Expression Of Growth-related Genes Research Articles

Gene expression associated with indicated faster growth of crossbreeding inSinocyclocheilus grahami

In this study, pure-breeding and crossbreeding of Sinocyclocheilus grahami were established to test heterosis and expression of growth-related genes which were examined in the first-generation (F1). Genetic distances results showed that Muyang river (M) and Sanbaimu reservoir (S) populations had smaller interspecific distances (genetic distance: 0.000) while larger distances were shown to other two populations (0.024 of Jiuzhai vauclusian spring [J] and 0.044 of Chenglong vauclusian spring [C]). Full-sib families were created by using the Muyang river population as females: MM, MS, MJ and MC. Growth performance had significant differences between each group of F1 hybrids; the fastest growth group was shown in MJ while the slowest was in MS. For growth-related genes, the fast growth group of MJ hybrids showed significantly higher levels of ghrelin expression in strong expression tissues of the intestine and liver. Among the four combinations, mRNA levels of insulin-like growth factor I (IGF-I) were the highest expression in MJ hybrids than others in all tested tissues. Myostatin b and somatostatin1 (SST1) were strongly expressed in the brain and MJ hybrids showed relatively lower expression level. In the muscle, slow growth group of MS hybrids showed extremely higher expression levels of these two genes, especially SST1 gene. In conclusion, associating growth with growth-related genes expression indicated faster growth of crossbreeding in S. grahami and can make a contribution to commercial fish production in the future.

Modulatory Effects of Single and Complex Vitamins on the In Vitro Growth of Murine Ovarian Follicles.

Vitamin is a well-known co-factor for many metabolic processes and its roles in fertility and follicular growth have been studied. Vitamin supplementation is frequently achieved by daily ingestion in the form of a complex capsule. However, the role of single and complex vitamins in in vitro maturation of murine follicles is not fully elucidated. In this study, we evaluated the effects of two forms of vitamins. Pure L-ascorbic acid, and multi-vitamin (vitamin C + vitamin B complex) was treated at two different concentrations (50 and 100µg/ml), to pre-puberty murine follicles during in vitro maturation. To determine the specific stage of growth that is affected by treatment with vitamins, the vitamins were treated from day 0, 4, 9, and 13. Growth of each follicle was assessed by measuring diameters of whole expanded area and of the granulosa cells. Expression of follicular and oocyte growth-related genes and the effect of vitamin on the viability of follicles was assessed using senescence associated β-galactosidase staining. Treatment with vitamins promoted the in vitro growth of murine follicles and the upregulated the expression of granulosa cell- and oocyte-specific genes such as BMP15, Fsh receptor, and GDF9. The proliferation of the granulosa cells was enhanced by the treatment of vitamin. Fifty µg/ml concentration vitamin showed greater effects compared to higher concentration. The viability of in vitro grown follicles was also significantly improved in vitamin-treated follicles. The effects of single L-ascorbic acid and complex vitamin were not significantly different to those of day 4 and day 9 follicles. Vitamins promoted murine follicle development in vitro with different effects on specific growth stage. Supplementation of vitamins during in vitro maturation of murine follicles is an efficient strategy for in vitro expansion of follicular cells. These results could be customized to the sophisticated culture of follicles retrieved from aged or cancer-survived female that contain smaller number of follicles with reduced potential to develop into mature follicles.

Transcriptome profiles of corticosterone-induced cytotoxicity reveals the involvement of neurite growth-related genes in depression

Corticosterone (CORT), the main HPA-axis glucocorticoid hormone in rodents, is involved in the regulation of animal stress responses. However, the neural mechanisms underlying the effects of corticosteroids on depression are yet to be elucidated. We found that fluoxetine reversed neurite growth inhibition induced by CORT in PC12 cells, a widely used model system for neurobiological and neurotoxicological studies. Transcriptome profiling showed that 1,609 genes were up-regulated, whereas 1,764 genes were down-regulated significantly in the CORT group in comparison with the Control group. Of them, the expression of 589 DEGs was reversed after fluoxetine treatment, and genes related to cell morphogenesis, neurite growth, and immune function were involved in the neuroprotective effect of fluoxetine against CORT. Furthermore, expression of neurite growth-related genes, such as such as Calpain 2 (Capn2), vesicle-associated membrane protein 7 (Vamp7) and C-type natriuretic peptide (Cnp), altered in a brain region- or treatment-specific manner in the animal models of depression. Therefore, the interaction between stress, glucocorticoids, and neurite growth inhibition may be a candidate pathophysiology underlying major depressive disorder (MDD), and the identification of Capn2, Vamp7 and Cnp might provide insight into treatment of MDD.

