We describe the complete sequence, genomic organization, and FISH chromosome mapping of the human VAMP2. We identified a 7-kb clone, pISSHG2b3A, containing the entire structure of VAMP2. Previous studies performed by others identified a 5-kb clone, pVPC5-2, containing the incomplete VAMP2. The pVPC5-2 clone was partially sequenced and mapped to the broad region 17pter-->p12 by somatic cell hybridization. Our clone overlaps the pVPC5-2 clone and extends approximately 2 kb at the 3' end. In this study, we mapped this gene more precisely on 17p12 by FISH and we found a new polymorphic microsatellite, (GT)(7)CC(GT)(5), in exon V. This microsatellite, revealing three alleles with frequencies of 0.778, 0.139, and 0.083, might be useful for future linkage studies. Finally, we localized three previously known markers, stSG12859, TIGR-A002F11, and WIAF-1699 (alias stSG4044), in the 3' untranslated region of the gene.
The murine Na(+)/myo-inositol cotransporter (SLC5A3) gene (Slc5a3) was cloned, the restriction sites mapped, and the coding region sequenced. Similar to other mammalian counterparts, including human, the gene has a single coding exon, with an open reading frame of 2.2 kb. The predicted protein of 718 amino acids is also highly conserved, compared to other mammalian homologs. Using fluorescence in situ hybridization, Slc5a3 was localized to the telomeric region of mouse chromosome 16, which is syntenic to human chromosome 21q22. An increased Slc5a3 copy number may explain the increased levels of myo-inositol in the brains of trisomy 16 mice and the increased rate of transport of myo-inositol into cultured neurons derived from trisomy 16 mice.
We have used data from chromosomally unbalanced offspring observed at birth, as well as data from sperm chromosome analysis, to study the meiotic segregation of reciprocal translocations. Using data from a total of 1,597 unbalanced children, we have observed an excess in maternal origin for all modes of imbalance. This excess is particularly marked for the 3:1 unbalanced mode, for which we have also observed a maternal age effect, indicating a close relationship with autosomal trisomies. In addition, a statistical analysis of data from 34 different published studies using sperm chromosome analysis has demonstrated that factors which, for reasons of viability, produce a predisposition for a particular mode of imbalance at birth also appear to favor meiotic production of this type of imbalance. Thus the production of unbalanced gametes of a particular type is influenced by the size of the imbalance.
A family of negative regulators of JAK signaling pathway referred to as suppressor of cytokines signaling (SOCS) or cytokine-inducible SH2 protein (CIS) has been recently identified. In order to find additional members of this family, we have used a consensus amino acid sequence contained in the well-conserved central SH2 domain to search DNA databases. We isolated cDNA coding for the human homologue of SOCS-5, referred to as CIS6. Northern blot analysis revealed CIS6 mRNA expression in various tissues such as heart, muscle, spleen, and thymus and in all myeloma cell lines examined. The gene was assigned to human chromosome bands 2p21 and 3p22 by in situ hybridization. CIS6 is structurally related to other members of the CIS family and therefore could act as a negative regulator of signal transduction.
Sex determination in mammals is controlled by the Y-linked SRY gene, which encodes a transcription factor with a DNA-binding motif of the HMG type. The only conserved region in this gene is the HMG-box, whose nucleotide sequence is currently available in a number of mammalian taxa. However, nothing is known about this gene in bats. Here, we report partial sequences of the SRY HMG-box from four microbat and four megabat species. We used the SRY HMG- box sequences from micro- and megabats to test the phylogenetic relationships between microbats, megabats, and primates. In maximum parsimony and maximum-likelihood trees, mega- and microbat branches start in the same internal node, which is consistent with a monophyletic origin of this mammalian group.
Copper does not exist in a free state within cells but is found consistently bound to metalloproteins. Specific metallochaperones escort copper to numerous targets within the cell, providing protection from the toxic effects of intracellular free copper. Many metallochaperones have been characterized in yeast, mouse, and human. To further characterize mouse metallochaperones, we cloned murine Ccsd from an adult mouse cDNA brain library, including both the coding region and the 5' and 3' UTRs. We obtained a 1,174-bp cDNA with an 825-bp open reading frame, translating a 274 amino acid protein that is 86.9% identical to human CCS. Using a mouse x hamster radiation hybrid panel, we mapped Ccsd to a proximal position on mouse chromosome 19. We mapped human CCS to 11q13 (homologous with mouse chromosome 19), utilizing a human x hamster radiation hybrid panel. The human and mouse metallochaperones are ubiquitously expressed in the major tissues of the body but seem to have different transcription products.