Biology subjects

Luu, B.

Publications and source records attributed to Luu, B..

4 recordsLinked to original sources

bioRxiv2025

Two closed systems for long-term propagation of the marine tunicate Botryllus schlosseri isolated from natural seawater

Advanced methodologies for Botryllus schlosseri artificial seawater systems are needed to decrease dependency of large-scale culture on natural seawater and expand use of this important new model organism to more inland laboratories. We constructed two botryllid tunicate customized closed aquaculture systems, a static system consisting of lightly aerated jars fed with commercial filter feeder diet, and a recirculating aquaculture system (RAS) consisting of standard marine RAS components fed live microalgae and zooplankton diets. Initially, static tunicate culture yielded exponential growth in contrast to the RAS system, which yielded poor survival and negligible growth. Modifications were made to the RAS system to improve water treatment proficiency that greatly improved tunicate survival and growth. Experiments were performed isolating feed and water type as variables that differed between the static and RAS systems to evaluate their effects. A live feed combination achieved five-fold greater growth relative to a commercial concentrate diet. B. schlosseri maintained in optimized RAS water achieved two-fold faster growth relative to animals maintained with freshly prepared artificial seawater indicating that the RAS water was beneficial to the animals. Feeding frequency of the RAS system was increased from three times per week to daily. The RAS system and procedural modifications resulted in comparable growth rates in the static and RAS systems. Both optimized systems are suitable for long-term propagation and sustenance of botryllid tunicate populations supporting both sexual and asexual modes of reproduction with a current residence time of over 24 months.

zoology↗

bioRxiv2025

Proteome Dynamics Across the Blastogenic Cycle of Botryllus schlosseri Reveals Targets for Cell Immortalization

The colonial tunicate Botryllus schlosseri regenerates weekly through a cyclical process in which adult zooids are replaced by a new generation of buds. While this dynamic asexual development is a hallmark of the species, its molecular regulation remains poorly understood. This study presents the first comprehensive proteomic analysis of B. schlosseri blastogenesis at the individual zooid level, using data-independent acquisition mass spectrometry to quantify protein abundance across developmental stages. The results reveal extensive proteome remodeling between proliferating buds and degenerating zooids. Co-expression analysis identified stage-specific protein modules enriched for biosynthesis and cell cycle pathways in buds, and for apoptosis, catabolism, and metabolic remodeling in zooids. A focused comparison between takeover buds and takeover zooids uncovered distinct regulatory programs controlling proliferation and senescence. Key proteins, including CDK1, CDK2, HDAC2, and PCNA, were identified as candidate regulators of cell cycle progression. These findings provide a molecular framework for understanding regeneration in a basal chordate and offer protein targets that may enable cell cycle re-entry and long-term culture of tunicate primary cells. Summary StatementThis study maps proteome dynamics during the blastogenic cycle in Botryllus schlosseri, identifying candidate proteins that regulate cell proliferation and offer targets for tunicate cell line development.

developmental biology↗

bioRxiv2018

Subclonal architecture, evolutionary trajectories and patterns of inheritance of germline variants in pediatric glioblastoma

Pediatric glioblastoma (pGBM) is a lethal cancer with no effective therapies. Intratumoral genetic heterogeneity and mode of tumor evolution have not been systematically addressed for this cancer. Whole-genome sequencing of germline-tumor pairs showed that pGBM is characterized by intratumoral genetic heterogeneity and consequent subclonal architecture. We found that pGBM undergoes extreme evolutionary trajectories, with primary and recurrent tumors having different subclonal compositions. Analysis of variant allele frequencies supported a model of tumor growth involving slow-cycling cancer stem cells that give rise to fast-proliferating progenitor-like cells and to non-dividing cells. pGBM patients germlines had subclonal structural variants, some of which underwent dynamic frequency fluctuations during tumor evolution. By sequencing germlines of mother-father-patient trios, we found that inheritance of deleterious germline variants from healthy parents cooperate with de novo germline and somatic events to the tumorigenic process. Our studies therefore challenge the current notion that pGBM is a relatively homogeneous molecular entity.

cancer biology↗

bioRxiv2018

Childhood cerebellar tumors mirror conserved fetal transcriptional programs

The study of the origin and development of cerebellar tumours has been hampered by the complexity and heterogeneity of cerebellar cells that change over the course of development. We used single-cell transcriptomics to study >60,000 cells from the developing murine cerebellum, and show that different molecular subgroups of childhood cerebellar tumors mirror the transcription of cells from distinct, temporally restricted cerebellar lineages. Sonic Hedgehog medulloblastoma transcriptionally mirrors the granule cell hierarchy as expected, whereas Group 3 medulloblastoma resemble Nestin+ve stem cells, Group 4 medulloblastomas resemble unipolar brush cells, and PFA/PFB ependymoma and cerebellar pilocytic astrocytoma resemble the prenatal gliogenic progenitor cells. Furthermore, single-cell transcriptomics of human childhood cerebellar tumors demonstrates that many bulk tumors contain a mixed population of cells with divergent differentiation. Our data highlight cerebellar tumors as a disorder of early brain development, and provide a proximate explanation for the peak incidence of cerebellar tumors in early childhood.

cancer biology↗