Effects of dietary Radix Rehmanniae Preparata polysaccharides on the growth performance, immune response and disease resistance of Luciobarbus capito

This work explores the effects of dietary Radix Rehmanniae Preparata polysaccharide (RRPP) supplementation on the growth performance, nonspecific immune responses, immune- and growth-related gene expression and disease resistance to Aeromonas hydrophila in Luciobarbus capito. Diets containing five concentrations of 0%, 0.05%, 0.1%, 0.2% and 0.4% RRPP were fed to fish for 60 d. The results indicated that the growth performance significantly increased in the 0.1%, 0.2% and 0.4% RRPP groups compared with that in the control (P < 0.05). The activities of serum lysozyme (LAZ), acid phosphatase (ACP), superoxide dismutase (SOD), alkaline phosphatase (AKP) and total protein (TP) were significantly increased in the appropriate RRPP supplemented groups (P < 0.05). With respect to immune- and growth-related genes, such as interleukin (IL)-1β, IL-8, tumor-necrosis factor (TNF)-α, interferon (IFN)-γ, growth hormone (GH), insulin-like growth factor (IGF)-I and IGF-II, up-regulation were observed in the three organs (kidney, spleen, gut) of the fish fed with RRPP, compared with the control. In contrast, the mRNA expression of IL-10 and transforming-growth factor (TGF)-β were downregulated. After challenge with A. hydrophila, the final survival rate was significantly higher in fish fed the RRPP supplement than that in the control group (P < 0.05). In conclusion, RRPP enhanced the growth performance, immune response and disease resistance of Luciobarbus capito, with the greatest effects at 0.2% RRPP.

Expression of alpha-amylase and growth-related genes during early larval developmental stages of Clarias magur

To understand the carbohydrate utilization ability during developmental stages of Clarias magur, the mRNA levels and enzyme activity of amylase were studied. Furthermore, the transcript levels of some important growth genes like growth hormone (GH), insulin-like growth factor I (IGF-I) and insulin-like growth factor binding protein (IGFBP) were evaluated. The enzymatic activity and mRNA expression of alpha-amylase along with expression of growth-related genes were examined from hatching until 34 days post-hatching (dph) by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Subsequently, mRNA expression pattern revealed the significantly (P < .05) high transcript level of alpha-amylase during early stages and early peaks were found at 3 to 6 dph, later the expression decreased till the end of experiment. Growth-related genes like GH, IGF-I and IGFBP showed a variable level of mRNA expression pattern from 0 dph to 34 dph. However, there was no significant difference (P > .05) in the mRNA expression of growth-related genes among the different time points of the present study. Moreover, the amylase activity revealed almost same pattern as that of its mRNA expression. In general, the present results suggested that C. magur has the ability to utilize the digestible carbohydrates during the early stages and can be helpful in developing low cost feeds for larvae.

Identification of muscle and adipose gene expression patterns in lean and obese pigs

Obesity is a major risk factor of preventable deaths worldwide, with increasing rates being observed in adults and children. To understand the mechanisms of obesity development, genetically lean (Duroc strain) and obese (Rongchang strain) pigs were used to identify potential differences in muscle and adipose development patterns following consumption of an identical diet for 180 days. Lean pigs had a significantly higher lean percentage (67.79% versus 44.71%) and lower obesity index (0.68 versus 0.84) than obese pigs. They also exhibited significantly lower adipocyte volumes and higher myofibre cross-sectional areas. Quantitative polymerase chain reaction showed that lean pigs had a significantly higher expression of muscle growth-related genes and lower expression of lipogenesis-related genes. By contrast, obese pigs had higher expression of a myostatin-related gene and lower expression of lipolysis-related genes. Additionally, the mitochondrial DNA copy number was higher in the muscle and lower in adipose tissue in lean compared with obese pigs. These results indicate that lean pigs have a distinct development pattern from obese pigs, involving lipogenesis, muscle growth, and energy metabolism. This study provides a basis for exploring the mechanisms of adipose deposition and muscle growth in obesity. Keywords: Obesity, mitochondrial DNA, Sus scrofa

