Replacement of fresh algae with commercial formulas to enrich rotifers in larval rearing of yellowtail kingfish Seriola lalandi (Valenciennes, 1833)

This study compared the efficacy of four products that are commonly used in hatchery for nutritional enhancement of rotifer Brachionus plicatilis as the starter food for yellowtail kingfish Seriola lalandi larvae. This experiment consisted of one fresh algae and three enrichment products: (1) Fresh algae were a mixture of Nannochloropsis and Isochrysis at 2:1 on a cell concentration basis; (2) S.presso, (Selco S.presso ^®, INVE Aquaculture); (3) Algamac 3050^® (Aquafauna, USA); (4) Nutrokol ^® (Nutra‐Kol, Australia). Survival rates of the fish fed rotifers enriched with fresh microalgae (40.69%) and S.presso (31.21%) were higher than those fed Algamac 3050 (10.31%). On 3 day post hatch (DPH), fish feeding incidence in the fresh algae treatment was significantly higher than that in other treatments. On 6 DPH, fish showed the lowest feeding incidence in the Algamac 3050 treatment. The methods of enrichment did not affect total lipid levels in either rotifer or fish larvae, but Algamac 3050 enrichment achieved the highest DHA/EPA ratio and lowest EPA/ARA ratio in both rotifers and fish larvae. This study indicates that fresh algae can be replaced by S.presso, but Algamac 3050 is not as good as other formula for rotifer enrichment in rearing yellowtail kingfish larvae in this system.     

Flexural deformities of the distal interphalangeal joint (clubfeet)

A true clubfoot results from a flexural deformity of the distal interphalangeal joint that is characterised by a shortening of the deep digital flexor tendon musculotendinous unit. Flexural deformities are a problem not only in foals but are also responsible for the clubfoot conformation seen in mature horses. Treatment is most successful when the cause is investigated and therapy initiated as early as possible, and when the biomechanical properties of the foot are thoroughly understood. Flexural deformities in foals and mature horses are addressed through appropriate farriery, often combined with surgery.     

Use of response surface methodology to study the combined effects of temperature and salinity on hatching and deformity of the hybrid grouper,Epinephelus fuscoguttatus (♀) × Epinephelus polyphekadion (♂)

This study seeks to identify the optimal combination of temperature and salinity for the embryo development of the hybrid groupers, Epinephelus fuscoguttatus (♀) × Epinephelus polyphekadion (♂), using the central composite design and response surface methodology. Results have shown that the low hatching rates of fertilized eggs and high deformity rates of larvae were the result of lower or higher temperature/salinity levels. The linear effects of temperature and salinity were significant in both hatching rates and deformity rates (p < .01). Similar results were observed in the quadratic effects of temperature and salinity (p < .01). Effects of temperature were positively related to salinity effects (p < .05). Salinity effects were more remarkable than temperature on hatching rates, but not the same on deformity rates. Model equations were established for temperature and salinity effects on hatching rates and deformity rates. A high coefficient of determination (R² > .97) was found for the adequacy and predictive capability of model equations, indicating that these models can be applied to prediction. The optimal combination of temperature and salinity was 27.58°C/30.94, which was derived from the statistical optimization approach. In this condition, the hatching rate was the highest at 85.73%, and the deformity rate was the lowest at 5.96%, with a high desirability function of 0.957. The results of this study can be applied to improve hatching and decrease deformity in future cultures of hybrid groupers.     

胚胎发育中骨骼肌组织的形成及调控

在胚胎发育中,骨骼肌组织的形态发生是许多基因精密调控的复杂生物学过程。综述了骨骼肌组织在胚胎发育过程中的起源、骨骼肌组织形成过程及调控机制。     

Lipid metabolism and cellular features of skeletal muscle and subcutaneous adipose tissue in pigs differing in IGF-II genotype

In pigs, a paternally (pat) imprinted mutation in the IGF-II gene is associated with increased muscle mass and decreased backfat thickness. The aim of this study was to determine whether this mutation influenced cellular, biochemical and metabolic features of skeletal muscle and adipose tissue. Muscle (trapezius) and subcutaneous adipose tissue (SCAT) were collected from pigs (106kg) carrying (Qpat, n=6) or not carrying (qpat, n=7) the mutation. Adipocytes were isolated from those tissues by collagenase treatment. Lipid content and activity of lipogenic enzymes were determined using standard assays. Gene expression levels were determined by real-time PCR. Levels of IGF-II mRNA were higher (P<0.01) in muscle of Qpat than in that of qpat pigs, but they did not differ significantly between the two groups in SCAT. Whereas levels of IGF-I mRNA in muscle were similar in both groups, they were higher (P<0.05) in SCAT of Qpat pigs than in that of qpat pigs. Muscle lipid content and intramuscular adipocyte diameters were not influenced significantly by the IGF-II genotype. In SCAT, the reduction of backfat thickness in Qpat pigs compared with qpat pigs was associated with lower (P<0.05) lipid content and smaller (P<0.05) adipocytes, with no significant genotype-effects on expressions and/or activities of lipogenic enzymes. In summary, our results suggest that the IGF-II mutation altered body composition in pigs by favoring myofiber hypertrophy and repressing adipose cell development in SCAT.     

Glycogen synthase 1 (GYS1) mutation in diverse breeds with polysaccharide storage myopathy

Background: A missense mutation in the GYS1 gene was recently described in horses with polysaccharide storage myopathy (PSSM).
Objectives: The first objective was to determine the prevalence of the GYS1 mutation in horses with PSSM from diverse breeds. The second objective was to determine if the prevalence of the GYS1 mutation differed between horses diagnosed with PSSM based on grade 1 (typically amylase-sensitive) or grade 2 (typically amylase-resistant) polysaccharide.
Animals: Eight hundred and thirty-one PSSM horses from 36 breeds.
Procedures: Horses with PSSM diagnosed by histopathology of skeletal muscle biopsy samples were identified from the Neuromuscular Disease Laboratory database. Eight hundred and thirty-one cases had blood or tissue that was available for DNA isolation; these 831 cases were genotyped for the GYS1 mutation by restriction fragment length polymorphism.
Results: The PSSM mutation was identified in horses from 17 different breeds. The prevalence of the GYS1 mutation in PSSM horses was high in Draft- (87%) and Quarter Horse-related breeds (72%) and lower in Warmbloods (18%) and other light horse breeds (24%), when diagnosis was based on grade 2 diagnostic criteria. Overall, the PSSM mutation was present in 16% of grade 1 and 70% of grade 2 PSSM horses.
Conclusions and Clinical Importance: GYS1 mutation causes PSSM in diverse breeds and is the predominant form of PSSM in Draft- and Quarter Horse-related breeds. False-positive diagnosis, as well as the possibility of a second glycogenosis in horses with neuromuscular disease (type 2 PSSM), might explain the absence of the GYS1 mutation in horses diagnosed with excessive glycogen accumulation in muscle.