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1.
美洲黑石斑鱼营养成分分析与营养价值评价 总被引：4，自引：0，他引：4
In this experiment, the contents of the main nutrients such as protein, fat, moisture, ash, calcium and phosphorus were analysed, and the contents of the trace elements, amino acids and fatty acids in its muscle were determined for Centropristis striata. Moreover, its nutritional value was evaluated and compared with other fishes,livestocks and poultries. The results showed that the content of dry matter and protein are higher in its muscle. Then, all of 17 common amino acids（AA） contents in muscle was 17.51% in the fresh sample, and 7 of them are human essential amino acids（EAA）41.58% in the total amino acids（TAA）. The ratio of essential amino acids to nonessential amino acids（EAA/NEAA） was 84.46% ,and the essential amino acids index（EAAI） was 57.71. According to AAS and CS,which basically accorded with the issued standard value by FAO and WHO. The content of 5 delicious amino acids was 44.37% in the TAA, and the ratio of branched chain amino acids to aromatic amino acids was 2.83. The content of polyunsaturated fatty acids was 22.3% rich in its muscle also, in particular EPA and DHA. In conclusion, Centropristis striata is a species of delicious and high nutritional value,which well deserves exploitation and utilization. At the same time, this experiment was preparing for the next study to provide reference data for artificial feed and the expansion of aquaculture. 相似文献
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真鲷天然抗性相关巨噬蛋白全长cDNA的克隆与序列分析 总被引：1，自引：0，他引：1
Natural resistance associated macrophage protein (Nmmp) is an innate resistance protein to intracellular parasites, which is expressed plentifully in macrophage ceils. Nramp has been studied in mouse, human, cattle, rainbow trout and channel catfish.However, tittle was known about the structure of Pagrus major Nramp. In order to get the complete sequence of Pagrus major Nramp, a pair of primer is designed according to a 200bp known sequence of Pagrus major Nramp cDNA. By the use of SMART RACE, the full Nramp of Pagrus major cDNA about 5 000 bp was obtained, including about 200 bp 5‘ terminal region (UTR),complete encoding region and 3‘ terminal region. There were 3 ployA signals, which showed many possibilities of cutting at 3‘ terminal region. The character of Pagrus major Nramp nucleotide sequence and deduced amino acid sequence are analyzed. 12 putative transmembrane(TM) regions, a consensus transport motif (CTM), a predicted protein kinase C phosphroylation site and three predicted N-link glycosylation sites are indicated in its deduced amino acid sequence. The ‘consense transport motif‘ CTM is located etween TM8 and TM9. Furthermore, a protein kinase C phosphroylation site and three N-link glycosylation sites were predicted. The lignment of amino acid sequences between Pagrus major Nramp cDNA and several animals is analyzed and the deduced amino acid equence of Pagrus major Nrarnp had 77.8%, 83.0%, 82.3%, 80.0%, 81.1%, 60.4%, 70.3%, 58.5%, 69.5% identity ith rainbow trout α(AAD20721), rainbow trout β(AAD20722), channel catfish(AF400108), fathead minnow (AAF01778),common carp (CABal96), mouse 1 ( AAA39838 ), mouse 2 ( AAC42051 ), human 1 ( D50403 ), human 2 ( NP - 0(106(18 ),respectively. The alignment reveals high conservation in TM and CTM regions. Analysis result makes us get familiar with the structure nd character of fish Nramp, furthermore, offers some infonnat/on for the enhancement of immunity of fish and genetic amelioration on fish breeding. 相似文献
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水产养殖动物基因组研究的现状及其应用前景 总被引：3，自引：0，他引：3
The genomic resources from human and several model organisms have been increased very fast since 1990. The techniques for developing genomic resources have already been very advanced and smart. These could make scientists see and improve organism in genomic level. For Chinese aquaculture scientists and aquatic industry, developing genomic resources and genetic tools for the native species are most important in the genomic era. The genomic resources and genetic tools for several aquatic species have been developed and some of them have been used in the marker based selection and other researches. The genome research work on aquaculture species was reviewed in this paper, especially a USDA genome project was focused. Some functional genomic research for aquatic animal was also discussed here. The importance and necessity of China aquaculture species genome project were discussed. Common carp and other cultured fishes in Cyprinidae such as grass carp, silver carp, bighead carp etc were recommended as the candidate species for genome research, because the output of all carps is almost up to 1/3 of total fisheries output in China. Common carp with another virtue for genome research is that there are much more families and strains in common carp than those in other cultured species in China, and those families and strains are the basis for genome research and mapping quantitative trait loci associated with important economic trait. Although the first linkage map of common carp made by Sun needs to be added with more markers for mapping QTL and Type I markers ,it has laid the groundwork for QTL mapping and markerassisted selection in common carp. Because the model organism zebrafish and common carp, grass carp and other carps cultured in China all belong to Cyprinidae, the China carp genome research will obtain a lot of useful information from zebrafish genome research. How the China carp genome program will be conducted and what kinds of strategy involved in this program were all suggested. How the results of the genome research of aquaculture species will be used in the aquaculture industry was reviewed and analyzed here. 相似文献