Modulation of digestive enzyme activity, blood health, oxidative responses and growth-related gene expression in GIFT by heat-killed Lactobacillus plantarum (L-137)

The current study was performed to investigate the effects of dietary heat-killed Lactobacillus plantarum (HK L-137) on growth, digestive enzyme activity, intestinal morphology and oxidative status in genetically improved farmed tilapia (GIFT). For 12 weeks, fish were fed a control diet (HKL0) or a diet supplemented with HK L-137 at a concentration of 50 (HKL50), 100 (HKL100) or 1000 (HKL1000) mg kg−1 feed. At the final sampling, the HKL100 group had significantly (P < 0.05) increased performance parameters (FBW, WG, SGR and FER) compared to the control group, while the HKL50 and HKL1000 groups showed weaker improvements. Mucosal thickness and villus length were significantly (P < 0.05) increased in the HKL50 and HKL100 groups in the anterior, middle and posterior intestine, but muscle thickness was significantly (P < 0.05) improved only in the anterior and middle intestine. Amylase, lipase and protease activity was significantly (P < 0.05) increased in fish fed 50 or 100 mg HK L-137 per kg diet compared to control fish. Significant modulation of blood haematocrit, haemoglobin levels, and RBC and WBC counts (P < 0.05) occurred in fish fed HK L-137, while total cholesterol and GPT were decreased by HK L-137. Furthermore, antioxidative enzyme (SOD and CAT) activity were significantly (P < 0.05) higher in the HKL100 group than in the control group, while MDA levels were lower. Furthermore, fish fed HK L-137 showed enhanced total serum protein and IgM levels. Interestingly, qRT-PCR revealed significant (P < 0.05) upregulation of the growth-related gene IGF-I and the glucose regulation gene G6PD but downregulation of the fatty acid synthase (FAS) gene in all HKL groups compared to the control group. Thus, we conclude that the use of HK L-137 is an efficient strategy to achieve economically feasible and sustainable tilapia production.

Effects of dietary protein levels on growth, feed utilization and expression of growth related genes of juvenile giant grouper (Epinephelus lanceolatus)

A 6-week growth trial was conducted to study the effects of dietary protein levels on growth, feed utilization, ammonia excretion and expression of growth related genes of juvenile giant grouper (Epinephelus lanceolatus). Seven experimental diets were formulated to contain 38% (P38), 42% (P42), 46% (P46), 50% (P50), 54% (P54), 58% (P58) or 62% (P62) dietary crude protein (CP) (dry-matter basis). Experimental fish (average initial body weight: 5.39 ± 0.05 g) were randomly distributed into 21 glass tanks (length 60 cm × width 45 cm × height 50 cm) at a density of 15 fish / tank and fed their prescribed diets to apparent satiation twice daily (08: 00 and 16:30) by hand. All tanks were connected to the mechanical and biological water filters as a recycling system, and each experimental treatment had three replicates. At the end of the trial, two fish per tank were collected for whole-body composition analysis, and other three fish per tank were individually weighed and dissected to obtain liver and intraperitoneal fat (IPF) weights. Total RNA was extracted from grouper liver and pituitary using Trizol Reagent. Results showed that weight gain% (WG%) of fish was remarkably increased as dietary CP levels increased from 38% to 54%, and when it continued to rise from 54% to 62%, there only had a slight increment in values of this parameter. Analysis of a nonlinear exponential model indicated that the optimal dietary protein requirement for maximum growth of giant grouper was estimated to be 56% of dry matter. Daily feed intake (DFI) and feed conversation ratio (FCR) were decreased with the increasing of dietary CP levels. Fish fed P38 and P42 showed lower lipid retention efficiency (LRE) and lower contents of liver lipid, whole-body protein as well as muscle protein than fish fed other dietary CP levels. The water ammonia production was linearly related to dietary CP levels. Expression of pituitary growth hormone (GH) and hepatic target of rapamycin (TOR), S6 kinase 1 (S6K1) as well as insulin growth factor I (IGFI) were lower in fish fed P38, P42 and P46 than those in fish fed P50, P54, P58 and P62. Generally, the optimal dietary crude protein requirement for maximum growth of giant grouper was estimated to be 56% of dry matter.

