Aquaculture 2022

February 28 - March 4, 2022

San Diego, California

TRANSCRIPTOMIC AND PHYSIOLOGICAL EFFECTS OF DIETARY PREBIOTICS CHITOSAN, INULIN, AND ß-GLUCAN ON JUVENILE Totoaba macdonaldi

Clara E. Galindo-Sánchez*, Oscar E. Juárez, Sara Enciso-Contreras ,  Felipe Aguilera,  Edgar López-Landavery,  Juan Pablo Lazo and Fabiola Lafarga-De la Cruz

 

 Centro de Investigación Científica y de Educación Superior de Ensenada, Baja California, México.

 



Dietary prebiotics such as  0.5% chitosan, 1% inulin  and  0.1% β-glucan have improved the growth, digestion and immune response of different fish species under culture conditions; however, their effects in  totoaba  juveniles are unknown. In this study, the effects of such prebiotics were evaluated in juvenile  T. macdonaldi including  measurements of  immune response (i.e., leucocyte and respiratory burst in blood) ; digestibility and digestive enzymes (i.e. , trypsin, amylase, and lipase), and RNA-seq transcriptomics of the liver.

 Fish fed the chitosan  added diet showed the highest respiratory burst, immunoglobulin gene expression ,  and the lowest lipase activity . Differentially expressed genes analysis resulted in significantly higher expression  of  proteolysis, digestion, and lipid hydroxylation  genes (DEGs, Fig 1). Fish fed the inulin diet showed the highest diet apparent digestibility coefficient, trypsin and lipase activities , and the highest expression of trypsin-like and quimiotrypsin-like genes in the liver .  In fish fed the β-glucan diet , DEGs were detected mainly in the category of adaptive immune response (Table 1), with downregulation of immunoglobulins and upregulation of genes of the complement system.

 Fish fed the  chitosan diet showed the highest number of DEGs, while  those fed the β-glucan diet the lowest.

 In conclusion, based on the results from the present study, dietary inulin inclusion can improve the digestibility of experimental diets, while c hitosan can stimulate the immune system of juvenile totoaba.