Deletion and duplication of DNA sequences is associated with the embryonic lethal phenotype of the t9 complementation group of the mouse t complex.

We have analyzed the genomic structure of three mouse t haplotypes of the t9 complementation group. Each of these t haplotypes, tw18, t4, and tks1, is known to have resulted from a rare recombination event between a complete t haplotype and a wild-type chromosome. Using molecular probes that identify sequences in the distal portion of the t complex, we have shown that each of these t haplotypes contains a similar (perhaps identical) deletion of one group of t complex sequences, and duplication of another group. These data suggest that the recombination events that produced these three t haplotypes involved similar unequal crossovers within the distal inversion. The deletion and duplication of genetic material associated with all members of the t9 complementation group tested provides a molecular explanation for the recessive lethal mutation associated with these t haplotypes

Pharmacologic modulation of experimentally induced allergic asthma

Allergic asthma is the most frequent disease of the respiratory tract. The aim of the current experimental and clinical studies was to find new sources of drugs able to control asthmatic inflammation and airway hyperresponsiveness. Our experimental studies were focused on efficiency evaluation of substances able to influence activities of ion channels, phosphodiesterase (PDE) isoforms, substances from the group of polyphenols and NO metabolism modulators during experimentally induced allergic asthma

Genomic organization, sequence analysis and expression of all five genes encoding the small subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase from tomato

We have cloned and sequenced all five members of the gene family for the small subunit (rbcS) of ribulose-1,5-bisphosphate carboxylase/oxygenase from tomato, Lycopersicon esculentum cv. VFNT LA 1221 cherry line. Two of the five genes, designated Rbcs-1 and Rbcs-2 , are present as single genes at individual loci. Three genes, designated Rbcs-3A, Rbcs-3B and Rbcs-3C , are organized in a tandem array within 10 kb at a third independent locus. The Rbcs-2 gene contains three introns; all the other members of the tomato gene family contain two introns. The coding sequence of Rbcs-1 differs by 14.0% from that of Rbcs-2 and by 13.3% from that of Rbcs-3 genes. Rbcs-2 shows 10.4% divergence from Rbcs-3 . The exon and intron sequences of Rbcs-3A are identical to those of Rbcs-3C , and differ by 1.9% from those of Rbcs-3B . Nucleotide sequence analysis suggests that the five rbcS genes encode four different precursors, and three different mature polypeptides. S 1 nuclease mapping of the 5′ end of rbcS mRNAs revealed that the mRNA leader sequences vary in length from 8 to 75 nucleotides. Northern analysis using gene-specific oligonucleotide probes from the 3′ non-coding region of each gene reveals a four to five-fold difference among the five genes in maximal steady-state mRNA levels in leaves.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47566/1/438_2004_Article_BF00329650.pd

A subcloning strategy for DNA sequence analysis.

We describe here a new strategy of fragment preparation for sequencing procedures using endlabelled DNA fragments as substrates (2,3) which is directly applicable to DNA fragments cloned into the Pst I site of pBR322, or in modified form, to inserts into the BamH I or Sal I site of the same plasmid. Ordered sets of subclones of predetermined overlap are are generated. These can be sequenced directly without further strand- or fragment separation steps