Expression and localization of cFLIP anti-apoptotic protein in the porcine corpus luteum and corpora albicans during the estrous cycle and pregnancy

We determined expression and localization of the anti-apoptotic cellular FLICE inhibitory protein (cFLIP) in the porcine corpora lutea (CL) and corpus albicans (CA) during estrous and pregnancy. The CL and CA were collected at different stages of estrous to determine cFLIP immunolocalization, and mRNA and protein expression. The mRNA expression of the short cFLIP isoform (cFLIPS) was higher at the early and mid CL stages, and lower by the late CL stage (P < 0.01); mRNA expression of the long cFLIP isoform (cFLIPL) was higher at the mid CL stage, and lower at the early and late CL stages (P < 0.01). Levels of cFLIPS and cFLIPL were steady and high during the early and mid CL stages, and had significantly decreased (P < 0.01) by the late stage. The cFLIP protein was highly expressed in the early and mid CL stages of estrous, but weakly ex-pressed in the late stage. Expression of cFLIPS showed no significant difference between preovulatory corpus albicans (CA1) and corpus albicans (CA2) coexistent with the CL from the previous estrus, but cFLIPL mRNA expression was higher during CA1 than CA2. The expression of cFLIPS showed no significant difference between CA1 and CA2, but cFLIPL was not detected. The cFLIP protein was weak-ly expressed in the CA. Expression of cFLIPS and cFLIPL mRNA and proteins was observed in the CL, and the cFLIP protein was highly expressed during pregnancy. We propose that cFLIPS/L acts as a survival factor, and performs an anti-apoptotic function in the porcine CL.

Expression and tyrosine phosphorylation of sp32 regulate the activation of the boar proacrosin/acrosin system

The current study investigated the relationship between the level of expression and tyrosine phosphorylation of the sperm protein 32 (sp32) and the activation of the boar proacrosin/acrosin system. The acrosomal membrane proteins of boar sperm for use in different treatment experiments (i.e., fresh sperm, freezing and thawing, capacitation, and acrosome reaction) were separated, stained by Coomassie brilliant blue, and analyzed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and western blot. The results showed that there were differences in the expression level of sp32 among capacitated, frozen-thawed, and post acrosomal reaction sperms. sp32 expression was higher and significantly higher in capacitated and post-acrosomal reaction sperms than in frozen-thawed sperms and fresh semen, respectively. The level of sp32 tyrosine phosphorylation was significantly different between the frozen-thawed sperms and sperms in the other experimental groups. However, bands with molecular masses of 38 to 170 ku in the fresh semen group were more noticeable, indicating that large acrosomal membrane proteins underwent modification and degradation during capacitation and the acrosomal reaction. As a proacrosin binding protein, sp32 shows upregulated expression and increase in tyrosine phosphorylation levels during the activation of the boar proacrosin/acrosin system.

[Mutational analysis of Meq, RLORF4, RLORF12 and 132bpr genes of epidemic Marek's disease virus strains highly passaged on chicken embryo fibroblast]

