Plant & Animal Genomes XIII Conference Plant & Animal Genomes XIII ConferenceJanuary 15-19, 2005
Town & Country Convention Center
San Diego, CA
Frederick C.C Leung , Ying Wang
Prolactin receptor (PRLR) is a member of the growth hormone/prolactin cytokine receptor superfamily. Unlike those in mammals and fish, avian prolactin receptor has a unique extracellular region with a duplicated ligand binding domain. Moreover, the truncated PRLR proteins corresponding to the intracellular domain have been identified specifically in the chicken testis. Therefore, investigation of the genomic structure of PRLR gene in birds is of great importance for better understanding its evolutionary pathway and regulatory mechanism in controlling its specific spatial expression pattern. In present study, we first sequenced and analyzed the genomic organization of the chicken prolactin receptor gene (cPRLR). cPRLR disperses over 34 kb on chromosome Z and consists of 15 exons and 14 introns. In addition, combined our sequencing information on cPRLR and cGHR with other released genome resources, we also mapped 13 genes including PRLR and GHR on chicken chromosome Z and compared the synteny with other vertebrate chromosomes including human, chimpanzee, rat, mouse and zebrafish. Strikingly, highly conserved syntenies were noticed between four mammalian species and chicken. However, some changes in gene order and orientation within the conserved region were found among these species, indicating that intra-chromosomal inversions have occurred more frequently than inter-chromosomal translocations since the divergence of birds and mammals. Although zebrafish PRLR and GHR were localized on two distinct linkage groups (LG10 and LG8), two chromosome regions on LG5 and LG21 were consistently observed in all species examined, strongly suggesting that the two syntenies are extremely conserved during vertebrate genome evolution.