O objetivo neste trabalho foi identificar genes candidatos relacionados à ovulação em suínos. Para tanto, investigou-se a expressão diferencial dos genes STAR (steroidogenic acute regulator), GATA (GATA-binding protein 4), PGF2α (prostaglandin F2α), P4R (progesterone receptor), FSHR (follicle-stimulating hormone receptor) e CYP19 (cytochrome P450 aromatase) em células foliculares ovarianas por meio de reação em cadeia da polimerase em tempo real (qRT-PCR) quantitativo em tempo real. Esses genes codificam para receptores hormonais (FSHR e P4R) hormônio (PGF2α), proteínas esteroidogênicas (STAR e CYP19) e fator de transcrição (GATA). As células foliculares foram coletadas durante a fase folicular do ciclo estral de porcas com alto e baixo número de leitões/leitegada. Houve diferença na abundância de transcritos entre porcas com alta e baixa prolificidade para os genes STAR, GATA, PGF2α, P4R and CYP19. Para o gene do FSHR, a alteração na abundância dos transcritos não foi significativamente diferente. Considerando que foi analisado somente o nível de transcrição desses genes mencionados, não se pode fazer inferências com relação à tradução ou atividade proteica. Portanto, ensaios de sequenciamento gênico e outras análises funcionais serão necessários para complementar esses achados e possibilitar melhor entendimento da complexidade biológica desses genes e seu uso como marcadores para prolificidade em suínos.

The main purpose of the present study was to identify for candidate genes related to ovulation in swines. To do so, it was investigated in ovarian follicular cells through quantitative real-time PCR the differential expression of the following genes: steroidogenic acute regulator (STAR), GATA-binding protein 4 (GATA), prostaglandin F2α (PGF2α), progesterone receptor (P4R), follicle-stimulating hormone receptor (FSHR), and cytochrome P450 aromatase (CYP19). These genes encode hormone receptors (FSHR and P4R), hormone (PGF2α), steroidogenic proteins (STAR and CYP19) and transcription factor (GATA). Folicular cells were collected from sows with high and low number of piglets/litters during the follicular phase of the estrus cycle. There was difference in transcript abundance among low and high prolific sows for the STAR, GATA, PGF2α, P4R and CYP19 genes. For the FSHR gene, the fold change was not considered to be significantly different. Because in the present study only the transcript level of the above mentioned genes was analyzed, no inference can be made regarded to protein translation or activity. Therefore, gene sequence trials and other functional studies will be necessary to complement the present results, allowing a better understanding on biological complexity of these genes and their use as markers for prolificity in swines.

Investigou-se neste trabalho a associação entre o marcador microssatélite IGF-I em uma população F2 (N=459) gerada pelo acasalamento entre suínos nativos brasileiros e fêmeas comerciais com características de desempenho, cortes de carcaça e qualidade da carne. A análise de associação foi feita por meio de um modelo que incluiu genótipo, sexo e grupo como efeitos fixos e pais como efeito aleatório. Os genótipos do IGF-I apresentaram associação significativa com nove características quantitativas, resultados que corroboram análises prévias de QTL obtidas para essa região cromossômica em suínos. Efeitos aditivos de dominância, assim como a interação genótipo × sexo, foram estimados e estão descritos neste trabalho. De acordo com os resultados obtidos, este marcador será útil nas análises de QTL na população analisada.

This study investigated the association between IGF-I microsatellite marker in an F2 population (N=459) generated by mating of native boars to Brazilian commercial sows with performance, carcass cut, and meat quality traits. Association analyses were carried out using a statistical model that included genotype, sex, and group as fixed effects and sire as random effect. The IGF-I genotypes were significantly associated with different quantitative traits and these results corroborate with previous QTL analyses obtained for this chromosome region in swine. Additive and dominance effects, as well as a genotype-sex interaction, were estimated and discussed in the text. According to the results obtained, this marker is suitable for QTL search in the genotyped population.

