Expression of the male reproduction-related gene (Mar-Mrr) in the spermatic duct of the giant freshwater prawn, Macrobrachium rosenbergii

Abstract

Phosphorylated sperm proteins are crucial for sperm maturation and capacitation as a priori to their fertilization with eggs. In the freshwater prawn, Macrobrachium rosenbergii, a male reproduction-related protein (Mar-Mrr) was known to be expressed only in the spermatic ducts as a protein with putative phosphorylation and may be involved in sperm capacitation in this species. We investigated further the temporal and spatial expression of the Mar-Mrr gene using RT-PCR and in situ hybridization and the characteristics and fate of the protein using immunblotting and immunocytochemistry. The Mar-Mrr gene was first expressed in 4-week-old post larvae and the protein was produced in epithelial cells lining the spermatic ducts, at the highest level in the proximal region and decreased in the middle and distal parts. The native protein had a MW of 17 kDa and a high degree of serine/threonine phosphorylation. It was transferred from the epithelial cells to become a major protein at the anterior region of the sperm. We suggest that it is involved in sperm capacitation and fertilization in this open thelycal species and this is being investigated.

Comparative Transcriptome Analysis of Gonads for the Identification of Sex-Related Genes in Giant Freshwater Prawns (Macrobrachium Rosenbergii) Using RNA Sequencing

“…Meanwhile, the other two testis-specific genes, including male reproductive-related protein Mar-Mrr and male reproductive tract-specific Kazal-type proteinase inhibitor, showed a specific testicular expression pattern. Earlier studies had demonstrated that Mar-Mrr was specially expressed in the male reproductive tract, and was required for sperm function [11,14,65]. Thus, combining the current results indicates that Mar-Mrr is implicated in male-reproduction.…”

“…Although the Z and W chromosomes have not been identified, the results still provided a useful resource and comprehensive knowledge of genomic structure of M. rosenbergii [10]. However, sex-related genes and a list of biological pathways involved in gonads development have been revealed [11][12][13][14][15][16], the potential molecular mechanisms of sex determination in M. rosenbergii are still not well understood.Currently, along with the emergence of next generation sequencing (NGS), RNA-sequencing (RNA-seq) was widely applied to detect the expression profiles of genes and identify the sex-related genes in aquaculture species, especially those lacking genomic sequences, due to its high throughput and low cost. To date, some progresses have been made in the characterization of sex-related genes and pathways in M. rosenbergii [16], Macrobrachium nipponense [17], Silver Sillago [18], Olive Flounder [19], Pacific abalone [20], Pacific white shrimp [21], catfish [22], and Acipenser dabryanus [23].…”

“…Although the Z and W chromosomes have not been identified, the results still provided a useful resource and comprehensive knowledge of genomic structure of M. rosenbergii [10]. However, sex-related genes and a list of biological pathways involved in gonads development have been revealed [11][12][13][14][15][16], the potential molecular mechanisms of sex determination in M. rosenbergii are still not well understood.…”

Sex and tissue specific gene expression patterns identified following de novo transcriptomic analysis of the Norway lobster, Nephrops norvegicus

“…Serine threonine protein kinases were found to be highly expressed in the testes of E. sinensis [ 50 ]; the authors suggesting that STPKs may play a key role in both mitotic and meiotic divisions and extensive cellular re-modelling through cell cycle phases during spermatogenesis. In M. rosenbergii , a male reproductive-related protein homologous with STPK was found to be expressed exclusively in the sperm ducts as a protein with a putative role in phosphorylation and with a function involved with sperm capacitation and/or fertilization [ 51 ]. In N. norvegicus , 24 transcripts annotated as STPK were detected exclusively in the testes suggesting that several isoforms could have different functions in male reproduction (Additional file 4 : Table S3).…”

Optimizing Hybrid de Novo Transcriptome Assembly and Extending Genomic Resources for Giant Freshwater Prawns (Macrobrachium rosenbergii): The Identification of Genes and Markers Associated with Reproduction

“…An initial step towards understanding the molecular basis of the genetic regulation of maturation has already been initiated for M . rosenbergii [ 18 , 19 , 20 ], and this has included a focus on the progress of sexual differentiation ( i.e. , sex-linked markers) [ 21 , 22 , 23 ].…”