Muscle Cellularity Research Articles

Effect on Muscle Cellularity of Diet Supplementation with Nannochloropsis gaditana Microalgae in the Final Fattening Phase of Gilthead Seabream Culture up to Commercial Size

Previous studies have shown that Nannochloropsis gaditana can partially replace fishmeal in the diet of gilthead seabream, Sparus aurata. However, its effect on muscle growth is hardly known. This experiment was carried out with gilthead seabream adults that were fed with N. gaditana at two inclusion levels (2.5 or 5%) either raw (R2.5 and R5 groups) or cellulose-hydrolyzed (H2.5 and H5 groups) for 45 days in the final fattening phase. The body length and body weight were measured in all fish at the beginning and end of the experiment. Also, the white muscle transverse area (WM), size, number and fibrillar density of the white fibers were measured in 9 fish group−1. After 45 days, the body parameters and the WM did not show significant differences among the groups. However, muscle cellularity did show significant differences, such that the hypertrophy values were higher in the H2.5 and H5 than in the R2.5 and R5 groups. On the contrary, R2.5 and R5 showed the highest fibrillar density and hyperplasia values, which are often positively correlated with the fillet firmness and therefore could improve the final quality of the fish. No significant differences attributable to the inclusion levels of N. gaditana were observed.

Dietary inclusion of blood hydrolysates affects muscle growth in European seabass (Dicentrarchus labrax)

Dietary supplementation with hydrolysates has been suggested to influence muscle protein synthesis and fish growth. This study assessed the impact of including 3% swine blood hydrolysates (BH) in a plant-based diet on muscle cellularity and the expression of molecular markers related to muscle fibre proliferation and hypertrophic growth of European seabass. Three BH fractions were obtained by two different processes, autohydrolysis (AH-H) and enzymatic hydrolysis followed by micro- (RMF-H) and nanofiltration (RNF-H). Each BH was added to a commercial-based diet, where 50% of fishmeal was replaced by vegetable proteins (negative control, NC). A fishmeal-based diet was used as positive control, PC. The diets were fed to juveniles (12 g) during 74 days. The RMF group showed down-regulation of myod1 and fgf4, essential to myoblast proliferation and differentiation, and upregulation of mafbx, responsible for protein breakdown, resulting in impairment of muscle hyperplasic growth and the lowest muscle fibres number. However, compensatory growth mechanisms were observed through capn1 downregulation and mymk upregulation, suggesting decreased muscle proteolysis and increased myoblast fusion. Despite this, the compensatory mechanisms were insufficient as RMF group had the worst growth. RNF group had a final weight similar to the NC, but downregulation of fgf4, fgf6 and capn1 may compromise growth potential at long term. The expression of these genes in the AH group was similar to that in the FM-based diet. Despite not having demonstrated growth promotion ability, BH affect muscle growth and cellularity factors, prompting further research on commercial-sized fish to reveal their impact on important commercial traits.

Comparison of nutritional quality, flesh quality, muscle cellularity, and expression of muscle growth-related genes between wild and recirculating aquaculture system (RAS)-farmed black rockfish (Sebastes schlegelii)

Comparison of nutritional quality, flesh quality, muscle cellularity, and expression of muscle growth-related genes between wild and recirculating aquaculture system (RAS)-farmed black rockfish (Sebastes schlegelii)

Exposure to different temperature regimes at early life stages affects hatching, developmental morphology, larval growth, and muscle cellularity in rainbow trout, Oncorhynchus mykiss.

