Biology subjects

Lee, Y.-J.

Publications and source records attributed to Lee, Y.-J..

3 recordsLinked to original sources

bioRxiv2019

Conservation and Divergence of Related Neuronal Lineages in the Drosophila Central Brain

Wiring a complex brain requires enormous cell specificity. This specificity is laid out via a developmental process where neural stem cells produce countless diverse neurons. To help elucidate this process and resolve the considerable dynamic specificity, we need to observe the development of multiple neuronal lineages. Drosophila central brain lineages are predetermined, comprised of a fixed set of neurons born in pairs in a specific order. To reveal specific roles of lineage identity, Notch-dependent sister fate specification, and temporal patterning in morphological diversification, we mapped approximately one quarter of the Drosophila central brain lineages. While we found large aggregate differences, we also discovered similar patterns of morphological specification and diversification. Lineage identity plus Notch state govern primary neuronal trajectories, whereas temporal fates diversify terminal elaborations in target-specific manners. In addition, we identified related lineages of analogous neuron types produced in similar temporal patterns. Two stem cells even yield identical series of dopaminergic neuron types, but with completely disparate sister neurons. These phenomena suggest that large changes in morphological diversity can be the consequence of relatively small differences in lineage fating. Taken together, this large-scale lineage mapping study reveals that relatively simple rules drive incredible neuronal complexity.

developmental biology↗

bioRxiv2019

Long-Term Outcomes of Pediatric Graves Disease Patients Treated with Anti-Thyroid Drugs: Experience from a Taiwan Medical Center

Graves disease (GD) is the most common cause of thyrotoxicosis in children and adolescents, accounting for 15% of all thyroid diseases during childhood. Anti-thyroid drugs (ATD) are recommended as the first-line treatment in children and adolescents. However, the remission rate is lower in children than in adults, and the optimal treatment duration and favorite factors associated with remission remain unknown. We aimed to investigate long-term outcomes of pediatric GD patients receiving ATD. We retrospectively reviewed medical charts of 300 pediatric GD subjects, who were initially treated with ATD and followed up for more than one year, from 1985 to 2017 at MacKay Childrens Hospital. The 300 patients comprised 257 (85.7%) females and 43 (14.3%) males, median age at diagnosis was 11.6 (range 2.7-17.8) years, and median follow-up period was 4.7 (range 1.1-23.9) years. Overall, 122 patients achieved the criteria for discontinuing ATD treatment, seventy-nine (39.9%) patients achieved remission, with a median follow-up period of 5.3 (range 1.5-20.1) years. Patients in the remission group were more likely to be aged < 5 years (remission vs. relapse vs. ongoing ATD; 11.4 vs. 0 vs. 2.6%, P=0.02), less likely to have a family history of thyroid disease (24.1 vs. 42.1 vs. 52.6 %, P=0.001), and had lower TRAb levels (42.8 vs. 53.6 vs. 65.1 %, P=0.02).\n\nConclusionLong-term ATD remains an effective treatment option for GD in children and adolescents. Pediatric GD patients aged < 5 years, having no family history of thyroid disease and having lower TRAb levels were more likely to achieve remission.

physiology↗

bioRxiv2019

Assessing chromatin accessibility in maize using ATAC-seq

Background: Maize is an important crop that has a complex genome. A better understanding of maize chromatin architecture provides great opportunities for crop improvement, because chromatin accessibility influences gene expression, thereby affecting agricultural traits. The newly developed method for chromatin profiling, Assay for Transposase Accessible Chromatin with high-throughput sequencing (ATAC-seq), has been developed to investigate chromatin accessibility. Result: We adapt this method by testing parameters of several key steps and generate the first ATAC-seq protocol for maize. We demonstrate that purification of maize nuclei to eliminate organelles can be achieved without the need for cell sorting, and that only a standard bench-top centrifuge is required for sample preparation. Finally, our sequence analyses confirm that our protocol of ATAC-seq can be successfully used to assess the chromatin landscape in maize. Conclusion: The ATAC-seq provides a useful technique to study the chromatin accessibility. Given the parameters tested in our study, it can be a simple and practical method for maize and may be a foundation for similar studies in other crop species.

genomics↗