| 1. |
- Richards, Stephen, et al.
(author)
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Genome Sequence of the Pea Aphid Acyrthosiphon pisum
- 2010
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In: PLoS biology. - : Public Library of Science (PLoS). - 1544-9173 .- 1545-7885. ; 8:2, s. e1000313-
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Journal article (peer-reviewed)abstract
- Aphids are important agricultural pests and also biological models for studies of insect-plant interactions, symbiosis, virus vectoring, and the developmental causes of extreme phenotypic plasticity. Here we present the 464 Mb draft genome assembly of the pea aphid Acyrthosiphon pisum. This first published whole genome sequence of a basal hemimetabolous insect provides an outgroup to the multiple published genomes of holometabolous insects. Pea aphids are host-plant specialists, they can reproduce both sexually and asexually, and they have coevolved with an obligate bacterial symbiont. Here we highlight findings from whole genome analysis that may be related to these unusual biological features. These findings include discovery of extensive gene duplication in more than 2000 gene families as well as loss of evolutionarily conserved genes. Gene family expansions relative to other published genomes include genes involved in chromatin modification, miRNA synthesis, and sugar transport. Gene losses include genes central to the IMD immune pathway, selenoprotein utilization, purine salvage, and the entire urea cycle. The pea aphid genome reveals that only a limited number of genes have been acquired from bacteria; thus the reduced gene count of Buchnera does not reflect gene transfer to the host genome. The inventory of metabolic genes in the pea aphid genome suggests that there is extensive metabolite exchange between the aphid and Buchnera, including sharing of amino acid biosynthesis between the aphid and Buchnera. The pea aphid genome provides a foundation for post-genomic studies of fundamental biological questions and applied agricultural problems.
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| 2. |
- Carr, Tiffany, et al.
(author)
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Oncogenic and Tumor Suppressor Functions for Lymphoid Enhancer Factor 1 in E2a-/- T Acute Lymphoblastic Leukemia
- 2022
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In: Frontiers in Immunology. - : Frontiers Media SA. - 1664-3224. ; 13
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Journal article (peer-reviewed)abstract
- T lymphocyte acute lymphoblastic leukemia (T-ALL) is a heterogeneous disease affecting T cells at multiple stages of their development and is characterized by frequent genomic alterations. The transcription factor LEF1 is inactivated through mutation in a subset of T-ALL cases but elevated LEF1 expression and activating mutations have also been identified in this disease. Here we show, in a murine model of T-ALL arising due to E2a inactivation, that the developmental timing of Lef1 mutation impacts its ability to function as a cooperative tumor suppressor or oncogene. T cell transformation in the presence of LEF1 allows leukemic cells to become addicted to its presence. In contrast, deletion prior to transformation both accelerates leukemogenesis and results in leukemic cells with altered expression of genes controlling receptor-signaling pathways. Our data demonstrate that the developmental timing of Lef1 mutations impact its apparent oncogenic or tumor suppressive characteristics and demonstrate the utility of mouse models for understanding the cooperation and consequence of mutational order in leukemogenesis.
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| 3. |
- Stewart, Joshua D., et al.
(author)
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Research Priorities to Support Effective Manta and Devil Ray Conservation
- 2018
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In: Frontiers in Marine Science. - : Frontiers Media S.A.. - 2296-7745. ; 5, s. 1-27
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Research review (peer-reviewed)abstract
- Manta and devil rays are filter-feeding elasmobranchs that are found circumglobally in tropical and subtropical waters. Although relatively understudied for most of the Twentieth century, public awareness and scientific research on these species has increased dramatically in recent years. Much of this attention has been in response to targeted fisheries, international trade in mobulid products, and a growing concern over the fate of exploited populations. Despite progress in mobulid research, major knowledge gaps still exist, hindering the development of effective management and conservation strategies. We assembled 30 leaders and emerging experts in the fields of mobulid biology, ecology, and conservation to identify pressing knowledge gaps that must be filled to facilitate improved science-based management of these vulnerable species. We highlight focal research topics in the subject areas of taxonomy and diversity, life history, reproduction and nursery areas, population trends, bycatch and fisheries, spatial dynamics and movements, foraging and diving, pollution and contaminants, and sub-lethal impacts. Mobulid rays remain a poorly studied group, and therefore our list of important knowledge gaps is extensive. However, we hope that this identification of high priority knowledge gaps will stimulate and focus future mobulid research.
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| 4. |
- Xu, Wei, et al.
(author)
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E2A transcription factors limit expression of Gata3 to facilitate T lymphocyte lineage commitment
- 2013
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In: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 121:9, s. 1534-1542
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Journal article (peer-reviewed)abstract
- The E2A transcription factors promote the development of thymus-seeding cells, but it remains unknown whether these proteins play a role in T lymphocyte lineage specification or commitment. Here, we showed that E2A proteins were required to promote T-lymphocyte commitment from DN2 thymocytes and to extinguish their potential for alternative fates. E2A proteins functioned in DN2 cells to limit expression of Gata3, which encodes an essential T-lymphocyte transcription factor whose ectopic expression can arrest T-cell differentiation. Genetic, or small interfering RNA-mediated, reduction of Gata3 rescued T-cell differentiation in the absence of E2A and restricted the development of alternative lineages by limiting the expanded self-renewal potential in E2A(-/-) DN2 cells. Our data support a novel paradigm in lymphocyte lineage commitment in which the E2A proteins are necessary to limit the expression of an essential lineage specification and commitment factor to restrain self-renewal and to prevent an arrest in differentiation.
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