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G Tosser-Klopp

Publications and source records attributed to G Tosser-Klopp.

7 recordsLinked to original sources
PubMed2006

Identification of differential gene expression in in vitro FSH treated pig granulosa cells using suppression subtractive hybridization.

FSH, which binds to specific receptors on granulosa cells in mammals, plays a key role in folliculogenesis. Its biological activity involves stimulation of intercellular communication and upregulation of steroidogenesis, but the entire spectrum of the genes regulated by FSH has yet to be fully characterized. In order to find new regulated transcripts, however rare, we have used a Suppression Subtractive Hybridization approach (SSH) on pig granulosa cells in primary culture treated or not with FSH. Two SSH libraries were generated and 76 clones were sequenced after selection by differential screening. Sixty four different sequences were identified, including 3 novel sequences. Experiments demonstrated the presence of 25 regulated transcripts.A gene ontology analysis of these 25 genes revealed (1) catalytic; (2) transport; (3) signal transducer; (4) binding; (5) anti-oxidant and (6) structural activities. These findings may deepen our understanding of FSH's effects. Particularly, they suggest that FSH is involved in the modulation of peroxidase activity and remodelling of chromatin.

Animals↗
PubMed2001

Conserved synteny and gene order difference between human chromosome 12 and pig chromosome 5.

A comparative map of human chromosome 12 (HSA 12) and pig chromosome 5 (SSC 5) was constructed using ten pig expressed sequence tags (ESTs). These ESTs were isolated from primary granulosa cell cultures by differential display (EST b10b), or from a granulosa cDNA library (VIIIE1, DRIM, N*9, RIIID2 and RVIC1) or from a small intestine cDNA library (ATPSB, ITGB7, MYH9, and STAT2). Also used were two Traced Orthologous Amplified Sequence Tags (TOASTs) (LALBA, TRA1), one microsatellite-associated gene (IGF1) and finally five human YACs selected for their cytogenetic position, with a view to increasing the number of informative markers for the comparison. Large-insert clones were obtained by screening a pig bacterial artificial chromosome (BAC) library with specific primers for each EST and TOAST and for IGF1. These BACs were used as probes for fluorescent in situ hybridisation (FISH) both on porcine and human metaphases. In addition, the human YACs were FISH mapped on pig chromosomes. This allowed us to refine and, in some cases, to correct the previous mapping obtained with a somatic cell hybrid panel. While these data confirm chromosome painting results showing that the distal part of SSC 5p arm is conserved on HSA 22, while the rest of the chromosome corresponds to HSA 12, they also demonstrate gene-order differences between human and pig. In addition, it was also possible to determine the position of the synteny breakpoint.

Animals↗
PubMed2001

Pregnancy-associated plasma protein-A (PAPP-A) in ovine, bovine, porcine, and equine ovarian follicles: involvement in IGF binding protein-4 proteolytic degradation and mRNA expression during follicular development.

IGF binding protein-4 (IGFBP-4) proteolytic degradation is a common feature of preovulatory follicles from human, ovine, bovine, porcine, and equine ovary. In all these species, the protease is a zinc-dependent metalloprotease and its ability to degrade IGFBP-4 is IGF dependent. The human intrafollicular IGFBP-4-degrading protease has recently been identified as pregnancy-associated plasma protein-A (PAPP-A). The aim of this study was to investigate whether PAPP-A is also involved in IGFBP-4 degradation in ovine, bovine, porcine, and equine preovulatory follicles and to study the expression of PAPP-A mRNA in bovine and porcine granulosa cells from different classes of follicles. Immunoneutralization and immunoprecipitation with polyclonal antibodies raised against human PAPP-A inhibited IGFBP-4 proteolytic degradation in preovulatory follicular fluid from the four species studied. As previously reported for the intrafollicular proteolytic activity degrading IGFBP-4, recombinant human PAPP-A generated in vitro 17- and 10-kDa IGFBP-4-proteolytic fragments. Recombinant PAPP-A activity was also shown to be IGF dependent and was inhibited by heparin-binding domain-containing peptides. In all mammalian species studied, the PAPP-A sequences showed high degree of identity. Moreover, the PAPP-A gene was localized on porcine chromosome 1 (1q29-1q213), in agreement with the localization of human PAPP-A gene on human chromosome 9q33.1. In bovine and porcine ovaries, real-time quantitative RT-PCR showed that PAPP-A mRNA expression in granulosa cells was maximal in fully differentiated follicles and was positively correlated with expression of P450 aromatase and LH receptor mRNAs. Overall, these data show that PAPP-A is responsible for IGFBP-4 degradation in ovine, bovine, porcine, and equine preovulatory follicles. The high expression of PAPP-A mRNA in granulosa cells from large, differentiated follicles suggest that it is a new functional marker of follicular development.

Amino Acid Sequence↗
PubMed1998

Regional localisations of VIM, HSD3b, ACTA1 and PGM1 in pigs.

The comparative map between human and pig has progressed rapidly over the past 2 years. Nevertheless, some points still need to be clarified, particularly the correspondences between human chromosome 10 (HSA10) and porcine chromosome 10 (SSC10) and between human chromosome 1 (HSA1) and porcine chromosomes. The gene codings for vimentin (VIM) carried by HSA10 and three genes carried by HSA1 (hydroxy delta 5 steroid dehydrogenase 3 beta: HSD3B: alpha actin 1: ACTA1: and phosphoglucomutase 1: PGM1) were selected and the regional localisations on pig chromosomes were determined using a well-characterised somatic cell hybrid panel.

3-Hydroxysteroid Dehydrogenases↗
PubMed1997

A first catalog of genes involved in pig ovarian follicular differentiation.

As a first step toward the characterization of genetic expression in pig ovaries, we have selected 238 clones by differential hybridization from a pig granulosa cell cDNA library, using probes prepared from RNA extracted from either untreated or FSH-treated cells and, in order to generate expressed sequence tags (ESTs), we have performed 3' and 5' single-pass sequencing of these clones. Sequences of the 3' end of the 167 clones that produced informative sequence data were first compared with each other, revealing a redundancy level of 21%. Sequences from the 136 unique clones were analyzed for similarities with sequence data included in Genbank and EMBL databases. Among these unique clones, 54 (40%) matched significantly with sequences from either Genbank of EMBL: 4 with known genes in pig, 35 matched with previously reported human genes, and 15 with other mammalian genes. Eighty-two clones (60%) showed no significant match with any gene or DNA sequence in the Genbank and EMBL databases and thus may represent new pig transcripts.

Animals↗
PubMedDate not supplied

Functional study and regional mapping of 44 hormono-regulated genes isolated from a porcine granulosa cell library.

cDNA clones from a pig granulosa cell cDNA library were isolated by (differential hybridisation for follicle stimulating hormone (FSH) regulation in granulosa cells in a previous study. The clones that did not match any known sequence were studied for their expression in granulosa cells (treated or not by FSH) and in fresh isolated ovarian follicles mainly by comparative RT-PCR analysis. These results give functional data on genes that may be implicated in follicular growing. These ESTs have been localised on the porcine genome, using a somatic cell hybrid panel, providing new type I markers on the porcine map and information on the comparative map between humans and pigs.

Animals↗