Submitted to: Animal Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/8/2005
Publication Date: 8/1/2005
Citation: Karsi, A., Wolters, W.R., Waldbieser, G.C. 2005. Assignment of immune-related genes to the channel catfish, ictalurus punctatus, genetic map. Animal Genetics 36:502-506. Interpretive Summary: Development of informative genetic markers is essential for production of high-resolution linkage maps which can then be used to identify genes that control important production traits. However, compared with other farm animals, fish genetic maps have relatively few markers. This project was designed to develop genetic markers for genes involved in immunity. Repeating sequences termed microsatellites were identified in DNA sequences of 18 genes involved in channel catfish immunity pathways, and the microsatellite sequences were variable in catfish populations. Sequence variation allowed us to place the markers the catfish genetic linkage map. The placement of known genes on the map will permit researchers to compare the relatively map-poor catfish map with map-rich species such as zebrafish and some mammals, and will help identify chromosomal regions that control important traits. This information will assist researchers in the identification and selection of genetically superior catfish for commercial production.
Technical Abstract: Eighteen new genes, adenosine A1 receptor (ADORA1), complement component 4 beta (C4b), complement component 8 beta (C8b), chemokine ligand 19 (CCL19), chemokine ligand 21 (CCL21), chemokine ligand 25 (CCL25), chemokine receptor 2 (CCR2), chemokine receptor 5 (CCR5), chemokine receptor 4 (CCR4), chemokine receptor 7 (CCR7), chemokine receptor 9 (CCR9), interleukin 1 beta (IL1B), integrin II beta (ITGB2), novel immune type receptor 2 (NITR2), novel immune type receptor 4 (NITR4), natural killer cell lysin (NKLYSIN), nucleotide excision repair gene (RAD23B), and tumor necrosis factor alpha (TNFA), were assigned to the channel catfish (Ictalurus punctatus) genetic linkage map. Polymorphic microsatellite markers were developed for NITR-2, NITR-4, and RAD23B from short tandem repeats in the available sequence. Polymorphic microsatellite markers were developed for the remaining fifteen genes by short tandem repeat-anchored primer (STRAP) sequencing of catfish bacterial artificial chromosomes. Two gene clusters (MYOG – nRAMP – ADORA1) and (CCR4 – CCR2 – CCR5) displayed conservation of synteny between catfish and mammals. Assignment of eighteen new genes to the catfish linkage map will aid integration of genetic and physical maps and comparative mapping between channel catfish and map rich species.