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In order to investigate the difference in utilization of diets with different quality in Jian carp（Cyprinus carpio var. Jian）and allogynogenetic silver curcian carp(Carassius auratus gibelio), a 55 d growth trial was conducted and low quality diet (LQ-diet) and high quality diet (HQ diet) were tested. LQ-diet contained 33.91% dietary protein which is mainly from soybean meal while HQ-diet contained 45.59% dietary protein which is mainly from fish meal. The initial average body weights were from 5.58 g to 5.82 g for two fish strains. The trial was carried out in a system consisting of 12 self circulation 320 L tanks. During the experiment, the fish were fed to satiation twice a day (at 9: 00 and 15:00), and uneaten feed was collected 1 h after feeding and dried. Feces were collected twice a day (at 11:00 and 16:45) from the fecal traps and dried at 70 ℃. The results show that feed intake was higher in Jian carp than in allogynogenetic silver curcian carp when fed LQ diet, while there was no significant difference between weight gain, feed conversion efficiency, protein efficiency rate and apparent digestibility. When fed HQ diet, Jian carp showed a lower feed intake, but higher feed conversion efficiency and protein efficiency rate than allogynogenetic silver curcian carp while there was no significant difference in the weight gain and apparent digestibility of both species. For Jian carp, feed intake and protein efficiency rate for the fish fed HQ diet and LQ diet were not significantly different, while the fish fed HQ diet showed higher weight gain, feed conve
rsion efficiency and apparent digestibility. For allogynogenetic silver curcian carp, the fish fed HQ diet showed significantly higher feed intake, apparent digestibility, weight gain, feed conversion efficiency and lower protein efficiency rate. For Jian carp, body contents of dry matter, protein, lipid and energy for the fish fed HQ diet and LQ diet were significantly higher. For allogynogenetic silver curcian carp, body contents of dry matter and protein was significantly higher, while body contents of lipid and energy were affected by diet qualities. Compared to Jian carp, allogynogenetic silver curcian carp showed better utilization when fed LQ diet while poorer utilization when fed HQ diet. 相似文献
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动植物蛋白源替代鱼粉研究进展 总被引：42，自引：5，他引：37
With the fast development of aquaculture, fish meal needs increased in recent years, however the quantity of fish catching decreases gradually. Fishmeal is a limited feed resource, and serious concem exists on the future availability of this feedstuff for incorporation in fish diets. Undoubtedly, fish meal is well recognized as the best dietary protein source for most marine carnivorous fishes which required high dietary protein levels compared to omnivorous or herbivorous fish. Fishmeal is known for their high content of essential amino acids and fatty acids, low carbohydrates, high digestibility, low levels of anti-nutritional factors (for fresh fish meal) and is a very good source of minerals and is highly palatable. Thus fish meal is in high demand as the protein source for many formulated diets. However, production of fish meal consumes approximately 35 % of the total global fish catch, and the increasing price and potentially unstable supply in the market could be limiting factors for marine fish culture. There have been strong efforts to define and develop cost-effective protein sources that can, at least partly, substitute for expensive high-quality fish meals in least-cost feed formulations. The search for fish meal substitutes and altemative dietary protein sources is an international research priority that could be of considerable economic advantages. Therefore it is urgent task to find animal and plant protein sources in place of fish meal. Among these, plant feedstuffs have received most attention in recent years, but due to their amino acid unbalances, .presence of anti-nutritional factors and low palatability, a high level of replacement of fish meal with plant feedstuffs in omnivorous fish is generally not well accepted. This paper reviews the research status for other protein sources replacing fish meal based on available information in the literature. Animal and plant protein sources nutrient values are evaluated from the aspect of digestibility, antinutrients, physiological status and suitable supplementation. 相似文献
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鳗源嗜水气单胞菌主要外膜蛋白基因克隆及其表达 总被引：5，自引：0，他引：5