In this study, the effects of temperature on hatching, yolk-sac absorption, larval metamorphosis, post-metamorphic growth, developmental morphology, and muscle cellularity were assessed in rainbow trout, during its early development (until 52 days post-hatching, dph). From the eyed-ova stage, embryos were exposed to either low (8 ± 1 °C, LT-8) or high (16 ± 1 °C, HT-16) temperatures until hatching. Following hatching, half of the sac-fry from LT-8 group were shifted to higher temperature (16 ± 1 °C, LHT-16), and half from HT-16 group were shifted to medium temperature (13 ± 1 °C, HMT-13), for larval rearing. Incubating the eyed-ova at 16 °C preceded the hatching by 6 days, synchronized hatching duration, and minimized hatchlings' size-variation. However, it yielded smaller and morphologically less developed individuals compared to those incubated continuously at 8 ± 1 °C. Post-hatch shifting of sac-fry to high and medium temperatures, respectively, from the initial low and high regimes differentially affected the length and weight of fish. The effect on length was immediate and temporary, but on weight, it appeared to be permanent. Red muscle hypertrophy was observed to be high in HT-16 and HMT-13 individuals (high-temperature incubated groups). White muscle hypertrophy was high in HT-16 and LHT-16 individuals (high post-hatch rearing temperature groups). The effect of early-life temperature regimes on developmental morphology was found to be strong at 22 dph (82.5%) and comparatively weak at 52 dph (65%). The post-hatch rearing temperature caused an immediate but temporary effect on fin development, mainly pectoral, caudal, and anal fin (seen only at 22 dph, not at 52 dph). Contrarily, incubation temperature affected fin position, in a delayed but persistent manner (subtle at 22 dph, but stronger at 52 dph). Overall, this study provides new insights on temperature-dependent changes in developmental morphology, muscle cellularity, and larval growth in rainbow trout and shows that incubation temperature affects ontogeny profoundly than post-hatch thermal regimes.

PSIII-A-11 Effects of Maternal Nutrition and Selenium Status on Postnatal Muscle Growth and Meat Quality

Abstract To investigate the effects of maternal nutritional plane and selenium (Se) level on offspring muscle development in first parity ewes, Rambouillet ewes (n = 84) were stratified by BW and randomized to receive diets formulated to contain adequate Se (ASe) or high Se (HSe) initiated at breeding. On d 40 of gestation, ewes were assigned randomly within Se treatments supply 60% (RES), 100% (CON), or 140% (HI) of NRC requirements. Offspring were slaughtered at 180 ± 2.2 d of age. Psoas major (PM), longissimuss dorsi (LD), and semimembranosus (SM) samples were snap frozen and analyzed for fiber diameter and type, celluarity, calpain 1 autolysis, and calpastatin expression. Within the PM RNA was increased (P=0.04) in HSe vs. ASe and CON vs. HI. Protein was greater (P=0.05) in ASe than HSe within HI. RES had greater (P=0.09) protein than CON. Calpain 1 had more autolysis in HSe vs. ASe (P≤0.03) in CON and HI. Calpastatin with lower molecular weights was greater (P≤0.01) in the Ase than HSe from CON. Within the SM, ASe had greater (P≤0.05) DNA and RNA concentrations than HSe within HI. Calpastatin immunoreactivity was less (P=0.04) for RES-ASe than all treatments except CON-HSe. Within the LD, calpain 1 had more (P≤0.01) autolytic degradation in CON-ASe than other treatments. Maternal diet did not influence fiber type or diameter. The influence of treatments on skeletal muscle cellularity and calpain system activation is not consistent between muscle types. The PM was most influenced by selenium in the HI group. Conversely, the LD showed more activation of calpain in the CON-ASe. Maternal diet and selenium possibly changed muscle development in offspring which could result in altered quality and yield of lamb produced.

Diallel Cross Application and Histomolecular Characterization: An Attempt to Develop Reference Stock of Labeo ariza.