Effect of feeding less shell, extruded and enzymatically treated palm kernel cake on expression of growth-related genes in broiler chickens

Palm kernel cake (PKC) is a residue of palm kernel after oil extraction and can be used as a by-product feedstuff for livestock. In the current study, various post-treated PKC fed to broiler chickens and their growth performance and expression of genes related to growth trait studied. A total of 2500-day-old broiler chicks were randomly assigned to following five isocaloric and isonitrogenous diets: 0% PKC (control: corn-soybean meal), 25% PKC in the forms of either untreated or less-shell or extrudedor enzymatically-treated. Each treatment group consisted of five replicates with 100 chicks each. Growth performance and expression of 27 selected genes related to growth and metabolism pathways were investigated. Chickens were fed with treated PKC diets had lower (p < .05) body weight gain, inferior feed conversion ratio (FCR) and higher feed intake. The expression of genes involved in mTOR (GRB2, GRB10), FoxO (FOXO3) and insulin (PRKCZ) signalling pathways, glycolysis/gluconeogenesis (ENO1), fructose and mannose metabolism and apoptosis (RHOBTB2, LOC101750363) were significantly up-regulated in broilers fed with less-shell PKC. It can be concluded that the shell reduction, enzymatic and extrusion treatment practiced in this study did not change PKC feeding potentials in broiler chickens.HighlightsSignificant up-regulation of eight genes which involved in energy metabolism and growth related functions were observed in broilers fed with less-shell palm kernel cake (PCK).The DEGs (differentially expressed genes), which were upregulated in less shell palm kernel cake fed broilers constituted the pathways related to energy and metabolism such as mTOR, glycolysis, fructose and mannose metabolism, FOXO, apoptosis, and insulin signaling pathway.Higher bulk density and lower water holding capacity of palm kernel cake may lead to higher feed consumption in palm kernel cake incorporated diets.

Change in Hair Growth-related Gene Expression Profile in Human Isolated Hair Follicles Induced by 5-alpha Reductase Inhibitors, Dutasteride and Finasteride, in the Presence of Testosterone

Objective: 5-α Reductase (5AR) subtypes I and II are suggested to be involved in the development of Andro-Genetic Alopecia (AGA); however, the involvement of type I 5AR in the pathogenesis of AGA and downstream molecular events following androgen receptor inhibition are still poorly understood. We investigated the changes in gene expression levels of growth factors and related molecules responsible for hair growth, such as enzymes and transcription factors, using the bulbar portions of plucked human hair follicles, and evaluated the involvement of type I 5AR in human hair growth. Methods: Anagen hairs were plucked from male donors with AGA and cultured in medium containing Di-Hydro Testosterone (DHT) or testosterone in the presence or absence of the 5AR inhibitors, dutasteride or finasteride. Total RNA extracted from the bulbar portions of hair follicles was subjected to quantitative reverse transcriptase polymerase chain reaction analysis to assess gene expression levels of growth factors and other related molecules. Results: DHT stimulation resulted in a trend to decrease the expression of genes encoding fibroblast growth factor 7 (FGF7; p=0.52), insulin-like growth factor 1 (IGF1; p=0.85) and WNT family member 5A (WNT5a; p=0.08). Subsequently, testosterone stimulation led to decreased expression of genes encoding FGF7 (p=0.53), IGF1 (p=0.93) and WNT5a (p=0.51), which was reversed by dutasteride or finasteride treatment. Conclusion: Among the assessed growth factors and other molecules related to hair growth, the expression levels of FGF7, IGF1 and WNT5a were reversed by 5AR inhibitors under testosterone stimulation. Our data suggest this assay may be useful to deeper dissect the effect of 5AR on human hair follicles and supports the previously unreported involvement of type I 5AR in hair growth.

