In humans, a mutation of the zinc finger e-box-binding homeobox 2 (ZEB2) gene is associated with Mowat-Wilson Syndrome, a condition known to cause severe deficits in speech and language ability. Despite this, there is little known regarding the neural mechanism of how ZEB2 affects language. To investigate such mechanisms, zebra finches provide a relevant animal model due to their ability to learn song as well as key similarities between human and zebra finch brains. Specifically, the zebra finch HVC (proper name), a premotor cortical component of the zebra finch song circuit, is structurally and genetically analogous to the human laryngeal motor cortex, a speech control region. As male zebra finches engage in song learning during developmental critical periods while females do not, generating a timeline of ZEB2 protein expression in the zebra finch HVC and comparing between sexes would aid in understanding its role in both the development of song circuitry and language production. To create this timeline of sex-specific differential expression, levels of ZEB2 protein expression were quantified at key developmental time points between male and female zebra finches. Preliminary results suggest a sex-specific upregulation of ZEB2 during the critical period for vocal learning in the HVC of zebra finch males compared with females. More data is needed to establish a timeline of ZEB2 expression corresponding to key developmental points in zebra finch song learning. Such results would implicate ZEB2 as an important gene in song circuitry development with a potential translation to development of analogous structures in humans.

The Human Genome Project found about 20,000-25,000 protein coding genes, however, estimates claim there to be as many as 500,000 proteins in the human body. This can be explained by variants generated by alternative splicing. Splicing is a eukaryotic process where noncoding sequences, introns, are excised and coding sequences, exons, are ligated together to form mature messenger RNA. Histone acetylation, which is an epigenetic modification of the proteins that regulate chromatin structure, is shown to affect splicing. We found that an insertion in the gene encoding histone deacetylase Hda1 suppresses the temperature sensitive phenotype of the second step splicing factor mutant Prp16-2. This insertion was in the Arb2 domain which is responsible for increasing Hda1 interaction with the chromatin. We sought to determine if other splicing factors are similarly affected by the Hda1 mutation by evaluating changes in the temperature sensitive phenotype of double mutants of the Arb2 domain of Hda1 and the first step splicing factor Prp2. Deletion of the Arb2 domain has no effect on the temperature sensitive phenotype of the Prp2 mutant strain, Prp2-1. This suggests Hda1 as a potential second step regulator of splicing and implies histone modification can affect specific steps of spliceosome assembly. These results provide further evidence of a model whereby yeast spliceosome assembly is tightly coupled to histone modification. Paired with existing evidence of transcription-dependent targeting of Hda1, this could pave the way for future research into targeted histone modification as a mechanism for alternative splicing.

Neural lineages are defined as groupings of neurons formed by individual, genetically specified neuroblasts. These lineages are distinguishable due to their axon tracts that are recognizable at later developmental stages, which progress towards the neuropil, which is a network at the center of the embryonic brain. Lineages interact with other lineages in a preferential and predictable manner, and vary in factors such as axon length and growth cone size. Growth cones exist at the tip of the developing axon tract, and are used to guide its growth. We aim to distinguish between lineages, specifically at earlier developmental stages, and gain a better understanding of lineage phenotype and interaction. We used transmission electron microscopy to generate 3D reconstructions of neural lineages in mid-late stage Drosophila embryos. Specifically, lineages that have been traced belonging to the mushroom body and lineages that have yet to be traced in the posteromedial region. We confirmed that lineage phenotype varies most notably in length and growth cone size, and we speculate that neurons of different lineages interact in a stereotyped manner already at this early stage in their development. Our findings will provide insight into the problem of the development of circuitry: how does the association of neurons with specific lineages shape the neural circuits of the differentiated brain.

Over the past few years, the pipeline to produce safe and effective pharmacological drugs has become much more streamlined, resulting in a significantly expanded market for many diseases, ailments, and conditions. Yet, within this pipeline, developing a highly productive, stable, and single-cell-derived cell line is essential for the efficient manufacture of biological drug products. This continues to be a major goal for the pharmaceutical industry. In this study, our objective was to develop an effective cell line development (CLD) process capable of meeting the growing demands within an accelerated timeline. To achieve this, we harnessed a combination of high-throughput imaging, advanced screening methodologies, single-cell printing technologies, and early-stage product analysis to evaluate every step in the CLD process of CHO cells. Using a panel of selective cell viability assays, we have filtered out pools and clones with undesirable properties in the early stage, resulting in fittest and desirable lines moving to the next stage. We hope to eventually obtain an optimized workflow that enables the selection of clonal cell lines with high productivity, quality, and monoclonality, assessed through parameters like peak viable cell density (VCD) and protein expression. Future endeavors could explore the integration of emerging genetic engineering techniques and analytical tools to refine the CLD process, elevating the efficiency and reliability of biopharmaceutical production.