Stimulation of ovarian development in white shrimp, Fenneropenaeus merguiensis De Man, with a recombinant ribosomal protein L10a

• A natural autofluorescence of ovary was the first time used to distinguish vitellogenic stages.
• rRpL10a was rapidly detected and accumulated in the ovary after muscular injection.
• rRpL10a stimulated the synchronous development of the early vitellogenic stages within 7 days.
• MF level in the hemolymph was the highest in stage II of ovarian maturation.

Ribosomal protein L10a (RpL10a) is encoded by an essential gene related to the early stages of ovarian development. A recombinant RpL10a protein was produced and evaluated to determine its ability to stimulate ovarian development in the white shrimp Fenneropenaeus merguiensis De Man. The transportation of injected recombinant RpL10a to the ovary was monitored using FITC-conjugated rRpL10a in an in vivo assay. FITC-rRpL10a was imported into the ovarian tissue within 24 h after injection, observed with a fluorescence microscope. The signal was not detected in muscle tissue; thus, muscle was not a target tissue. A dose of 180 μg of rRpL10a/shrimp was effective for inducing the ovaries to reach stages I and II of vitellogenesis within 7 days after the first injection. Observations of the ovarian natural autofluorescence in tissue sections were performed to determine the stage of vitellogenesis in F. merguiensis and were shown to provide the same results as were obtained using sections stained according to the standard hematoxylin and eosin staining procedure, which spent more time. Methyl farnesoate (MF) levels were examined via a HPLC technique in different stages of ovarian development following RpL10a injection, and the observed MF levels indicated that the concentration of MF in the hemolymph increased in stage II of vitellogenesis.