Biochemical Mechanisms for Geographical Adaptations to Novel Toxin Exposures in Butterflyfish

Some species of butterflyfish have had preyed upon corals for millions of years, yet the mechanism of butterflyfish specialized coral feeding strategy remains poorly understood. Certain butterflyfish have the ability to feed on allelochemically rich soft corals, e.g. Sinularia maxima. Cytochrome P450 (CYP) is the predominant enzyme system responsible for the detoxification of dietary allelochemicals. CYP2-like and CYP3A-like content have been associated with butterflyfish that preferentially consumes allelochemically rich soft corals. To investigate the role of butterflyfish CYP2 and CYP3A enzymes in dietary preference, we conducted oral feeding experiments using homogenates of S. maxima and a toxin isolated from the coral in four species of butterflyfish with different feeding strategies. After oral exposure to the S. maxima toxin 5-episinulaptolide (5ESL), which is not normally encountered in the Hawaiian butterflyfish diet, an endemic specialist, Chaetodon multicinctus experienced 100% mortality compared to a generalist, Chaetodon auriga, which had significantly more (3-6 fold higher) CYP3A-like basal content and catalytic activity. The specialist, Chaetodon unimaculatus, which preferentially feed on S. maxima in Guam, but not in Hawaii, had 100% survival, a significant induction of 8-12 fold CYP3A-like content, and an increased ability (2-fold) to metabolize 5ESL over other species. Computer modeling data of CYP3A4 with 5ESL were consistent with microsomal transformation of 5ESL to a C15-16 epoxide from livers of C. unimaculatus. Epoxide formation correlated with CYP3A-like content, catalytic activity, induction, and NADPH-dependent metabolism of 5ESL. These results suggest a potentially important role for the CYP3A family in butterflyfish-coral diet selection through allelochemical detoxification

The Effect of Vojta's Reflex Locomotion on the Stability of Patients with Hereditary Polyneuropathy

This thesis deals with the influence of Vojta's reflex locomotion on stability of the pacients suffering from hereditary neuropathy. In the review of knowledges there is presented the part about hereditary neuropathies, it's classification, clinical symptoms and diagnostics. The second part of the review is about the stability and it's determination. The last part is dedicated to Vojta's reflex locomotion. In experimental part, there is presented studies, which evaluates the influence of Vojta's reflex locomotion on the sensitive functiones (discrimination, texture perception, vibration perception) and the postural stability (using Balance Master system) in the two groups of the pacients suffering from hereditary neuropathy. The first groupe was measured before and after Vojta's therapy and the second groupe (control one) was measured in the same way, but without therapy. Consequently, the basic statistic indicators of gained set of data were calculated. As a conclusion, there has been some changes before and after therapy in sensitive functiones (vibrations perception, discrimination) and postural function and one test of postural stability in the group of patients threated with Vojta's reflex therapy, compared to control group. Powered by TCPDF (www.tcpdf.org

Canopy-Forming Seaweeds in Urchin-Dominated Systems in Eastern Canada: Structuring Forces or Simple Prey for Keystone Grazers?

Models of benthic community dynamics for the extensively studied, shallow rocky ecosystems in eastern Canada emphasize kelp-urchin interactions. These models may bias the perception of factors and processes that structure communities, for they largely overlook the possible contribution of other seaweeds to ecosystem resilience. We examined the persistence of the annual, acidic (H2SO4), brown seaweed Desmarestia viridis in urchin barrens at two sites in Newfoundland (Canada) throughout an entire growth season (February to October). We also compared changes in epifaunal assemblages in D. viridis and other conspicuous canopy-forming seaweeds, the non-acidic conspecific Desmarestia aculeata and kelp Agarum clathratum. We show that D. viridis can form large canopies within the 2-to-8 m depth range that represent a transient community state termed ‘‘Desmarestia bed’’. The annual resurgence of Desmarestia beds and continuous occurrence of D. aculeata and A. clathratum, create biological structure for major recruitment pulses in invertebrate and fish assemblages (e.g. from quasi-absent gastropods to .150 000 recruits kg21 D. viridis). Many of these pulses phase with temperature driven mass release of acid to the environment and die-off in D. viridis. We demonstrate experimentally that the chemical makeup of D. viridis and A. clathratum helps retard urchin grazing compared to D. aculeata and the highly consumed kelp Alaria esculenta. In light of our findings and related studies, we propose fundamental changes to the study of community shifts in shallow, rocky ecosystems in eastern Canada. In particular, we advocate the need to regard certain canopy-forming seaweeds as structuring forces interfering with top-down processes, rather than simple prey for keystone grazers. We also propose a novel, empirical model of ecological interactions for D. viridis. Overall, our study underscores the importance of studying organisms together with cross-scale environmental variability to better understand the factors and processes that shape marine communities

Structures of 5ESL (A) of <i>S</i>. <i>maxima</i> and 5ESL 15,16 epoxide (5ESLO) (B).

<p>Structures of 5ESL (A) of <i>S</i>. <i>maxima</i> and 5ESL 15,16 epoxide (5ESLO) (B).</p

Effects of dietary exposure to 5ESL on the hepatic content of CYP2M1-like protein (A) and catalytic activity (B) of and CYP2 in four species of butterflyfish.

<p>Different letters indicate significant (P ≤ 0.05) differences between untreated and treated fish (N = 6–8).</p

Effects of dietary exposure to <i>S</i>.<i>maxima</i> tissue homogenate on the hepatic content (A) and catalytic activity (B, C) of and CYP3A in four species of butterflyfish.

<p>Different letters indicate significant (P ≤ 0.05) differences between untreated and treated fish (N = 6–8).</p

The percentage survival of butterflyfish after a 7 day oral exposure to high dose (3.0mg/kg), or low dose (1.0mg/kg) of 5ESL.

<p>Each value represents the total survival of 6–8 individuals.</p

Effects of dietary exposure to <i>S</i>.<i>maxima</i> tissue homogenate on the hepatic content CYP2K1-like and CYP2M1-like (A, B) and catalytic activity (C) of and CYP2 in four species of butterflyfish.

<p>Different letters indicate significant (P ≤ 0.05) differences between untreated and treated fish (N = 6–8).</p