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Saikia, S.

Publications and source records attributed to Saikia, S..

2 recordsLinked to original sources
bioRxiv2023

Assessing variation in Citrus limon "Assam lemon": morphological, seed availability pattern, and biochemical diversity across different districts of Assam

The Assam lemon is a highly valued Citrus cultivar known for its unique aroma, flavor, and seedless fruit characteristic. This study aimed to investigate for the first time the morphological, seeding pattern, and biochemical, variations within 133 populations of Assam lemon cultivar growing across 22 districts of Assam, India, and including control population, with the objective to offer comprehensive understanding that could facilitate the improvement of breeding programs and further improvement of this important cultivar. Using the dendrogram-based UPGMA algorithm, morphological and seeding pattern data were analyzed at both district and population levels. The resulting dendrograms revealed two major clusters, where all the populations of Upper Assam districts were in the same cluster with the original stock (control population). However, populations from Tinsukia and Dhemaji districts displayed more close similarities with the control population in comparison to other populations of Upper Assam districts. Another interesting observation was regarding flowering patterns, while some populations displayed both bisexual and unisexual flowers with less concentration of unisexual flowers, others had bisexual and unisexual flowers of almost equal concentration. Unisexual flowers contained only the male reproductive organs with 40 anthers, while bisexual flowers had 36 anthers. Seeding patterns were examined across the districts, and it was found that populations from Tinsukia, Dhemaji, Lakhimpur, Dibrugarh, Jorhat, and the control population exhibited seedless characteristic while populations from other selected districts displayed a combination of seedless and seeded traits. Interestingly, Golaghat district appears as the linking district and showed availability of both seeded and seedless Assam lemon fruit, connecting the regions of Upper, Central, Lower and North Assam and Barak valley. Biochemical analysis showed significant variations across districts, however, the populations from Dhemaji, Tinsukia, Lakhimpur, Dibrugarh, and Jorhat districts displayed similarity with the control population. The study also investigated variability in soil nutrient content revealing substantial variation among the populations studied, potentially influencing observed morphological variations. This comprehensive investigation provides valuable insights into the morphological, seeding pattern, and biochemical diversity within the Assam lemon cultivar. These findings can be instrumental in breeding programs to enhance this Citrus cultivar, particularly in producing high-quality seedless fruits to meet consumer demands.

plant biology↗
bioRxiv2022

The G-protein-coupled estrogen receptor, a gene co-expressed with ERα in breast tumors, is regulated by estrogen-ERα signalling in ERα positive breast cancer cells.

PurposeThe purpose of this study was to assess the relationship between GPER, a seven transmembrane G-protein coupled estrogen receptor, and ER in breast tumors, and to make inroads into the mechanistic basis and clinical significance. MethodsTCGA-BRCA data was mined to examine the relationship between GPER and ER expression. GPER mRNA, and protein expression were analyzed in ER-positive or -negative breast tumors from two cohorts using immunohistochemistry, western blotting, or RT-qPCR. The Kaplan-Meier Plotter was employed for survival analysis. The influence of estrogen in vivo was studied by examining GPER expression levels in estrus or diestrus mouse mammary tissues, and the impact of 17{beta}-estradiol (E2) administration in juvenile or adult mice. The effect of E2, or propylpyrazoletriol (PPT, an ER agonist) stimulation on GPER expression was studied in MCF-7 and T47D cells, with or without tamoxifen or ER knockdown. ER-binding to the GPER locus was explored by analysing ChIP-seq data (ERP000380), in silico prediction of estrogen response elements, and chromatin immunoprecipitation assay. ResultsClinical data revealed significant positive association between GPER and ER expression in breast tumors. The median GPER expression in ER-positive tumors was significantly higher than ER-negative tumors. High GPER expression was significantly associated with longer overall survival of patients with ER-positive tumors. In vivo experiments showed a positive effect of E2 on GPER expression. E2 induced GPER expression in MCF-7 and T47D cells; an effect mimicked by PPT. Tamoxifen or ER-knockdown blocked the induction of GPER. Estrogen-mediated induction was associated with increased ER occupancy in the upstream region of GPER. ConclusionGPER expression is positively associated with ER in breast tumors, and a transcriptional target of the estrogen-ER signalling axis. More in-depth studies are required to establish the significance of GPER-ER co-expression, and their interplay in breast tumor development, progression, and treatment.

cancer biology↗