemaker Phillip H. Klesius 《Fish physiology and biochemistry》2006,32(1):83-92
The hemoglobin-β gene of channel catfish, Ictalurus punctatus, was cloned and sequenced. Total RNA from head kidneys was isolated, reverse transcribed and amplified. The sequence of the
channel catfish hemoglobin-β gene consists of 600 nucleotides. Analysis of the nucleotide sequence reveals one open reading frame and 5′- as well as 3′-untranslated
regions. The open reading frame of the sequence potentially encodes 148 amino acids with a calculated molecular mass of 16.3 kDa.
The pI and charge at pH 7.0 of the deduced hemoglobin-β protein were 7.28 and 0.47, respectively. Overall, 22 amino acid residues were conserved throughout the sequences, including
His64 and His93, the sites for heme-binding. Unlike the counterpart of other common cultured fish such as Salmo salar, Oncorhynchus nerka, Oncorhynchus mykiss, Cyprinus carpio and Ctenopharyngodon idella, the hemoglobin-β of channel catfish did not have cysteine. The amino acid sequence of channel catfish hemoglobin-β shows 84% homology with that of Silurus asotus (both are in the order Siluriformes). However, comparison with those of other fish species shows homology ranging from 53 to 68%. Structural analysis by the
3D-PSSM program displays that channel catfish hemoglobin-β has eight α-helices, A–H. 相似文献
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Photosynthetic activities of seedlings of Zostera marina were successively measured using a gas volumeter for 6 days at seven light (0–400 μmol photons/m2 per s) and 11 water temperature conditions (5–35°C). The seedlings were collected from mature plants (Ise Bay, central Japan),
and stored and cultured in incubators accurately controlled at each test temperature. The maximum gross photosynthesis (P
maxg) was recorded at an optimal water temperature of 29°C after 0 days. After 6 days, P
maxg appeared at 25°C and most plants cultured at 29–30°C bleached and withered after the drastic increase of light compensation
point (I
c). On the contrary, at 5–28°C, the photosynthetic activities either changed little (5–25°C) or recovered after a temporal
reduction (26–28°C); seedlings survived and looked healthy after being cultured for 6 days. The recovery was thought to be
an acclimation to tolerate higher water temperature. As a result, the critical upper water temperature for Z. marina seedlings was proposed as 28°C. The temperature was consistent with the previously reported maximum water temperature in
habitats around the southern boundary of Z. marina in the northern hemisphere. 相似文献
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