Estimates of combining ability and heterosis for growth traits in a full diallel cross of three strains of common carp, Cyprinus carpio L.

We attempted to determine the combining ability and heterosis of body weight by performing 3 × 3 complete diallel crosses derived by crossing three common carps (Cyprinus carpio var. jian, Cyprinus carpio haematopterus Temminck et Schlegel and Cyprinus carpio haematopterus). In total, 1650 fish were tagged when they were 1.5 months of age. After five months, Jian carp (♂) × Huanghe carp (♀) attained greater weight than pure and other hybrids. By crossing with Jian, Huanghe and Heilongjiang carps have improved body weight compared to their purebred. Significant principal components (PCs) were generated from growth performance data and their statistical loadings. The first principal component had the highest Eigen value of 2.81 and accounted for 70.31% of the variability in the data set. Two crosses, Jian carp (♂) × Huanghe carp (♀) and Huanghe carp (♂) × Jian carp (♀) showed high SCA with regard to body weight. Both Heilongjiang carp (♂) × Jian carp (♀) and Heilongjiang carp (♂) × Huanghe carp (♀) had higher heterosis compared to their purebreds. Significant positive phenotypic correlations were also observed between body weight and body length, thickness and height. The aforementioned results listed were identified as the foundation for common carp selective breeding programs.Keywords: Common carp, cross-breeding, heterosisAfrican Journal of Biotechnology Vol. 12(22), pp. 3514-352

Decreased Genetic Drift under the Overlapping Conservation

contributed equally to this work. A B S T R A C T S In order to understand the genetic drift under closed population using equaled family size, two overlapping conservation methods proposed (increment and decrement) were introduced to compare with the discrete population. Finally, the article showed body weight controlled by hundred loci having average gene effect. For increment, the second generation had the parents composed of 400 original population and 100 from first generation; the third population consisted of 300 original population, 100 from first generation and 100 from second generation. The fourth population was composed 200 from original population, 100 from first population, 100 from second population, 100 from third population, and 100 from the fourth population. The fifth population was achieved by randomly selecting 100 from each population. For decrement, the method has the opposite direction. For different population, both more than one thousand and less than family sizes 10 have the stable gene frequency despite the different initial gene frequency and sex ratio. Despite several generations were maintained together, less than 5 generations increment conservation can make the gene frequency improved to less than 0.5, while more than 0.5, increment conservation can make them decrease to less than 5 generations and reach the stable higher gene frequency in the following generations. Generally, less than 0.4 gene frequency can use in the increment conservation. More than 0.7, you can use the decrement method. When 100 loci which have average gene effect and random initial gene frequency were assumed, both increment and decrement conservation methods can keep the phenotype stable

Combined QTL and Genome Scan Analyses With the Help of 2b-RAD Identify Growth-Associated Genetic Markers in a New Fast-Growing Carp Strain

Common carp is one of the oldest and most popular cultured freshwater fish species both globally and in China. In a previous study, we used a carp strain with a long breeding tradition in China, named Huanghe, to create a new fast-growing strain by selection for fast growth for 6 years. The growth performance at 8 months of age has been improved by 20.84%. To achieve this, we combined the best linear unbiased prediction with marker-assisted selection techniques. Recent progress in genome-wide association studies and genomic selection in livestock breeding inspired common carp breeders to consider genome-based breeding approaches. In this study, we developed a 2b-RAD sequence assay as a means of investigating the quantitative trait loci in common carp. A total of 4,953,017,786 clean reads were generated for 250 specimens (average reads/specimen = 19,812,071) with BsaXI Restriction Enzyme. From these, 56,663 SNPs were identified, covering 50 chromosomes and 3,377 scaffolds. Principal component analysis indicated that selection and control groups are relatively clearly distinct. Top 1% of Fst values was selected as the threshold signature of artificial selection. Among the 244 identified loci, genes associated with sex-related factors and nutritional metabolism (especially fat metabolism) were annotated. Eighteen QTL were associated with growth parameters. Body length at 3 months of age and body weight (both at 3 and 8 months) were controlled by polygenic effects, but body size (length, depth, width) at 8 months of age was controlled mainly by several loci with major effects. Importantly, a single shared QTL (IGF2 gene) partially controlled the body length, depth, and width. By merging the above results, we concluded that mainly the genes related to neural pathways, sex and fatty acid metabolism contributed to the improved growth performance of the new Huanghe carp strain. These findings are one of the first investigations into the potential use of genomic selection in the breeding of common carp. Moreover, our results show that combining the Fst, QTL mapping and CRISPR–Cas9 methods can be an effective way to identify important novel candidate molecular markers in economic breeding programs

Responses of adult crayfish to macro-nutrients intake alteration during juvenile stage on metabolism and intestinal microbiota

Red swamp crayfish Procambarus clarkii is becoming an ecologically and economically important crustacean species in China. In present study, whether the macro-nutrients intake intervention during early life in crayfish resulting long-term influences on nutritional use and metabolism were evaluated in view of the concept of nutritional programming effects. Juvenile crayfish underwent a 14 days of high-carbohydrate (43%) low-protein (17%) nutritional stimulus, following a 70 days of routine dietary feeding (carbohydrate 15%, protein 36%), until adulthood. Short- (14 days) and long-term (84 days) effects were evaluated respectively in terms of growth performances, digestive enzymes activities, body compositions, and intestinal microbiota (long-term only). Data showed that in the short term, it enhanced the activities of amylase and lipase but reduced the activity of trypsase in hepatopancreas. In the long term, it decreased the growth performances (SR and WGR) and modified the diversity of intestinal microbiota obviously (p < 0.05). Throughout the period it increased body crude protein level. All results indicated that early nutritional events caused long-term impacts on nutrient use thus affect physiology and growth until adulthood. In short, present work provided evidences to support the existence of nutritional programming effects in juvenile crayfish

