Genetic analysis of attractin homologs.

Attractin (ATRN) and Attractin-like 1 (ATRNL1) are highly similar type I transmembrane proteins. Atrn null mutant mice have a pleiotropic phenotype including dark fur, juvenile-onset spongiform neurodegeneration, hypomyelination, tremor, and reduced body weight and adiposity, implicating ATRN in numerous biological processes. Bioinformatic analysis indicated that Atrn and Atrnl1 arose from a common ancestral gene early in vertebrate evolution. To investigate the genetics of the ATRN system and explore potential redundancy between Atrn and Atrnl1, we generated and characterized Atrnl1 loss- and gain-of-function mutations in mice. Atrnl1 mutant mice were grossly normal with no alterations of pigmentation, central nervous system pathology or body weight. Atrn null mutant mice carrying a beta-actin promoter-driven Atrnl1 transgene had normal, agouti-banded hairs and significantly delayed onset of spongiform neurodegeneration, indicating that over-expression of ATRNL1 compensates for loss of ATRN. Thus, the two genes are redundant from the perspective of gain-of-function but not loss-of-function mutations.

Endometriosis: insights into its pathogenesis and treatment.

Clinical and basic science research in endometriosis has been severely hampered by the lack of accurate noninvasive diagnostic tools. The advent of powerful genomic and proteomic technology may help elucidate the etiology and pathophysiology of this complex and enigmatic disease and open new avenues for diagnosis and treatment. Genomic techniques have demonstrated that certain gene products are abnormally expressed in endometriotic tissues.

The use of precision glass syringes and a noncontact microsolenoid dispenser for the production of high-throughput low-density arrays.

The advantages of using nondisposable precision glass syringes in automated high-throughput microdispensers and a single-channel noncontact microsolenoid dispenser in creating highly uniform and reproducible protein, nucleic acid, and organic compound array filters, slides, and plates are described. Using a HydraPlus-One system, protein solutions of up to 100 mg/mL (in 100 nL) can be spotted onto slides and plates at a speed of 0.6 s per spot. Using the Hydra microdispenser and Tango liquid handling system, as little as 100 nL of polymerase chain reaction (PCR)-amplified human cancer-related genes, housekeeping genes, and protein solutions can be spotted onto nylon membranes, coated slides, or plates. Using these microdispensers equipped with syringes, up to 6144 uniform and reproducible spots per membrane and up to 1000 spots per slide, with a precision variation of less than 10%, were printed at a speed of as fast as 2.5 min per membrane.

DNA sequencing using rolling circle amplification and precision glass syringes in a high-throughput liquid handling system.

An automated high-throughput method that employs rolling circle amplification (RCA) to generate template for large-scale DNA sequencing has been developed using liquid handling systems equipped with precision glass syringes. A protocol was designed to perform the sequencing analysis from template preparation to thermal cycle sequencing within the same vessel, thus minimizing the amount of liquid handling and transfer. The amplified DNA was directly used for cycle sequencing with no need for any purification procedures. Total RCA reaction volumes as low as 500 nL generated sufficient templates for successful sequencing. Reducing the RCA total reaction volumes by a 40-fold factor, from a total of 20 microL to 500 nL, resulted in a significant reduction in cost, from $1.25/reaction to less than $0.04/reaction. Additionally, the volume of the sequencing reactions was reduced from a total of 20 to 10 microL, thus generating a further cost advantage. This high-throughput DNA sequencing protocol maximizes the speed and precision of processing while significantly reducing the cost of amplification.

The high-speed Hydra-Plus-One system for automated high-throughput protein crystallography.

An automated high-throughput dispenser has been developed for the setup of protein crystallization trials by vapor diffusion or Microbatch methods. The Hydra-Plus-One is composed of a Hydra-PP system equipped with a motorized XYZ-platform, 96 precision glass syringes and a single-channel microsolenoid dispenser, which transfers 100 nl-50 micro l of protein solution with an accuracy of > 90% at a speed of 60s per 96 wells. Up to 300 micro l of premixed cocktails can be aspirated with the 96-syringe-assembly and dispensed into reservoir and droplet wells within 60s. The Hydra-Plus-One combines high precision, reliability and speed in a cost-effective high-throughput system ideally suited for protein crystallization

Identification and preliminary characterization of mouse Adam33.

BACKGROUND: The metalloprotease-disintegrin family, or ADAM, proteins, are implicated in cell-cell interactions, cell fusion, and cell signaling, and are widely distributed among metazoan phyla. Orthologous relationships have been defined for a few ADAM proteins including ADAM10 (Kuzbanian), and ADAM17 (TACE), but evolutionary relationships are not clear for the majority of family members. Human ADAM33 refers to a testis cDNA clone that does not contain a complete open reading frame, but portions of the predicted protein are similar to Xenopus laevis ADAM13. RESULTS: In a 48 kb region of mouse DNA adjacent to the Attractin gene on mouse chromosome 2, we identified sequences very similar to human ADAM33. A full-length mouse cDNA was identified by a combination of gene prediction programs and RT-PCR, and the probable full-length human cDNA was identified by comparison to human genomic sequence in the homologous region on chromosome 20p13. Mouse ADAM33 is 44% identical to Xenopus laevis ADAM13, however a phylogenetic alignment and consideration of functional domains suggests that the two genes are not orthologous. Mouse Adam33 is widely expressed, most highly in the adult brain, heart, kidney, lung and testis. CONCLUSIONS: While mouse ADAM33 is similar to Xenopus ADAM13 in sequence, further examination of its embryonic expression pattern, catalytic activity and protein interactions will be required to assess the functional relationship between these two proteins. Adam33 is expressed in the mouse adult brain and could play a role in complex processes that require cell-cell communication.