An official website of the United States government
Abstract Background/ObjectivesRNA polymerase II is a multifunctional complex that is critical for gene regulation and environmental responses. Its POLR2I subunit in human is associated with various pathologies, including cancer chemoresistance. However, much of our understanding of how POLR2I could function indirectly derives from studies of its homologs in yeasts called Rpb9. Here, we endogenously humanized therpb9gene of the fission yeastSchizosaccharomyces pombeto examine the functional capabilities of POLR2I. MethodsWe edited the genomicrpb9locus inS. pombeso that it encodes the human POLR2I protein, and investigated functional and structural conservation. ResultsWith our humanized yeast system, we find widespread functional complementation by humanPOLR2IofS. pombe rpb9roles in yeast growth, chronological aging, and stress responses. We also find thatPOLR2Icomplements novel roles for yeastrpb9in facultative heterochromatin assembly, resistance against the chemotherapy 5-fluorouracil, and resistance against the fungicide thiabendazole. In contrast, we find thatPOLR2Icannot complement the role ofrpb9in resistance against the transcription elongation inhibitor 6-azauracil (6-AU) in our system. Interestingly,POLR2Icould complement 6-AU resistance if ectopically expressed. Lastly, we observe extensive structural homology between Rpb9 and POLR2I proteins. ConclusionsOur study establishes an endogenous cross-species gene complementation strategy that uncovers both conserved and rewired functions of fission yeastrpb9and its human homolog,POLR2I. In addition to validating conserved roles, we also identified conservation of previously unrecognized roles ofrpb9in heterochromatin formation and chemoresistance.
more »
« less
Genome annotation of Aspergillus melleus strain CBS 546.65
ABSTRACT The fungusAspergillus melleusis an important biosynthesis host for varied commercial applications. Gene annotation of a previously published genome produced 12,841 protein-coding genes and identified 102 biosynthetic gene clusters.
more »
« less
- PAR ID:
- 10656442
- Editor(s):
- Pritchard, Leighton
- Publisher / Repository:
- American Society for Microbiology
- Date Published:
- Journal Name:
- Microbiology Resource Announcements
- Volume:
- 14
- Issue:
- 10
- ISSN:
- 2576-098X
- Page Range / eLocation ID:
- e00519-25
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Abstract PremiseAs the sister clade to angiosperms, extant gymnosperms are crucial for reconstructing ancestral gene regulatory networks in seed plants. This highlights the need for model systems representing each of their distinct lineages. However, tools to quickly and effectively investigate gene function in gymnosperms are still limited due to the challenges of long life cycles and large genome sizes. Species within the xerophytic genusEphedra(Gnetales) have comparatively smaller genomes and shrubby growth habits with shorter life spans, making them better suited for greenhouse cultivation and laboratory experiments. MethodsWe implement virus‐induced gene silencing (VIGS) to manipulate gene expression inEphedra tweedieanaviaAgrobacterium‐mediated vacuum infiltration of tobacco rattle virus (TRV1 and TRV2) into seedlings. ResultsTreatment resulted in highly efficient gene silencing of theE. tweedieana PHYTOENE DESATURASE(PDS) orthologEtwPDS. The expected photobleaching phenotype was observed as early as two weeks, and lasted at least five months in stems, shoot tips, leaves, axillary meristems, and lateral branches of treated plants. DiscussionWe report on virus‐induced targeted gene silencing ofPDSin a Gnetales representative to further enable functional studies of the genetic mechanisms underpinning adaptations in gymnosperms, an important and underrepresented lineage of seed plants.more » « less
-