Effects of Different Sources of Culture Substrate on the Growth and Immune Performance of the Red Swamp Crayfish (<i>Procambarus clarkii</i>)

The substrate in the aquatic environment plays a crucial role in nutrient deposition and recovery for the growth of aquatic organisms. In order to optimize the culture medium of Procambarus Clarkii, culture media from different sources were selected in this study to explore their effects on the growth and immune performance of red swamp crayfish. The results showed that the weight gain rate (WGR), body length growth rate (BLGR) and specific growth rate (SGR) in group I2 were the highest, followed by group I1 and group I3. The WGR and SGR of crayfish in the I1 and I2 groups were significantly higher than those in the I3 group (p p < 0.05). α diversity analysis of 16S rRNA data showed that there was no statistically significant difference in the abundance of intestinal flora among the three culture substrate groups. The β diversity in the Xitangni group, crayfish Tangni group and Shuitangni group was significantly different. These changes in microbiota suggest that using different substrates to culture crayfish leads to differences in gut microbiota diversity. To sum up, the growth in crayfish and immune performance influenced by the culture substrate condition and aquatic breeding sediment substrates, rather than crab pool and paddy field pond sediment substrates, showed a better effect

The complete mitochondrial genome of the common strain black carp (Cyprinus carpio var. baisenensis)

The common strain black carp (Cyprinus carpio var. baisenensis), known for its black skin is cultured in the integrated rice-agriculture system and non-escape property under torrential floods. The total mitogenome length of Cyprinus carpio var. baisenensis obtained in this study was 16,478bp, consisting of 13 protein-coding genes, 22 tRNA genes, 2rRNA genes (large and small), a light strand origin of replication, and one major non-coding region. By providing the complete mitochondrial genomes of Cyprinus carpio var. baisenensis, we will further understand the phylogenetic relationships within genus

Genomics and transcriptomics of the Chinese mitten crabs (Eriocheir sinensis)

Abstract To gain a deeper understanding of the genetic factors influencing the growth and development of Eriocheir sinensis, a well-known species of hairy crab found in Yangcheng Lake, this study focused on the de novo genome and full-length transcriptome information of the selected subjects. Specifically, Yangcheng Lake hairy crabs were chosen as the experimental samples. Initially, a genome analysis was performed, resulting in the identification of gene fragments with a combined length of 1266,092,319 bp. Subsequently, a transcriptome analysis was conducted on a mixture of tissues from four different sites, namely muscle, brain, eye, and heart, to further investigate the genetic characteristics at the transcriptome level. The Pacific Biosciences (Pacio) single-molecule real-time sequencing system generated a total of 36.93 G sub-fragments and 175,90041 effective inserts. This research contributes to the indirect comprehension of genetic variations underlying individual traits. Furthermore, a comparison of the obtained data with relevant literature emphasizes the advantages of this study and establishes a basis for further investigations on the Chinese mitten crab

Effect of Dietary Selenium on the Growth and Immune Systems of Fish

Dietary selenium (Se) is an essential component that supports fish growth and the immune system. This review attempts to provide insight into the biological impacts of dietary Se, including immunological responses, infection defense, and fish species growth, and it also identifies the routes via which it enters the aquatic environment. Dietary Se is important in fish feed due to its additive, antioxidant, and enzyme properties, which aid in various biological processes. However, excessive intake of it may harm aquatic ecosystems and potentially disrupt the food chain. This review explores the diverse natures of dietary Se, their impact on fish species, and the biological methods for eliminating excesses in aquatic environments. Soil has a potential role in the distribution of Se through erosion from agricultural, industrial, and mine sites. The research on dietary Se’s effects on fish immune system and growth can provide knowledge regarding fish health, fish farming strategies, and the health of aquatic ecosystems, promoting the feed industry and sustainable aquaculture. This review provides data and references from various research studies on managing Se levels in aquatic ecosystems, promoting fish conservation, and utilizing Se in farmed fish diets

Comparative transcriptomics identifies genes differentially expressed in the intestine of a new fast-growing strain of common carp with higher unsaturated fatty acid content in muscle.

We have created a new, fast-growing strain of common carp with higher unsaturated fatty acid content in muscle. To better understand the impacts of gene regulation in intestinal tissue on growth and unsaturated fatty acid content, we conducted a comparative RNA-Seq transcriptome analysis between intestine samples of Selected and Control groups (and corroborated selected results by PCR). After eight weeks of cage culture, weight gain of the Selected group was 20.84% higher. In muscles of the control group, monounsaturated fatty acids (FAs) were more abundant, whereas polyunsaturated FAs were more abundant in muscles of the Selected group. In total, we found 106 differentially expressed genes (DEGs) between the two groups. Only the endocytosis pathway was significantly enriched in DEGs, with two upregulated genes: il2rb and ehd1. The latter is involved in the growth hormone/insulin-like growth factor (Gh/Igf) axis, which plays a key role in the regulation of growth in animals. tll2, which is known to be associated with intestinal regeneration, was extremely highly upregulated in both transcriptomic (infinite) and qPCR (610.70) analyses. Two of the upregulated genes are associated with the fatty acid metabolism, several genes are likely to be indicators of heightened transcription levels, several are associated with metabolic and developmental roles, several with neuronal functions (including two with vision), several with the immune system, and two downregulated genes with the development of vasculature. The higher growth rate of the Selected group is likely to be at least partially attributed to increased endocytosis efficiency and genetically-driven behavioural differences (higher aggression levels). There are some indications that this new strain might have slightly impaired immune responses, and a higher propensity for inherited diseases leading to sight impairment, as well for neurodegenerative diseases in general, but these indications still need to be confirmed