Simple SummaryDiallel crosses are breeding schemes used to estimate combining ability and the effects of reciprocal crosses among strains or varieties. Using this diallel cross scheme, we produced a crossbred population of Ariza labeo (Labeo ariza), a newly potential aquaculture species in Bangladesh. The improved performances of this crossbreed were observed phenotypically (growth performances) and genetically (variation at selected microsatellite loci) and manifested through myofiber histology. Captive breeding of this species in carp hatcheries of Bangladesh could be initiated and facilitated through maintaining the gene pool of the L. ariza of Kangsha and the Atrai River. Conservation could also be considered for advancing the better performer crossbred (G4K♀A♂) as the reference diallel crossbred. The simple yet efficient breeding technique and the manifestation of growth performances using histological and phenotypical observations will encourage the hatchery operators of Bangladesh and elsewhere to initiate the induced breeding of L ariza in large scale aquaculture.The objective of the present study was to evaluate the growth performance and genetic variation in diallel crosses of Ariza labeo (Labeo ariza) originating from three geographically separated rivers (Atrai, Jamuna and Kangsha) in Bangladesh. Intra (G1K♀K♂, G2J♀J♂, and G3A♀A♂) and inter (G4K♀A♂, G5K♀J♂, G6A♀K♂, G7A♀J♂, G8J♀K♂, and G9J♀A♂) stocks were produced following diallel cross (sex ratio—1:1 and n = 48; 16 from each river). Reproductive and growth performance, muscle cellularity and genetic variation following genotyping of eight microsatellite markers (Lr1, Lr2, Lr3, Lr22, Lr24, Lr27, Lr28 and Lr29) and analysis of all crossbreeds was performed. The fertilization (95% ± 2.11%), hatching (88% ± 1.03%), and survival rates (82% ± 1.88%) of G4K♀A♂ were higher compared to other groups. With respect to length and weight gains (2.67 ± 0.4 cm and 3.39 ± 0.2 g), SGR (3.23% ± 0.20%), and heterosis (8.87% and 24.74%) G4K♀A♂ was the superior group. A higher number of hyperplastic muscle fibers, mean number of alleles (2.75) and mean observed heterozygosity (0.417) from G4K♀A♂ could be interpreted to mean that G4K♀A♂ comprise better performance efficiency compared to others and are considered for continuing the L. ariza stock improvement program.

Fillet texture, physicochemical indexes, muscle cellularity and molecular expression in muscle of Yellow River carp (Cyprinus carpio haematopterus) in response to dietary hydroxyproline supplementation

The 8-week rearing trial was conducted to estimate the effect of dietary hydroxyproline (Hyp) supplementation on growth performance, amino acid profiles, fatty acid profiles, and collagen concentration in muscle samples, liquid holding capacity (LHC), pH, cooking loss and antioxidant activities in flesh of post-mortem, histomorphology, ultrastructure and molecular expression of muscle samples, and raw- and cooked-fillet texture characteristics of Yellow River carp (Cyprinus carpio haematopterus). Six isoproteic and isolipidic practical diets were formulated to contain graded levels of Hyp (1.36, 3.93, 7.14, 8.86, 11.45 and 13.69 g/kg of dry matter). A total of 840 carps with an average initial weight of 17.90 ± 0.28 g were randomly allocated to 24 polypropylene tanks with funnel-shaped bottom (400 L capacity filled to 300 L and 35 fish per tank). The results showed that no significant differences were found in growth performance and morphology parameter among all treatments (P > 0.05). With the increase of dietary Hyp levels, the glycine (Gly) content, and the proportion of 22:6n-3, n-3 PUFA and collagen concentration in carp fillet showed a significant ascending tendency, while arginine and proline were in downtrend (P < 0.05). Liquid loss, lipid loss and cooking loss were significantly decreased with the increasing dietary Hyp levels (P < 0.05), and the pH values in muscle samples of carp fed with dietary Hyp (> 3.93 g/kg) were significantly higher than that in control group (P < 0.05). Dietary Hyp supplementation improved the antioxidant properties of hepatopancreas and muscle with the increasing dietary Hyp levels (P < 0.05). Overall, we posed that appropriate dietary Hyp supplementation can promote myogenesis and collagen synthesis in muscle of carp, ultimately improved the raw- and cooked-fillet texture characteristics. The current research will be contributed to find an efficient way to ensure predictable and firmer texture of farmed Yellow River carp.

Cross breeding programme modulates reproductive outcomes, growth performances and cellular muscle growth of indigenous climbing perch, Anabas testudineus

