Reproduction and breeding最新文献

Disease-resistant grass carp (DR-GGC) was obtained by backcrossing gynogenetic grass carp (GGC, 2n = 48, female) with common grass carp (Ctenopharyngodon idellus [GC], 2n = 48, male). The genetic constitution and the potential mutation associated with growth dominance in DR-GGC were analyzed by genomic in situ hybridization (GISH), whole-genome resequencing (WGRS) and RNA-sequencing (RNA-seq). The GISH results showed partial translocations and deletions in the chromosomes of DR-GGC compared with GC. The WGRS results demonstrated that there were numerous genetic variations between DR-GGC and its parents, among which DR-GGC had the highest genomic heterozygosity and GGC had the highest genomic purity. The RNA-seq results revealed that the differentially expressed genes (DEGs) were significantly enriched in cellular processes and immune pathways in DR-GGC and GGC compared with GC. Meanwhile, the combined analysis of WGRS and RNA-seq identified DEGs with overlapping mutation loci in DR-GGC and GGC compared with GC. These DEGs were significantly enriched in the pathways of growth, metabolism, and immunity, including cellular metabolism, biosynthesis, glycolysis/gluconeogenesis, and extra cellular matrix (ECM) receptor interactions. These results provide a genetic basis for exploring the better growth characteristics and disease resistance of DR-GGC than GC, valuable information on the genetic breeding for grass carp, and a further understanding of the genetic characteristics of gynogenetic individuals.

In previous studies, an allodiploid lineage (WR-F1-F5) was established by the distant hybridization of white crucian carp (Carassius cuvieri, WCC, ♀) and red crucian carp (Carassius auratus red var., RCC, ♂), an allodiploid fish (WR-II) was produced by WR-F1 (♀) × WCC (♂). In this study, the nutrients in the muscle and ovary of WR-II and its parents (WCC, RCC, and WR) were investigated, including protein, fat, amino acid, docosahexaenoic acid (DHA), moisture, and ash. The results showed that the protein content of WR-II in muscle and ovary (17.90 % and 25.60 % respectively) was higher than that of WR, and was significantly higher than that of WCC and RCC (p < 0.05). The fat content of WR-II in muscle and ovary (4.30 % and 5.31 % respectively) was higher than that of WR and was significantly higher than that of WCC and RCC (p < 0.05), and the muscle and ovary of WR-II showed rich DHA content (0.32 % and 0.54 % respectively) than that of WCC and RCC (p < 0.05). Fifteen amino acids were detected in WR-II and its parents, the total amino acid (TAA) content of WR-II in muscle and ovary (15.49 % and 18.43 % respectively) was significantly higher than that of WCC (p < 0.05), the delicious amino acid (DAA) content of WR-II in muscle and ovary (6.56 % and 8.29 % respectively) was different degrees higher than that of WCC, RCC, and WR. The moisture and carbohydrates of WR-II in muscle and ovary were lower than those in WCC and RCC. Furthermore, protein, fat, TAA, and DAA content in the ovary were significantly higher than those in muscle (p < 0.05), showing tissue differences in all detected fish. This study indicated that WR-II had the characteristics of high protein, high fat, high DHA, high TAA, high DAA, low moisture, and low carbohydrates, which provided theoretical support for its application.

The Asian arowana (Scleropages formosus) has gained immense popularity in the ornamental fish trade due to its striking color variations. However, ongoing debates persist regarding the taxonomic classification of these distinct color varieties as separate species. This paper aims to address this issue by employing mtDNA sequencing, microsatellite genotyping, and crossing experiments. Phylogenic analyses using mitochondrial and nuclear markers across green, golden, and red varieties showed that individuals from these tree color varieties were mixed in several clusters. Crossing between different varieties generated fertile offspring. These data indicates that three color morphs of the Asian arowana should not be classified as distinct species. Acknowledging the aesthetic significance of these varieties, a holistic understanding of their taxonomic status is crucial for informed conservation strategies and sustainable management of this species.

