Transcriptome and comparative chloroplast genome analysis of Taxus yunnanensis individuals with high and low paclitaxel yield.

Paclitaxel is a potent anti-cancer drug that is mainly produced through semi-synthesis, which still requires plant materials as precursors. The content of paclitaxel and 10-deacetyl baccatin III (10-DAB) in Taxus yunnanensis has been found to differ from that of other Taxus species, but there is little research on the mechanism underlying the variation in paclitaxel content in T. yunnanensis of different provenances. In this experiment, the contents of taxoids and precursors in twigs between a high paclitaxel-yielding individual (TG) and a low paclitaxel-yielding individual (TD) of T. yunnanensis were compared, and comparative analyses of transcriptomes as well as chloroplast genomes were performed. High-performance liquid chromatography (HPLC) detection showed that 10-DAB and baccatin III contents in TG were 18 and 47 times those in TD, respectively. Transcriptomic analysis results indicated that genes encoding key enzymes in the paclitaxel biosynthesis pathway, such as taxane 10-ß-hydroxylase (T10ßH), 10-deacetylbaccatin III 10-O-acetyltransferase (DBAT), and debenzoyl paclitaxel N-benzoyl transferase (DBTNBT), exhibited higher expression levels in TG. Additionally, qRT-PCR showed that the relative expression level of T10ßH and DBAT in TG were 29 and 13 times those in TD, respectively. In addition, six putative transcription factors were identified that may be involved in paclitaxel biosynthesis from transcriptome data. Comparative analysis of plastid genomes showed that the TD chloroplast contained a duplicate of rps12, leading to a longer plastid genome length in TD relative to TG. Fifteen mutation hotspot regions were identified between the two plastid genomes that can serve as candidate DNA barcodes for identifying high-paclitaxel-yield individuals. This experiment provides insight into the difference in paclitaxel accumulation among different provenances of T. yunnanensis individuals.

Enantioselective α-Amination of Amides by One-Pot Organo-/Iodine Sequential Catalysis.

An one-pot organo- and iodine sequential catalysis strategy for reactions of amides with pyrazole-based primary amines was described to synthesize chiral α-amino amides with a quaternary stereocenter. This methodology exhibited strong asymmetric induction, resulting in a typical enantiomeric excess value exceeding 99% and diastereoselectivity up to >99:1 dr. Moreover, the reaction was conducted without the use of any metals or strong bases.

Comparative genomic analysis of Sanghuangporus sanghuang with other Hymenochaetaceae species.

Sanghuangporus sanghuang is a medicinal macrofungus with antioxidant and antitumor activities, and it is enriched with secondary metabolites such as polysaccharides, terpenes, polyphenols, and styrylpyrone compounds. To explore the putative core genes and gene clusters involved in sanghuang biosynthesis, we sequenced and assembled a 40.5-Mb genome of S. sanghuang (SH1 strain). Using antiSMASH, local BLAST, and NCBI comparison, 12 terpene synthases (TPSs), 1 non-ribosomal peptide synthase, and five polyketide synthases (PKSs) were identified in SH1. Combining the transcriptome analysis with liquid chromatography mass spectrometry-ion trap-time of flight analysis, we determined that ShPKS1, one phenylalanine aminolyase (ShPAL), and one P450 monooxygenase (ShC4H1) were associated with hispidin biosynthesis. Structural domain comparison indicated that ShPKS2 and ShPKS3 are involved in the biosynthesis of orsellinic acid and 2-hydroxy-6-methylbenzoic acid, respectively. Furthermore, comparative genomic analysis of SH1 with 14 other fungi from the Hymenochaetaceae family showed variation in the number of TPSs among different genomes, with Coniferiporia weirii exhibiting only 9 TPSs and Inonotus obliquus having 20. The number of TPSs also differed among the genomes of three strains of S. sanghuang, namely Kangneng (16), MS2 (9), and SH1 (12). The type and number of PKSs also varied among species and even strains, ranging from two PKSs in Pyrrhoderma noxium to five PKSs in S. sanghuang SH1. Among the three strains of S. sanghuang, both the structural domains and the number of PKSs in strains MS2 and SH1 were consistent, whereas strain Kangneng exhibited only four PKSs and lacked the PKS with the structural domain KS-AT-DH-KR-ACP. Additionally, Sanghuangporus species exhibited more similar PKSs to Inonotus, with higher gene similarity around five PKSs, while showing differences from those of other fungi in the same family, including Phellinus lamaoensis. This result supports the independent taxonomic significance of the genus Sanghuangporus to some extent.

Transcriptome Analysis Reveals the Putative Polyketide Synthase Gene Involved in Hispidin Biosynthesis in Sanghuangporus sanghuang.