Changes in bud morphology, growth-related genes and nutritional status during cheliped regeneration in the Chinese mitten crab, Eriocheir sinensis.

During pond culture of Eriocheir sinensis, a high limb-impairment rate restricts the industry development and quality. Therefore, research on limb autotomy and regeneration has important practical significance for the industrial development and basic biology of E. sinensis. This study evaluated the changes in bud morphology, growth-related gene expression and nutritional status during cheliped regeneration in E. sinensis. The study found that the new cheliped was pre-formed in the bud and then regenerated with the completion of molting of E. sinensis. The new cheliped was similar in morphology to the normal cheliped after the first molting but smaller in size. The qRT-PCR results of growth-related genes showed that the expression levels of EcR-mRNA (ecdysteroid receptor) and Chi-mRNA (chitinase) were significantly up-regulated, whereas the expression of MIH-mRNA (molt-inhibiting hormone) was significantly down-regulated (P < 0.05). The nutritional status during the regeneration process showed that the hepatopancreas total lipid content decreased significantly within 28 days and was significantly lower in the autotomy group than in the control group at 14 d and 21 d (P < 0.05). The hepatopancreas fatty acid composition results showed that saturated fatty acids (SFA), highly unsaturated fatty acids (HUFA) and n-3/n-6 were significantly higher in the autotomy group than in the control group at 21 d (P < 0.05), whereas the ∑ n-6 PUFA and ∑ n-3 PUFA at 1 d and 7 d, and the monounsaturated fatty acid (MUFA) at 28 d in the autotomy group were significantly lower than in the control group (P < 0.05). Moreover, the levels of eicosatetraenoic acid (ARA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) showed that DHA was significantly lower at 7 d and significantly higher at 21 d in the autotomy group than in the control group (P < 0.05), whereas ARA and EPA were not significantly different between the two groups. Muscle L-tryptophan content was significantly lower at 1 d and significantly higher at 7 d in the autotomy group than in the control group (P < 0.05). These results indicate that during the cheliped regeneration process, crabs could accelerate molting and regeneration by regulating growth-related gene expression (e.g., EcR-mRNA and MIH-mRNA) and nutrient metabolism (e.g., lipid metabolism).

Expression patterns of candidate genes reflecting the growth performance of goats subjected to heat stress

The study is an attempt to elucidate the molecular mechanisms governing growth performance during heat stress in goats. The primary objective of the study was to establish the influence of heat stress on the expression patterns of different growth related genes in Malabari goats. The study was conducted for a period of 45days in 12 Malabari goats randomly allocated into two groups: MC (n = 6; Malabari control) and MHS (n = 6; Malabari heat stress). At the end of study period, all 12 animals were slaughtered and their liver tissues were collected for gene expression and histopathological studies. The temperature-humidity-index (THI) inside the shed (74.9) proved that the animals were not stressed while in the outside environment (86.5) the animals were extremely distressed. The hepatic growth hormone (GH), growth hormone receptor (GHR), insulin-like growth factor-1 (IGF-1), leptin (LEP) and leptin receptor (LEPR) gene expression patterns were significantly (P < 0.05) lower in heat stress group as compared to the control group animals. In addition, negative correlation (P < 0.05) was also established between THI and all the growth related gene expression in the study. The hepatic histopathological section showed more fatty and degenerative changes (P < 0.05) in hepatocytes in MHS group as compared to MC group. The study offers the first thorough insight into the expression patterns of different growth related genes during heat stress exposure in goats. Further, the study established GH, GHR, IGF-1, LEP, LEPR genes to be the ideal markers to reflect growth potential in Malabari goats.

Development of cardiovascular and neurodevelopmental metrics as sublethal endpoints for the Fish embryo toxicity test.

