Biology subjects

R, R.

Publications and source records attributed to R, R..

2 recordsLinked to original sources

bioRxiv2021

Immune stimulation alters chemical profiles of Tribolium castaneum

Group-living individuals experience immerse risk of disease transmission and parasite infection. Especially in social, but also in some non-social insects, disease control with immunomodulation takes place not only via individual immune defenses, but also via infochemicals such as contact cues and (defensive) volatiles to mount a group level immunity. However, little is known about whether an activation of the immune system leads to changes in chemical phenotypes, which may mediate these responses. We here asked whether individual immune experience resulting from wounding or injection of heat-killed Bacillus thuringiensis leads to changes in the chemical profiles of female and male adult red flour beetles (Tribolium castaneum), which are non-social but gregarious. We analyzed insect extracts using GC-FID to study the chemical composition of (1) cuticular hydrocarbons (CHCs) as candidates for the transfer of immunity-related information between individuals via contact, and (2) stink gland secretions, with target analysis of benzoquinones as main active compounds regulating external immunity. Despite a pronounced sexual dimorphism in CHC profiles, wounding stimulation led to similar profile changes in males and females with increases in the proportion of methyl-branched alkanes compared to naive beetles. While changes in the overall secretion profiles were less pronounced, absolute amounts of benzoquinones were transiently elevated in wounded compared to naive females. We suggest that the changes in different infochemicals may mediate immune status signaling in the context of both internal and external immune responses in groups of this non-social insect, thus showing parallels to social immunity.

evolutionary biology↗

bioRxiv2020

Whole Exome Sequencing of a large family with Primary Open Angle Glaucoma reveals its vast complexity

PurposeTo identify the pathogenic variants associated with POAG by using Whole Exome Sequencing (WES) data of a large South Indian family. MethodsWe recruited a large five generation of South Indian family (n=84) with positive family history of POAG. All study participants had comprehensive ocular evaluation (of the 84, 19 study subjects were diagnosed as POAG). Sanger sequencing of the candidate genes associated with POAG (MYOC, OPTN and TBK1) showed no genetic variation in the POAG affected family members. Therefore, we performed whole exome sequencing (WES) for 16 samples including (9 POAG and 7 unaffected controls) and the data was analysed using an in-house pipeline for prioritizing the pathogenic variants based on its segregation among the POAG individual. ResultsWe identified one novel and five low-frequency pathogenic variants with consistent co-segregation in all affected individuals. The variant c.G3719A in RPGR-interacting domain of RPGRIP1 that segregated heterozygously with the six POAG cases is distinct from variants causing photoreceptor dystrophies, reported to affect the RPGR protein complex signaling in primary cilia. The cilia in TM cells has been reported to mediate the intraocular pressure (IOP) sensation. Furthermore, we identified a novel c.A1295G variant in Rho guanine nucleotide exchange factors Gene 40 (ARHGEF40) and likely pathogenic variant in the RPGR gene, suggesting that they may alter the RhoA activity essential for IOP regulation ConclusionOur study supports that low-frequency pathogenic variants in multiple genes and pathways probably affect the pathogenesis of Primary Open Angle Glaucoma in the large South Indian family.

genomics↗