An experiment was carried out for quality seed production of indigenous climbing perch, Anabas testudineus using cross breeding technique. Live fingerlings of A. testudineus were collected from three wild sources such as Kailla beel of Mymensingh (Mk), Salakandi beel of Mymensingh (Ms) and Shamganj beel of Netrokona (Ns) of Bangladesh. The collected wild A. testudineus were separately reared for a year in three replicated cages installed in separate earthen ponds for each stock. Forty eight mature broods (16 from each wild source stock with 1:1 sex ratio) were successfully induced bred with carp pituitary extracts following cross-breeding technique for producing three conspecific and three heterospecific cross groups. Three conspecific groups were designated as Line-1, Kailla beel ♀ × Kailla beel ♂ (Mk♀ × Mk♂); Line 2, Salakandi beel ♀ × Salakandi beel ♂ (Ms♀ × Ms♂) and Line 3, Shamgonj beel ♀ × Shamgonj beel ♂ (Ns♀ × Ns♂); whereas three heterospecific groups were designated as Line 4, Salakandi beel ♀ × Shamgonj beel ♂ (Ms♀ × Ns♂); Line 5, Kailla beel ♀ × Salakandi beel ♂ (Mk♀ × Ms♂) and Line 6, Shamgonj beel ♀ × Kailla beel ♂ (Ns♀ × Mk♂). In general, heterospecific crossbred groups (Line 4–6) showed higher reproductive performances than the conspecific crossbred groups (Line 1–3). More precisely, Line 4 (Ms♀ × Ns♂) showed the significantly (p < 0.05) highest rate of fertilization (82.43 ± 1.56%), hatching (93.79 ± 1.96%) and survival of larvae (77.54 ± 2.21%) compared to other crossbred line groups. After six months rearing of 30 dph fry of different crossbred lines, the significantly (p < 0.05) highest performances of all growth parameters and survival rate were found in Line 4 than the others crossbred lines. Muscle cellularity analyses also demonstrated that both the percentages of new hyperplastic muscle fibers and hypertrophic fibers were significantly higher in heterospecific crossbred groups (Line 4–6) than the conspecific crossbred groups (Line 1–3). The findings of our study suggested that heterospecific crossbreds of A. testudineus, particularly Line 4 showed improved reproductive outcomes, growth performances and cellular muscle growth over the conspecific crossbred groups. Therefore, Line 4 (Salakandi beel ♀ × Shamgonj beel ♂) can be considered as superior stock and base population for continuing the future breeding and stock improvement programme of A. testudineus in the hatcheries of Bangladesh and elsewhere.

A comparative study on growth, muscle cellularity and flesh quality of farmed and imitative ecological farming loach, Misgurnus anguillicaudatus

This study was carried to compare amino acids content, muscle cellularity, and flesh quality between farmed and imitative ecological farming loach, Misgurnus anguillicaudatus. Loach from farmed (average body weight 15.03 ± 0.36 g, average body length 13.41 ± 0.17 cm) and imitative ecological farming population (average body weight 12.44 ± 0.62 g, average body length 13.80 ± 0.26 cm) were used to analyze growth, body parameters, muscle composition, texture characteristics, amino acids content, relationship between muscle cellularity and textural parameters, and myogenic regulatory factors expression. The results showed the final weight, condition factor, hepatosomatic index and viscera index of farmed loach were significantly higher (p < 0.05) than of imitative ecological farming loach. Hardness, cohesiveness, adhesiveness, and resilience and Phe, Glu, and Tyr contents of imitative ecological farming loach were significantly higher than of farmed loach (p < 0.05). Meanwhile, muscle density of loach showed a positive and significant correlation with hardness (p < 0.05). Expression of growth-related genes including MyoD in farmed loach was significantly higher than in imitative ecological farming loach (p < 0.05). In conclusion, the flesh quality of imitative ecological farming loach is better than that of farmed loach.

The effects of salinity on growth, gill tissue and muscle cellularity in Lophiosilurus alexandri juvenile, a Neotropical freshwater catfish

The present study investigated the effects of salinity on growth, mortality, gill morphology and muscle cellularity in Lophiosilurus alexandri. Fish were submitted to the following salinity for 28 days: 0 (S0), 2.5 (S2.5), 5.0 (S5), 7.5 (S7.7) and 10 (S10) ppt. Growth and protein efficiency ratio (PER) decreased with the increase of salinity. All fish from S10 died between the 16th and 21st day of the experiment. Mortality in S7.5 was 78% at the end of 28 days of salinity exposure. Increased salinity was accompanied by increased vascular congestion, hyperplasia of gill filament epithelium, lamellar fusion and loss of structural integrity of pillar cells. Fish at S2.5 and S5 had higher mucosal cell hyperplasia. Chloride cell quantity was higher in fish in the S2.5 to S7.5. In general, L. alexandri juvenile exposed to treatments of freshwater and S2.5 had similar patterns of muscle cellularity, with high averages for the most of the variables of muscle cellularity evaluated. The large fibre size classes tended to decrease with increasing salinity. L. alexandri juveniles may be cultivated up to 2.5 g of salt/L, and superior concentrations change growth, induce damage to gills and modify muscle cellularity.

