Reproduction and breeding最新文献

Based on the distant hybridization derived from Hypophthalmichthys nobilis (bighead carp, BIC, 2n ​= ​48) (♀) ​× ​Megalobrama amblycephala (blunt snout bream, BSB, 2n ​= ​48) (♂), we obtained a novel hybrid (BB) in this study. We comparatively investigated the morphological traits, chromosome numbers, DNA contents, microsatellite patterns, and DNA variations in 5S rDNA and Hox genes. The chromosome and flow cytometer results indicated that BB was a diploid hybrid with 48 chromosomes. We confirmed successful hybridization with microsatellite DNA markers and analyzed the Hox gene family in the parental and hybrid lines. The sequences of 5S rDNA in BB mapped to those in BIC and BSB, indicating that the genetic materials of BB were derived from BIC and BSB. The breeding experiment showed that BB had the characteristics of herbivore and fast growth. This diploid hybrid is of great significance for fish genetic breeding and applied research.

The reproductive development process of rice is not only important for basic developmental biology research, but also of great benefit to production practice. However, current understanding of the reproductive growth process is relatively limited, especially in the later stages of development. Here we report that OsGAMYBL2, a homologous gene of GAMYB, is required for pollen maturation and germination in rice, and that loss of function of OsGAMYBL2 leads to male sterility in rice. We generated three alleles of OsGAMYBL2 knockout mutants using CRISPR/Cas9 system, all of them lost fertility when grown in the paddy field. Semi-section and electron microscopy observations revealed that there are no visible morphological changes in the outer and inner surfaces of anther and in the surface of mature pollens between mutants and wild type. However, pollens at late developmental stages exhibited much lighter pollen viability staining and some of them shriveled. In vitro and in vivo germination experiments showed that mutant pollens fail to germinate, leading to abnormal pollen tube formation and subsequent defective pollination. Furthermore, we observed that as compared with high temperature at 30 ​°C, low-temperature at 22 ​°C affects less on osgmybl2 fertility. Collectively, we proposed that OsGAMYBL2 is likely involved in the regulation of starch accumulation during later pollen development with a thermal-sensitive way, which improves our understanding on the reproductive development in plants.

Type III polyketide synthase (PKS III) superfamily members are involved in plant secondary metabolism, which is important for plant development and resistance to biological and abiotic stress. However, the functions of most PKS III superfamily members in rice (Oryza sativa L.) remain unknown. Here, we identified PKS III genes in rice and performed phylogenetic analysis. This divided the 28 rice PKS III superfamily genes into six subgroups, the chalcone synthase (CHS) group and the CHS-like groups CHSL I–V. These PKS III genes share significant genomic synteny. CHS, CHSL I, and II genes are present in single copies in the rice genome, whereas CHSL III–V are present in gene clusters. The chromosomal regions harboring PKS III genes contain numerous transposable elements, which might underlie the duplication and expansion of the PKS III superfamily. Heatmap analysis indicated that PKS III genes in the same subgroup have similar expression patterns. We knocked out two anther-specific genes (OsPKS1 and OsPKS2) from subgroup CHSL II in rice to investigate their roles in male reproduction. The double knockout mutant ospks1/2 exhibited severer defects in exine and no-pollen phenotype, which is different from the partially abortive-pollen phenotype of the ospks1 and ospks2 single mutants. OsPKS1 is upregulated in ospks2 mutants and OsPKS2 is upregulated in ospks1 mutants, suggesting that the coordinated activities of OsPKS1 and OsPKS2 are essential for pollen development. Our findings provide new clues about the evolution of the PKS III superfamily and reveal the synergistic roles of OsPKS1 and OsPKS2 in regulating male reproduction in rice.

Interploid cross is regularly observed in plants and often results in phenotypic changes, including reduced fertility and heterosis. Yet few triploids have been observed in animals due to the rare coexistence of diploid and allotetraploid populations in species. However, heterosis in growth traits and innate immunity have been detected in the allotriploids obtained from interploid crossing of the male allotetraploids of red crucian carp and common carp (4nAT) with the females of their inbred parents. Here, we obtained two new types of allotriploids (3nR₂C and 3nRC₂) by the interploid crossing of female 4nAT with the inbred parents (red crucian carp and common carp, respectively). The embryos of the two allotriploids developed normally through the zygote, cleavage, blastula, gastrula, segmentation and hatching stages, and high fertilization rates (3nR₂C: 91.31%, 3nRC₂: 84.09%) and hatching rates (3nR₂C: 72.96%, 3nRC₂: 71.15%) were observed. The measured DNA content and chromosome numbers suggested that both 3nR₂C and 3nRC₂ were allotriploids with 150 chromosomes. Intermediate characteristics of some morphological traits, such as the body length to body height ratio (BL/BH), were observed in 3nR₂C and 3nRC₂. In contrast to the stage II oocytes in the ovaries of the inbred parents, cystic structures formed by small, underdeveloped oogonia were observed in the two allotriploids. In contrast to the observation of mature spermatids in the testes of the inbred parents, spermatids with irregular shapes that began to degrade and disintegrate were observed in the two allotriploids. These results revealed abnormal gonad development in the allotriploids. Taken together, our results indicate that the two new allotriploids will be significant in aquaculture.

