ABSTRACT
The mammalian sex-determining pathway is controlled by the presence or absence of SRY expression in the embryonic gonad. Expression of SRY in males is believed to initiate a pathway of gene expression resulting in testis development. In the absence of SRY, ovary development ensues. Several genes have now been placed in this pathway but our understanding of it is far from complete and several functional classes of protein appear to be absent. Sex-determining genes frequently exhibit sexually dimorphic patterns of expression in the developing gonad both before and after overt differentiation of the testis or ovary. In order to identify additional sex-determining or gonadal differentiation genes we have examined gene expression in the developing gonads of the mouse using cDNA microarrays constructed from a normalized urogenital ridge library. We screened for genes exhibiting sexually dimorphic patterns of expression in the gonad at 12.5 and 13.5 days post-coitum, after overt gonad differentiation, by comparing complex cDNA probes derived from male and female gonadal tissue at these stages on micro-arrays. Using in situ hybridization analysis we show here that two genes identified by this screen, protease nexin-1 (Pn-1) and vanin-1 (Vnn1), exhibit male-specific expression prior to overt gonadal differentiation and are detected in the somatic portion of the developing gonad, suggesting a possible direct link to the testis-determining pathway for both genes.
Subject(s)
Carrier Proteins/biosynthesis , Cell Adhesion Molecules/biosynthesis , Gene Expression Regulation, Developmental , Ovary/embryology , Sex Differentiation/genetics , Testis/embryology , Amidohydrolases , Amyloid beta-Protein Precursor , Animals , Carrier Proteins/genetics , Cell Adhesion Molecules/genetics , DNA, Complementary/metabolism , Female , GPI-Linked Proteins , Gene Library , In Situ Hybridization , Male , Mice , Mice, Inbred C3H , Oligonucleotide Array Sequence Analysis , Ovary/metabolism , Protease Nexins , Receptors, Cell Surface , Reverse Transcriptase Polymerase Chain Reaction , Testis/metabolism , Time Factors , Transcription, GeneticABSTRACT
Progressive epilepsy with mental retardation (EPMR) is an autosomal recessive central nervous system disorder characterized by childhood onset epilepsy and subsequent mental retardation. The locus for EPMR has been mapped to human chromosome 8p23. We recently reported the construction of a YAC contig across the 4 centimorgan minimum genetic region that harbors the disease locus. We now report further delineation of the critical region to <700 kb. Our mapping strategy relied on the identification of nine novel microsatellite markers and the construction of a complete BAC contig across the critical region. Several partial gene sequences have been identified from the region and are being analyzed as candidate genes for EPMR.
Subject(s)
Chromosome Mapping , Chromosomes, Human, Pair 8/genetics , Epilepsy/genetics , Genes, Recessive/genetics , Intellectual Disability/genetics , Microsatellite Repeats , Base Sequence , Chromosomes, Artificial, Yeast , DNA, Complementary , Epilepsy/complications , Exons , Female , Haplotypes , Humans , Intellectual Disability/complications , Male , Molecular Sequence Data , Pedigree , Sequence Analysis, DNA , Sequence Tagged SitesABSTRACT
The childhood-onset spinal muscular atrophies are a clinically heterogeneous group of autosomal recessive disorders characterized by selective degeneration of the anterior horn cells with subsequent weakness and atrophy of limb muscles. The disease locus has been mapped to a region of chromosome 5q13 characterized by genetic instability and DNA duplication. Among the duplicated genes in this region, SMNT (telomeric copy; survival motor neuron) is thought to be the major disease determining gene since it is missing in the majority of SMA patients and since small, intragenic mutations in the gene have been associated with the disorder. Approximately half of the severely affected SMA I patients are also missing both homologues of a neighboring gene, the neuronal apoptosis inhibitory protein (NAIP). These data indicate that loss of NAIP may affect disease severity and further, that the molecular events underlying the childhood-onset SMAs are complex, possibly involving multiple genes. We report a third multicopy gene in the SMA region, encoding the p44 subunit of basal transcription factor II (BTF2p44). One copy of this transcription-repair gene is deleted in at least 15% of all SMA cases.
