Banca de QUALIFICAÇÃO: ELEM CRISTINA MACEDO BARRA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : ELEM CRISTINA MACEDO BARRA
DATE: 30/08/2024
TIME: 14:00
LOCAL: Sala virtual
TITLE:

IDENTIFICATION AND IN VITRO VALIDATION OF MOLECULAR MARKERS OF THERMOTOLERANCE IN DAIRY BUFFALOS’ POPULATIONS (Bubalus bubalis) IN THE AMAZON

KEY WORDS:

Buffalo; Thermotolerance; Global Warming; Stress; Milk.

PAGES: 35
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUMMARY:

The Bubalus bubalis species is known worldwide for being animals that adapt well to the hot and humid climate of tropical and subtropical countries. However, this does not mean that these animals do not suffer from the increase in environmental temperature. In recent years, global warming has caused direct and indirect losses in livestock farming, given that animals subjected to strong heat waves tend to reduce their milk production, in addition to the changes caused in the composition of the milk. As if that were not enough, animals subjected to moderate or high levels of stress have a decrease in reproduction and in the immune system. Because of this, for some years now, measures have been sought to mitigate the damage that heat stress can cause to livestock farming. One of the solutions found is the selection of thermotolerant animals through molecular biology. The objective was to investigate new molecular markers of thermotolerance in dairy buffaloes. To identify possible thermotolerance polymorphisms, blood was collected from 104 Murrah dairy buffaloes. After DNA extraction, polymerase chain reaction was performed to amplify the promoter region of the heat shock protein 70 gene, with subsequent sequencing of the samples to identify the polymorphic sites. Then, skin tissue from the dorsal region of the tail of 10 buffaloes was collected, 5 of which were characterized as homozygous and 5 as heterozygous. The tissues were then treated and cultured in HAM's and DMEM culture medium plus 10% fetal bovine serum and incubated in an oven at 38.5°C with 5% CO2 saturation. The cells were cultured until the first passage and then the heat resistance test was performed, with the control group maintained at 38.5°C and the test group at 42°C for 6 hours. Upon completion of the test, the samples underwent cell viability testing. An aliquot of the cells was then removed and subjected to RNA extraction with subsequent gene expression analysis. The environmental parameters of temperature and humidity and the animals' practical comfort index were also evaluated. In addition, infrared thermography was used to assess the animals' skin surface temperature. The sequencing result demonstrated the presence of 15 polymorphic sites, with one of these mutations being observed in all animals on the farm (C - A). In addition, there was the insertion of a base (G) at position 128 in 3 animals and a deletion (G) at position 650 in 1 animal. Regarding gene expression, 1 heterozygous animal in the test group did not express the IFN-γ gene. Calculations of the humidity and temperature index revealed that the animals between 7:00 am and 12:00 pm presented mild heat stress and from 1:00 pm to 2:00 pm moderate heat stress; The calculation of the index of practical comfort climatic conditions for buffaloes showed that the animals were in the danger zone between 12:00 and 14:00.

COMMITTEE MEMBERS:
Presidente - 1556914 - EDNALDO DA SILVA FILHO
Interna - 1733442 - ANA RITA DE LIMA
Interno - 1557097 - IGOR GUERREIRO HAMOY
Externa ao Programa - 1356993 - JAMILE ANDREA RODRIGUES DA SILVA - UFRAExterna à Instituição - RENATA COELHO RODRIGUES - UFPA
Externa à Instituição - MARCELA DA SILVA CORDEIRO - IFPA
Externa à Instituição - NATHALIA NOGUEIRA DA COSTA - UFPA