The Wilderness Act and Fish Stocking: An Overview of Legislation, Judicial Interpretation, and Agency Implementation

Many high-elevation lakes in designated wilderness are stocked with native and nonnative fish by state fish and game agencies to provide recreational fishing opportunities. In several areas, this practice has become controversial with state wildlife managers who support historical recreational use of wilderness, federal wilderness managers who assert that stocking compromises some of the ecological and social values of wilderness, and different public groups that support one or the other position. Herein we examine this controversy from the perspective of the 1964 Wilderness Act, its judicial interpretation, the policies of the federal agencies, and formal agreements between federal and state agencies. Although some state stocking programs restore native fish populations, other programs may compromise some of the ecological and social values of wilderness areas. Further, although current federal regulations recognize state authority for fish stocking, judicial interpretation gives federal agencies the authority for direct involvement in decisions regarding fish stocking in wilderness. Where there are differences of opinion between state and federal managers, this judicial interpretation strongly points to the need for improved cooperation, communication, and coordination between state wildlife managers and federal wilderness managers to balance recreational fishing opportunities and other wildlife management activities with wilderness values. Received 28 March 2000; Accepted 16 August 2000.     

Genome Duplications and Accelerated Evolution of Hox Genes and Cluster Architecture in Teleost Fishes

The early origin of four vertebrate Hox gene clusters duringthe evolution of gnathostomes was likely caused by two consecutiveduplications of the entire genome and the subsequent loss ofindividual genes. The presumed conserved and important rolesof these genes in tetrapods during development led to the generalassumption that Hox cluster architecture had remained unchangedsince the last common ancestor of all jawed vertebrates. Butrecent data from teleost fishes reveals that this is not thecase. Here, we present an analysis of the evolution of vertebrateHox genes and clusters, with emphasis on the differences betweenthe Hox A clusters of fish (actinopterygian) and tetrapod (sarcopterygian)lineages. In contrast to the general conservation of genomicarchitecture and gene sequence observed in sarcopterygians,the evolutionary history of actinopterygian Hox clusters likelyincludes an additional (third) genome duplication that initiallyincreased the number of clusters from four to eight. We document,for the first time, higher rates of gene loss and gene sequenceevolution in the Hox genes of fishes compared to those of landvertebrates. These two observations might suggest that two differentmolecular evolutionary strategies exist in the two major vertebratelineages. Preliminary data from the African cichlid fish Oreochromisniloticus compared to those of the pufferfish and zebrafishreveal important differences in Hox cluster architecture amongfishes and, together with genetic mapping data from Medaka,indicate that the third genome duplication was not zebrafish-specific,but probably occurred early in the history of fishes. Each descendingfish lineage that has been characterized so far, distinctivelymodified its Hox cluster architecture through independent secondarylosses. This variation is related to the large body plan differencesobserved among fishes, such as the loss of entire sets of appendagesand ribs in some lineages.     

Interaction of the anterior fat body protein with the hexamerin receptor in the blowfly Calliphora vicina.

In late larvae of the blowfly, Calliphora vicina, arylphorin and LSP-2 proteins, which belong to the class of hexamerins, are selectively taken up by the fat body from the haemolymph. Hexamerin endocytosis is mediated by a specific membrane-bound receptor, the arylphorin-binding protein (ABP). Using the two-hybrid technique, we found that the anterior fat body protein (AFP) interacts with the hexamerin receptor. AFP, a homologue of the mammalian calcium-binding liver protein regucalcin (senescence marker protein-30), exhibits a strong binding affinity for a naturally occurring C-terminal cleavage fragment of the hexamerin receptor precursor (the P30 peptide) and other receptor cleavage products that contain P30. Expression of AFP mRNA and protein is restricted to the anterior part of the fat body tissue and to haemocytes in last-instar larvae. AFP mRNA occurs in all postembryonic developmental stages. Our results suggest that AFP plays a role in the regulation of hexamerin uptake by fat body cells along the anterior-posterior axis.     

Depolarisation induces rapid and transient formation of intracellular sphingosine-1-phosphate.

Formation of sphingosine-1-phosphate (SPP) by sphingosine kinase serves as a signalling pathway for various membrane receptors. Here, we show that membrane depolarisation is another mechanism by which this pathway can be activated. Formation of [(3)H]SPP as well as levels of endogenous SPP were rapidly and transiently increased in PC12 pheochromocytoma cells depolarised with high KCl. Time course and maximum were similar to those induced by bradykinin. Depolarisation-induced SPP production was also observed in RINm5F insulinoma cells, dependent on extracellular Ca(2+) and fully suppressed by verapamil, thus apparently caused by Ca(2+) influx via voltage-gated Ca(2+) channels. Studies with sphingosine kinase inhibitors and overexpression of sphingosine kinase revealed a partial contribution of this pathway to depolarisation-induced noradrenaline release and Ca(2+) increase.     

Phytanic acid and docosahexaenoic acid increase the metabolism of all-trans-retinoic acid and CYP26 gene expression in intestinal cells.