Subject(s)
DNA Repair , Gene Deletion , Muscular Atrophy, Spinal/genetics , Nerve Tissue Proteins/genetics , Transcription Factors, TFII , Transcription Factors/genetics , Transcription, Genetic , Chromosome Mapping , Cyclic AMP Response Element-Binding Protein , Female , Gene Dosage , Genome , Humans , Male , Pedigree , RNA-Binding Proteins , SMN Complex Proteins , Survival of Motor Neuron 1 Protein , Transcription Factor TFIIHABSTRACT
A study was conducted on the feasibility of isolating genes and pseudogenes that map to chromosome 13 by a hybridization-based approach using a 13-specific library and pools of repeat-free cDNA clones. Five pairs of cDNA and chromosome 13 genomic clones were identified and characterized. Partial or full-length sequence was derived from all cDNAs, and database searches were performed for putative gene identification. Partial sequence was also obtained from the chromosome 13 genomic clones for comparison with those of the hybridizing cDNAs. As a result of these analyses we identified three genes, a putative homologue of a porcine mRNA encoding an unidentified hepatic protein, a putative homologue of a yeast integral membrane protein, and a gene for a translationally controlled tumor protein, and two processed pseudogenes, ribosomal proteins L23a and S3a. The latter was formerly identified as the v-fos transformation effector gene, Fte-1, and recently cited as a possible candidate for the BRCA2 gene on chromosome 13. All genes and pseudogenes were localized to cytogenetic bands by in situ hybridization of metaphase chromosomes with probes derived from the chromosome 13 genomic clones.
Subject(s)
Chromosomes, Human, Pair 13/genetics , Pseudogenes/genetics , Amino Acid Sequence , Base Sequence , Humans , Molecular Sequence Data , Polymerase Chain Reaction , Repetitive Sequences, Nucleic Acid , Sequence Homology, Amino Acid , Sequence Homology, Nucleic AcidABSTRACT
Various types of physical mapping data were assembled by developing a set of computer programs (Integrated Mapping Package) to derive a detailed, annotated map of a 4-Mb region of human chromosome 13 that includes the BRCA2 locus. The final assembly consists of a yeast artificial chromosome (YAC) contig with 42 members spanning the 13q12-13 region and aligned contigs of 399 cosmids established by cross-hybridization between the cosmids, which were selected from a chromosome 13-specific cosmid library using inter-Alu PCR probes from the YACs. The end sequences of 60 cosmids spaced nearly evenly across the map were used to generate sequence-tagged sites (STSs), which were mapped to the YACs by PCR. A contig framework was generated by STS content mapping, and the map was assembled on this scaffold. Additional annotation was provided by 72 expressed sequences and 10 genetic markers that were positioned on the map by hybridization to cosmids.
Subject(s)
Breast Neoplasms/genetics , Chromosome Mapping/methods , Chromosomes, Human, Pair 13/genetics , Neoplasm Proteins/genetics , Software , Transcription Factors/genetics , BRCA2 Protein , Base Sequence , Chromosomes, Artificial, Yeast/genetics , Chromosomes, Human, Pair 13/ultrastructure , Cosmids/genetics , DNA, Complementary/genetics , Disease Susceptibility , Female , Gene Expression , Humans , In Situ Hybridization, Fluorescence , Molecular Sequence Data , Oligonucleotide Probes , Polymerase Chain Reaction , Repetitive Sequences, Nucleic Acid , Selection, GeneticABSTRACT
Electrophoretic analyses of collagenous material have shown that the parietal yolk sac carcinoma (PYSC) ascitic tumour synthesizes polypeptide chains that migrate as type IV procollagen. Having molecular weights of 185,000 and 160,000, these polypeptides are sensitive to collagenase. When the PYSC cells are injected subcutaneously, they form a solid tumour, and type I collagen predominates. The electrophoretic analyses of sulfated glycosaminoglycans and enzymatic degradation have shown a predominance of heparan sulfate in the ascitic tumour, and of chondroitin sulfate B in the solid tumour. Cells cultured from ascitic tumours have maintained the same collagen and sulfated glycosaminoglycan patterns as the original cells, whereas in the solid tumour culture only chondroitin sulfate AC has been detected.
Subject(s)
Chondroitin Sulfates/analysis , Chondroitin/analogs & derivatives , Collagen/analysis , Glycosaminoglycans/analysis , Heparitin Sulfate/analysis , Mesonephroma/analysis , Animals , Ascites , Cells, Cultured , Chondroitin Sulfates/biosynthesis , Collagen/biosynthesis , Dermatan Sulfate/analysis , Mesonephroma/metabolism , Mice , Neoplasm Transplantation , Procollagen/analysisABSTRACT
The site of histone synthesis was studied in polytene cells of the salivary glands of the Rhynchosciara americana (Diptera). It was found that, as is the case in non-polytene systems, these proteins are synthesized in the cytoplasm in a class of light polysomes which contain 3-4 ribosomes. This class of polyribosomes is most active at about 5 days before pupation when the nuclei are most active in DNA synthesis and the chromosomes of the gland show many open 'DNA puffs'.