Temporal expression pattern of myostatin transcripts during chicken embryogenesis Padrão de expressão temporal de transcritos de miostatina durante a embriogênese da galinha

No presente estudo, estimou-se a abundância dos transcritos da miostatina foi estimada durante a embriogênese de galinha por análises de RT-PCR competitiva. Níveis basais de mRNA desse gene foram detectados até o estádio HH15, enquanto acúmulos significativos nesses níveis foram observados apenas no estádio HH24, seguido por redução na abundância desses transcritos a partir do estádio HH26. Tais descobertas preliminares proporcionam informações relevantes sobre a ativação do fator de crescimento miostatina durante o desenvolvimento in ovo de aves

Efeito da idade da vaca e da data juliana de nascimento sobre o ganho médio diário de bezerros de corte no período pré-desmame Effects of age of the dam and julian birth date on average daily gain of beef calves from birth to wean

Estudaram-se os efeitos da idade da vaca ao parto (IDV) e da data juliana de nascimento (DJN) sobre o ganho médio diário no período pré-desmame de bezerros de corte e determinaram-se os respectivos fatores de correção (FC), utilizando 463.971 e 39.220 dados das raças Nelore e Tabapuã, respectivamente. O modelo estatístico continha os efeitos de IDV, modelada por um polinômio segmentado quadrático-quadrático com um nó aos sete anos e de DJN do bezerro, modelada por um polinômio segmentado com três segmentos quadráticos e dois nós, aos 185 e 295 dias. Tanto a IDV como a DJN influenciaram significativamente o ganho médio diário dos bezerros no período pré-desmame. Para os dois efeitos foram encontradas diferenças entre as duas raças. Para a IDV, os melhores ganhos ocorreram aos seis anos para a raça Tabapuã e aos nove anos para a raça Nelore. Quanto ao efeito da DJN, os melhores ganhos ocorreram no inverno para ambas as raças. Os FC foram calculados por raça, sendo os da IDV calculados separadamente para machos e fêmeas e as do DJN por estação. A determinação de fatores de correção deverá possibilitar melhor precisão da seleção, reduzindo os efeitos não genéticos que concorrem para a variação dessa característica.<br>The effects of age of dam (IDV) and julian birth date (DJN) on daily weight gain of beef calves from birth to wean were analyzed and correction factors were calculated. Data from 463,971 and 39,220 Nelore and Tabapuã animals were used in the analyses. The IDV, modeled by a polynomial segmented quadratic-quadratic with a knot at seven years and DJN modeled by a polynomial segmented with three quadratic segments and two knots at 185 and 295 days were included in the statistical model. The IDV and DJN had significant effects on daily weight gain of beef calves from birth to wean, and significant difference between breeds was observed for both effects. The best daily weight gain from birth to wean was observed for cows averaging 6 and 9 years for Tabapuã and Nelore breeds, respectively. The best daily weight gain from birth to wean was also observed in the winter for both breeds. Correction factors were calculated for breed, and those for IDV were calculated separately for males and females. The correction factors for DJN were calculated for each season. The calculated correction factors allowed higher precision in the selection of animals by reducing the non genetic effects on the variation of daily weight gain from birth to wean

Placental hydroxymethylation vsmethylation at the imprinting control region 2 on chromosome 11p15.5

In addition to methylated cytosines (5-mCs), hydroxymethylcytosines (5-hmCs) are present in CpG dinucleotide-enriched regions and some transcription regulator binding sites. Unlike methylation, hydroxymethylation does not result in silencing of gene expression, and the most commonly used methods to study methylation, such as techniques based on restriction enzymatic digestion and/or bisulfite modification, are unable to distinguish between them. Genomic imprinting is a process of gene regulation where only one member of an allelic pair is expressed depending on the parental origin. Chromosome 11p15.5 has an imprinting control region (ICR2) that includes a differentially methylated region (KvDMR1) that guarantees parent-specific gene expression. The objective of the present study was to determine the presence of 5-hmC at the KvDMR1 in human placentas. We analyzed 16 third-trimester normal human placentas (chorionic villi). We compared two different methods based on real-time PCR after enzymatic digestion. The first method distinguished methylation from hydroxymethylation, while the other method did not. Unlike other methylation studies, subtle variations of methylation in ICRs could represent a drastic deregulation of the expression of imprinted genes, leading to important phenotypic consequences, and the presence of hydroxymethylation could interfere with the results of many studies. We observed agreement between the results of both methods, indicating the absence of hydroxymethylation at the KvDMR1 in third-trimester placentas. To the best of our knowledge, this is the first study describing the investigation of hydroxymethylation in human placenta using a genomic imprinting model

Increased expression of ID2, PRELP and SMOC2 genes in patients with endometriosis

Endometriosis is a benign, estrogen-dependent disease with symptoms such as pelvic pain and infertility, and it is characterized by the ectopic distribution of endometrial tissue. The expression of the ID2, PRELP and SMOC2 genes was compared between the endometrium of women without endometriosis in the proliferative phase of their menstrual cycle and the eutopic and ectopic endometrium of women with endometriosis in the proliferative phase. Paired tissue samples from 20 women were analyzed: 10 from endometrial and peritoneal endometriotic lesions and 10 from endometrial and ovarian endometriotic lesions. As controls, 16 endometrium samples were collected from women without endometriosis in the proliferative phase of menstrual cycle. Analysis was performed by real-time polymerase chain reaction (PCR). There was no significant difference between gene expression in the endometrium of women with and without endometriosis. The ID2 gene expression was increased in the most advanced stage of endometriosis and in ovarian endometriomas, the PRELP was more expressed in peritoneal lesions, and the SMOC2 was highly expressed in both peritoneal and endometrioma lesions. Considering that the genes studied participate either directly or indirectly in cellular processes that can lead to cell migration, angiogenesis, and inappropriate invasion, it is possible that the deregulation of these genes caused the development and maintenance of ectopic tissue