Differential expression pattern of heat shock protein 70 gene in tissues and heat stress phenotypes in goats during peak heat stress period

Abstract

It has been established that the synthesis of heat shock protein 70 (Hsp70) is temperature-dependent. The Hsp70 response is considered as a cellular thermometer in response to heat stress and other stimuli. The variation in Hsp70 gene expression has been positively correlated with thermotolerance in Drosophila melanogaster, Caenorhabditis elegans, rodents and human. Goats have a wide range of ecological adaptability due to their anatomical and physiological characteristics; however, the productivity of the individual declines during thermal stress. The present study was carried out to analyze the expression of heat shock proteins in different tissues and to contrast heat stress phenotypes in response to chronic heat stress. The investigation has been carried out in Jamunapari, Barbari, Jakhrana and Sirohi goats. These breeds differ in size, coat colour and production performance. The heat stress assessment in goats was carried out at a temperature humidity index (THI) ranging from 85.36-89.80 over the period. Phenotyping for heat stress susceptibility was carried out by combining respiration rate (RR) and heart rate (HR). Based on the distribution of RR and HR over the breeds in the population, individual animals were recognized as heat stress-susceptible (HSS) and heat stress-tolerant (HST). Based on their physiological responses, the selected animals were slaughtered for tissue collection during peak heat stress periods. The tissue samples from different organs such as liver, spleen, heart, testis, brain and lungs were collected and stored at -70 °C for future use. Hsp70 concentrations were analyzed from tissue extract with ELISA. mRNA expression levels were evaluated using the SYBR green method. Kidney, liver and heart had 1.5-2.0-fold higher Hsp70 concentrations as compared to other organs in the tissue extracts. Similarly, the gene expression pattern of Hsp70 in different organs indicated that the liver, spleen, brain and kidney exhibited 5.94, 4.96, 5.29 and 2.63-fold higher expression than control. Liver and brain tissues showed the highest gene expression at mRNA levels as compared to kidney, spleen and heart. HST individuals had higher levels of mRNA level expression than HSS individuals in all breeds. The Sirohi breed showed the highest (6.3-fold) mRNA expression levels as compared to the other three breeds, indicating the better heat stress regulation activity in the breed.

Effect of Heat Stress on the Expression of HSP70, UCP3 and CYP450 Genes in Liver; Longissimus Dorsi and Semitendinosus Muscle of Growing Pigs

“…In the present study, the expression of HSP70 in liver of pigs after 21 d of exposure to HS increased 4-fold compared to TNad. This increased HSP70 expression in liver coincides with the 5-fold increase in HSP70 expression in liver and brain of HS tolerant goats during the peak of a HS period, compared to HS susceptible goats reported by Rout et al (2016). Also Nagayach et al (2017) observed an increase in HSP70 expression in liver and heart of goats during the summer.…”

Impacto del estrés por calor en la producción de ovinos de pelo. Revisión

“…La reducida expresión de HSP70 en ovejas Suffolk fue asociada con una disminución en la viabilidad de las células mononucleares sanguíneas cultivadas in vitro, y consecuentemente, con una menor adaptación a climas calientes. Es preciso señalar que la HSP70 es el marcador genético mayormente expresado en razas de ovinos y cabras adaptadas a condiciones ambientales de EC (26,27,28) . No obstante, se debe tomar en cuenta que, si bien en ovinos de pelo solamente se han logrado detectar los genes ligados con la síntesis de la HSP70, en la actualidad ya se cuenta con la identificación de varios genes asociados con la termo-tolerancia de pequeños rumiantes adaptadas al EC.…”

“…En ovinos nativos del desierto se han identificado genes de termo-tolerancia asociados con coloración y pigmentación de la piel (FGF2, GNA13, PLCB1), metabolismo energético y digestivo (MYH, TRHDE, ALDH1A3 y GPR50), y respuesta inmune (9,28,29) . Recientemente, en razas de la India adaptadas al EC también se encontraron algunas mutaciones en los polimorfismos G1270A y C888T ligados al gen GPR50, las cuales se asociaron con una mejor tolerancia térmica (29) .…”

Identification and characterization of developmental, tissue, and evolutionary transcription start sites in Bos taurus indicus

“…These researchers suggested that individual TSSs may simply be additive, or may have expression output limitations that make transcription of additional TSSs favourable, also they suggested that having multiple TSSs could enable a faster response to stimuli 28 . Similarly, HSP genes have been extensively reported to respond to external stress stimuli 29 , so observing more variation in the number of TSSs in indicus sub-species may indicate their higher ability to respond to stress. Future research exploring a time series response could shed light on the latter hypothesis.…”