Transcription Level of HSP70, HSP90β, HSF1 and HSF3 Variation in Fayoumi and Leghorn Chicken's Breeds in Response to chronic Heat Stress.

Heikal, Hanim S.; Hemeda, Shabaan A.; Mahboub, Hamada D.H.; Sheraiba, Nagwa I.

doi:10.21608/jcvr.2025.459061

Transcription Level of HSP70, HSP90β, HSF1 and HSF3 Variation in Fayoumi and Leghorn Chicken's Breeds in Response to chronic Heat Stress.

Document Type : Original Article

Authors

10.21608/jcvr.2025.459061

Abstract

Climate is one of the most significant constraints on poultry production. Poultry, in particular, is highly sensitive to environmental challenges related to temperature, especially heat stress. High temperatures, particularly when combined with high humidity, place extreme stress on birds, which results in decreased performance. In general, organisms are stressed by changes in environmental temperature, which may lead to the evolution of genetic adaptations to withstand severe temperatures. The purpose of this study was to study the effect of chronic heat stress on the mRNA expression levels of the HSP70, HSP90β, HSF1, and HSF3 genes in the stress-sensitive organs of two chicken breeds LGH and FYM, additional we studied the modulatory effect of acetic acid on the genes expression level. Four groups were used in the experiment: a control or thermoneutral group (TN), a chronic heat stress group (CHS), a thermoneutral group supplemented with acetic acid (TN+AA), and a chronic heat stress group supplemented with acetic acid (CHS+AA). To determine the transcriptional mRNA expression levels of HSP70, HSP90β, HSF1, and HSF3, samples were taken from the liver and brain. The findings showed that Fayoumi chickens exhibited higher concentrations of HSP70 and HSP90β mRNA expression compared to Leghorn chickens under chronic heat stress, indicating greater heat resistance in Fayoumi chickens. This suggests that Fayoumi chickens have inherited thermotolerance traits. After chronic heat exposure, HSF1 mRNA decreased in Fayoumi chicken brain tissue but remained unchanged in liver tissue, while in Leghorn chickens, HSF1 mRNA increased in liver tissue. Additionally, HSF3 expression decreased in Fayoumi chicken brain tissue but increased in Leghorn chickens under chronic heat stress. Acetic acid supplementation provided greater protection against heat stress in Fayoumi chickens compared to Leghorns.

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