The fathead minnow fish embryo toxicity (FET) test has been proposed as a more humane alternative to current toxicity testing methods as younger organisms are thought to experience less distress during toxicant exposure. However, the FET test protocol does not include endpoints that allow for the prediction of sublethal adverse outcomes, limiting its utility relative to other test types. Researchers have proposed the development of sublethal endpoints for the FET test to increase its utility. The present study 1) developed methods for previously unmeasured sublethal metrics in fathead minnows (i.e., spontaneous contraction frequency and heart rate) and 2) investigated the responsiveness of several sublethal endpoints related to growth (wet wt, length, and growth-related gene expression), neurodevelopment (spontaneous contraction frequency, eye size, and neurodevelopmental gene expression), and cardiovascular function and development (pericardial area, heart rate, and cardiovascular system-related gene expression) as additional FET test metrics using the model toxicant 3,4-dichloroaniline. Of the growth, neurological, and cardiovascular endpoints measured, length, eye size, and pericardial area were found to be more responsive than the other endpoints evaluated. Future studies linking alterations in these endpoints to longer-term adverse impacts are needed to fully evaluate the predictive power of these metrics in chemical and whole-effluent toxicity testing. Environ Toxicol Chem 2018;37:2530-2541. © 2018 SETAC.

Antifungal Activity of Essential Oil Compounds (Geraniol and Citral) and Inhibitory Mechanisms on Grain Pathogens (Aspergillus flavus and Aspergillus ochraceus).

The grain contamination by Aspergillus spp. has been a serious issue. This study exhibited the excellent antifungal effects of the essential oil compounds (EOCs) geraniol and citral against common grain pathogens (A. flavus and A. ochraceus) in vitro and in situ. The inhibitory mechanisms were also evaluated from the perspective of cell membrane permeability, reactive oxygen species (ROS) generation, and Aspergillus spp. growth-related gene expression. Meanwhile, the combined effects of EOCs in the vapor phase and modified atmosphere packaging (MAP) were examined to find an alternative preservation method for controlling Aspergillus spp. The results indicated that citral exhibited the antifungal activity mainly by downregulating the sporulation- and growth-related genes for both pathogens. Geraniol displayed inhibitory effectiveness against A. flavus predominantly by inducing the intracellular ROS accumulation and showed toxicity against A. ochraceus principally by changing cell membrane permeability. Furthermore, the synthetic effects of EOCs and MAP (75% CO2 and 25% N2) induced better grain quality than the current commercial fumigant AlP. These findings reveal that EOCs have potential to be a novel grain preservative for further application.

The Interaction between DELLA and ARF/IAA Mediates Crosstalk between Gibberellin and Auxin Signaling to Control Fruit Initiation in Tomato

Fruit initiation following fertilization in angiosperms is strictly regulated by phytohormones. In tomato (Solanum lycopersicum), auxin and gibberellin (GA) play central roles in promoting fruit initiation. Without fertilization, elevated GA or auxin signaling can induce parthenocarpy (seedless fruit production). The GA-signaling repressor SlDELLA and auxin-signaling components SlIAA9 and SlARF7 repress parthenocarpy, but the underlying mechanism is unknown. Here, we show that SlDELLA and the SlARF7/SlIAA9 complex mediate crosstalk between GA and auxin pathways to regulate fruit initiation. Yeast-two-hybrid and coimmunoprecipitation assays showed that SlARF7 and additional activator SlARFs interact with SlDELLA and SlIAA9 through distinct domains. SlARF7/SlIAA9 and SlDELLA antagonistically modulate the expression of feedback-regulated genes involved in GA and auxin metabolism, whereas SlARF7/SlIAA9 and SlDELLA coregulate the expression of fruit growth-related genes. Analysis of procera (della), SlARF7 RNAi (with downregulated expression of multiple activator SlARFs), and entire (iaa9) single and double mutants indicated that these genes additively affect parthenocarpy, supporting the notion that the SlARFs/SlIAA9 and SlDELLA interaction plays an important role in regulating fruit initiation. Analysis of the GA-deficient mutant gib1 showed that active GA biosynthesis and signaling are required for auxin-induced fruit initiation. Our study reveals how direct crosstalk between auxin- and GA-signaling components is critical for tomato fruit initiation.