Effects of different ratios of crude protein and non-fibrous carbohydrates on growth, metabolism, physiology, nutrient utilization and muscle cellularity of Lophiosilurus alexandri, a carnivorous freshwater fish

The aim of this research was to evaluate the effects of different ratios of crude protein/non-fibrous carbohydrates (CP/NFC) on growth, metabolism, physiology, nutrient utilization efficiency and muscle cellularity of juvenile Lophiosilurus alexandri. Treatments consisted of isoenergetic diets (4500 kcal/kg) with CP/NFC ratios of 0.78; 1.02; 1.26 and 1.60, delivered for 75 days. Polynomial regression analysis showed that the different CP/NFC ratios affected weight gain and specific growth rate with estimated maximum values of 1.27 and 1.25, respectively. Feed conversion rate and the hepatosomatic index had minimum values with CP/NFC ratios of 1.33 and 1.02, respectively. Muscle and liver glycogen levels were maximized with CP/NFC content of 0.87 and 1.26, respectively. The CP/NFC ratio of 1.20 maximized the deposition of lipids in the muscle while that of 1.11 maximized the concentration of total soluble proteins in the same tissue. Plasma total cholesterol, non-HDL cholesterol and triglycerides increased linearly with increasing dietary CP/NFC ratio. Ratios estimated at 0.99, 0.94, 0.93 and 0.98 minimize the concentrations of HDL, total protein, alanine aminotransferase and creatinine in fish plasma, respectively. Nucleus diameter of hepatocytes increased linearly with increasing dietary CP/NFC ratio, while percentage of liver tissue nuclei decreased linearly. Hypertrophic muscle fibers were influenced by diets with the estimated ratio of 1.21 CP/NFC maximizing the occurrence of these fibers. Fish body crude protein increased linearly with increasing CP/NFC ratios in the diet. Fish body content of mineral matter, total phosphorus and visceral fat were minimized with the ratios of 1.34, 1.38 and 1.12, respectively. There were no effects of CP/NFC ratios on the viscerosomatic index, feed intake, carcass yield, the enzymes aspartate aminotransferase and gamma-glutamyl transferase, percentages of cytoplasmic and capillary sinusoids in liver tissue, and body dry matter, crude energy, total lipids, viscera dry matter. It is concluded that diets containing CP/NFC within 1.11–1.33 improve productive performance and nutrient use efficiency of fish. The different CP/NFC ratios also interfere with some plasma and metabolic variables that, associated with performance results, indicate a better physiological state of juvenile L. alexandri with an initial average weight of 30 g.

Muscle cellularity, growth performance and growth-related gene expression of juvenile climbing perch Anabas testudineus in response to different eggs incubation temperature

Although indigenous climbing perch (Anabas testudineusis) is a highly valuable species, slow growth pattern during the culture period impeding its commercial success in aquaculture. In many fish species, it has been demonstrated that incubation temperature of eggs influenced the muscle development and growth rates, which persisted throughout the subsequent larval and juvenile phases. Therefore, this study aimed to investigate whether different incubation temperature of eggs prior to hatching can stimulate the muscle development, growth, and growth-related gene expression of the slow-growing indigenous species of climbing perch. The fertilized eggs of A. testudineus from an artificial breeding program were incubated under control temperature of 24°C (IT24), 26°C (IT26), 28°C (IT28), and 30°C (IT30) in 10L glass aquaria with four replicated units for each temperature treatment. After hatching, the larvae from each incubated temperature were separately reared at ambient temperature for 10 days in aquarium, 20 days in hapas, and the next 42 days in cages, totaling 72 days post-hatching (dph). The hatching rates were found significantly (P<0.05) higher in IT28 compared to the other incubation temperature treatments. After 72 dph, the growth performances (%length gained, %weight gained and SGR) were found to be significantly highest (P<0.05) in the IT28, followed by the treatments IT30, IT26, and IT24, respectively. Survival rate (73±1.257%) was also found to be highest in the same treatment. The rate of new muscle fiber formation was identified to be significantly highest (P<0.05) in IT28 followed by the IT26, IT30 and IT24, respectively. The relative mRNA expression level of GHRH, IGF1, IGF2 and PRL was also significantly highest in the IT28 (P<0.05) compared to other treatments. Results from the present study clearly suggested that 28°C is the optimum eggs incubation temperature of the native strain of A. testudineus for its highest growth performances in captive breeding condition.

