ABSTRACT
Rohu, Labeo rohita, is one of the most important aquaculture species in the Indian subcontinent. Understanding the molecular-level physiological responses to thermal stress or climate change is essential. In the present work, transcriptome sequencing was carried out in the muscle tissue of the rohu in response to heat stress (35 °C) in comparison with the control (28 °C). A total of 125 Gb of sequence data was generated, and the raw-reads were filtered and trimmed, which resulted in 484 million quality reads. Reference-based assembly of reads was performed using L. rohita genome, and a total of 90.17% of reads were successfully mapped. A total of 37,462 contigs were assembled with an N50 value of 1854. The differential expression analysis revealed a total of 107 differentially expressed genes (DEGs) (15 up-, 37 down-, and 55 neutrally regulated) as compared to the control group (Log2FC > 2, P < 0.05). Gene enrichment analysis of DEGs indicates that transcripts were associated with molecular, biological, and cellular activities. The randomly selected differentially expressed transcripts were validated by RT-qPCR and found consistent expression patterns in line with the RNA-seq data. Several transcripts such as SERPINE1(HSP47), HSP70, HSP90alpha, Rano class II histocompatibility A beta, PGC-1 and ERR-induced regulator, proto-oncogene c-Fos, myozenin2, alpha-crystallin B chain-like protein, angiopoietin-like protein 8, and acetyl-CoA carboxylases have been identified in muscle tissue of rohu that are associated with stress/immunity. This study identified the key biomarker SERPINE1 (HSP47), which showed significant upregulation (~ 2- to threefold) in muscle tissue of rohu exposed to high temperature. This study can pave a path for the identification of stress-responsive biomarkers linked with thermal adaptations in the farmed carps.
Subject(s)
Carps , Cyprinidae , Animals , Transcriptome , Cyprinidae/genetics , RNA-Seq , Genes, RegulatorABSTRACT
The present study was conducted to assess the effect of exposure to heat stress on the HSP70 gene expression pattern ex vivo in chickens. The adult healthy birds (n = 15) grouped into three replicates of n = 5 each were used to isolate peripheral blood mononuclear cells (PBMCs). The PBMCs were subjected to heat stress at 42 °C for 1 h, and cells without heat stress (NHS) were taken as control. The cells were seeded in 24 well plates and incubated in a humidified incubator at 37 °C under 5% CO2 for recovery. HSP70 expression kinetics were evaluated at 0, 2, 4, 6, and 8 h of the recovery period. Compared with NHS, the expression pattern of HSP70 was upregulated gradually from 0 to 4 h with peak (p < 0.05) expression recorded at 4 h of recovery time. mRNA expression of HSP70 escalated in a time-dependent manner from 0 to 4 h of heat exposure and thereafter exhibited a gradually decreasing pattern till 8 h of the recovery period. The findings from this study highlight the protective role of HSP70 against the deleterious effects of heat stress in chicken PBMCs. Further, the study demonstrates the possible use of PBMCs as a cellular system in assessing the heat stress effect in chickens ex vivo.