Foi investigada a associação entre os polimorfismos de base única (SNPs) T2411C e T3266G da leptina e as características de carcaça em suínos F2 procedentes do cruzamento de machos da raça Piau com matrizes comercias de composição genética Landrace, Large White e Pietrain. As análises de associação foram feitas usando um modelo estatístico que incluía genótipo, sexo e lote como efeitos fixos, e pai e erro como efeitos aleatórios. O SNP T2411C esteve associado ao peso da copa sem pele e sem gordura (BSW), à espessura de gordura subcutânea na altura da última costela a 6,5 cm da linha média (P2), ao peso da paleta sem pele e sem gordura e ao peso do filezinho (SLW). O SNP T3266G foi associado a idade de abate, peso do bacon, BSW, espessura da gordura subcutânea entre a última e a penúltima vértebra lombar, na linha média, espessura da gordura subcutânea na altura da última costela na linha média, P2 e peso da costela. Os genótipos combinados para ambos os SNP estiveram associados a P2, peso total da copa, rendimento de carcaça e peso do filezinho. Os SNPs analisados têm potencial para ser explorados como marcadores para composição de carcaça em suínos.

It was investigated the association between leptin gene single nucleotide polymorphisms (SNPs) T2411C and T3266G with carcass traits in F2 pigs obtained by crossing native Brazilian Piau with commercial sows composed of Landrace, Large White and Pietrain breeds. Association analyses were performed using a statistical model that included genotype, sex, and batch as fixed effects, sire and error as random effects. The T2411C SNP was associated with skinless and fatless boston shoulder weight (BSW), backfat thickness at last rib, 6.5 cm from the midline (P2), skinless and fatless picnic shoulder weight, and sirloin weight (SLW). The T3266G mutation was associated with slaughter age, bacon weight, BSW, midline backfat thickness between last and last but one lumbar vertebra, midline backfat thickness at last rib, P2 and rib weight. Phenotypic associations were also performed by combining genotypes for both SNPs. Associations with P2, carcass yield, total boston shoulder weight, and SLW were observed. The results obtained demonstrate that the SNPs analyzed have potential to be explored as markers for carcass composition in pigs.

In order to characterize the expression of genes associated with immune response mechanisms to mastitis, we quantified the relative expression of the IL-2, IL-4, IL-6, IL-8, IL-10, IFN-γ and TNF-α genes in milk cells of healthy cows and cows with clinical mastitis. Total RNA was extracted from milk cells of six Black and White Holstein (BW) cows and six Gyr cows, including three animals with and three without mastitis per breed. Gene expression was analyzed by real-time PCR. IL-10 gene expression was higher in the group of BW and Gyr cows with mastitis compared to animals free of infection from both breeds (p < 0.05). It was also higher in BW Holstein animals with clinical mastitis (p < 0.001), but it was not significant when Gyr cows with and without mastitis were compared (0.05 < p < 0.10). Among healthy cows, BW Holstein animals tended to present a higher expression of all genes studied, with a significant difference for the IL-2 and IFN-γ genes (p < 0.001). For animals with mastitis no significant difference in gene expression was observed between the two breeds. These findings suggest that animals with mastitis develop a preferentially cell-mediated immune response. Further studies including larger samples are necessary to better characterize the gene expression profile in cows with mastitis.

The objective was to map QTL on porcine chromosome 4 and to associate them with carcass and internal organ traits in an F2 population. The F1 population was produced by outbreed crossing, using two native Brazilian breed Piau boars and 18 commercial sows. A total of 617 F2 animals issued from 11 F1 boars and 54 F1 sows were typed for a total of five microsatellite markers. The data were analyzed by multiple regressions developed for the analysis of crosses between outbred lines, using the QTL Express software. Significant evidence for QTL was found for pig chromosome 4 regarding carcass and internal organ traits. All QTL were detected in the same region of the chromosome, designated FAT1.