Hybrid bream (BBTB) is a high-quality bream derived from a hybrid lineage of blunt snout bream (Megalobrama amblycephala, 2n ​= ​48, BSB, ♀) ​× ​topmouth culter (Culter alburnus, 2n ​= ​48, TC, ♂). In this study, to explore the laws of artificial propagation of BBTB in a brackish water environment, 150 pairs of BBTB with an average weight of 1000 ​g were selected as brood fish, and a successful artificial propagation experiment was carried out at the Freshwater Fish Nansha (Nanfan) Breeding Center (2‰–5‰ brackish water). The fertilization and hatching rate was 86% and 78%, respectively, and a total of 1 ​800 ​000 larvae were obtained. After 26 days of cultivation, 400 ​000 larvae survived, showing a survival rate of 22%. This study is of great significance regarding the basic theories and applications of fish genetics.

Tryptophan (Trp) influences several physiological functions, including reproduction, stress and immune function in fishes. The present study investigates the effect of dietary Trp supplementation on growth, reproduction, health of Silver barb, Barbonymus gonionotus. A basal diet (control/T1) with varying level of L-Trp at 0.4% (T2), 0.8% (T3) and 1.6% (T4) were fed to experimental fishes (71.04 ​± ​1.62 ​g) for 60 days period. Results indicate higher growth in groups fed 0.4% L-Trp compared to control (p ​< ​0.05). Percent survival was found to be low in all fed groups; however, 0.4% L-Trp (83.33 ​± ​3.33) was not significant as compared to control (93.33 ​± ​3.33). Significant effect (p ​< ​0.05) of dietary L-Trp was evident on the expression level of GnRH-II gene, with 6.26-fold-changes observed at 0.4% level. Reproductive functions (gonado-somatic index, fecundity and egg diameter) were better in groups fed 0.4% L-Trp (p ​< ​0.05). Ovarian histology indicates advanced maturation in fed groups, compared to the control. However, plasma melatonin showed elevated level in 0.8% and 1.6% L-Trp fed groups (p ​< ​0.05). Hemato-biochemical indices as a measure of the health status of the fish indicates elevated total leukocyte and decreased erythrocyte counts in fed groups (p ​< ​0.05). Blood glucose was lower (48.11 ​± ​1.63 ​mg. dl⁻¹), whereas respiratory burst activity (0.60 ​± ​0.02) was higher in 0.4% Trp compared to other groups (p ​< ​0.05). In conclusion, dietary L-Trp supplementation at 0.4% helps to augment growth performance in Silver barb, besides improving reproductive performance.

The red swamp crayfish (Procambarus clarkii) is a well-known invasive species. It has become one of the most important freshwater aquaculture resources in China. In this study, we reported the karyotype and whole mitochondrial genome of Procambarus clarkii. In addition, we performed transcriptome analysis of Procambarus clarkii from two different body size populations. The three large individuals, namely, the LS group, were randomly chosen, with body lengths and weights of 16.24–18.85 ​cm and 38.96–45.36 ​g, respectively. The three small individuals, namely, the SS group, were randomly chosen, with body lengths and weights of 10.50–12.70 ​cm and 19.56–25.95 ​g, respectively. Comparative transcriptomic analysis of Procambarus clarkii characterized 36 differentially expressed genes (DEGs), comprising 20 upregulated genes and 16 downregulated genes in the SS group. Functional analyses revealed that four genes (metalloreductase STEAP4-like (Steap4), myosin heavy chain fast skeletal muscle, muscle-like (MH), vitelline membrane outer layer protein I-like protein (VMO-I), and secreted protein acidic and rich in cysteine (SPARC)) were involved in the regulation of cell proliferation, muscle growth and energy metabolism, suggesting that four genes were related to growth in P. clarkii. We validated the expression levels of these four differentially expressed genes in LS and SS using Quantitative real-time PCR. These results provide insights into the regulatory mechanisms underlying the difference in P. clarkii growth.

Camellia oleifera is a unique edible oil tree species in China and one of the four major woody oil tree species in the world. Its products are widely used in forestry, agriculture and fishery, medicine, daily chemicals, light textile and so on. In recent years, C. oleifera has become a topic of great scientific interest because of its unique value. However, few lipidomics studies on C. oleifera were reported. In this study, “XiangLin1” (XL1) and “XiangLin210” (XL210) were analyzed by non-targeted LC-MS/MS and 1329 metabolites were identified. The 99 significantly different lipids (SDLs) were matched with the criteria of P ​< ​0.05 and variable importance in the projection (VIP) value ​> ​1. Compared with XL1, XL210 has 59 SDLs down-regulated and 40 SDLs up-regulated. Through correlation analysis, we concluded that glycerolipids (GLs), glycerophospholipids (GPs) and sphingolipids (SPs) had strong correlation within and between classes. Our results will provide a reference for the subsequent study on the lipid synthesis mechanism of C. oleifera by the multi-omics technology.

Unfriendly environments like drought, cold or any other properties stress lead to a certain reduction of crop yield and quality. Abscisic acid (ABA), as an important plant hormone, plays a very important role in plant growth and resisting plant stress responses. The discovery of ABA receptor crystal structure is a very critical event and provide a very important role for ABA signaling pathways to be exposed to us more clearly. In this process, the screening of ABA receptor agonists played a decisive role in the analysis of ABA crystal structure. Further, various ABA receptor agonists have been screened out, and their functions have also been analyzed. Together, structural studies suggest a detailed mechanism for ABA and receptor binding and regulation of downstream ABA signal pathway, which provide new thoughts for improvement of crop yield and quality through the rational utilize the designed ABA agonists.