Abstract PremiseA complicating factor in analyzing allopolyploid genomes is the possibility of physical interactions between homoeologous chromosomes during meiosis, resulting in either crossover (homoeologous exchanges) or non‐crossover products (homoeologous gene conversion). Homoeologous gene conversion was first described in cotton by comparing SNP patterns in sequences from two diploid progenitors with those from the allopolyploid subgenomes. These analyses, however, did not explicitly consider other evolutionary scenarios that may give rise to similar SNP patterns as homoeologous gene conversion, creating uncertainties about the reality of the inferred gene conversion events. MethodsHere, we use an expanded phylogenetic sampling of high‐quality genome assemblies from seven allopolyploidGossypiumspecies (all derived from the same polyploidy event), four diploid species (two closely related to each subgenome), and a diploid outgroup to derive a robust method for identifying potential genomic regions of gene conversion and homoeologous exchange. ResultsWe found little evidence for homoeologous gene conversion in allopolyploid cottons, and that only two of the 40 best‐supported events were shared by more than one species. We did, however, reveal a single, shared homoeologous exchange event at one end of chromosome 1, which occurred shortly after allopolyploidization but prior to divergence of the descendant species. ConclusionsOverall, our analyses demonstrated that homoeologous gene conversion and homoeologous exchanges are uncommon inGossypium, affecting between zero and 24 genes per subgenome (0.0–0.065%) across the seven species. More generally, we highlighted the potential problems of using simple four‐taxon tests to investigate patterns of homoeologous gene conversion in established allopolyploids.more » « less
-
Abstract PremiseCentropogonsubgenusCentropogoncomprises 55 species found primarily in midelevation Andean forests featuring some of the most curved flowers among angiosperms. Floral curvature is linked to coevolution with the sicklebill hummingbird, which pollinates most species. Despite charismatic flowers, there is limited knowledge about the phylogenetic relationships and floral evolution. MethodsWe conducted the first densely sampled phylogenomic analysis of the clade using methods that account for incomplete lineage sorting on a sequence capture dataset generated with a lineage‐specific probe set. Using phylogenetic comparative methods, we test for correlated evolution of two traits central to sicklebill pollination. ResultsWe improve understanding of species relationships by more than doubling past taxon sampling. We confirm the monophyly of the subgenus and two sections, and the non‐monophyly of remaining sections. The subgenus is characterized by high gene tree discordance. Three widespread species display contrasting phylogenetic dynamics, withC. cornutusforming a clade andC. granulosusandC. solanifoliusforming non‐monophyletic, biogeographically clustered lineages. Correlated evolution of floral curvature and inflorescence structure has led to multiple putative losses of sicklebill pollination. ConclusionsCentropogonsubgenusCentropogonadds to a growing body of literature of Andean plant clades with high gene tree discordance. This phylogeny serves as a foundational framework for further macroevolutionary investigations into the environmental and biogeographic factors shaping the evolution of pollination‐related traits.more » « less
-
Abstract BackgroundThe brown anole is a model species of the genusAnolis, a squamate (encompassing lizards and snakes) group widely studied in evolutionary, behavioral, and developmental biology. Full genome annotation, the establishment of gene editing techniques, and comprehensive description of reproductive tract morphology and embryogenesis in this species have laid the foundation for functional studies. However, analysis of brown anole oogenesis is still required and vital to optimize genome modification, mutant line establishment, and analyses of the evolution of reproductive developmental mechanisms. ResultsHere, we characterize ovary morphology and gametogenesis in the female brown anole,Anolis sagrei,using brightfield imaging, microCT, histology staining, electron microscopy, and confocal imaging. We define 10 stages of oocyte maturation, which commences inside the oogonial nest within the germinal bed and concludes with the mature follicle ready to ovulate based on follicle size, yolk acquisition, and follicular, cellular, and basement membrane architecture. ConclusionsWe describe the complete oogenesis of the brown anole in 10 stages and report that oogenesis is highly conserved within iguanians, a suborder of lizards. With our staging framework, we lay the foundation for functional studies of oogenesis and optimized gene‐editing.more » « less
- Free Publicly Accessible Full Text
-
Accepted Manuscript
- Journal Article:
- https://doi.org/10.1128/mra.00519-25
