Meeting Abstract
16.4 Friday, Jan. 4 Dual function of a putative epidermal growth factor receptor in the decapod crustacean Macrobrachium rosenbergii SHARABI, O.*; VENTURA, T.; MANOR, R.; AFLALO, E.D.; SAGI, A.; Ben Gurion University of the Negev; University of the Sunshine Coast, Queensland, Australia; Ben Gurion University of the Negev; Ben Gurion University of the Negev; Ben Gurion University of the Negev omrisha@post.bgu.ac.il
Epidermal growth factor receptors (EGFRs) are highly conserved members of the tyrosine kinase receptor superfamily found in all multicellular organisms. In arthropods, EGFRs have been found to be involved in proper development of embryos and of adult wings, legs, ovaries and eyes, as well as to affect body size. In search for genes involved in growth and development in our model organism, the decapod crustacean Macrobrachium rosenbergii, we used next generation sequencing to create a comprehensive transcript library of larvae and juveniles. We have identified the expression of several genes assigned to the cross-talking signal transduction pathways activated by EGFRs and insulin receptors, including a transcript coding for an M. rosenbergii EGFR (Mr-EGFR). The deduced protein showed sequence similarity to other arthropod EGFRs. The gene was found to be expressed in most, but not all, tissues. We examined its role in juvenile animals using functional genomics methods, by temporary silencing of the Mr-EGFR transcript through weekly injections of double-stranded Mr-EGFR. This resulted in a significant reduction in growth, a delay in the appearance of a male secondary sex character (appendix masculine).The EGFR silenced animals development abnormal eyes which included irregular organization of the ommatidium, unorganized receptor cells occupying large area of the dioptric portion and lack of the crystalline tract layer. However, all portion of the optic ganglion appeared to have normal morphology. To our knowledge, this is the first report of an EGFR identified in crustaceans, and its proven involvement in decapod growth and development demonstrates its significance.
