Heritability of growth traits and correlation with hepatic gene expression among hybrid striped bass exhibiting extremes in performance

Authors: Fuller, Adam; Beck, Benjamin; McEntire, Matthew - Matt; PEATMAN, ERIC - Auburn University; Abernathy, Jason

Submitted to: Cogent Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/12/2018
Publication Date: 3/28/2018
Publication URL: https://handle.nal.usda.gov/10113/6723279
Citation: Fuller, S.A., Beck, B.H., McEntire, M.E., Peatman, E., Abernathy, J.W. 2018. Heritability of growth traits and correlation with hepatic gene expression among hybrid striped bass exhibiting extremes in performance. Cogent Biology. 4:1453319.

Interpretive Summary: We set out to better understand the genetic basis behind growth variation in hybrid striped bass (HSB) by determining whether gene expression changes could be detected between the largest and smallest HSB in a population using a whole animal gene expression approach by sequencing RNA from the liver. Fingerlings from 47 families were grown in four ponds for four months, fed until full twice per day with a high fish protein commercial diet. After pond growth, all families were ranked by weight gain and six individuals from the fastest growing and six individuals from the slowest growing families were collected, euthanized, and liver tissue was harvested for RNA extraction and sequencing. We identified 86 differentially expressed genes (DEGs) between groups. Evidence from this study may have revealed that larger HSB could be more efficient feeders than their smallest counterparts, and/or, that several DEGs in this study are similar to those that are affected where food is restricted. Our candidate gene list may also provide some evidence that both physiological and behavioral factors may be at work in regards to HSB growth when different families are raised together.

Technical Abstract: We set out to better understand the genetic basis behind growth variation in hybrid striped bass (HSB) by determining whether gene expression changes could be detected between the largest and smallest HSB in a population using a global gene expression approach by RNA sequencing of liver. Fingerlings from 47 families were grown in four replicate earthen ponds for 115 d and fed to apparent satiation twice per day with a standard high fish protein commercial diet. After pond growth, all HSB families were ranked by weight gain and six individuals from the fastest growing families (mean 240.8 +/- 9.75 g; 242.0 +/- 11.52 mm) and six individuals from the slowest growing families (mean 153.5 +/- 52.38 g; 223.3 +/- 21.31 mm) were collected, euthanized, and liver tissue was harvested for total RNA extraction and RNA sequencing. We identified 86 differentially expressed genes (DEGs) between groups. This included 40 up-regulated (1.89 ' fold-change < 7.66) and 46 down-regulated (-1.71 > fold-change ' -4.59) genes in large HSB, as we are using small HSB as the baseline for comparison. Evidence from this study may have revealed that larger HSB could be more efficient feeders than their smallest counterparts, and/or, that several DEGs in this study are similar to those that are affected where nutrition is restricted. Our candidate gene list may also provide some evidence that both physiological and behavioral factors may be at work in regards to HSB growth when communally reared.