Effects of taurine or sodium diformate supplementation to a low fishmeal plant‐based diet fed to European sea bass ( Dicentrarchus labrax )

The effects of either taurine (T) or sodium diformate (NDF) supplementation to a low fishmeal (FM) plant-based diet on growth, health status, immunity and muscle cellularity of European sea bass, Dicentrarchus labrax, were investigated. Four isoproteic (44% CP) and isolipidic (17% L) diets were produced to contain 46% FM as a control diet, or 20% FM and a mixture of plant nutrients (PMX). The plant-mix diets were either supplemented or not with 1% T or 0.3% NDF. Each diet was fed to triplicate groups of seabass (mean, 13.71 g) for 13 weeks. Fish fed the PMX diet supplemented with T or NDF was recorded to have a significantly higher feed intake, weight gain and a better feed conversion rate than other groups. The diet composition did not significantly alter the biochemical or essential amino acid composition of fish, except for the slightly reduced lipid content of T-fed fish in comparison to the PMX-fed fish. These supplements further enhanced blood profile, immunity response and myocytes ultrastructure relative to fish fed the PMX diet. Accordingly, these results suggest that supplementation of low-FM/plant-mix diet with either 1% T or 0.3% NDF can promote growth, normalize physiological conditions and improve the striated muscle structure of juvenile seabass.

Dietary Antioxidant Supplementation Promotes Growth in Senegalese Sole Postlarvae.

Somatic growth is a balance between protein synthesis and degradation, and it is largely influenced by nutritional clues. Antioxidants levels play a key role in protein turnover by reducing the oxidative damage in the skeletal muscle, and hence promoting growth performance in the long-term. In the present study, Senegalese sole postlarvae (45 days after hatching, DAH) were fed with three experimental diets, a control (CTRL) and two supplemented with natural antioxidants: curcumin (CC) and grape seed (GS). Trial spanned for 25 days and growth performance, muscle cellularity and the expression of muscle growth related genes were assessed at the end of the experiment (70 DAH). The diets CC and GS significantly improved growth performance of fish compared to the CTRL diet. This enhanced growth was associated with larger muscle cross sectional area, with fish fed CC being significantly different from those fed the CTRL. Sole fed the CC diet had the highest number of muscle fibers, indicating that this diet promoted muscle hyperplastic growth. Although the mean fiber diameter did not differ significantly amongst treatments, the proportion of large-sized fibers (>25 μm) was also higher in fish fed the CC diet suggesting increased hypertrophic growth. Such differences in the phenotype were associated with a significant up-regulation of the myogenic differentiation 2 (myod2) and the myomaker (mymk) transcripts involved in myocyte differentiation and fusion, respectively, during larval development. The inclusion of grape seed extract (GS diet) resulted in a significant increase in the expression of myostatin1. These results demonstrate that both diets (CC and GS) can positively modulate muscle development and promote growth in sole postlarvae. This effect is more prominent in CC fed fish, where increased hyperplastic and hypertrophic growth of the muscle was associated with an upregulation of myod2 and mymk genes.

