Genetic assessment of three Fagaceae species in forest restoration trials

Restoring isolated patches of forest ecosystems in degraded landscapes could potentially lead to genetic loss and inbreeding. Therefore, this study determined the occurrence of genetic diversity among the tree species Castanopsis tribuloides, C. calathiformis, and Lithocarpus polystachyus all of which were proven previously to be effective native tree species in the restoration of upland evergreen forests in northern Thailand when using the seed sample collection method. We tested our hypothesis as to whether the genetic diversity of a plant population that had been planted from the seeds of 4–6 adult trees would be lower and whether incidences of fixation index (Fis) would be higher among the second generation seedlings of these three Fagaceae species in isolated forest restoration trial plots. Microsatellite primers were selected from the entire genome sequence of C. tribuloides and the genetic sequences of C. tribuloides, L. polystachyus, and C. calathiformis were analyzed. Our results indicated a high degree of genetic diversity (He) in C. tribuloides (0.736) and C. calathiformis (0.481); however, a low level of genetic diversity was observed in L. polystachyus (0.281) within the restored forest. The fixation index for the second generation of L. polystachyus and C. calathiformis in the restored forest showed evidence of inbreeding. These results imply the efficiency of the seed sample collection method and verify that it does not reduce the level of genetic diversity in C. tribuloides and C. calathiformis. However, it may result in incidences of an inbreeding phenomena, suggesting the need to increase the number of adult trees used at the seed collection stage

Genetic diversity and ancestry of the Khmuic-speaking ethnic groups in Thailand: a genome-wide perspective

Abstract The Khmuic-speaking populations are believed to be the descendants of one of the earliest groups to settle in Mainland Southeast Asia. In Thailand, there are two agricultural Khmuic-speaking ethnic groups, the Khamu and Lua (Htin). These peoples primarily reside in scattered locations along the mountainous Thailand–Laos border in Nan province. In this study, we conducted genome-wide SNP analysis on 81 individuals from three Khamu and two Lua villages in northern Thailand. Our findings revealed that both the Khamu and Lua groups possess genetic structures that are distinct from other ethnicities in Southeast Asia, indicating a unique history of migration and settlement. Within the Khmuic group, the Khamu populations living in different locations exhibited similar genetic structures and displayed genetic affinities only with some hill-tribes and Tai-Kadai (Kra-Dai)-speaking groups in Thailand, suggesting potential intermixing or cultural exchange. Furthermore, the Lua people displayed a distinctive population structure, which could be attributed to the founder effect and endogamous marriage practices. Additionally, we discovered a relationship between the Khmuic-speaking populations in Thailand and a Neolithic ancient sample obtained from the Tham Pha Ling archaeological site in Laos. This study provides new insight into genetic substructure within the Khmuic-speaking people and their potential relationship to the indigenous inhabitants of Mainland Southeast Asia

Gut Microbiota-Mediated Pharmacokinetic Drug–Drug Interactions between Mycophenolic Acid and Trimethoprim-Sulfamethoxazole in Humans

Mycophenolic acid (MPA) and trimethoprim-sulfamethoxazole (TMP-SMX) are commonly prescribed together in certain groups of patients, including solid organ transplant recipients. However, little is known about the pharmacokinetic drug–drug interactions (DDIs) between these two medications. Therefore, the present study aimed to determine the effects of TMP-SMX on MPA pharmacokinetics in humans and to find out the relationship between MPA pharmacokinetics and gut microbiota alteration. This study enrolled 16 healthy volunteers to take a single oral dose of 1000 mg mycophenolate mofetil (MMF), a prodrug of MPA, administered without and with concurrent use of TMP-SMX (320/1600 mg/day) for five days. The pharmacokinetic parameters of MPA and its glucuronide (MPAG) were measured using high-performance liquid chromatography. The composition of gut microbiota in stool samples was profiled using a 16S rRNA metagenomic sequencing technique during pre- and post-TMP-SMX treatment. Relative abundance, bacterial co-occurrence networks, and correlations between bacterial abundance and pharmacokinetic parameters were investigated. The results showed a significant decrease in systemic MPA exposure when TMP-SMX was coadministered with MMF. Analysis of the gut microbiome revealed altered relative abundance of two enriched genera, namely the genus Bacteroides and Faecalibacterium, following TMP-SMX treatment. The relative abundance of the genera Bacteroides, [Eubacterium] coprostanoligenes group, [Eubacterium] eligens group, and Ruminococcus appeared to be significantly correlated with systemic MPA exposure. Coadministration of TMP-SMX with MMF resulted in a reduction in systemic MPA exposure. The pharmacokinetic DDIs between these two drugs were attributed to the effect of TMP-SMX, a broad-spectrum antibiotic, on gut microbiota-mediated MPA metabolism