Recently, much work has been devoted to study MD-induced oncogenesis and the genes involved in this process. Among many genes in the MDV genome, several genes such as Meq, RLORF4, RLORF12, and 132bpr have been considered recently associated with virulence of MDV. In this paper, primers of Meq, RLORF4, RLORF12 and 132bpr genes were designed and synthesized, based on the published whole genome sequence of MDV strain GA. The genes of Meq, RLORF4 and RLORF12 from four Chinese epidemic MDV strains highly passaged on chicken embryo fibroblast (CEF), i. e. L-SYp85C, L-MSp75C, L-CZp75C, and L-ZYp75C, as well as their corresponding parent strains, i. e. L-SY, L-MS, L-CZ, and L-ZY, the reference virulent strain J-1 and the vaccine strain 814 were amplified by PCR respectively. Then the PCR products of interest were cloned and sequenced respectively. The results of sequence comparison and analysis of Meq genes in the study indicated that Meq genes from the two strains L-ZYp75C and L-CZp75C contained single nucleotide insertion and deletion. The Meq gene from strain L-ZYp75C contained an extra cytidine (C) insertion at nucleotide position 529 and a single thymidine (T) deletion at nucleotide position 602, resulting in a frameshift mutation. And this frameshift mutation could lead to changes in deduced amino acid sequence from position 177 to 200 of Meq gene. The extra C insertion at nucleotide position 625 in Meq gene of strain L-CZp75C was also predicted to cause frameshift mutation in three overlapping genes (Meq, RLORF6 and 23KD genes). The comparison of nucleotide sequences of RLORF4 genes in the study revealed that the RLORF4 gene of strain L-SYp85C contained a fragment deletion in Open Reading Frame (ORF) from nucleotide position 215 to 265, resulting in 17 amino acids deletions, which were not found in other sequenced strains. Comparison of nucleotide sequences of RLORF12 genes in the study revealed several mutations. The RLORF12 gene of strain L-MSp75C contained a single T deletion at nucleotide position 67 and of 814 vaccine strain a large fragment deletion from nucleotide position 18 to 86, both of the deletions located in Origin of replication site (Ori) of MDV genome. But strain L-ZYp75C possessed an unique "TGTTGGG" deletion in its RLORF12 gene. When the four Chinese epidemic MDV strains were serially passaged on CEF, the number of copies of the 132bp repeats increased from 2 to more than 10 copies. All of above results indicated that deletion and/or insertion mutation occurred in Meq, RLORF4, RLORF12 and 132bpr after serial passage of these four Chinese epidemic MDV strains on CEF.

[Cloning and sequence analysis of the Meq gene of 4 Marek's disease virus isolates from China]

Earlier studies have determined that the repeat regions of oncogenic serotype 1 MDV (Marek's disease virus) encode a basic leucine zipper protein, Meq, which structurally resembles the Jun/Fos family of transcriptional activators. Meq has been suggested as the MDV-associated oncogene. In this paper, based on the published sequence of Meq gene of GA strain of MDV, a pair of primers were designed and synthesized. Meq gene ORF (Open reading frame) of the four Chinese local MDV isolates, the reference strain J-1 and the vaccine strain 814 were amplified by using polymerase chain reaction(PCR). Then the PCR products were cloned and sequenced respectively. The results of sequence comparison indicated that the sequences of Meq gene in different strains are relatively conserved and homology of the amino acid sequences is 96.5%-99.7%. The proline-rich repeats of Meq gene of four MDV isolates have site mutations, and it is related to MDV's virulence. Two unique site mutations appear in Meq gene of Chinese local MDV isolates, but they aren't present in Meq gene of the published MDV strains from abroad and the early domestic strains. It seems that some regularities exist between such mutations in four Chinese local MDV isolates and the virulence of MDV, but the regularities need further research.

Cryptosporidium infection and diarrhea in rural and urban areas of Jiangsu, People's Republic of China

Screening of infants and children under age 15 years for Cryptosporidium oocysts in their stools was carried out in the suburb of Xuzhou City and six rural areas of Jiangsu Province. The infection rate varied from 0.7 to 5.06%. Of the total of 5,089 children examined, 89 (1.75%) were oocyst positive. The incidence was evidently higher in the group of children under age 4 years than it was in children from 4 to 15 years (P less than 0.01). Routine blood examination and immunoassay performed on blood samples from some of the infected children indicated that more than half of them had anemia and lower cellular immunity. Diarrhea was the main symptom of cryptosporidiosis. It was intermittent or persistent and was present in 57 of the 89 children positive for Cryptosporidium oocysts, while the other 32 children were asymptomatic carriers. Examination of stool specimens of adult members and domestic animals of about half of the infected families showed that two mothers, one pig, and one dog were positive for Cryptosporidium oocysts.