Muscle is one of the important quality of fish. However, there is still a lack of sufficient understanding of the mechanism of muscle growth regulation in fish. In this study, the expression patterns of 10 reported muscle development related genes are analyzed in zebrafish during growth or under water flow stress. Myogenic regulatory factors (MyoD, MyoG, MRF4), myostatin regulatory genes (Mstna, Mstnb) and myoblast development-related genes (Pax7, Prmt5, Desmin, MYHC) are significantly increased expression at somite stage and muscle effect stage embryos in zebrafish. The mRNA levels of the muscle development related genes are up-regulated in 7-day fries and 30-day juvenile of zebrafish. And there are differences in the expression levels of seven muscle development related genes (MyoD, Myf5, MyoG, Mstna, Mstnb, Desmin, MYHC) between the large and small individuals of 20-day-old zebrafish. Results indicated that short-term water flow stressing can promote zebrafish muscle growth, while prolonged water flow stress may lead to motor fatigue and affect growth in zebrafish. This research provides a foundation for further exploration of the growth regulation mechanism in fish, and is helpful on fish farming.

Chinese Kunming dog (CKD) is a working breed widely used by army, customs and police across the country. To better evaluate a breeding population's potential working performance and implement selective breeding for future offspring, a temperament test with five subsets, including following to trainer (FO), reaction to stranger (RS), tease by towel (TT), chase and fetch (CF) and tug of war (TW), was annually operated by the Kunming Police Dog Base since 2019. To fully utilize this behavioral data, 92 breeding animals of CKDs were genotyped by a 50K SNP chip, and a GWAS method supporting repeated measurement was adopted to estimate heritabilities and explore genetic variants associated with the five subsets. The heritabilities estimated for the five subsets ranged from 0,03 to 0.14, which showed a possibility for genetic improvement. Meanwhile, in total seven novel SNPs were identified associated with subsets FO, TT, CF and TW. In addition to that five of the seven loci are separately located within ACOT11, PRDM16, SAMD12, CPA1 and ENSCAFG00000023173 genes. Nevertheless, genetic effects of these novel loci on dog temperament should be further validated by a larger dataset in the future.

Baling Tieshan Reservoir is one of the important artificial inland lakes in Hunan Province, with abundant aquatic resources, including high-quality fish species such as organic bighead carp. In order to further utilize the resource advantages of Baling Tieshan Reservoir and create a high-quality brand, this experiment analysis the biological characteristics and excellent traits of Baling Tieshan organic bighead carp (BTOBC) through techniques such as gene cloning, qRT-PCR, and paraffin section, and provides experimental basis for improving the quality of BOTBC. Pond-cultured bighead carp (PCBC) was used as a control for comparison. The findings reveal that BTOBC exhibits excellent traits in terms of body color, body shape and meat quality, which better meets the market and consumers' demands. Analysis of muscle nutrient composition and observation of muscle fiber histomorphology demonstrate a higher muscle fat proportion, and umami amino acid (AA) content, higher muscle fiber density, enhanced taste in BTOBC. Blood index and liver histology observation indicate that BTOBC has relatively healthier physiological conditions. mRNA expression detection of umami taste receptor genes T1r1 and T1r3 in various tissues shows that the meat of BTOBC has a more delicious taste. This study provides a comprehensive understanding of the nutritional characteristics of BTOBC and explores its excellent traits, which can serve as a reference for subsequent processing, comprehensive utilization, and healthy breeding in the reservoir area. Moreover, it offers a scientific basis for the rational use of reservoir resources and the sustainable development of reservoir fisheries.

