Characterization of Zebrafish Vitellogenin gene family for potential development of receptor-mediated gene transfer method

Abstract

Vitellogenin gene (vtg) family was characterized in zebrafish (Danio rerio). There are at least seven distinct vtgs which fall into three groups: A (vtg1 and vtg4-7), B (vtg2) and C (vtg3). vtg3 encodes a Vtg without phosvitin domain and may represent a primitive vtg in vertebrates. Genome mapping indicated that vtg3 is located on chromosome 11 and other vtgs on chromosome 22. Expression study showed that in addition to the female liver, vtg mRNAs are also present in adipose tissues. Furthermore, vtg mRNAs can be induced in the liver, intestine and testis of male fish after estrogen treatment. The current finding of extrahepatic vtg expression challenges the traditional belief that liver is the only organ for vtg expression in oviparous vertebrates. Vtg-polylysine conjugates were made and conjugate-DNA complexes were used in receptor-mediated gene transfer study. Efforts were also made to determine the receptor-binding domain in fish Vtg.