A pair of primers were designed according to the published nucleotide sequence of a putative outer membrane protein gene (omp) of Aeromonas hydrophila . With the specific primers, a target fragment about 1.1 kb was amplified from Aeromonas hydrophila ML316 via PCR .The target fragment was inserted into the linearized pGEM-T easy vector. After enzyme restriction and sequencing analysis,the nucleotide data had been further analyzed by DNAman and ClutalW software. The analysis results showed that the cloned DNA fragment had a longest open reading frame (ORF) of 1035 nt,it predicted to be encoded a 344 aa protein with the molecular weight of 36 kD. Hydrophobicity analysis suggested that the protein was highly hydrophilic, especialy at the first 24 aminoacid, this region could function as signal peptide. The homologious comparison proved the cloned gene had 96% homology to the sequence of the omp gene, and the alignment of the amino acid sequence was 98% . The recombinant plasmid was constructed with the target gene and the expressing vector pGEX-4T-1 and then was transformed into E. coli BL21（DE3）by BamH and Sal I .The fusion protein was expressed under the IPTG inducing condition,and exhibited about 62 kD in size,very close to the predicted molecular weight of GSTMOMP, furthermore,the fusion protein was specifically recognized by antiserum which raised against the major outer membrane protein of AHML316. Considering all these together, it proved that the cloned gene represented the major outer membrane protein gene of AHML316, and the expressed gene products shared identical antigenicity with the natural main outer membrane protein,and also provided technical support for developing an advanced gene engineering vaccine against Aeromonas hydrophila. 相似文献
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蓝太阳鱼生长激素全长cDNA的克隆与序列分析 总被引：7，自引：1，他引：7
The full length cDNA encoding growth hormone of a freshwater fish, Lepomis cyanellus, (LcGH) was cloned from pituitary RNA with RT-PCR, 3‘ and 5‘ RACE (rapid amplification of cDNA ends). The LcGH cDNA (Genbank No. AY530822), about 989nt (nucleotide) long, consisted of a open reading frame with 615nt long, 5‘and 3‘untranslated regions with 93nt and 224nt long respectively, and a 57nt poly (A) tail. The DNA sequence analysis showed that there are typical Kozak sequence and polyadenylation signal. The pregrowth hormone peptide of 204aa deduced from LcGH cDNA included a putative signal peptide (17aa) locating in its Nterminal. There exist a Asn-Cys-Thr glycosylation site at amino acid 201, and 4 cysteine residues (No. 69, 177, 194, 202) that are essential to construct two S-S bonds in this pregrowth hormone peptide. Homological comparision among LcGH and other species growth hormones showed that There is high homology (more than 85%) between growth hormone of Lepomis cyanellus and that of most perciformes fish, but low homology (less than 70%) in comparison with other species such as Siluriformes and Cypriniformes fish. 相似文献
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彭泽鲫的分子遗传分析及其与方正银鲫A系的比较 总被引：16，自引：2，他引：16
Genetic homogeneity between Pengze crucian carp and strain A of silver crucian carp was studied by using transferrin,isozyme and RAPD markers.The studied individuals of Pengze crucian carp showed transferring patterns were the same of silver crucian carp A strain while distinct from those of other crucian carp populations.As far as isozyme is concerned,the MDH,LDH and EST are all of the same with only slight differences in SOD between them.The RPAD patterns clearly indicated high homogeneity among 16 individuals (6 sampled from individuals of two years old and the others aged one) from crucian carp of Pengze and 5 individuals from strain A of silver crucain carp.Nearly indentical banding patterns were observed among all individuals.Average genetic distance within all the individuals is only 0.011,suggesting crucian carp of Pengze might possess indentical genetic background with strain A of silver crucian carp. 相似文献
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线纹尖塘鳢的形态生物学与核型 总被引：6，自引：0，他引：6
This paper reports the morphological character and karyotype of Oxyeleotris lineolatus. Oxyeleotris lineolatus is native in Australia and call
ed sleepy cod. It belongs to Oxyeleotris, Eleotridae, Gobioidei, Perciformes in taxonomy. Recently, it was introduced to China and local people were not familiar with it. So we carried out this study. 30 individuals have been observed and some data were recorded. It has a large mouth that is in front and up. The mandible stands out and is longer than the up jaw. There are many rows of thin teeth in up and down jaws. The pelvie fins are located in chest and pectoral fins are large and fanlike. There are two dorsal fins. The tail fin is circular. Gill rakers are sparse and the number of gill rakers is 8-12+3-4. The gas bladder belongs to physoclistaus and its stomach is strong and I-like. The intestine is thick and short and no pyloric caecas. The length of the digestive path is 48.1％-80.3% of the length of body. Its liver has two lobes and the liver weight is 4.1%-7.2% of the body weight. The digestive organs characters are same as the trait of flesheater fish. Its scale belongs to ctenoid scale and its body surface shows several long lines. There is not lateral line in the body. The number of vertebra is 26-27 and it has 10-11 pairs rib. The number of diploid chromosome is 2n=46 and the karyotype formula is 2sm+8st+36t，NF=48. The relative length of chromosome is from 1.37% to 3.48% and it is continuity. No strange size chromosomes relation to sex was observed. The karyotype of Oxyeleotris lineolatus is similar to that of Oxyeletris marmoratus Bleeker from South East Asia and both of them belong to Oxyeleotri. It testifies the correctness of traditional classification on cytology. 相似文献
11.
