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| Author(s): |
José Eduardo de Oliveira Zanon
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Medicina Veterinária e Zootecnia (FMVZ/SBD) |
| Defense date: | 2006-03-23 |
| Examining board members: |
Alicio Martins Junior;
José Buratini Júnior;
José Fernando Garcia
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| Advisor: | Alicio Martins Junior |
| Abstract | |
With the objective to semiquantify the gene expression for gonadotrophins receptors in dominant follicles in Nelore and Marchigiana prepubertal heifers and Nelore adult cows, being searched differences that make possible the search of answers for the low developmental potential of oocytes from prepubertal heifers that allow the use of these in programs of animal genetic improvement, had been used 8 animals, being three Nelore heifers, three Marchigiana heifers, with 7 months of age, and two Nelore heifers, with 25 months of age. Accompaniment of the follicular wave was carried through daily ultrasonografic exams for two months, and the animals had been slaughtered at the moment that dominant follicle presented maximum diameter (8, 10 and 14 mm, respectively). Dominant follicles had been dissected and isolated, and extraction of total RNA was performed. Four reactions of synthesis of cDNA from each sample had been made. For analysis of the semi-quantitative gene expression, reactions of Duplex-PCR had been carried through, using themselves two initiating oligonucleotídeos in each reaction, one for housekeeping gene, gapdh, and another one for the target gene, fshr and lhr. These reactions had been carried through in third copy from each source of cDNA of each sample, and the products had been applied in poliacrilamida gel electrophoresis, and photographed. The results had been gotten from the reason enter the intensity of the band of the target gene and the intensity of the band of the housekeeping gene, and the average values had been analyzed in a statistical software. Lower relative expression of lhr in Nelore heifers was found when compared with the Nelore adult cows and the Marchigiana heifers. An alternative splicing for lhr was detected, that presented similar behavior to the gene standard. Significant difference in the expression of the gene of the FSHr between the studied groups was not found. The results suggest a importance of the LH in the final periods of follicular development, demonstrated for the lower relative expression of lhr in the dominant follicles of Nelore heifers in relation to the adult cows in this study, that can after be the one of the reasons for the low developmental capacity of oocytes of these animals after in vitro fertilization (AU) | |