The river prawn, Macrobrachium americanum (M. americanum) , is a large amphidromous species distributed along the Pacific coast of America. This prawn has commercial value due to its size and taste, making it a good option for aquaculture production. Sustainable prawnshrimp production requires a constant supply of high-quality hatchery and laboratory-reared larvae . To raise prawn larvae, the quality of adult reproduction is critical . critical. The basic concepts of M. americanum reproduction have begun to be unraveled, but our knowledge of the mechanism that regulates
reproduction at the molecular level is limited. To address this issue, we performed transcriptome assembly and differential expression analysis among testes, vas deferens, and terminal ampulla of M.
aA mericanum.
Adult males of
M. americanum were captured in an estuary and a river located in Tomatlán, Jalisco and Puerto Vallarta, Jalisco, respectively. Total RNA extraction was performed using the TRIsure reagent following the manufacturer´s guidelines with modifications. Approximately one µg of high-quality RNA was used to prepare cDNA libraries, using the Zymo-Seq RiboFreeTM Total RNA Library kit. The libraries were sequenced on the HiSeq 2500 platform (2 x 150 bp) by genomic service provider Novogene. The sequences were evaluated to determine their quality with FastQC software, and the adapters were removed using the SeqPrep software to obtain clean obtain clean readings. A combined transcriptome with the three tissues was constructed using Trinity software. Sequences were compared against Swissprot and nonredundant Macrobrachium sp. databases and Geneand Gene Ontology (GO) databases using BLASTx and Blast2GO. Differential expression analysis among tissues was executed using EdgeR
Differential expression analysis among tissues was executed using EdgeR.
The transcriptome assembly generated 1,059,447 unigenes, of which 7,222 genes had significant hits (e-value < 1x10-5 ) when compared against the Swissprot database. Based on Swissprot annotation, a total of 6,271 unigenes were annotated in GO, which were classified into three functional categories: cellular components (6,741), molecular functions (8,625), and biological process (40,628). About 20% of unigenes annotated in GO were involved in a reproductive process or reproduction within the category of biological processes . Based on Gene Ontology classification and comparison with data f rom other publications, about 70 genes were related to sex to sex determination, testis development, spermatogenesis, spermiogenesis, fertilization, maturation of testicular cells, neuropeptides, hormones, hormone receptors, and/or embryogenesis. Differential expression analysis showed 179 transcripts differentially expressed (FDR < 0.05, Log2FC >1) among the tissues.
These results provide new molecular information about M. americanum reproduction, representing a reference point for further genetic studies of this species.