Hispidin is an important styrylpyrone produced by Sanghuangporus sanghuang. To analyze hispidin biosynthesis in S. sanghuang, the transcriptomes of hispidin-producing and non-producing S. sanghuang were determined by Illumina sequencing. Five PKSs were identified using genome annotation. Comparative analysis with the reference transcriptome showed that two PKSs (ShPKS3 and ShPKS4) had low expression levels in four types of media. The gene expression pattern of only ShPKS1 was consistent with the yield variation of hispidin. The combined analyses of gene expression with qPCR and hispidin detection by liquid chromatography-mass spectrometry coupled with ion-trap and time-of-flight technologies (LCMS-IT-TOF) showed that ShPKS1 was involved in hispidin biosynthesis in S. sanghuang. ShPKS1 is a partially reducing PKS gene with extra AMP and ACP domains before the KS domain. The domain architecture of ShPKS1 was AMP-ACP-KS-AT-DH-KR-ACP-ACP. Phylogenetic analysis shows that ShPKS1 and other PKS genes from Hymenochaetaceae form a unique monophyletic clade closely related to the clade containing Agaricales hispidin synthase. Taken together, our data indicate that ShPKS1 is a novel PKS of S. sanghuang involved in hispidin biosynthesis.

Draft genome sequence of endolichenic fungus Dothichiza sp. strain YAFEF048, isolated from Usnea longissima on Haba Snow Mountain.

In this study, we report a draft genome sequence of the endolichenic fungus Dothichiza sp. strain YAFEF048, isolated from the lichen Usnea longissima on Haba Snow Mountain. The genome resource will support future research into the endolichenic lifestyle and potential secondary metabolite diversity of this fungus.

Effect of Crystallographic Orientations on Bendability in a Strongly Textured Mg-9Al Extrusion Plate and Texture Evolution during Three-Point Bending.

The dependence of bendability on crystallographic orientations and texture evolution was investigated in a strongly textured Mg-9Al extrusion plate by bending along four directions. Results show that the bars have relatively small and reasonably close bendability when bent along the extrusion direction, transverse direction, and through-thickness direction. In contrast, the bendability of the 45° bar is much larger. Microstructure examination indicates that twins are prevalent in all bars. Furthermore, a detailed analysis of deformation mechanisms suggests that the initial texture transforms towards a basal texture during bending. Nevertheless, the texture transformation efficiency is drastically lower when basal slip-in contrast to tensile twinning-is the dominant deformation mechanism. The difference in texture evolution efficiency was used to rationalize the varied bendability along different directions. The findings of this provide insights into improving the bendability of magnesium alloys.

Duplication of SOX3 in an SRY-negative 46,XX male with prostatic utricle: case report and literature review.

BACKGROUND: 46,XX male disorders of sex development are rare. Approximately 80% of cases of testicular tissue differentiation may be due to translocation of SRY to the X chromosome or an autosome. SRY-negative 46,XX males show overexpression of pro-testis genes, such as SOX9 and SOX3, or failure of pro-ovarian genes, such as WNT4 and RSPO1, which induces testis differentiation, however, almost all testicles exhibit dysgenesis. Following inadequate exposure to androgens during the embryo stage, remnants of the Mullerian duct and incomplete closure of the urogenital sinus lead to enlargement of prostatic utricles. This condition is associated with proximal hypospadias and disorders of sex development. Many cases are asymptomatic, but show increased rates of postoperative complications and surgical failure. CASE PRESENTATION: A 5-year-old Chinese boy with scrotal hypospadias and bilateral cryptorchidism with prostatic utricles was presented. Gonadal histology showed ovo-testicular tissue on the right side and testicular tissue on the left side; all testicular tissue exhibited dysgenesis. Furthermore, chromosome karyotype analysis revealed 46,XX and, the presence of SRY was ruled out by polymerase chain reaction analysis. Whole-genome analysis showed the boy has a 1.4-Mb duplication in the Xq27.1q27.2 region (arr[hg19]Xq27.1q27.2:139585794-140996652) involving SOX3. No SOX3 duplication was observed in the parents, who had a normal phenotype. CONCLUSIONS: We report the first case of an SRY-negative 46 XX male with prostatic utricle caused by SOX3 duplication. SOX3 duplication may cause sex reversal, and all 46,XX SRY-negative males should be screened for SOX3 mutations. Gonadal biopsy is recommended to evaluate ovarian and testicular tissue development. Testicular dysgenesis and low exposure to male hormones during fetal development can lead to enlarged prostatic utricles. Thus endoscopic examination should be performed preoperatively to detect prostatic utricles in SRY-negative 46,XX males to determine the surgical plan and reduce postoperative complications.