Challenge with fumonisins B1 and B2 changes IGF-1 and GHR mRNA expression in liver of Nile tilapia fingerlings

Although fumonisins are identified as responsible for alterations in weight gain, little information is available on their effects on expression of growth-related genes, especially for Nile tilapia (Oreochromis niloticus) fingerlings. In this study, Nile tilapia fingerlings were treated with increasing levels of fumonisin B1 (FB1) and fumonisin B2 (FB2) (diets of 0, 20, 40, and 60 mg/kg) to evaluate their effects on weight gain (WG), feed intake (FI), feed efficiency (FE), growth hormone receptor (GHR) and insulin growth factor 1 (IGF-1) mRNA expression in liver of this fish. All variables were evaluated at 15 and 30 days of treatment. Diet containing 0 mg fumonisin/kg was used as control treatment. Treatment with 20, 40, and 60 mg fumonisin/kg of diet significantly reduced WG (P&lt;0.0001) and FE (P&lt;0.0001), while GHR and IGF-1 mRNA expression was reduced both at 15 and 30 days of treatment. Feed intake was not affected by diets in any of the evaluated periods. These results indicate that fumonisins (FB1 + FB2) affect the growth of Nile tilapia fingerlings through mechanisms that involve reduction of GHR and IGF-1 expression.

Interactive effects of salinity and complete fishmeal replacement on growth, food consumption, and gene expression of hepatic IGF-I, IGF-II and growth hormone receptors in Nile tilapia,Oreochromis niloticus(L.)

A 12-week feeding trial was conducted using Nile tilapia, Oreochromis niloticus (L.) to evaluate the interactive effects of fishmeal replacement and salinity on growth, feed utilization efficiencies and relative expression of growth related genes. Two iso-nitrogenous and iso-energetic diets were prepared (32% protein). The control diet included 15% fishmeal (FM diet) and fishmeal component in non-fishmeal diet (NFM) was eliminated by a mixture of poultry by-product meal, high protein distillers dried grains and distillers dried grains with soluble. The NFM diet was supplemented with DL-methionine and L-lysine. Duplicated group of fish with initial mean weight of 6 g, reared in four salinity levels (0, 4, 8 and 12 g/L) were fed one of the two diets twice a day to near satiety. At the end of the experiment, growth, feed utilization efficiency and expression of growth related genes were compared. The specific growth rate (SGR), mean feed intake (MFI) and feed conversion ratio (FCR) were not affected by the diets while salinity effects were significant. The fish in the 4 g/L salinity showed the highest SGR and MFI while fish in the 0 g/L treatment showed the lowest FCR. Relative expression of hepatic IGF-I and IGF-II was regulated by salinity but not by the diet. Expression of growth hormone receptor gene was not affected by either diet or salinity. The present findings provide evidence for the possibility of total fishmeal replacement in saline waters (0–12 g/L) without compromising growth, feed utilization and body composition of Nile tilapia.

Melatonin Promotes Cheliped Regeneration, Digestive Enzyme Function, and Immunity Following Autotomy in the Chinese Mitten Crab, Eriocheir sinensis.

