The secretory proteome plays an important role in the pathogenesis of phytopathogenic fungi. However, the relationship between the large-scale secretome of phytopathogenic fungi and their lifestyle is not fully understood. In the present study, the secretomes of 150 plant pathogenic fungi were predicted and the characteristics associated with different lifestyles were investigated. In total, 94,974 secreted proteins (SPs) were predicted from these fungi. The number of the SPs ranged from 64 to 1,662. Among these fungi, hemibiotrophic fungi had the highest number (average of 970) and proportion (7.1%) of SPs. Functional annotation showed that hemibiotrophic and necrotroph fungi, differ from biotrophic and symbiotic fungi, contained much more carbohydrate enzymes, especially polysaccharide lyases and carbohydrate esterases. Furthermore, the core and lifestyle-specific SPs orthogroups were identified. Twenty-seven core orthogroups contained 16% of the total SPs and their motif function annotation was represented by serine carboxypeptidase, carboxylesterase and asparaginase. In contrast, 97 lifestyle-specific orthogroups contained only 1% of the total SPs, with diverse functions such as PAN_AP in hemibiotroph-specific and flavin monooxygenases in necrotroph-specific. Moreover, obligate biotrophic fungi had the largest number of effectors (average of 150), followed by hemibiotrophic fungi (average of 120). Among these effectors, 4,155 had known functional annotation and pectin lyase had the highest proportion in the functionally annotated effectors. In addition, 32 sets of RNA-Seq data on pathogen-host interactions were collected and the expression levels of SPs were higher than that of non-SPs, and the expression level of effector genes was higher in biotrophic and hemibiotrophic fungi than in necrotrophic fungi, while secretase genes were highly expressed in necrotrophic fungi. Finally, the secretory activity of five predicted SPs from Setosphearia turcica was experimentally verified. In conclusion, our results provide a foundation for the study of pathogen-host interaction and help us to understand the fungal lifestyle adaptation.

In this study, we selected natural polyploidy loach (diploid, triploid and tetraploid) and hybrid F₁ generation obverse cross (4 × 2) and inverse cross (2 × 4) by diploids and tetraploids as the research model. The MSAP (methylation-sensitive amplified polymorphism) reaction system was established by our laboratory to explore methylation levels and pattern diversification features at the whole genome level of the polyploidy loach. The results showed that the total methylation and full methylation rates decreased on increased ploidy individuals; moreover, the hemimethylation rate showed no consistent pattern. Compared with diploid loach, the methylation patterns of tetraploid sites changed 68.17%, and the methylation patterns of triploid sites changed 73.05%. The proportion of hypermethylation genes is significantly higher than the proportion of demethylation genes. The methylation level of reciprocal cross F₁ generation is lower than the male diploid and higher than the female tetraploid. The hemimethylation and total methylation rate of the cross hybrid F₁ generation is significantly higher than the orthogonal F₁ generation (p < 0.01). After readjusting, the methylation pattern of genome DNA of reciprocal hybrids changed 69.59% and 72.83%, respectively.

The phenotypic sex of fish is usually plastic. Low-temperature treatment induces the masculinization of Takifugu rubripes, resulting in pseudo-males (PM) with the physiological sex of a male (M) and genetic sex of a female (F). For a comparison of gonadal transcriptomes, we collected gonads from three groups of T. rubripes (F, M, and PM) for high-throughput transcriptome sequencing. The results provided 467,640,218 raw reads (70.15 Gb) and a total of 436,151,088 clean reads (65.43 Gb), with an average length of 150 bp. Only 79 differentially expressed genes (DEGs) were identified between F and PM, whereas 12,041 and 11,528 DEGs were identified between F and M, and PM and M, respectively. According to the functional annotation of DEGs, 13 DEGs related to gonadal development were screened (LOC101066759, dgat1, limk1, fbxl3, col6a3, fgfr3, dusp22b, svil, abhd17b, srgap3, tmem88b, bud4, and mustn10) which might participate in formating PM. A quantitative PCR of the DEGs confirmed the reliability of the RNA-seq. Our results provide an important contribution to the genome sequence resources for T. rubripes and insight into the molecular mechanism of masculinization in a cultured fish subject to low-temperature treatment.

As a new freshwater aquaculture product, triploid loaches (Misgurnus anguillicaudatus) are characterized by fast growth, high-quality meat, high edibility, high resistance to disease, and sterility. In this study, a natural tetraploid loach (4n = 100) (♀) was crossed with a diploid loach (2n = 50) (♂), thus creating the hybrid triploid loach (3n = 75). The histological observations of triploid offspring and diploid controls at 4 days post-hatching (dph), 15dph, 22dph, and 50dph showed that most of the hybrid triploid loaches were abortive in the early gonad differentiation process. To explore its fertility mechanism, through transcriptome analyses of triploid offspring and diploid controls at four periods, 10 differentially expressed genes related to the early fertility mechanism were identified: amh, hormad1, rec8, h2b, plvap, zp3, h2a, nrb0b1, ddx4, and esr2. According to the Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses of DEGs, two pathways were identified that are closely related to the early fertility mechanism at 50dph: the estrogen signaling pathway and steroid biosynthesis. The findings laid a foundation for further exploration of their molecular inhibition mechanism in hybrid triploid loaches.

Natural tetraploid loach (Misgurnus anguillicaudatus) living in the Changjiang River basin and adjacent area in China has been considered a true genetic tetraploidy (4n = 100) with four sets of homologous chromosomes. Here, we reported its further supporting evidence provided by the cold‐shock androgenesis. Viable androgenetic progeny appeared when eggs were cold‐shocked at 3°C for 60 min, starting 5 min after fertilization with sperm of natural tetraploid males, although the survival rate was significantly lower than control group. The majority (87%) of androgenetic embryos were diploid (2n = 50) and all‐paternal inheritance was verified in larval stage by microsatellite genotypes. Microscopic observations confirmed the elimination of both egg nucleus and second polar body from a fertilized egg, followed by the cleavage exclusively with sperm nucleus. Thus, the appearance of normal diploid androgenetic progeny from sperm of natural tetraploid loach revealed the presence of four chromosome sets in tetraploid males.