The optimum velocity for Atlantic salmon post-smolts in RAS is a compromise between muscle growth and fish welfare

It is increasingly common to rear Atlantic salmon smolts for longer periods in recirculating aquaculture systems (RAS) before transfer to sea cages. The conditions for this part of the life cycle are currently being optimized, especially the water velocity in the tanks since its impact has been correlated with.growth. Earlier studies indicate that higher water velocities promote growth in salmon, nonetheless, the optimal velocity and its associated health and welfare consequences are yet to be established. In the present study, we determined the effects of different water velocities on growth, muscle development and welfare to estimate the optimum velocity for the rearing of post-smolts in RAS.We divided 2400 salmon post-smolts (average start weight 80 g) into twelve tanks (200 fish per tank) and set the water velocities in four triplicate tanks to low (L) – 0.5 body length per second (BL/s); medium (M) – 1.0 BL/s; high (H) – 1.8 BL/s; and very high (VH) – 2.5 (BL/s). The velocity for the VH group was the highest tested for salmon post-smolts to date. The trial lasted for three months and organ samples were collected at three time points. Time-lapse cameras revealed a relatively even fish distribution in the tank in L and M groups. In contrast, fish in H and VH groups displayed strong schooling behavior at specific regions in the tanks. We observed a close to a linear relationship between water velocity and average growth rate, which resulted in a 5.7% higher average body weight in the VH group in comparison to the L group at termination. The condition factors of fish from the L group was lower than in the other three groups. Muscle cellularity analysis revealed smaller fibers in the L group, while bigger muscle fibers were identified in H and VH groups which contributed to somatic growth. Nonetheless, increased cases of inflammation were observed in H and VH groups. Muscle proteomics revealed decreased translation and carbohydrate activity in the L group. The overall external welfare status of the fish was favorable; however, increased incidence of skin damage (i.e., scale loss, hemorrhaging) and pelvic fin damage (i.e., splitting) in the H and VH groups was documented. Skin histology revealed relatively thinner epidermis at higher velocities. On the other hand, increased cases of aneurysm, lamellar clubbing and fusion were identified at higher velocities too.In conclusion, the increased body weight of fish reared in high water velocities was likely mostly due to enhanced somatic growth of muscle fibers. These findings provide further evidence that elevated water velocities have positive effects on the growth rate of post-smolts even at the highest levels tested to date. On the other hand, the external welfare scores, histological analyses and the molecular data indicate that mucosal health was negatively affected by higher velocities. Thus, based on this study, the optimal water velocity for long term rearing of salmon post-smolts in RAS is most likely located slightly above 1 body length per second.

Influence of partial replacement of fish meal and fish oil with vegetable products on the growth and muscle cellularity of juvenile shi drum, Umbrina cirrosa

Seven-month-old shi drum (Umbrina cirrosa) specimens (mean weight 18.98 g, mean length 11.80 cm) were classified into 2 groups, a control group (C) fed a standard diet and a vegetal group (V) fed a diet with partial replacement of fish meal and fish oil by vegetable products. The body and muscle parameters were studied on days 0, 27, and 62 of the experiment. On day 27, body length was similar in both groups, but body weight was significantly lower in group V than in group C. The transverse area of the white muscle was also significantly lower in V than in C. Hypertrophy was higher in C than in V, whereas hyperplasia was higher in V than in C. On day 62, the body parameters showed similar results to those found on day 27. Muscle cellularity was different from that found on day 27, since hypertrophy was higher in V than in C and hyperplasia was higher in C than in V. The feed conversion rate and specific growth rate were similar in both groups, but the daily intake rate was lower in V than in C. Therefore, it seems that the percentage of vegetables in the vegetal feed was excessively high and this caused less acceptance by the fish. The hepatosomatic, viscerosomatic, and intestinal length indices were similar in both groups. Survival was nearly 100% in both groups.

Effects of faba bean on growth performance and fillet texture of Yellow River carp, Cyprinus carpio haematopterus