Association between the interannual variation in the oceanic environment and catch rates of bigeye tuna (Thunnus obesus) in the Atlantic Ocean 
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下载免费PDF全文 The environmental processes associated with variability in the catch rates of bigeye tuna in the Atlantic Ocean are largely unexplored. This study used generalized additive models (GAMs) fitted to Taiwanese longline fishery data from 1990 to 2009 and investigated the association between environmental variables and catch rates to identify the processes influencing bigeye tuna distribution in the Atlantic Ocean. The present findings reveal that the year (temporal factor), latitude and longitude (spatial factors), and major regular longline target species of albacore catches are significant for the standardization of bigeye tuna catch rates in the Atlantic Ocean. The standardized catch rates and distribution of bigeye tuna were found to be related to environmental and climatic variation. The model selection processes showed that the selected GAMs explained 70% of the cumulative deviance in the entire Atlantic Ocean. Regarding environmental factors, the depth of the 20 degree isotherm (D20) substantially contributed to the explained deviance; other important factors were sea surface temperature (SST) and sea surface height deviation (SSHD). The potential fishing grounds were observed with SSTs of 22–28°C, a D20 shallower than 150 m and negative SSHDs in the Atlantic Ocean. The higher predicted catch rates were increased in the positive northern tropical Atlantic and negative North Atlantic Oscillation events with a higher SST and shallow D20, suggesting that climatic oscillations affect the population abundance and distribution of bigeye tuna. 相似文献
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Liping Li Rui Wang Wanwen Liang Xi Gan Ting Huang Yan Huang Jian Li Yunliang Shi Honglin Luo Ming Chen 《广西水产科技》2014,(1)
Previously, we reported 10 PEGE types of 85 tilapia Streptococcus agalactiae(GBS), which shifted from Streptococcus iniae in China, by using PEGE method. Presently, larger and more representative tilapia GBS were isolated, for the ?rst time in China, to characterize their serotypes and genetic diversities more precisely than had done before. 168 GBS strains were distributed in ?ve provinces of China, in which Guangdong, Guangxi and Hainan were the major ones, holding36.9%(62/168), 37.5%(63/168) and 19.6%(33/168), respectively. Serotypes, Ia, Ib and III, were observed in these strains and the most predominant one was Ia(95.2%), which mainly distributed in Guangdong, Guangxi and Hainan. Ia initially occurred in 2009, it shoot up to 32.1% in 2010,but decreased to 16.1% in 2011 before went up to 45.2% in 2012. Ib sporadically occurred during2007–2011, III onlyoccurred in 2012. 14 different PFGE types, including 4 new types(N, O,P and Q), were observed, in which B, D, F and G were the predominant types, holding 83.9%(141/168) of the total GBS strains. Ia corresponded to 11 PFGE types(A–H, N–P), in which type D predominated(51%). Ib represented 3 genotypes(I, J and Q) and III harbored only 2genotypes(N and F). Type N and Fsynchronously presented in Ia and III. In summary, the genetic diversity of tilapia GBS varied by serotypes and changed with geographical locations and years.Although Iastillpredominated, new rareserotypeIII alreadyoccurred in China. 相似文献
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In this experiment, a feeding trial was performed to determine the effects of fructooligosaccharide (FOS) on growth performance, digestive enzyme activity and immune response of Japanese sea bass, Lateolabrax japonicus juveniles (initial weight 38.3 ± 0.5 g), and the fish were examined following feeding with six levels of FOS (0, 0.5, 1, 2, 4 and 6 g/kg) for 28 days. Significant enhancement of weight gain (WG) and specific growth rate (SGR) was found in fish fed 1 g/kg FOS incorporated diets (p < .05), while the feed conversion ratio (FCR) in the 1, 2 g/kg FOS groups reduced significantly compared with the control (p < .05). Besides, the crude lipid in the 4, 6 g/kg FOS groups increased