In the pond culture of juvenile Eriocheir sinensis, a high limb-impairment rate seriously affects the culture success. Therefore, it is particularly important to artificially promote limb regeneration. This study evaluated the effects of melatonin on cheliped regeneration, digestive ability, and immunity, as well as its relationship with the eyestalk. It was found that the injection of melatonin significantly increased the limb regeneration rate compared with the saline group (P < 0.05). The qRT-PCR results of growth-related genes showed that the level of EcR-mRNA (ecdysteroid receptor) and Chi-mRNA (chitinase) expression was significantly increased following the melatonin injection, while the expression of MIH-mRNA (molt-inhibiting hormone) was significantly decreased (P < 0.05). Melatonin significantly increased lipase activity (P < 0.05). We observed that the survival rates of limb-impaired and unilateral eyestalk-ablated crabs were substantially improved following melatonin treatment, whereas the survival of the unilateral eyestalk-ablated crabs was significantly decreased compared with the control group (P < 0.05). Furthermore, the results of serum immune and antioxidant capacity revealed that melatonin significantly increased the total hemocyte counts (THC), hemocyanin content, total antioxidant capacity (T-AOC), acid phosphatase (ACP), and glutathione peroxidase activity (GSH-Px), whereas the immune-related parameters were significantly decreased in eyestalk-ablated crabs (P < 0.05). Therefore, these findings indicate that melatonin exerts a protective effect on organism injury, which could promote limb regeneration by up-regulating the expression of growth-related genes, improve digestive enzyme activity, and strengthen the immune response, particularly antioxidant capacity.

Larval dietary protein complexity affects the regulation of muscle growth and the expression of DNA methyltransferases in Senegalese sole

Due to its high protein synthesis and deposition rates, skeletal muscle protein deposition is a major determinant of fish growth. Dietary protein complexity is likely to influence protein utilization and deposition in skeletal muscle, possibly affecting fish myogenesis. In this study, three microdiets were formulated with different degree of hydrolysis of dietary protein as the changing factor: one diet contained a mix of intact protein sources targeting a peptide with molecular weight >20 kDa (Intact); a second diet contained a hydrolysate with polypeptides ranging from 5 to 70 kDa (PartH); and a third diet contained a high level of a protein hydrolysate mostly composed of small peptides (<5 kDa) (HighH). A possible effect on the regulation of muscle growth in Senegalese sole larvae was evaluated through white muscle cellularity and the expression of muscle growth-related genes at 16 and 36 DAH. The PartH diet promoted white muscle growth during the metamorphosis climax (16 DAH), which was reflected on increased body weight. At 36 DAH, different diets induced different expression patterns of genes encoding for the myogenic regulatory factors, which affected muscle growth dynamics, ultimately promoting growth potential in the Intact group. A lower recruitment of small-sized fibres in the PartH and HighH groups led to reduced potential for muscle growth, which resulted on further reduced somatic growth. Accordingly, fish fed the Intact diet grew better up to a late juvenile stage (60 DAH) and were still heavier than others even after 30 days of feeding all groups on the same commercial diet, at 90 DAH. The up-regulation in the transcript levels of genes encoding for de novo DNA methyltransferases in the HighH group suggest a potential for nutritional programming in this species.

De novo transcriptome assembly for the rose spotted snapperLutjanus guttatusand expression analysis of growth/atrophy-related genes

The rose spotted snapper is an important fishery resource with potential for farming in several Latin American countries. Since transcriptomic information was not available for this species, we generated a reference transcriptome from eleven tissues (brain, heart, gonad, liver, gut, muscle, white skin, dark skin, and visceral fat) using Illumina HiSeq2000 platform. Transcriptome assembly and annotation were performed with Trinity and Trinotate respectively; 267,601 contigs were assembled, average contig length was 845 bp; 85,677 putative protein sequences were identified. Sixty-six per cent of them showed a significant match to the SwissProt Database. From this assembly, we selected growth/atrophy-related genes to investigate the effect of dietary protein source on gene expression. Pacap expression was measured in the brain; igf1, igf2 and ghr were measured in liver; and mtor, igf1, igf2, myod1, myod2, myogenin, foxo3a, foxo3b, murf1, mafbx, mstn1 and mstn2 were measured in muscle. A feeding trial with juveniles was performed, in which three diets were formulated, a fishmeal-based diet (FM), a terrestrial animal protein diet (PPM) with porcine meat meal and poultry by-products meal, and a vegetable diet (VEG) with a blend of soybean protein concentrate and corn gluten. A reduced expression of somatotropic and myogenic genes in fish fed the VEG diet was observed; however, expression of atrophy genes did not increase with this diet suggesting that atrophy mechanisms were not involved. These results indicate that protein from a vegetable source does not provide proper amino acid requirements to juvenile fish, decreasing expression of myogenic and other growth-related genes.