Biology subjects

Kaur, N.

Publications and source records attributed to Kaur, N..

3 recordsLinked to original sources

bioRxiv2018

Survival and development of potato psyllid (Hemiptera: Triozidae) on Convolvulaceae: effects of a plant-fungus symbiosis (Periglandula)

Plant species in the family Solanaceae are the usual hosts of potato psyllid, Bactericera cockerelli ([S]ulc) (Hemiptera: Psylloidea: Triozidae). However, the psyllid has also been shown to develop on some species of Convolvulaceae (bindweeds and morning glories). Developmental success on Convolvulaceae is surprising given the rarity of psyllid species worldwide associated with this plant family. We assayed 14 species of Convolvulaceae across four genera (Convolvulus, Calystegia, Ipomoea, Turbina) to identify species that allow development of potato psyllid. Two populations of psyllids were assayed (Texas, Washington). The Texas population overlaps extensively with native Convolvulaceae, whereas Washington State is noticeably lacking in Convolvulaceae. Results of assays were overlain on a phylogenetic analysis of plant species to examine whether Convolvulaceae distantly related to the typical host (potato) were less likely to allow development than species of Convolvulaceae more closely related. Survival was independent of psyllid population and location of the plant species on our phylogenetic tree. We then examined whether presence of a fungal symbiont of Convolvulaceae (Periglandula spp.) affected psyllid survival. These fungi associate with Convolvulaceae and produce a class of mycotoxins (ergot alkaloids) that may confer protection against plant-feeding arthropods. Periglandula was found in 11 of our 14 species, including in two genera (Convolvulus, Calystegia) not previously known to host the symbiont. Of these 11 species, leaf tissues from five contained large quantities of two classes of ergot alkaloids (clavines, amides of lysergic acid) when evaluated by LC-MS/MS. All five species also harbored Periglandula. No ergot alkaloids were detected in species free of the fungal symbiont. Potato psyllid rapidly died on species found to harbor Periglandula and fungus-produced alkaloids, but survived on species in which the mutualism was absent. These results support the hypothesis that a plant-fungus symbiotic relationship affects the suitability of certain Convolvulaceae to potato psyllid.

ecology↗

bioRxiv2018

Mapping molecular HLA typing data to UNOS antigen equivalents for improved virtual crossmatch

BackgroundVirtual crossmatch utilizes HLA typing and antibody screen assay data as a part of organ offers in deceased donor allocation systems. Histocompatibility labs must convert molecular HLA typings to antigen equivalencies for entry into the United Network for Organ Sharing (UNOS) UNet system. While an Organ Procurement and Transplantation Network (OPTN) policy document provides general guidelines for conversion, the process is complex because no antigen mapping table is available. We present a UNOS antigen equivalency table for all IMGT/HLA alleles at the A, B, C, DRB1, DRB3/4/5, DQA1, and DQB1 loci.\n\nMethodsAn automated script was developed to generate a UNOS antigen equivalency table. Data sources used in the conversion algorithm included the World Marrow Donor Association(WMDA) antigen table, the HLA Dictionary, and UNOS-provided tables. To validate antigen mappings, we converted National Marrow Donor Program (NMDP) high resolution allele frequencies to antigen equivalents and compared with the UNOS Calculated Panel Reactive Antibodies (CPRA) reference panel.\n\nResultsNormalized frequency similarity scores between independent NMDP and UNOS panels for 4 US population categories (Caucasian, Hispanic, African American and Asian/Pacific Islander) ranged from 0.85 to 0.97, indicating correct antigen mapping. An open source web application (ALLele to ANtigen (\"ALLAN\")) and web services were also developed to map unambiguous and ambiguous HLA typing data to UNOS antigen equivalents based on NMDP population-specific allele frequencies (http://www.transplanttoolbox.org).\n\nConclusionsThis tool sets a foundation for using molecular HLA typing to compute the virtual crossmatch and may aid in reducing typing discrepancies in UNet.

bioinformatics↗

bioRxiv2018

Identification of reference genes for real-time PCR gene expression studies during seed development and under abiotic stresses in Cyamopsis tetragonoloba (L.) Taub.

Guar (Cyamopsis tetragonoloba) is an important industrial crop. The knowledge about genes of guar involved in various processes can help in developing improved varieties of this crop. qRT-PCR is a preferred technique for accurate quantification of gene expression data. This technique requires the use of appropriate reference genes from the crop to be studied. Such genes have not been yet identified in guar. The expression stabilities of the 10 candidate reference genes, viz., CYP, ACT 11, EF-1, TUA, TUB, ACT 7, UBQ 10, UBC 2, GAPDH and 18S rRNA were evaluated in various tissues of guar under normal and abiotic stress conditions. Four different algorithms, geNorm, NormFinder, BestKeeper and {triangleup}Ct approach, were used to assess the expression stabilities and the results obtained were integrated into comprehensive stability rankings. The most stable reference genes were found to be CYP and ACT 11(tissues), ACT 11, UBC 2 and ACT 7 (seed development), ACT 7 and TUB (drought stress), TUA, UBC 2 and CYP (nitrogen stress), TUA and UBC 2 (cold stress), GAPDH and ACT 7 (heat stress) and GAPDH and EF-1a (salt stress). These results indicated the necessity of identifying a suitable reference gene for each experimental condition. Four selected reference genes were validated by normalizing the expression of CtMT1 gene. To the best of our knowledge this is the first report on the identification of reference genes in guar. These findings are likely to provide a boost to the gene expression studies in this important crop.

genetics↗