significantly compared with the control (p < .05). On the other hand, the erepsin and lipase activities significantly elevated in intestine of fish fed 2 g/kg FOS (p < .05) and the lysozyme activity in serum of fish fed 2 g/kg FOS were significantly higher than that in the control (p < .05). Moreover, the alkaline phosphatase activities in serum of fish fed 0.5, 1, 2 g/kg FOS were significantly higher than in control (p < .05). Regression analysis showed that the relationships between dietary FOS levels and either SGR, FCR, erepsin or lysozyme activities were best expressed by regression equations, and the optimal inclusion levels are 1.37, 1.80, 3.06, 3.11, 1.93 and 1.80 g/kg for SGR, FCR, erepsin, lipase, lysozyme and total superoxide dismutase activities, respectively. Overall, this study revealed that FOS incorporated diets could beneficial for L. japonicus culture in terms of increasing the growth, digestion and immune activities. Under the present experimental condition, the optimal supplementary level of FOS in the diet of L. japonicus is 1–3 g/kg. 相似文献
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Iciar Martinez Amaya Velasco Ricardo Pérez-Martín Eskil Forås Michiaki Yamashita Carmen G. Sotelo 《Journal Of Aquatic Food Product Technology》2013,22(4):289-297
The purpose of this work was to evaluate the suitability of a method based on the presence of two restriction sites (for Hae III and Hindf I) in the mitochondrial NADH dehydrogenase subunit 5 (mt ND5) gene to identify Scomber species. The evaluation was performed on 144 reference and market samples by sequencing of the entire 505-bp fragment of the mt ND5 gene and of a 464-bp fragment of the Kocher fragment of the cytochrome b gene (mt Cytb). Sequence analysis of any of the two fragments allows the identification of each of the four Scomber species, but S. japonicus and S. colias had the same restriction sites at the ND5 amplicon and would not have been differentiated by this analysis. Similarly, loss of the Hae III site in some S. scombrus individuals would have misidentified them as not being Scomber. All the market products were correctly labeled except one acquired in Spain labeled as originating in the Atlantic and containing S. japonicus. 相似文献
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Two gonadotropins (GtH; Qa and Qb) were purified by gel filtration and ion exchange chromatography from the pituitaries of Indian walking catfish (Clarias batrachus). The presence of GtH during purification was assessed by in vitro oocyte maturation and in vivo steroidogenic activity, and their identities were determined by elution profiles, molecular weight, biological activities and yield. The molecular weights of Qa and Qb were 37 and 42 kDa, respectively, and composed of distinct subunits (Qa: 20 and 14 kDa and Qb: 26 and 18 kDa). Polyclonal antibodies raised against Qa immunostained Qa, Qb and pituitary GtH cells. A competitive Qa‐ELISA was developed whose sensitivity was 6.25 ng mL?1 (1.25 ng well?1) with intra‐ (3.5%) and inter‐ (12.4%) assay coefficients of variation. Displacement curves parallel to the standard were obtained with plasma and pituitary extracts of catfish, Qb and carp GtHII. The assay was validated by measuring the plasma Qa levels after LHRH treatment and in relation to ovarian growth in the female catfish during different reproductive phases. Based on the results, Qa and Qb corresponded to fish LH and FSH respectively. The findings will increase the knowledge of the mechanisms controlling fish reproduction and identification of sensitive phases in fish in captivity for hormonal manipulation. 相似文献
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Controlled infection of Poecilia reticulata Peters (guppy) with Tetrahymena by immersion and intraperitoneal injection 下载免费PDF全文
下载免费PDF全文 G Sharon M Pimenta‐Leibowitz M C L Vilchis N Isakov D Zilberg 《Journal of fish diseases》2015,38(1):67-74
