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The basis of fructophily in the yeast Zygosaccharomyces bailii has been shown to reside in the performance of transport systems for hexoses. In this study, a gene encoding a fructose-specific transporter was characterized. The strategy involved the functional complementation of a Saccharomyces cerevisiae strain that does not take up hexoses (hxt-null strain). This strain was transformed with a genomic library of Z. bailii. One transformant capable of growing on fructose, but not on glucose, was obtained. This transformant did not transport D-[14 C]glucose, and the kinetic parameters for D-[ 14 C]fructose were V max =3?3 mmol h "1 g "1 and K m =80?4 mM. As in the original strain of Z. bailii, fructose uptake was not inhibited by the presence of other hexoses or uranyl. The plasmid responsible for the observed phenotype was found to carry an ORF encoding a 616 amino acid protein with the characteristics of a membrane transporter, which was designated FFZ1 (fructose facilitator Zygosaccharomyces). The impairment in function observed in an S. cerevisiae transformant expressing a truncated Ffz1 protein lacking 67 amino acids at the C-terminus suggests an important role for this terminal part in the proper structure of the transporter.

A standard development embryological series is the primary basis to organize information of any embryological study and is also used to determine the age of eggs and embryos in field conditions. In this article, we calibrate developmental series of the broad-snouted caiman, Caiman latirostris, against an established series for Alligator mississippiensis. Morphometric measures and extend of the opaque-shell banding were also related to embryo age. In earlier stages, external morphological features alone can account for embryo age, but we suggest that morphometric measurements should be introduced later in the development. Unlike morphologic and morphometric attributes, the opaque patch was not a useful age predictor. As expected, a close correlation between embryonic development of C. latirostris and A. mississippiensis was observed.

Biogenic structures, herein interpreted as coprolites, were recorded in the ?upper Paleocene–Eocene Las Flores Formation, southeast Argentina. The coprolite origin is supported by several features, such as recurrent extrusive external morphology, longitudinal wrinkles, flattening of the ventral side, concentric and radial cracks, cryptocrystalline groundmass, and a phosphatic composition. A detailed comparative study with modern fecal masses, based on morphology, surface texture, micromorphology, mineralogical and chemical composition, suggest a crocodylian as the most probable producer, an interpretation also supported by the Patagonian paleontological record. This discovery, the first record on coprolites from Central Patagonia, provides new paleoenvironmental and paleoecological information for the studied successions.

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