Chromosomal polymorphism in the phyllostomatid bat,Mimon crenulatum (Geoffroy)

Resumen Se discribe el polimorfismo cromosomal en el murcielagoMimon crenulatum desde localidades en Trinidad, Colombia, y el Perù. Se hallaron tres tipos morfológicos para cromosomas considerado a representar el quinto par de autosomas en ejemplares de cada region geogràfica donde hemos estudiado la especia. Los tres tipos morfológicos de los cromosomas de quinto par evidentemente originado por medio de inversiones pericentricas son metacéntrico, subtelocéntrico, y acrocéntrico.     

The preparation of metabolically active suspensions of mouse liver cells

Zusammenfassung Einfache und schnelle Methode zur Isolierung freier Mäuse-Leberzellen. Freie Hepatozyten (bis 50% des Gewebes) zeigen so aktiven Stoffwechsel.

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This work was supported by grant No. CA05172 of the National Cancer Institute, U.S.P.H.S.     

The identification of εN-(β-aspartyl)-l-lysine in native and heated keratin

Zusammenfassung Chromatographisch (Ionenaustausch, Papierchromatographie, Dünnschichtchromatographie und Hochspannungselektrophorese) wird nach enzymatischer Hydrolyse von nativem und denaturiertem Wolle-Keratin (-Glutamyl)-lysin und (-Aspartyl)-lysin identifiziert und so die in Proteinen postulierte anomale Peptidverknüpfung nachgewiesen.

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Acknowledgments. The authors would like to thank Dr.B. Milligan for a gift of N(-aspartyl) lysine. They would also like to thank the Wool Industries Research Association for permission to publish this work and for a Post-Doctoral Fellowship to one of them (M.S.O.).     

The uptake and rate of clearance of125I γG globulin in lampreys (Lampetra fluviatilis)

Zusammenfassung Lampreten wurden mit menschlichem¹²⁵I-markierten,-Globulin injiziert, und die Aufnahme und Abgabe des Antigens wurden untersucht. Der Ort der Aufnahme des Antigens wurde autoradiographisch bestimmt.     

A proteomic view of the Plasmodium falciparum life cycle

The completion of the Plasmodium falciparum clone 3D7 genome provides a basis on which to conduct comparative proteomics studies of this human pathogen. Here, we applied a high-throughput proteomics approach to identify new potential drug and vaccine targets and to better understand the biology of this complex protozoan parasite. We characterized four stages of the parasite life cycle (sporozoites, merozoites, trophozoites and gametocytes) by multidimensional protein identification technology. Functional profiling of over 2,400 proteins agreed with the physiology of each stage. Unexpectedly, the antigenically variant proteins of var and rif genes, defined as molecules on the surface of infected erythrocytes, were also largely expressed in sporozoites. The detection of chromosomal clusters encoding co-expressed proteins suggested a potential mechanism for controlling gene expression.     

Genome sequence of the human malaria parasite Plasmodium falciparum

The parasite Plasmodium falciparum is responsible for hundreds of millions of cases of malaria, and kills more than one million African children annually. Here we report an analysis of the genome sequence of P. falciparum clone 3D7. The 23-megabase nuclear genome consists of 14 chromosomes, encodes about 5,300 genes, and is the most (A + T)-rich genome sequenced to date. Genes involved in antigenic variation are concentrated in the subtelomeric regions of the chromosomes. Compared to the genomes of free-living eukaryotic microbes, the genome of this intracellular parasite encodes fewer enzymes and transporters, but a large proportion of genes are devoted to immune evasion and host-parasite interactions. Many nuclear-encoded proteins are targeted to the apicoplast, an organelle involved in fatty-acid and isoprenoid metabolism. The genome sequence provides the foundation for future studies of this organism, and is being exploited in the search for new drugs and vaccines to fight malaria.     

Late DNA replication in the sex chromosomes ofDidelphis virginiana

Zusammenfassung Autoradiographisch wurde die späte DNS-Synthese derX- undY-Chromosomen vonDidelphis virginiana (Virginia Opossum) in Knochenmarkzellen untersucht. Die weiblichen Tiere zeigen typische späte Reduplikationsmuster in einemX, die männlichen das späte Reduplikationsmuster inX undY und inY allein.

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This study was supported in part by research grant No. AM-02504 and training grant No. Tl-AM-5277, National Institutes of Health. Dr.Reiss was a predoctoral trainee, National Institute of Arthritis and Metabolic Diseases, U.S. Public Health Service.