TNFα belongs to superfamily of tumor necrosis factor that can exert the pleiotropic effort in a large quantity of biological processes, including immune homeostasis, intracellular modulation and etiopathogenesis, but its regulatory role in mucosal immune regulation of fish is unclear. Currently, this study aimed to evaluate the immunoregulatory function of TNFα1 on gut barrier in teleost fish. In this study, TNFα1 sequences were identified from red crucian carp (RCC, Carassius auratus red var). The high-level expression of RCC-TNFα1 mRNA was detected in gill among all the isolated samples. Then, RCC-TNFα1 expression increased dramatically in immune-related tissues after A. hydrophila infection and in cultured fish cells after lipopolysaccharide (LPS) treatment. RCC-TNFα1 fusion protein was generated and purified in vitro. RCC receiving RCC-TNFα1 perfusion showed an increased levels of villi fusion and edema in injured midgut with the fuzzy appearance. In addition, The mRNA expressions of tight junction (TJ) genes, mucin genes and redox sensitive genes decreased sharply in TNFα1-treated midgut in comparison with those of the control (P < 0.05), whereas the expression levels of apoptotic genes involved in caspase signals and unfolded protein response (UPR) attained the dramatic increase. These results demonstrated that RCC-TNFα1 stimulation could impair midgut structural integrity and immune function by induction of antioxidant collapse and apoptotic activation.

The development of an effective method for predicting the transfer of biologics from plasma into breast milk is important to ensure the safe use of medications during lactation. The aim of this study was to develop a regression model that could predict the transfer of monoclonal antibodies (mAbs) and Fc-fusion proteins from plasma into breast milk. By searching various databases, a list of eleven mAbs and Fc-fusion proteins with available information of presence in the breast milk was generated. Physicochemical properties such as the isoelectric point (pI), molecular weight (MW), dissociation constant (K_d), and pharmacokinetic (PK) parameters such as clearance (CL), volume of distribution (V_d), and half-life (T_1/2) were collected or calculated. A two-variable non-linear regression analysis and a multivariate regression analysis were employed to establish correlation of milk-to-plasma (M/P) ratios with different combinations of two physicochemical properties. The 3D isoelectric point (pI) of the Fv region and the buried surface area (BSA) between the light and heavy chains (LC_HC) were two factors that emerged as a promising predictor of the milk-to-plasma concentration ratio (M/P). The correlation between M/P ratio, 3D pI of Fv region, and BSA_LC_HC was found to be good with R² of 0.9058. Other combinations of the physicochemical properties did not show a statistically significant correlation. The multivariate regression model was used to predict the MP ratios for 79 different mAbs. We believe that this regression model could serve as a valuable tool to estimate the M/P ratios of mAbs and Fc-fusion proteins. Further model validation is necessary when the M/P ratios of additional biologics are available. This could inform clinical decision-making and improve the safety of large molecule drug use during lactation.

Induced plant mutagenesis is a powerful technique to create genetic variation for agronomic traits and drought tolerance selection programs. The objective of this study was to determine the response of elite sorghum (Sorghum bicolor [L.] Moench) lines developed via gamma-radiation for grain yield, component traits, and drought tolerance to select best performing lines for cultivation in water-stressed environments. Ten newly developed mutant lines and four check varieties were evaluated in two growing seasons under drought-stressed (DS) and non-stressed (NS) conditions in Namibia. Mutant lines were evaluated using a factorial experiment laid out in a randomized complete block design with three replications in custom-made rainout-shelter facility. Data on grain yield and yield-related traits were collected and drought tolerance selection indices were computed using mean genotype yield under non-stressed condition and drought-stressed condition. Data were subjected to standard analysis of variance, correlation and principal component analyses. The interaction effect of genotype × drought stress × season was non-significant for most assessed traits suggesting the relatively stable performance of the test lines for selection. Grain yield response of test genotypes varied from 0.55 to 2.27 t/ha under DS and 1.84 to 4.05 t/ha in NS conditions. Grain yield positively and significantly (P < 0.05) correlated with harvest index (r = 0.79), panicle weight (r = 0.75) and panicle length (r = 0.37), and negatively correlated with days to flowering (r = −0.35) under DS condition. Principal component (PC) analysis identified two PCs accounting for 96.35 % of total genotypic variation based on drought tolerance selection indices. Biplot analysis using a combination assessed traits allowed selection of drought tolerant mutant lines designated as ML4, ML10, ML6, and ML5 with mean grain yield of 2.27, 2.05, 1.89 and 1.67 t/ha under DS conditions, in that order. The selected lines are recommended for further multi-environment evaluations for release and large-scale production in Namibia or other related agro-ecologies.