Tetrahymena is a protozoan parasite, which infects guppy, Poecilia reticulata Peters, and causes substantial economical losses in commercial farms worldwide. Studies of guppy infected by Tetrahymena require standardized infection protocols. The LD50 for Tetrahymena infection of guppies by intraperitoneal (IP) injection was calibrated, and the level obtained was 946 parasites per fish. Guppy infection with Tetrahymena by immersion, imitating the natural route of infection via the integument, was studied under normal or stress conditions. Exposure to cold and netting (CNI) and to cold only (CI) followed by immersion exposure to 10 000 Tetrahymena per mL resulted in 22.5% and 19.2% mortality, respectively, as compared to 14.2% and 10% in groups that were netted only (NI) or non‐stressed (I). Histopathology revealed that immersion infection resulted in a systemic infection. Lysozyme levels, measured 3 weeks after infection, were significantly higher in the CNI group (288 μg per mg protein) compared with CI‐, NI‐ and I‐treated groups (94.5, 64 and 62.3 μg mg?1, respectively). There was no evident parasite immobilization activity in body homogenates, suggesting no development of acquired immunity. Re‐infection by IP injection revealed no increase in protection in any of the treatment groups, mortality range of 56.3–75%, higher than in the non‐exposed control (40.6% mortality). 相似文献
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Qin-Cheng Huang Di‐Gen Qin Bei‐Ping Tan Tao Du Yuan-Zhi Yang Qi-hui Yang Shu‐Yan Chi Xiao-hui Dong 《Aquaculture Research》2020,51(2):816-827
A 5 × 3 factorial growth trial was conducted to evaluate optimal dietary protein and lipid levels (dietary protein level, DP; dietary lipid level, DL) for juvenile Sillago sihama (S. sihama) (2.0 ± 0.02 g, initial weight). Fish were fed 15 diets containing 5 DPs (350, 400, 450, 500 and 550 g/kg) and 3 DLs (60, 90 and 120 g/kg) for 8 weeks. The interaction between proteins and lipids significantly influenced the feed conversion ratio, condition factor, body composition, antioxidant indices and lipase activity (p < .05). DP 450 g/kg showed the highest average final body weight. DPs 500 and 550 g/kg significantly decreased the protein efficiency ratio (p < .05). DL 120 g/kg showed the highest percentage weight gain. The low feed conversion ratio was found in diets P45L12, P55L9 and P55L12. Diet P45L12 showed high superoxide dismutase activities. DP 450 g/kg showed the lowest average malondialdehyde content. Lipase activity was increased by increasing DP (p < .05) with a fall at DP 550 g/kg. Under the present experimental conditions, the optimal DP for S. sihama was 450 g/kg under the DL 120 g/kg. 相似文献
20.
William King V David L. Berlinsky Craig V. Sullivan 《Fish physiology and biochemistry》1995,14(6):489-500
Plasma estradiol-17 (E2), testosterone (T), 17,20-dihydroxy-4-pregnen-3-one (DHP) and 17,20,21-tri-hydroxy-4-pregnen-3-one (20-S) levels were measured by radioimmunoassay (RIA) in white perch (Morone americana) and white bass (M. chrysops) that were induced to undergo final oocyte maturation (FOM) with human chorionic gonadotropin (hCG). Plasma DHP levels increased in females of both species in association with oocyte germinal vesicle migration (GVM) and germinal vesicle breakdown (GVBD) and decreased thereafter. Plasma 20-S levels also increased with oocyte GVM in white bass, but were several-fold lower than DHP levels. Circulating E2 and T levels were greatest during GVM and GVBD in both species and decreased to low levels during oocyte hydration and ovulation. Follicles from white perch and white bass which received a priming injection of hCG in vivo, produced both DHP and 20-S in vitro after exposure to hCG and their oocytes underwent GVBD. Ovarian incubates from unprimed fish of either species produced only E2 and T and their oocytes did not complete GVBD. Oocytes from unprimed bass, but not perch, matured when follicles were exposed to hCG in vitro. Both trilostane and cycloheximide blocked in vitro production of DHP and 20-S and oocyte GVBD by white perch follices. DHP and 20-S were equipotent inducers of FOM in the GVBD bioassay. None of several other structurally-related steroids tested were effective within a physiological range of concentrations. These results indicate a role for DHP and 20-S in the control of FOM in white perch and white bass. 相似文献