Heat loss efficiency and HSPs gene expression of Nellore cows in tropical climate conditions.
Henrique Barbosa HooperCristiane Gonçalves TittoAngela Maria Gonella-DiazaFábio Luís HenriqueLina Fernanda Pulido-RodríguezAna Luisa Silva LongoThays Mayra da Cunha Leme-Dos-SantosAna Carina Alves Pereira de Mira GeraldoAlfredo Manuel Franco PereiraMario BinelliJúlio Cesar de Carvalho BalieiroEvaldo Antonio Lencioni TittoPublished in: International journal of biometeorology (2018)
Adaptation is a relevant characteristic to be understood in livestock animals in order to maintain and raise productivity. In Brazil, the Nellore beef cattle are widely disseminated and well-adapted breed that present good thermoregulatory characteristics for tropical environment conditions. Conversely, the physiological and cellular mechanisms required for thermoregulation and thermotolerance in this breed are still limited. The aim of this study was to comprehend the heat loss efficiency at the whole animal level and heat shock response at the cellular level of Nellore cows in tropical climate conditions. Healthy purebred Nellore cows were classified according to their capacity to lose body heat as Efficient or Inefficient based on vaginal temperature which was continuously monitored by data-loggers. Rectal, tail, and ocular temperatures, sweating rate, and respiratory frequency were collected to assess other thermoregulatory responses. Peripheral mononuclear cells were used for gene expression of heat shock proteins 60, 70, and 90 induced by in vitro heat treatments at 38, 40, and 42 °C. In our findings, the Efficient cows presented higher sweating rates compared to Inefficient cows that presented higher rectal temperature with greater amplitude of vaginal temperature profile. Transcription of the HSP genes was stable at 38 and 40 °C and decreased for all HSP genes at 42 °C. In conclusion, the Nellore efficiency to lose heat was mainly associated with their sweating capacity and cellular thermotolerance confirmed by the maintenance of heat shock proteins transcripts under heat stress. Taken together, this knowledge contributes as a future key for genetic selection of adapted animals.
Keyphrases
- heat shock
- heat stress
- climate change
- gene expression
- genome wide
- dna methylation
- healthcare
- induced apoptosis
- rectal cancer
- heat shock protein
- cell proliferation
- transcription factor
- cell cycle arrest
- peripheral blood
- oxidative stress
- machine learning
- bioinformatics analysis
- copy number
- current status
- pi k akt
- respiratory tract
- genome wide analysis