Fetal microchimerism in normal and embryo transfer bovine pregnancies

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Bovine fetal microchimerism in normal and embryo transfer pregnancies and its implications for biotechnology applications in cattle

Fetal cells and DNA have been detected in the maternal circulation during and after pregnancy in a few mammalian species. The incidence of similar microchimerism in cattle could have repercussion for the application of modern biotechnologies such as the transfer of transgenic embryos. To determine if feto-maternal leakage can occur in pregnant cows, we have analyzed maternal blood samples for the presence of fetal DNA during gestation and post-partum periods. Y chromosome-specific DNA was detected in up to 73% of blood samples from naturally mated heifers carrying conventional bull calves and a transgene-specific sequence in up to 50% of recipient cows carrying transgenic fetuses. These findings document for the first time that transplacental leakage of fetal DNA into the maternal circulation can occur in cattle despite the epitheliochorial placenta of ruminants, with potential implications for the utilization of recipient cows in the food chain

Loss of heterozygosity on chromosome 4q32-35 in sporadic basal cell carcinomas: evidence for the involvement of p33ING2/ING1L and SAP30 genes

Background: Studies on basal cell carcinoma (BCC) have demonstrated that patched gene and p53 gene located at 9q22.3 and 17p13 are the main genes responsible for the onset of this tumor. In order to identify a possible involvement of other tumor suppressor genes, we screened 19 cases of BCCs for loss of heterozygosity (LOH). Methods: The analysis was performed on tumoral tissue and on corresponding normal tissue by using a panel of 37 polymorphic markers spanning 26 chromosomal regions. Results: We observed that only four chromosomal regions, 4q32 (30.00%), 4q35 (27.27%), 9q21\u201322 (28.57%), and 9q22-qter (35.71%), demonstrated a significative LOH (>20%), even if others show a borderline percentage (15\u201320%) of imbalance (1q32, 3p24, 10p22.1, and 17q21.3). Conclusions: Our findings suggest that a new chromosomal region mapping in the long arm of chromosome 4 could be involved in sporadic BCC carcinogenesis. Further analyses indicate that the minimal deleted region in 4q32\u201335 includes p33ING2/ING1L and SAP30, whose deletion could impair the G1-phase checkpoint control and favor gene silencing, respectively

Highly sensitive chemiluminescent method for the detection of cell contamination

Minisatellite analysis is commonly used in forensic disputes but can also be applied to the investigation of cell contamination. Such a problem arises, for example, when transplantation is performed. The presence of contamination has been investigated by other authors using radioactive methods. In the present study we describe a method that allows the detection of contamination with high sensitivity without using radioactive substances. Our technique is based on the use of polymerase chain reaction (PCR) amplification of minisatellite sequences (VNTR), followed by chemiluminescent detection. In particular, biotin-labelled dCTP is included in the PCR mixture and detection of PCR products is obtained following the CSPD chemiluminescent protocol (Southern-Light Nucleic Acid Detection Systems). We applied this method to artificial mixes of DNA of two individuals with alleles of different sizes. We performed progressive dilutions of an individual DNA into the other's DNA and revealed a contamination of 1 in 2500 cells. We also tested our technique searching for maternal contamination in cord blood samples in 60 cases and revealed a 18.3% contamination. The technique that we set up proves to be a very sensitive one which could be applied not only to the detection of maternal cells in cord blood but also in studying any other kind of contamination