Mutations Upstream of ppp2ca Affect Body Weight in Asian Seabass

Area of Science:

• Aquaculture genetics
• Fish growth regulation
• Molecular mechanisms of growth

Background:

• Growth is a key economic trait in aquaculture.
• The ppp2ca gene is a candidate for growth regulation in Asian seabass, located within a major quantitative trait locus (QTL).
• The precise molecular mechanisms of ppp2ca in growth remain to be elucidated.

Purpose of the Study:

• To investigate the association of ppp2ca variations with body weight in Asian seabass.
• To explore the functional role of ppp2ca in cell proliferation.
• To characterize novel upstream mutations in ppp2ca and their effects on gene expression and fish growth.

Main Methods:

• Single nucleotide polymorphism (SNP) association analysis with body weight.
• Gene expression analysis across multiple tissues.
• In vitro functional assays (cell proliferation, dual-luciferase reporter assays).
• Identification and characterization of insertion-deletion (indel) mutations upstream of ppp2ca.
• Statistical analysis including permutation-based two-way ANOVA.

Main Results:

• A significant association was found between a ppp2ca SNP and body weight.
• ppp2ca exhibits ubiquitous expression, with reduced levels in fast-growing fish muscle.
• Knockdown of ppp2ca promoted cell proliferation, while overexpression suppressed it.
• Two novel upstream indels (10-bp insertion and 218-bp deletion) were identified.
• The 10-bp insertion enhanced ppp2ca expression, and the 218-bp deletion reduced it.
• A significant interaction between the two indels affected body weight.

Conclusions:

• Upstream mutations in ppp2ca significantly influence Asian seabass growth.
• These mutations impact ppp2ca expression, affecting cellular processes related to growth.
• The identified ppp2ca variations serve as valuable markers for selective breeding programs in aquaculture.
• Further research into the detailed functional roles of ppp2ca in growth regulation is warranted.