Project description:Myanmar locates in the crossroads of South Asia, Southeast Asia, and East Asia, and is known for high culture diversity in different ethnic groups. It is considered to be important for understanding human evolutionary history and genetic diversity in East Eurasia. However, relatively few studies have examined the population structure and demographic history in Myanmar to date. In this study, we analyzed more than 220,000 genome-wide SNPs in 175 new samples of five ethnic groups from Myanmar and compared them with the published data. Our results showed that the Myanmar population is intricately substructured, with the main observed clusters corresponding roughly to western/northern highlanders (Chin, Naga, and Jingpo) and central/southern lowlanders (Bamar and Rakhine). The gene flow inferred from South Asia has a substantial influence (~11%) on the gene pool of central/southern lowlanders rather than western/northern highlanders. The genetic admixture is dated around 650 years ago. These findings suggest that the genome-wide variation in Myanmar was likely shaped by the linguistic, cultural, and historical changes.
Project description:microRNAs (miRNAs) are small noncoding RNAs that mediate post-transcriptional gene regulation and have emerged as essential regulators of many developmental events. The transcriptional network during early embryogenesis of the purple sea urchin, Strongylocentrotus purpuratus, is well described and would serve as an excellent model to test functional contributions of miRNAs in embryogenesis. We examined the loss of function phenotypes of the major components of the miRNA biogenesis pathway. Inhibition of de novo synthesis of Drosha and Dicer in the embryo led to consistent developmental defects, a failure to gastrulate, and embryonic lethality, including changes in the steady state levels of transcription factors and signaling molecules involved in germ layer specification. We annotated and profiled small RNA expression from the ovary and several early embryonic stages by deep sequencing followed by computational analysis. All miRNAs have dynamic accumulation profiles through early development as do a large population of putative piRNAs (piwi-interacting RNAs). Defects in morphogenesis caused by loss of Drosha can be rescued with four miRNAs which permits a strong miRNA functional assay. Taken together our results indicate that post-transcriptional gene regulation directed by miRNAs is functionally important for early embryogenesis and is an integral part of the early embryonic gene regulatory network in S. purpuratus.
Project description:To explore the evolution of different cell types across species, we compared transcriptomes between different cell types between two echinoderm species, P. miniata and S. purpuratus. snRNA-seq was used to analyze to characterize diffente cell states. For each species, the time points were integrated into a common atlas and annotated. The fully processed and annotated P. miniata and S. purpuratus atlases are available as supplementary files.
Project description:To explore the evolution of different cell types across species, we compared transcriptomes between different cell types between two echinoderm species, P. miniata and S. purpuratus. snRNA-seq was used to analyze to characterize diffente cell states. For each species, the time points were integrated into a common atlas and annotated. The fully processed and annotated P. miniata and S. purpuratus atlases are available as supplementary files.
Project description:Four seed composition mutants (known as G15FN-109-1, G15FN-12-1, G15FN-23-3, and G15FN-54-3) were identified in a soybean fast neutron population developed in southern U.S. lines. The parent line for G15FN-109-1 is G00-3880, while the parent line for the other three mutants is G00-3213. Each mutant was compared to its respective parent line using CGH to identify the causative region/gene associated with the seed composition phenotypes.