Macrobrachium nipponense is an important commercial freshwater prawn species in China. Since larger individuals command higher market value, there is a pressing need to identify growth-related genes and single-nucleotide polymorphisms (SNPs) to facilitate genetic improvement in this species. Previous studies have suggested a potentially regulatory role of an actin-like protein (
ACTL) in the growth of
M. nipponense. Therefore, the present study aimed to functionally characterize the role of
ACTL in growth and identify growth-associated SNPs within this gene. The open reading frame of
Mn-ACTL is 1131 bp, encoding a protein with 377 amino acids. Blastx and phylogenetic analyses indicated that
Mn-ACTL shares a close evolutionary relationship with orthologs from
Macrobrachium rosenbergii and
Palaemon carinicauda. The highest expression level of
Mn-ACTL in muscle tissue detected by qPCR suggested its potential involvement in growth regulation. RNA interference experiments showed that prawns injected with
dsGFP exhibited larger body sizes than those injected with
dsACTL, indicating that knockdown of
Mn-ACTL expression inhibits growth performance in
M. nipponense. Furthermore, muscle tissue from the
dsACTL-injected group displayed looser myofibril packing, visibly eroded areas, and increased sarcomere spacing. Collectively, these results demonstrated that
ACTL positively regulates growth in
M. nipponense. Additionally, the T allele at locus S28_17149891 and the G allele at locus S28_17145758 were significantly associated with growth traits (
p < 0.05). In conclusion, this study confirmed the positive regulatory role of
ACTL in growth and identified growth-associated SNPs in
M. nipponense, providing valuable insights for breeding new varieties with enhanced growth performance in this species.
Full article
