Ploidy effects on genes regulating growth mechanisms during fasting and refeeding in juvenile rainbow trout (Oncorhynchus mykiss).
Diploid and triploid rainbow trout weighing approximately 3g were either fed for five weeks, or feed deprived for one week, followed by refeeding. During feed deprivation gastrointestinal somatic index decreased in diploids, but not triploids, and during refeeding, carcass growth rate recovered more quickly in triploids. Although not affected by ploidy, liver ghr2 and igfbp2b expression increased and igfbp1b decreased in fasted fish. Effects of ploidy on gene expression indicate potential mechanisms associated with improved recovery growth in triploids, which include decreased hepatic igfbp expression, which could influence IGF-I bioavailability, differences in tissue sensitivity to TGFbeta ligands due to altered tgfbr and smad expression, and differences in expression of muscle regulatory genes (myf5, mstn1a, and mstn1b). These data suggest that polyploidy influences the expression of genes critical to muscle development and general growth regulation, which may explain why triploid fish recover from nutritional insult better than diploid fish.
National Center for Cool and Cold Water Aquaculture, USDA/ARS, 11861 Leetown Rd, Kearneysville, WV 25427, United States. Electronic address: beth.cleveland@ars.usda.gov.
Beth M
BM
Cleveland
National Center for Cool and Cold Water Aquaculture, USDA/ARS, 11861 Leetown Rd, Kearneysville, WV 25427, United States.
Gregory M
GM
Weber
D000818:Animals; D001835:Body Weight; D016000:Cluster Analysis; D004171:Diploidy; D005215:Fasting / Q000378:metabolism*; D005247:Feeding Behavior; D018507:Gene Expression Regulation, Developmental; D013006:Growth Hormone / Q000378:metabolism; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D009132:Muscles / Q000378:metabolism; D017686:Oncorhynchus mykiss / Q000235:genetics* / Q000254:growth & development*; D009928:Organ Specificity / Q000235:genetics; D011003:Ploidies; D016212:Transforming Growth Factor beta / Q000378:metabolism; D057885:Triploidy
D016212:Transforming Growth Factor beta; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone
Compensatory growth; Fish; GeXP; Gene compensation; Gene dosage