Homozygous deletion in the coding sequence of the c-mer gene in RCS rats unravels general mechanisms of physiological cell adhesion and apoptosis.

The RCS rat presents an autosomal recessive retinal pigment epithelium dystrophy characterized by the outer segments of photoreceptors being phagocytosis-deficient. A systematic genetic study allowed us to restrict the interval containing the rdy locus to that between the markers D3Mit13 and D3Rat256. We report the chromosomal localization of the rat c-mer gene in the cytogenetic bands 3q35-36, based on genetic analysis and radiation hybrid mapping.

First prenatal diagnosis of defects in the HsPDX1 gene encoding protein X, an additional lipoyl-containing subunit of the human pyruvate dehydrogenase complex.

We have previously reported a genetic study of a neonatal lactic acidosis linked to a pyruvate dehydrogenase complex deficiency due to the absence of the protein X subunit. This rare autosomal recessive disorder is associated with specific deletions in this polypeptide which is encoded by the HsPDX1 gene, located on chromosome 11p1.3.

Spatial and temporal expression of the cystathionine beta-synthase gene during early human development.

We report the cystathionine-beta synthase (CBS) gene expression pattern during early human embryogenesis (3 to 6 weeks post conception) by in situ hybridization and in fetal and adult tissue by Northern Blot analysis. Probes were chosen to recognize either the common sequence to all known CBS mRNAs or the sequences of two different major exons 1 issued of we have previously identified. We demonstrate by in situ hybridization that CBS is continuously expressed from the earliest stages studied (22 days post conception) during embryogenesis in the tissues of developing embryos which will after birth present clinical abnormalities in homocystinuria patients.

Insulin-like 4 (INSL4) gene expression in human embryonic and trophoblastic tissues.

Polypeptide growth factors play an important role in the regulation of human embryonic development. Insulin-like 4 gene (INSL4) is a member of the insulin family, which includes insulin, IGF-I, IGF-II, relaxin, and INSL3. Using RT-PCR, we previously found abundant INSL4 mRNA in the human placenta.

Mapping of a congenital microcoria locus to 13q31-q32.

Congenital microcoria is an autosomal dominant disorder characterized by a pupil with a diameter <2 mm. It is thought to be due to a maldevelopment of the dilator pupillae muscle of the iris, and it is associated with juvenile-onset glaucoma. A total genome search for the location of the congenital microcoria gene was launched in a single large family.