A three-month feeding trial was conducted to investigate the effects of faba bean (Vicia faba L.) on growth performance, intramuscular collagen content, muscle cellularity and fillet texture of Yellow River carp, Cyprinus carpio haematopterus. Carps with an initial weight 500 ± 20 g were randomly divided into two treatments: commercial feed group (CFG) and faba bean group (FBG). Compared to CFG, the results indicated that carps fed with faba bean had poor growth performance, higher intramuscular collagen content, smaller fiber diameter and wider intermyofibrillar space. However, the fiber density was not influenced (P > 0.05). The faba bean components showed lower crude protein and amino acid imbalance, especially, the deficiency in the sulfuric amino acid. The raw-fillet and cooked-fillet texture of FBG were both significantly greater than that of CFG (P < 0.05). Muscle fiber diameter and cooked-fillet texture showed significant negative correlation (P < 0.05), significant positive correlation between intramuscular collagen content and cooked-fillet texture (P < 0.05), and no significant correlation between muscle fiber density and fillet texture (P> 0.05). In summary, faba bean could improve the fillet quality for Yellow River carp. These findings would contribute to define the optimal nutritional conditions of pond culture to improve the flesh quality of Cyprinus carpio haematopterus.

Similar cardiovascular disease histopathology and macrophages in heart tissues of younger adult SIV-infected and uninfected aged rhesus macaques

Abstract Cardiovascular disease is a major cause of morbidity in aging and in HIV-infected individuals despite efficacy of cART, and furthermore, is associated with macrophage activation and inflammation. Nonhuman primates simulate human disease, and we previously reported that distinct macrophage populations play different roles in the pathogenesis of disease during SIV infection in rhesus macaques. For example, in the lung, short-lived macrophages were more readily destroyed by SIV and contributed to AIDS pathogenesis. Long-lived alveolar macrophages on the other hand were not easily destroyed by virus and thus may contribute to a long-term virus reservoir that also promotes chronic inflammation. The present studies extend this work to characterize macrophages in heart and skeletal muscles affecting cardiomyopathy observed during SIV/HIV infection as well as in heart tissues of uninfected younger and older macaques. The results demonstrated that macrophages are distributed uniformly throughout the heart tissues in animals of all age groups. Increased percentages of macrophages, however, were observed in hearts of aged macaques with similar increased percentages of macrophages in SIV-infected younger adult macaques. Interestingly, the increased macrophages of both aged uninfected and younger SIV-infected macaques was not due to increases in the absolute numbers of macrophages but rather to decreased heart muscle cellularity. This suggested that cardiovascular disease observed in aged as well as HIV-infected individuals may be due to similar mechanisms of decreased number of heart muscle cells and dysfunctional inflammatory long-lived macrophages of the heart.

Evaluation of dietary histidine supplementation on meagre, Argyrosomus regius , juvenile growth, haematological profile, stress and muscle cellularity

Evaluation of dietary histidine supplementation on meagre, <i>Argyrosomus regius</i> , juvenile growth, haematological profile, stress and muscle cellularity

Molecular characterization of the myostatin gene and its regulation on muscle growth in Yesso scallop Patinopecten yessoensis

Myostatin (MSTN) belongs to the transforming growth factor β (TGF-β) family, which plays a critical role in negatively regulating muscle growth in vertebrates. However, little is known about its function in muscle growth of scallops that possess a large adductor muscle composed of striated and smooth muscle fibers. In this study, we first indentify and characterize the complete cDNA sequence of the myostatin gene from Yesso scallop P. yessoensis, an economically important species in Asian countries. The C-terminal mature TGF-β peptides are highly conserved in scallops, with sequence identity of >97% among these species. Gene expression at developmental stages revealed by whole-mount in situ hybridization indicates that myostatin is mainly expressed on the profusely ciliated rim of velum in veligers. The significant increase of muscle cellularity induced by RNA interference of myostatin can be explained as a result of a combination of hyperplasia and hypertrophy of MHC II striated myofibers, rather than myofiber growth of the paramyosin-rich smooth muscle. This is also evidenced by the quantification results of muscle gene expression, which indicate the significant increase of MHC expression after the inhibition of myostatin mRNA in the striated muscle, but not in the smooth muscle. For both of the striated and smooth muscles, however, no significant difference between the treatment and control groups is detected by real-time quantitative PCR analysis in other muscle genes. These findings suggest that the cellular targets of myostatin in scallop muscles are probably regulated by signaling directly to striated MHC. The new additional nuclei are potentially supplied by a population of satellite cells or muscle stem cell-like adult muscle precursors that may fuse with existing muscle fibers during muscle hypertrophy. These evidences found in this study highlight that myostatin may not only be involved in the development of larval musculature, but also play an important role in regulating scallop muscle growth.