Advancing the use of morphometric data for estimating and managing common bottlenose dolphin (Tursiops truncatus) mass

Knowledge of a dolphin's body mass is central to establishing body condition, comparing across individuals, and designing successful management programs. In the present study, sex‐specific prediction equations for estimating body mass were generated from morphometrics (i.e., length and girth) and ages of bottlenose dolphins residing under professionally managed care. Measurements of wild dolphins in Sarasota Bay, Florida, were used to generate sex‐specific body mass reference ranges. Gompertz growth models were fitted to length measurements and age to compare growth across populations. From the regression analyses, the body mass of managed females (R² = 0.937), managed males (R² = 0.953), wild females (R² = 0.979), and wild males (R² = 0.972) were predicted with high levels of accuracy. Managed adults had similar or longer asymptotic lengths compared to their wild conspecifics. To apply this information, ZooMorphTrak, a mobile software application, was developed to provide a new resource for management. The “Approximate” feature was designed to approximate body mass based on user inputs of individual morphometrics. The “Management” feature compared a managed dolphin's known body mass with respect to body mass reference ranges generated from wild dolphins. ZooMorphTrak, developed by the Chicago Zoological Society, is available for download at http://itunes.apple.com .     

TIE-2/VEGF-R2 SAR and in vitro activity of C3-acyl dihydroindazolo[5,4-a]pyrrolo[3,4-c]carbazole analogs

Orally bioavailable, dual inhibitors of TIE-2/VEGF-R2 were identified by elaborating the C3/N13 SAR around a fused pyrrolodihydroindazolocarbazole scaffold. Analogs bearing a C3-thiophencarbonyl group were evaluated in enzymatic and cellular biochemical assays; two orally bioavailable analogs were further profiled in functional assays and found to inhibit microvessel growth in rat aortic explant cultures and inhibit Ang-1-stimulated chemotaxis of HUVECs.     

Natural Variation in Maize Aphid Resistance Is Associated with 2,4-Dihydroxy-7-Methoxy-1,4-Benzoxazin-3-One Glucoside Methyltransferase Activity

Plants differ greatly in their susceptibility to insect herbivory, suggesting both local adaptation and resistance tradeoffs. We used maize (Zea mays) recombinant inbred lines to map a quantitative trait locus (QTL) for the maize leaf aphid (Rhopalosiphum maidis) susceptibility to maize Chromosome 1. Phytochemical analysis revealed that the same locus was also associated with high levels of 2-hydroxy-4,7-dimethoxy-1,4-benzoxazin-3-one glucoside (HDMBOA-Glc) and low levels of 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one glucoside (DIMBOA-Glc). In vitro enzyme assays with candidate genes from the region of the QTL identified three O-methyltransferases (Bx10a-c) that convert DIMBOA-Glc to HDMBOA-Glc. Variation in HDMBOA-Glc production was attributed to a natural CACTA family transposon insertion that inactivates Bx10c in maize lines with low HDMBOA-Glc accumulation. When tested with a population of 26 diverse maize inbred lines, R. maidis produced more progeny on those with high HDMBOA-Glc and low DIMBOA-Glc. Although HDMBOA-Glc was more toxic to R. maidis than DIMBOA-Glc in vitro, BX10c activity and the resulting decline of DIMBOA-Glc upon methylation to HDMBOA-Glc were associated with reduced callose deposition as an aphid defense response in vivo. Thus, a natural transposon insertion appears to mediate an ecologically relevant trade-off between the direct toxicity and defense-inducing properties of maize benzoxazinoids.     

Allotetraploids in Patagonia with Affinities to Western North American Diploids: Did Dispersal or Genome Doubling Occur First?

Amphitropical disjunct distributions between western North America and western South America have intrigued botanists for over a century. Here, specific examples of migration and speciation are investigated using herbaceous species from the phlox family (Polemoniaceae) as a model for considering the timing of dispersal relative to speciation. Comparative DNA sequencing reveals that, in Collomia and Navarretia, the South American species are allopolyploids, suggesting either two dispersals prior to the allopolyploidization event for each species with subsequent extirpation of the diploid progenitors from South America, or allopolyploid formation prior to dispersal with extirpation of these polyploids from North America. Divergence time estimates support a Pliestocene dispersal hypothesis and sequence data indicate that, at least in Collomia, hybridization of the diploid progenitors occurred in South America.     

