Biology subjects

Tamayo, B.

Publications and source records attributed to Tamayo, B..

5 recordsLinked to original sources

bioRxiv2021

Manual curation and phylogenetic analysis of chitinase family genes in the Asian citrus psyllid, Diaphorina citri

Chitinases are enzymes that digest the polysaccharide polymer chitin. Chitin is a major component of insect exoskeletons, which must be replaced multiple times during growth and development in a process known as molting. Insect genomes usually have multiple chitinase genes, some of which are required for molting and some whose functions are still unknown. Since knockdown of the chitinases required for molting causes high levels of lethality, chitinase genes have drawn interest as targets for RNAi-based pest control methods. The Asian citrus psyllid, Diaphorina citri, carries the bacterium that causes Huanglongbing, also known as citrus greening disease, which is devastating the citrus industry worldwide. We have identified and annotated 12 chitinase family genes from D. citri as part of a community effort to create high quality gene models to facilitate the design of interdictory molecules for pest control. Using predicted protein domain content and phylogenetic analysis, we categorized the D. citri chitinases according to a previously established classification scheme and re-evaluated the classification of chitinases in other hemipterans. In addition to chitinases belonging to known groups, we identified a novel class of chitinases present in D. citri and several related hemipterans that appears to be the result of horizontal gene transfer.

bioinformatics↗

bioRxiv2021

Annotation of glycolysis, gluconeogenesis, and trehaloneogenesis pathways provide insight into carbohydrate metabolism in the Asian citrus psyllid

Citrus greening disease is caused by the pathogen Candidatus Liberibacter asiaticus, which is transmitted by the Asian citrus psyllid, Diaphorina citri. There is no curative treatment or significant prevention mechanism for this detrimental disease that causes continued economic losses from reduced citrus production. A high quality genome of D. citri is being manually annotated to provide accurate gene models required to identify novel control targets and increase understanding of this pest. Here, we annotated genes involved in glycolysis, gluconeogenesis, and trehaloneogenesis in the D. citri genome, as these are core metabolic pathways and suppression could reduce this pest. Specifically, twenty-five genes were identified and annotated in the glycolysis and gluconeogenesis pathways and seven genes for the trehaloneogenesis pathway. Comparative analysis showed that the glycolysis genes in D. citri are highly conserved compared to orthologs in other insect systems, but copy numbers vary in D. citri. Expression levels of the annotated gene models were analyzed and several enzymes in the glycolysis pathway showed high expression in the thorax. This is consistent with the primary use of glucose by flight muscles located in the thorax. A few of the genes annotated in D. citri have been targeted for gene knockdown as a proof of concept, for RNAi therapeutics. Thus, manual annotation of these core metabolic pathways provides accurate genomic foundations for developing gene-targeting therapeutics to reduce D. citri.

bioinformatics↗

bioRxiv2020

Characterization of chitin deacetylase genes in the Diaphorina citri genome

Chitin deacetylases (CDAs) are one of the least understood components of insect chitin metabolism. The partial deacetylation of chitin polymers appears to be important for the proper formation of higher order chitin structures, such as long fibers and bundles, that contribute to the integrity of the insect exoskeleton and other structures. Some CDAs may also play a role in bacterial defense. Here we report the characterization of four CDA genes from the Asian citrus psyllid, Diaphorina citri, laying the groundwork for future study of these genes. D. citri is the vector for Candidatus Liberibacter asiaticus (CLas), which is responsible for the global outbreak of Huanglongbing (citrus greening) disease. The manual annotation was done as part of a collaborative community annotation project (https://citrusgreening.org/annotation/index).

genomics↗

bioRxiv2020

Chitin Biosynthesis Genes in Diaphorina citri

The polysaccharide chitin is critical for the formation of many insect structures, including the exoskeleton, and is required for normal development. Here we report the annotation of three genes from the chitin synthesis pathway in the Asian citrus psyllid, Diaphorina citri (Hemiptera: Liviidae), the vector of Huanglongbing (citrus greening disease). Most insects have two chitin synthase (CHS) genes but, like other hemipterans, D. citri has only one. In contrast, D. citri is unusual among insects in having two UDP-N-acetylglucosamine pyrophosphorylase (UAP) genes. One of the D. citri UAP genes is broadly expressed, while the other is expressed predominantly in males. Our work helps pave the way for potential utilization of these genes as pest control targets to reduce the spread of Huanglongbing.

genomics↗

bioRxiv2019

Chromosomal length reference assembly for Diaphorina citri using single-molecule sequencing and Hi-C proximity ligation with manually curated genes in developmental, structural and immune pathways

BackgroundDiaphorina citri is a vector of "Candidatus Liberibacter asiaticus" (CLas), the gram-negative bacterial pathogen associated with citrus greening disease. Control measures rely on pesticides with negative impacts on the environment, natural ecosystems and human and animal health. In contrast, gene-targeting methods have the potential to specifically target the vector species and/or reduce pathogen transmission. ResultsTo improve the genomic resources needed for targeted pest control, we assembled a D. citri genome based on PacBio long reads followed by proximity ligation-based scaffolding. The 474 Mb genome has 13 chromosomal-length scaffolds. 1,036 genes were manually curated as part of a community annotation project, composed primarily of undergraduate students. We also computationally identified a total of 1,015 putative transcription factors (TFs) and were able to infer motifs for 337 TFs (33 %). In addition, we produced a genome-independent transcriptome and genomes for D. citri endosymbionts. ConclusionsManual annotation provided more accurate gene models for use by researchers and also provided an excellent training opportunity for students from multiple institutions. All resources are available on CitrusGreening.org and NCBI. The chromosomal-length D. citri genome assembly serves as a blueprint for the development of collaborative genomics projects for other medically and agriculturally significant insect vectors.

genomics↗