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During first gamete interaction, oligosaccharides on the glycoproteins present in oocyte envelopes of the rock shrimp, Rhynchocinetes typus, play an important role in spermatozoon recognition prior to the onset of penetration. These oligosaccharides have terminal monosaccharides that may be recognized by means of specific lectins. A variety of marine species have monosaccharides on their oocyte envelopes, allowing them to interact with the spermatozoa. The number and location of the monosaccharides varies during oocyte maturation. However, this phenomenon has not been studied in shrimp. The present study evaluates the presence and location of monosaccharides on oocyte envelopes during maturation using seven specific lectins conjugated to FITC (GNL, LCA, Con-A BS-1, LTA, GLS-II,DBA); these recognize mannose (α 1-3) mannose, α-mannose, α-glucose, glucose, galactose, fucose, N-acetyl-glucosamine, and N-acetyl-galactosamine, respectively. Participation of these carbohydrates in the fertilization process was determined through the insemination of fresh oocytes with spermatozoa previously incubated with the different monosaccharides that block the active sites of the spermatozoa, inhibiting fertilization. The results showed the presence of N-acetyl-glucosamine and mannose on the oocyte envelopes, indicating that these sugars could be the receptors during the first gamete interaction. The results also suggested that glucose could be a complementary receptor to N-acetyl-glucosamine and mannose since, despite the low concentration of glucose on the envelope, this sugar generated a high degree of fertilization inhibition.Durante la primera interacción gamética, los oligosacaridos unidos a las glicoproteínas de las cubiertas ovocitarias del camarón de roca Rhynchocinetes typus tienen un importante rol en el reconocimiento del espermatozoide antes de iniciar la penetración. Estos oligosacáridos presentan en su zona terminal, monocacáridos que pueden ser reconocidos por lectinas específicas. Diversas especies marinas tienen monosacáridos en la cubierta externa de sus ovocitos que le permiten interactuar con los espermatozoides y su número y localización presenta cambios durante la maduración, sin embargo este fenómeno no ha sido estudiado en camarones. El presente estudio evalúa la presencia y localización de monosacáridos sobre la cubierta de los ovocitos durante su maduración usando siete lectinas específicas conjugadas con FITC (GNL, LCA , Con-A BS-1, LTA, GLS-II y DBA) las cuales reconocen manosa (α 1-3) manosa, α-manosa, α-glucosa, glucosa, galactosa, fucosa, N-acetil-glucosamina y N-acetilgalactosamina respectivamente. La participación de estos carbohidratos en el proceso de fecundación fue determinada mediante la inseminación de ovocitos frescos con espermatozoides incubados previamente con los diferentes monosacáridos que bloquean los sitios activos de los espermatozoides inhibiéndo la fecundación. Los resultados mostraron la presencia de N-acetil-glucosamina y manosa en la cubierta externa de los ovocitos maduros los cuales podían ser los receptores espermáticos durante la primera interacción gamética. También se sugiere que la glucosa podría ser un receptor complementario a los anteriormente mencionados debido que a pesar que su concentración en las cubiertas es baja, genera una alta inhibición de la fecundación.

During first gamete interaction, oligosaccharides on the glycoproteins present in oocyte envelopes of the rock shrimp, Rhynchocinetes typus, play an important role in spermatozoon recognition prior to the onset of penetration. These oligosaccharides have terminal monosaccharides that may be recognized by means of specific lectins. A variety of marine species have monosaccharides on their oocyte envelopes, allowing them to interact with the spermatozoa. The number and location of the monosaccharides varies during oocyte maturation. However, this phenomenon has not been studied in shrimp. The present study evaluates the presence and location of monosaccharides on oocyte envelopes during maturation using seven specific lectins conjugated to FITC (GNL, LCA, Con-A BS-1, LTA, GLS-II,DBA); these recognize mannose (α 1-3) mannose, α-mannose, a-glucose, glucose, galactose, fucose, N-acetyl-glucosamine, and N-acetyl-galactosamine, respectively. Participation of these carbohydrates in the fertilization process was determined through the insemination of fresh oocytes with spermatozoa previously incubated with the different monosaccharides that block the active sites of the spermatozoa, inhibiting fertilization. The results showed the presence of N-acetyl-glucosamine and mannose on the oocyte envelopes, indicating that these sugars could be the receptors during the first gamete interaction. The results also suggested that glucose could be a complementary receptor to N-acetyl-glucosamine and mannose since, despite the low concentration of glucose on the envelope, this sugar generated a high degree of fertilization inhibition. [ABSTRACT FROM AUTHOR]