Determining the effects of species,environmental conditions and tracking method on the detection efficiency of portable PIT telemetry

The efficiency of portable passive integrated transponder (PIT) telemetry at detecting five fish species in a small river was evaluated under different environmental and tracking conditions. Significant differences between species were apparent, with detection efficiency varying between 0·7% (Leuciscus leuciscus) and 43·1% (Salmo trutta). Conditions of reduced flow and tracking in a downstream direction significantly increased detection efficiency for salmonids, while time of day had no significant effect for any species.     

Phosphotransferase-mediated regulation of carbohydrate utilization in Escherichia coli K12: location of the gsr (tgs) and iex (crr) genes by specialized transduction

A lysogen of Escherichia coli K12 with lambda cI857 S7 xis6 nin5 b515 b519 integrated into ptsI was induced and the lysates plated on a Pel- host [on which lambda strains with less than the wild-type amount of DNA form plaques at low frequency (Cameron et al., 1977)]. All of the 40 plaques examined contained phage able to transduce at least two of the genes known from bacteriophage P1 transduction experiments to be closely linked to ptsI. Assuming that each specialized transducing phage arose by a single illegitimate recombination event, the distribution of phage types showed that the gene order is cysA gsr ptsI (ptsH, iex) cysZ lig; both gsr+ and iex+ were dominant. Analysis of restriction endonuclease digests of the transducing phage confirmed that no unexpected DNA rearrangements had taken place and allowed the construction of a map of the sites of action of the restriction endonucleases EcoRI, HindIII, BamI and Kpn for over 20 kilobases of E. coli DNA. In an Appendix, we show cysA and cysZ mutants to be deficient in sulphate assimilation.     

Selected contribution: Variation and heritability for the adaptational response to exercise in genetically heterogeneous rats.

Adaptational response to aerobic exercise was artificially selected for across one generation in a founder population of 20 female and 20 male genetically heterogeneous rats (N:NIH). Selection for low and high response was based on the change in treadmill running capacity, assessed by meters (m) run to exhaustion before and after 24 days of modest treadmill running. The training response of the founder population averaged +222 m, with wide variation from a negative gain (-) of -110 m to a positive gain (+) of +430 m. Six pairs of the lowest (+13 m) and highest (+327 m) responders were mated. Mean response to training of the low-line (+242 m) offspring did not differ from the founder. The high-selected line gained 383 m from training, +161 m above the founder population. Narrow sense heritability estimated from regression of offspring on midparent values for response to training was 0.43 (P < 0.007). One generation of selection resulted in a 58% divide between the low and high lines. Selectively bred models of both intrinsic (untrained) and adaptation response can be useful in resolving the genetic basis of variation in aerobic capacity.