6 research outputs found
Recommended from our members
CELLULOSE DEGRADATION IN LUTEIBACTER: SUSPECTED GENETIC MECHANISMS AND BIOCHEMICAL APPLICATIONS
The role of Luteibacter as a cellulose degradation microorganism is examined in this thesis. An overview of some of the key functions of cellulose in the biosphere is given as well as a review of cellulolytic strategies and mechanisms employed in the microscopic world. A brief characterization of the genus Luteibacter is also provided. Experiments were aimed at evaluating loss of function cellulase mutants and abnormal phenotypic mutants in order to better characterize potential genetic pathways used by Luteibacter in cellulose degradation. While there is still much work to be done evaluating this system, initial results indicate that the protein GfcC as well as a phosphokinase and a type I secretion system likely play important roles in Luteibacter’s ability to secrete cellulase. Future plasmid sequencing data will likely shed more light on the specific gene regions associated with cellulase production and secretion in Luteibacter. Further understanding of the mechanisms and genetics behind cellulose degradation in Luteibacter will provide key insights into the process of microbial cellulose utilization as a whole, a process which has implications in a wide variety of innovative biological and industrial fields
Human neocortical expansion involves glutamatergic neuron diversification
The neocortex is disproportionately expanded in human compared with mouse1,2, both in its total volume relative to subcortical structures and in the proportion occupied by supragranular layers composed of neurons that selectively make connections within the neocortex and with other telencephalic structures. Single-cell transcriptomic analyses of human and mouse neocortex show an increased diversity of glutamatergic neuron types in supragranular layers in human neocortex and pronounced gradients as a function of cortical depth3. Here, to probe the functional and anatomical correlates of this transcriptomic diversity, we developed a robust platform combining patch clamp recording, biocytin staining and single-cell RNA-sequencing (Patch-seq) to examine neurosurgically resected human tissues. We demonstrate a strong correspondence between morphological, physiological and transcriptomic phenotypes of five human glutamatergic supragranular neuron types. These were enriched in but not restricted to layers, with one type varying continuously in all phenotypes across layers 2 and 3. The deep portion of layer 3 contained highly distinctive cell types, two of which express a neurofilament protein that labels long-range projection neurons in primates that are selectively depleted in Alzheimer’s disease4,5. Together, these results demonstrate the explanatory power of transcriptomic cell-type classification, provide a structural underpinning for increased complexity of cortical function in humans, and implicate discrete transcriptomic neuron types as selectively vulnerable in disease
Human neocortical expansion involves glutamatergic neuron diversification.
The neocortex is disproportionately expanded in human compared with mouse1,2, both in its total volume relative to subcortical structures and in the proportion occupied by supragranular layers composed of neurons that selectively make connections within the neocortex and with other telencephalic structures. Single-cell transcriptomic analyses of human and mouse neocortex show an increased diversity of glutamatergic neuron types in supragranular layers in human neocortex and pronounced gradients as a function of cortical depth3. Here, to probe the functional and anatomical correlates of this transcriptomic diversity, we developed a robust platform combining patch clamp recording, biocytin staining and single-cell RNA-sequencing (Patch-seq) to examine neurosurgically resected human tissues. We demonstrate a strong correspondence between morphological, physiological and transcriptomic phenotypes of five human glutamatergic supragranular neuron types. These were enriched in but not restricted to layers, with one type varying continuously in all phenotypes across layers 2 and 3. The deep portion of layer 3 contained highly distinctive cell types, two of which express a neurofilament protein that labels long-range projection neurons in primates that are selectively depleted in Alzheimer\u27s disease4,5. Together, these results demonstrate the explanatory power of transcriptomic cell-type classification, provide a structural underpinning for increased complexity of cortical function in humans, and implicate discrete transcriptomic neuron types as selectively vulnerable in disease
Author Correction: Human neocortical expansion involves glutamatergic neuron diversification
In the version of this Article initially published, the Acknowledgements statement contained an error. Originally appearing with thanks for support given in part as follows, “R01EY023173 from The National Eye Institute, U01MH105982 from the National Institute of Mental Health and Eunice Kennedy Shriver National Institute of Child Health and Human Development, and R011EY023173 from The National Institute of Allergy and Infectious Disease,” the last number (R011EY023173) was mistakenly added and is not in fact a grant or one provided by the NIAID. The mention has been removed. The changes have been made to the online version of the Article