A novel (11)C-labeled thymidine analog, [(11)C]AZT, for tumor imaging by positron emission tomography.

Background: Nucleoside analogs labeled with positrons, such as (11)C and (18)F, are considered valuable in visualizing the proliferative activity of tumor cells in vivo using positron emission tomography (PET). We recently developed the (11)C-labeled thymidine analogs [(11)C]zidovudine ([(11)C]AZT) and [(11)C]stavudine ([(11)C]d4T) via the Pd(0)-Cu(I) co-mediated rapid C-C coupling reaction. In this study, to examine whether [(11)C]AZT and [(11)C]d4T might be useful for visualization of tumors in vivo, we performed PET imaging, tissue distribution studies, and metabolite analysis in tumor-bearing mice.

Comparative transcriptome analysis between planarian Dugesia japonica and other platyhelminth species.

Background: Planarians are considered to be among the extant animals close to one of the earliest groups of organisms that acquired a central nervous system (CNS) during evolution. Planarians have a bilobed brain with nine lateral branches from which a variety of external signals are projected into different portions of the main lobes. Various interneurons process different signals to regulate behavior and learning/memory.

Promotion of spermatogonial proliferation by neuregulin 1 in newt (Cynops pyrrhogaster) testis.

We have previously shown that mammalian follicle-stimulating hormone (FSH) promotes the proliferation of spermatogonia and their differentiation into primary spermatocytes in organ culture of newt testis. In the current study, we performed microarray analysis to isolate local factors secreted from somatic cells upon FSH treatment and acting on the germ cells. We identified neuregulin 1 (NRG1) as a novel FSH-upregulated clone homologous to mouse NRG1 known to control cell proliferation, differentiation and survival in various tissues.

Progressive activation of Delta-Notch signaling from around the blastopore is required to set up a functional caudal lobe in the spider Achaearanea tepidariorum.

In the development of most arthropods, the caudal region of the elongating germ band (the growth zone) sequentially produces new segments. Previous work with the spider Cupiennius salei suggested involvement of Delta-Notch signaling in segmentation. Here, we report that, in the spider Achaearanea tepidariorum, the same signaling pathway exerts a different function in the presumptive caudal region before initiation of segmentation.

The Dugesia ryukyuensis database as a molecular resource for studying switching of the reproductive system.

The planarian Dugesia ryukyuensis reproduces both asexually and sexually, and can switch from one mode of reproduction to the other. We recently developed a method for experimentally switching reproduction of the planarian from the asexual to the sexual mode. We constructed a cDNA library from sexualized D.

Highly conserved linkage homology between birds and turtles: bird and turtle chromosomes are precise counterparts of each other.

The karyotypes of birds, turtles and snakes are characterized by two distinct chromosomal components, macrochromosomes and microchromosomes. This close karyological relationship between birds and reptiles has long been a topic of speculation among cytogeneticists and evolutionary biologists; however, there is scarcely any evidence for orthology at the molecular level. To define the conserved chromosome synteny among humans, chickens and reptiles and the process of genome evolution in the amniotes, we constructed comparative cytogenetic maps of the Chinese soft-shelled turtle (Pelodiscus sinensis) and the Japanese four-striped rat snake (Elaphe quadrivirgata) using cDNA clones of reptile functional genes.