Cette étude a permis de mettre en évidence que la protéine CARP est un substrat de la calpaïne 3 (C3), protéase déficiente dans les dystrophies des ceintures de type 2A (LGMD2A). Nos résultats suggèrent que C3, en renforçant l’interaction de CARP avec la titine, pourrait moduler sa fonction de régulateur de la transcription génique. De plus, CARP pourrait intervenir dans la plasticité du muscle notamment en régulant l’activité de facteurs de transcription impliqués dans le contrôle de la masse musculaire ainsi que l’expression de protéines impliquées dans le remodelage. Nous proposons que la perte de ce mécanisme de régulation de CARP par C3 puisse participer à la physiopathologie de la LGMD2A. D’autre part, nous avons montré que l’expression de CARP augmente dans tous les modèles dystrophiques étudiés, suggérant que CARP serait un marqueur essentiel de ces maladies. Le contrôle de sa surexpression pourrait donc permettre d’envisager des solutions thérapeutiques pour ces maladies. / Calpain 3, a protease of the skeletal muscle is defective in Limb-Girdle Muscular Dystrophies type 2A (LGMD2A). During our study, we demonstrated that CARP (Cardiac Ankyrin Repeat Protein), is a calpain 3 substrate. Our hypothesis is that calpain 3 enhances CARP interaction with sarcomere thus preventing its passage and its nuclear activities. Our experiments showed that CARP acts on the function of several transcription factors amongst which some are involved in the regulation of muscle mass and that CARP regulates the expression of proteins involved in remodelling. Together, our results suggest that CARP could intervene in the remodelling of sarcomere. The loss of such a mechanism could participate in the pathophysiology of LGMD2A. On the other hand, we showed that the expression of CARP increases in all dystrophic models studied, suggesting that CARP is a key marker of these diseases. The control of its overexpression may constitute a therapeutic option for these diseases.

Addendum and erratum pasted onto back fly leaf. / Copy of author's previously published work inserted. / Bibliography: p. 169-215. / xiv, 215 p. : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Determines a reliable method of age determination, evaluates models of growth in wild populations, assesses growth patterns, describes the onset of the juvenile period, monitors the early life history of a wild population and reviews the literature on carp ecology. / Thesis (Ph.D.)--University of Adelaide, Dept. of Zoology, 1998?

Thesis (Ph. D.)--City University of Hong Kong, 2005. / "Submitted to Department of Biology and Chemistry in partial fulfillment of the requirements for the degree of Doctor of Philosophy." Includes bibliographical references (leaves 233-269).

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More knowledge about the spawning habits of the invasive silver (Hypophthalmichthys molitrix) and bighead (H. nobilis) carps in the United States could lead to a better understanding of how and where these fish are able to successfully reproduce and continue to expand their range. This study explored the possibility of combining multiple strategies (mobile tracking, catch-per-unit-effort [CPUE] of females, reproductive staging of females, and CPUE of larvae) to determine whether Asian carp were more likely to spawn in specific habitats. Additionally, I explored whether the timing of spawning was size-dependent for female Asian carp, and whether Asian carp larvae overlapped with those of native species in space and time. Adult females and larvae were collected weekly and transmittered adults were tracked generally monthly in Pool 26 of the Mississippi River during optimal spawning temperatures in 2011. Mixed model repeated-measures analyses indicated no effect of habitat on adult female or larvae CPUE. There were significant increases in Asian carp larvae CPUE on June 6 (t77 = 5.65, P < 0.001) and June 20 (t77 = 7.33, P < 0.001), indicating recent spawning bouts. Regression tree analysis found that the highest Asian carp larvae CPUE occurred at temperatures ¡Ý 22.5¡ãC and turbidities ¡Ý 163.5 NTU (0.50 larvae m-3). A multinomial baseline-category logit model suggested that there was a 0.83 probability of relocating a tagged fish in a backwater. Logistic regressions determined that 50% of silver carp females were mature at 688 mm total length and larger silver carp females had a higher probability of being spent earlier in the spawning season than smaller females. Asian carp represented 10% of all collected larvae and made up over half of the total larval catch on June 6, 2011. This study found little evidence suggesting that Asian carp are spawning in specific habitats. However, it is possible that the temporal collection pattern was too coarse to catch their potentially rapid response to spawning cues. Larger females may be contributing disproportionately to the population through early spawning, suggesting that population reduction could be increased by targeting these females.

Since their introduction to the United States in the 1970s, the invasive silver carp (Hypothalmichthys molitrix) has migrated into the native waters of 16 states with populations in the Mississippi, Missouri, Ohio and Illinois River systems expanding at exponential rates in the past decade. As this species advances towards Lake Michigan, the threat of their invasion into the Laurentian Great Lakes is becoming very real. Silver carp are opportunistic, capable of rapid and extensive dispersal. They have the potential to compete with native species for critical habitat and food, which are very important limiting resources in all freshwater systems. Understanding their diet and habitat selection could be helpful for predicting their expansion and impacts in systems they invade. In order to fully understand habitat selection, 77 silver carp were implanted with ultrasonic transmitters during Spring 2008 and Spring 2009 in Pools 26 (N=24) and 27 (N=53) of the Mississippi River. Fish were located monthly to assess macrohabitat use. To determine if phytoplankton availability was influencing habitat selection, environmental chlorophyll a (used as a surrogate for phytoplankton abundance) was quantified monthly at silver carp detection sites and at randomly generated points from all macrohabitats. 240 silver carp were sacrificed to analyze foregut chlorophyll a concentrations (Pool 26 N=141; Pool 27 N=99); chlorophyll a concentrations in the river at fish locations were measured. This allows us to determine utilization of available phytoplankton resources. Silver carp were detected mostly in channel border wing dike areas with island side channel also being a popular macrohabitat. Chlorophyll a concentrations in the river were higher in areas where carp were detected compared to random sites across all macrohabitat types (Ksa=1.28 p=0.080). There was no significant relationship between foregut chlorophyll a concentrations and what was available in the environment, suggesting silver carp are using resources similarly across all habitats. Given that this species accumulated high concentrations of phytoplankton in their guts even in areas of low phytoplankton concentrations, they may be able to successfully invade areas with scarce phytoplankton resources.

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