First identification of two co-existing genome-wide significant sex quantitative trait loci (QTL) in red tilapia using integrative QTL mapping.

Red tilapia ( Oreochromis spp .) is one of the most popular fish in China due to its bright red appearance, fast growth rate, and strong adaptability. Understanding the sex determination mechanisms is of vital importance for the selection of all-male lines to increase aquacultural production of red tilapia. In this research, the genetic architecture for sex from four mapping populations ( n=1 090) of red tilapia was analyzed by quantitative trait loci (QTL)-seq, linkage-based QTL mapping, and linkage disequilibrium (LD)-based genome-wide association studies. Two genome-wide significant QTL intervals associated with sex were identified on ChrLG1 (22.4-23.9 Mb) and ChrLG23 (32.0-35.9 Mb), respectively. The QTL on ChrLG1 was detected in family 1 (FAM1), FAM2, and FAM4, and the other QTL on ChrLG23 was detected in FAM3 and FAM4. Four microsatellite markers located within the QTL were successfully developed for marker-assisted selection. Interestingly, three ( lpp, sox14, and amh) of the 12 candidate genes located near or on the two QTL intervals were abundantly expressed in males, while the remaining genes were more highly expressed in females. Seven genes ( scly, ube3a, lpp, gpr17, oca2, cog4, and atp10a) were significantly differentially expressed between the male and female groups. Furthermore, LD block analysis suggested that a cluster of genes on ChrLG23 may participate in regulating sex development in red tilapia. Our study provides important information on the genetic architecture of sex in red tilapia and should facilitate further exploration of sex determination mechanisms in this species.

[Biosynthesis and metabolism regulation of terpenoids in Pogostemon cablin: a review].

The terpenoids in Pogostemon cablin have complex structures and abundant pharmacological effects. Patchouli alcohol(PA) and pogostone(PO) have a high medicinal value by virtue of anti-tumor, anti-inflammatory, antibacterial, antioxidant, and other biological activities. Due to the low content of terpenoid metabolites in P. cablin, the study of biosynthesis and metabolism regulation can provide a biosynthetic basis for obtaining high-content terpenoids. In this study, key enzyme genes in biosynthesis, transcription factors in metabolism regulation, spatio-temporal expression of terpene synthase were reviewed, aiming to provide a reference for the development, protection, and utilization of P. cablin resources.