Retinoids are essential for growth and cell differentiation of epithelial tissues. The effects of the food compounds phytol, the phytol metabolite phytanic acid, and the fatty acid docosahexaenoic acid (DHA) on the retinoid signaling pathway in intestinal cells were studied. Phytol inhibited the formation of all-trans-retinoic acid (RA) from dietary retinol in intestinal cells. Phytanic acid, a known retinoic X receptor (RXRalpha) and peroxisome proliferator activating receptor (PPARalpha) activator, also activated PPARdelta, and to a lesser degree PPARgamma, in a transactivation assay. Phytanic acid had no effect on intestinal RA hydroxylase CYP26 (also named P450RAI) gene expression and metabolism of all-trans-RA in intestinal Caco-2 cells. However, in combination with retinoic acid receptor (RAR)-ligands (all-trans-RA or synthetic Am580) phytanic acid enhanced the induction of CYP26 and RA-metabolism in comparison to treatments with all-trans-RA or Am580 alone. Also treatment with DHA did not affect CYP26 gene expression and RA-metabolism but cotreatment of the cells with DHA and all-trans-RA or Am580 enhanced the induction of CYP26, in comparison to the induction caused by all-trans-RA or Am580 alone. This study indicates that food compounds such as phytanic acid and DHA that are RXR-agonists and have an impact on intestinal CYP26 gene expression and metabolism of all-trans-RA in intestinal cells.     

Inhibition of photosynthesis by Colletotrichum lindemuthianum in bean leaves determined by chlorophyll fluorescence imaging

Infection of bean leaves by Colletotrichum lundemuthianum causes vein necrosis and subsequent localized wilting of the blade. The effect of infection on photosynthesis was investigated by imaging leaf chlorophyll fluorescence as a means of mapping stomatal and metabolic inhibition of photosynthesis. During infection, CO₂ assimilation (An), stomatal conductance to water vapour, and photosynthetic electron transport rate (J_t) decreased, whereas dark respiration increased. An decreased more than was expected from the reduction in green leaf area, showing that photosynthesis was inhibited in apparently healthy areas. Under subsaturating irradiance, images of J_t in air showed that photosynthesis decreased gradually, with this effect shifting from green to necrotic areas. Sudden increase in CO₂ concentration to 0·74% in the atmosphere around the leaf only partially reversed this inhibition, showing that both stomatal and metabolic inhibition occurred. Under limiting irradiance, decreases in J_t and in maximal J_t during high CO₂ exposure as leaf damage severity increased suggested that metabolic inhibition was mediated through an inhibition of Ribulose 1·5‐bisphosphate (RuBP) regeneration. Finally, the importance of our data in terms of assessing the loss of photosynthetic yield from visible symptoms – as is currently performed in epidemiology – is discussed.     

The cell polarity protein ASIP/PAR-3 directly associates with junctional adhesion molecule (JAM).

The establishment and maintenance of cellular polarity are critical for the development of multicellular organisms. PAR (partitioning-defective) proteins were identified in Caenorhabditis elegans as determinants of asymmetric cell division and polarized cell growth. Recently, vertebrate orthologues of two of these proteins, ASIP/PAR-3 and PAR-6, were found to form a signalling complex with the small GTPases Cdc42/Rac1 and with atypical protein kinase C (PKC). Here we show that ASIP/PAR-3 associates with the tight-junction-associated protein junctional adhesion molecule (JAM) in vitro and in vivo. No binding was observed with claudin-1, -4 or -5. In fibroblasts and CHO cells overexpressing JAM, endogenous ASIP is recruited to JAM at sites of cell-cell contact. Over expression of truncated JAM lacking the extracellular part disrupts ASIP/PAR-3 localization at intercellular junctions and delays ASIP/PAR-3 recruitment to newly formed cell junctions. During junction formation, JAM appears early in primordial forms of junctions. Our data suggest that the ASIP/PAR-3-aPKC complex is tethered to tight junctions via its association with JAM, indicating a potential role for JAM in the generation of cell polarity in epithelial cells.     

Study of pyoverdine type and production by Pseudomonas aeruginosa isolated from cystic fibrosis patients: prevalence of type II pyoverdine isolates and accumulation of pyoverdine-negative mutations

The lungs of cystic fibrosis patients are frequently colonized by Pseudomonas aeruginosa, which produces high-affinity fluorescent peptidic siderophores, pyoverdines. Three pyoverdines which differ in their peptide chain and are easily differentiated by isoelectric focusing exist, only one being produced by a given strain. P. aeruginosa isolates from cystic fibrosis patients of a German hospital were analyzed by sequential, pulse-field gel electrophoresis (PFGE) and for pyoverdine production and type. Only producers of type I and type II pyoverdine were found. There was a perfect correlation between the type of pyoverdine produced and the clonality determined by PFGE. PFGE clone C, the most prevalent among cystic fibrosis patients, and found in an aquatic environment, produced type II pyoverdine. Pyoverdine-negative mutants seemed to increase as a function of the lung colonization time, but retained the capacity to take up pyoverdines. Most isolates that took up type II pyoverdine were also able to utilize type I pyoverdine as judged by growth stimulation experiments. No correlation was observed between the loss of pyoverdine production and mucoidy.     

Microsatellites in the genus Xiphophorus,developed in Xiphophorus montezumae

Species of the genus Xiphophorus (swordtails and platies) are of great interest for the study of evolution of sexually selected traits like the sword, which is an elongation of ventral fin rays of the male caudal fin, that has evolved in several species within this genus. The detection of 10 microsatellites within the genus Xiphophorus will enable studies about the correlation of this trait with sexual reproductive success of males possessing swords of different lengths. These microsatellites will also be useful in determining population structure and enable paternity analysis in these species, where sperm storage is widespread.