How the expression of green fluorescent protein and human cardiac actin in the heart influences cardiac function and aerobic performance in zebrafish Danio rerio

Abstract

The present study examined how the expression of enhanced green fluorescent protein (eGFP) and human cardiac actin (ACTC) in zebrafish Danio rerio influences embryonic heart rate (R H ) and the swim performance and metabolic rate of adult fish. Experiments with the adults involved determining the critical swimming speed (U crit , the highest speed sustainable and measure of aerobic capacity) while measuring oxygen consumption. Two different transgenic D. rerio lines were examined: one expressed eGFP in the heart (tg(cmlc:egfp)), while the second expressed ACTC in the heart and eGFP throughout the body (tg(cmlc:actc,ba:egfp)). It was found that R H was significantly lower in the tg(cmlc:actc,ba:egfp) embryos 4 days post-fertilization compared to wild-type (WT) and tg (cmlc:egfp). The swim experiments demonstrated that there was no significant difference in U crit between the transgenic lines and the wild-type fish, but metabolic rate and cost of transport (oxygen used to travel a set distance) was nearly two-fold higher in the tg(cmlc:actc,ba:egfp) fish compared to WT at their respective U crit . These results suggest that the expression of ACTC in the D. rerio heart and the expression of eGFP throughout the animal, alters cardiac function in the embryo and reduces the aerobic efficiency of the animal at high levels of activity.

Transientgrb10aKnockdown Permanently Alters Growth, Cardiometabolic Phenotype and the Transcriptome inDanio rerio

“…To investigate embryonic cardiac phenotype, embryos were sedated using a concentration known to have no impact on cardiac function (0.04 % MS-222 solution (29) .cel files and normalised using the robust multi-array average (RMA) approach with a gene level summary. Zebrafish gene identities were assigned using the Affymetrix gene definitions.…”

“…To investigate embryonic cardiac phenotype, embryos were sedated using an anaesthetic concentration known to have no impact on cardiac function (0.04% MS-222 solution 25 ).…”

Altered Response to Total Body Irradiation of C57BL/6-Tg (CAG-EGFP) Mice

“… 27 , 28 In zebrafish Danio rerio overexpressing GFP, embryonic cardiac malfunction was observed as well as a defect in aerobic performance in adults. 29 In cells expressing transgenic GFP, studies showed different baseline of mitochondrial transcript expression in human T-cell line JURKAT cells, proteome modifications in breast cancer cell line, apoptosis in NIH/3T3, BHK-21, Huh-7, and HepG2 cells, protein burden in yeast Saccharomyces cerevisiae and myopathy in mouse muscle cells. 30 - 34 In addition, compared to their wild type counterparts, GFP transgenic cells showed altered response to insults including IR.…”