Quantifying torpor in small mammals non-invasively using infrared thermocouples

Measurements of torpor use are pivotal for many research areas concerning the thermal biology of endotherms. Here, I used infrared thermocouples to non-invasively examine torpor patterns in the small marsupial fat-tailed dunnart (Sminthopsis crassicaudata). Sensors were installed inside the nesting chambers to continuously monitor fur temperature in undisturbed animals. Firstly, to verify the measurements, fur temperature was monitored simultaneously with body temperature using internal radio transmitters (n=6). Secondly, I conducted a food restriction study to demonstrate the reliability of the method within a physiological experiment (n=8). Based on the correspondence of simultaneously measured fur and body temperature during torpor bouts, I was able to confirm that infrared thermocouples provide reliable temporal information on torpor patterns. Furthermore, torpor use was successfully monitored over a 20-day food restriction study. The method can easily be adapted to suit other small mammal or bird species and presents a useful, inexpensive approach for examining torpor patterns remotely and non-invasively in the laboratory.     

Localisation and measurement of VIP in the genitourinary system of man and animals

VIP is present in the genitourinary system of man and animals. In man the highest concentrations are found in the penis, the uterus and vagina and in the urinary bladder. VIP nerves heavily innervate the erectile tissue of the male external genitalia, the uterine smooth muscle and blood vessels, the seromucous glands of the cervix, and the lamina propria and vaginal epithelium. In the urinary bladder, VIP nerves are located beneath the transitional epithelium, in the lamina propria and in the smooth muscle. Other areas well innervated by VIP nerves include the prostate, seminal vesicles and vasa deferentia. Chemical (phenol- and 6-OHDA) or surgical (hypogastric or pelvic nerve section) extrinsic denervation fail to deplete the genitourinary system of its VIP content, supporting the view that VIP-containing nerves originate from local ganglion cells. Indeed, neuronal cell bodies containing VIP are seen in the paracervical ganglia of the female genitalia, the para- or intramural bladder ganglia and scattered through the base of the cavernosum body, the neck of the bladder and the prostate. The finding of elevated levels of VIP in the local circulation after induced penile erection in man and mammals and the ability of VIP to relax the detrusor muscle of the bladder suggests that the peptide may be involved in penile erection and bladder relaxation, as does the marked VIP depletion in the penis or bladder in patients suffering from diabetic impotence or bladder instability.     

Measurement of steroid sex hormones in serum: a comparison of radioimmunoassay and mass spectrometry

Concern has been raised about the adequacy of radioimmunoassays to measure steroid sex hormones in population studies. We compared steroid sex hormone measurements in serum by radioimmunoassay with mass spectrometry. Four male and four female serum pools with known relative concentrations of steroid sex hormones were measured multiple times by both methods. Because measurements are expected to increase linearly with concentration for each sex, we examined whether the linear regressions of hormone measurements on concentration were the same for radioimmunoassay and mass spectrometry. Estradiol, estrone, androstenedione, testosterone, and dehydroepiandrosterone sulfate were measured in female pools; testosterone, dihydrotestosterone, androstenedione, and dehydroepiandrosterone sulfate were measured in male pools. Regression slopes for radioimmunoassay and mass spectrometry measurements were comparable for all hormones except androstenedione, which had a steeper slope when measured by mass spectrometry (P < or = 0.02). Intercepts for radioimmunoassay and mass spectrometry were similar and close to zero for estradiol, androstenedione, dehydroepiandrosterone sulfate, and in male samples, testosterone. For testosterone in female samples, estrone, and dihydrotestosterone, radioimmunoassay and mass spectrometry intercepts differed significantly. Standard deviations of individual measurements by radioimmunoassay and mass spectrometry differed by hormone and serum concentration; neither method consistently measured hormone concentrations with less variability. Our findings suggest that although absolute concentrations may differ for some hormones, radioimmunoassay and mass spectrometry can yield similar estimates of between subject differences in serum concentrations of most steroid sex hormones commonly measured in population studies. Relative power of studies using radioimmunoassay and mass spectrometry will depend on the hormones measured and their serum concentrations.     

Role of hindbrain in inner ear morphogenesis: analysis of Noggin knockout mice

Signaling from rhombomeres 5 and 6 of the hindbrain is thought to be important for inner ear patterning. In Noggin −/− embryos, the gross anatomy of the inner ear is distorted and malformed, with cochlear duct outgrowth and coiling most affected. We attributed these defects to a caudal shift of the rhombomeres caused by the shortened body axis and the kink in the neural tube. To test the hypothesis that a caudal shift of the rhombomeres affects inner ear development, we surgically generated chicken embryos in which rhombomeres 5 and 6 were similarly shifted relative to the position of the inner ears, as in Noggin mutants. All chicken embryos with shifted rhombomeres showed defects in cochlear duct formation indicating that signaling from rhombomeres 5 and 6 is important for cochlear duct patterning in both chicken and mice. In addition, the size of the otic capsule is increased in Noggin −/− mutants, which most likely is due to unopposed BMP signaling for chondrogenesis in the peri-otic mesenchyme.