a lilliputian cooperator

TRENDS in Genetics Vol.17 No.6 June 2001316 News&Comment

http://tig.trends.com 0168–9525/01/$ – see front matter © 2001 Elsevier Science Ltd. All rights reserved.

In Brief

Stem cells from fatThe shortage of stem cells could now beavoided by transforming fat cells harvestedby liposuction into stem cells. Acollaborative effort between scientists atUCLA and the University of Pittsburghshows that the fat cells can be transformedinto muscle, bone and cartilage cells,previously possible only by using stem cellsderived from bone marrow, brain or fetaltissue. The use of fetal tissue for stem-cellresearch has already initiated a heateddebate on its ethical implications. Fat cellswould provide a plentiful and economicalalternative that could be used for replacingdead or injured tissue at various sites in thebody. [Zuk, P.A. et al. (2001) Tissue Eng.7, 211–228] AP

The Janus Serum Bank:forward thinking allowsretrospective analysisNamed after the two-faced Roman god, theJanus Serum Bank symbolizes thepossibility of looking for the causes ofdisease both retrospectively andprospectively. This vital biomedicalresource was highlighted in a recent JAMApublication that linked Chlamydiatrachomatis serotype and cervicalsquamous cell carcinoma [Anttila, T. et al.(2001) JAMA 285, 47–51]. Under the control of the Norwegian Cancer Society,the bank consists of 600 000 serumsamples obtained from 300 000Norwegians during medical examinationsand when donating blood. Mostindividuals have a time-course of sera inthe bank (up to 12 samples). The Janusproject currently cooperates with groupsfrom Scandinavia, the UK, Germany, theUS and Australia. Researchers can obtainbetween 500 to 3000 samples for projects;each sample from a patient comes withthree healthy age- and sex-matchedcontrols. The samples are coded foranonymity and the experiments are done‘blind’ – which samples are from controlsand which from patients are only revealedonce the results are in. Full details aboutthe project and how to apply for samplesare given on the Norweigan CancerSocieties website(http://www.kreft.no/forhelsepersonell/janusserumbank/english/). SG

A missense mutationassociated with schizophrenia

Schizophrenia is a complex heterogeneoussyndrome, involving both environmentaland genetic factors. Although a familialsubtype of catatonic schizophrenia istransmitted in an autosomal dominantmanner, the gene responsible has eludedscientists. Recently, however, a Germangroup led by K.P. Lesch spotted a missensemutation that co-segregates with thefamilial catatonia.

Studying the human chromosome 22 in a large pedigree, the researchers usedgenetic linkage analysis followed bypositional cloning to find the mutation. The new gene, named WKL1, is expressedonly in the nervous system, not in otherperipheral areas. The protein encoded bythe WKL1 gene is similar to ion channels,and structural analysis shows that theprotein conformation changes followingmutation – indicating a molecularmechanism for the pathogenesis of thisdisease. [Meyer, J. et al. (2001) Mol.Psychiatry 6, 302–306] MP

A Lilliputian cooperatorOrgans and organisms grow until theyreach their appointed size – and then theystop. But what tells them to stop? Why areour arms shorter than our legs, for instance?Ernst Hafen and colleagues at the Universityof Zurich are seeking regulators that linkgrowth and differentiation. They identifiedthe Lilliputian gene (lilli) in Drosophila thatcould be at the convergence of patterningmechanisms and pathways that regulate

growth during development. In thedeveloping Drosophila eye, the Rassignaling pathway controls growth, survivaland differentiation by different thresholds of MAP-kinase activity. Lilli cooperates with the Ras/MAP-kinase pathway in cell-fate specification in the developing eye. However, loss of Lilli also leads to areduction of cell and organ size. The geneencodes a nuclear protein related to theAF4/FMR2 family. In humans, mutationsaffecting these genes are associated withdiseases such as mental retardation andacute lymphoblastic leukemia. [Wittwer, F.et al. (2001) Development 128, 791–800;Halfar, K. et al. (2001) Development 128,1687–1696]. PL

Mining MedlineIt’s every child’s dream – a machine thatdoes your homework for you. EdwardMarcotte and colleagues at the University ofTexas and UCLA have programmed theircomputer to read the 12 million Medlineabstracts and find the ones they’re lookingfor. Their approach scores the abstracts onthe comparative overuse of certain‘discriminating words’. The group’sresearch focuses on building up networks of interacting proteins in yeast. Given thechoice between doing thousands ofexperiments and mining the availableinformation, they preferred the latter.Marcotte says, ‘It’s the lazy man’s approachto finding protein interactions.’ Despite hismodesty, the program has had lots ofinterest from other scientists keen to use itin their research. It has also allowed a rapidexpansion of the Database of InteractingProteins, curated by collaborator loannisXenarios, and will speed up theconstruction of other databases, such asSwissProt, where evaluation of theliterature is normally the rate-limiting step. [Marcotte, E.M. et al. (2001) Bioinformatics17, 359–363] HD

PartsList: a structuralgenomics resourceA valuable new resource called PartsListwas recently announced. Based on anessential protein structure, the protein fold,the idea behind the project is to use a ‘ranking’ comparison system. Theapproximately 420 known folds can be ranked on the basis of more than