A Second-Generation Genetic Linkage Map of Tilapia (Oreochromis spp.)Sequence data from this article have been deposited with the EMBL/GenBank data libraries under accession nos. G68180, G68324 and BV005269, BV005594.

Abstract

We constructed a second-generation linkage map of tilapia from the F 2 progeny of an interspecific cross between Oreochromis niloticus and Oreochromis aureus. The map reported here contains 525 microsatellite and 21 gene-based markers. It spans 1311 cM in 24 linkage groups, for an average marker spacing of 2.4 cM. We detected associations of sex and red color with markers on linkage group 3. This map will enable mapping and selective breeding of quantitative traits important to the economic culture of tilapia as a food fish and will contribute to the study of closely related cichlids that have undergone explosive adaptive radiation in the lakes of East Africa.

Linkage Maps for the Pacific Abalone (Genus Haliotis) Based on Microsatellite DNA Markers

“…Sex-related difference in recombination rate: Since the discovery of heterogeneous fractions of meiotic recombination between sexes in Drosophila (Morgan 1912), sex-specific differences in recombination rates have been found in a diverse range of organisms, for example, in plants (Burt et al 1991;De Vicente and Tanksley 1991;Graner et al 1991;Sewell et al 1999), mammals (Donis-Keller et al 1987;Mikawa et al 1999;Neff et al 1999;Lynn et al 2005), and aquatic animals such as teleost fishes (Sakamoto et al 2000;Kondo et al 2001;Singer et al 2002;Woram et al 2004;Kai et al 2005;Lee et al 2005;Gharbi et al 2006). Although limited information is available for molluscan species, higher recombination rates in females have been reported (eastern oyster, Yu and Guo 2003;Pacific oyster, Li and Guo 2004;Hubert and Hedgecock 2004), and in H. discus hannai as well (Liu et al 2006).…”

A Microsatellite-Based Genetic Linkage Map of the Cichlid Fish,Astatotilapia burtoni(Teleostei): A Comparison of Genomic Architectures Among Rapidly Speciating Cichlids

“…In addition, there is detailed knowledge on Hox genes (Hoegg and Meyer 2005;Hoegg et al 2007), Para-Hox genes (Siegel et al 2007), and several other genes related to coloration Salzburger et al 2007) and fertilization (Gerrard and Meyer 2007) for this key species. Genomic resources available from other cichlids include the tilapia Oreochromis niloticus (BAC library: Katagiri et al 2001; genetic maps: Kocher et al 1998;Katagiri et al 2005;Lee et al 2005), Haplochromis chilotes (BAC library: Watanabe et al 2003;ESTs: Watanabe et al 2004; cDNA microarrays: Kobayashi et al 2006), and Metriaclima zebra (Di Palma et al 2007; ESTs: Salzburger et al 2008;genetic map: Albertson et al 2003). Recently, the National Institutes of Health has committed to sequencing four cichlid genomes.…”

“…On the other hand, their generation requires high costs and is time consuming (reviewed in Erickson et al 2004). Most linkage maps based on microsatellites have been constructed for economically important fish species, such as the Atlantic salmon (Gilbey et al 2004), rainbow trout (Sakamoto et al 2000), European sea bass (Chistiakov et al 2005), and Nile tilapia (Kocher et al 1998;Lee et al 2005), to search for loci that affect commercially important traits. Research in the fields of ecology and evolution has recently begun to focus on identifying the genetic basis of adaptive trait evolution especially in natural populations of nonmodel organisms.…”

“…map: We initially screened 51 microsatellite markers from the available linkage maps of tilapia (Kocher et al 1998;Lee et al 2005) for their use in linkage mapping of A. burtoni and found rather low levels of polymorphism in our testcross, although amplification success was $50%. Thus, only a small number of markers are shared between the two maps, namely UNH106, UNH2191, UNH192, UNH2150, UNH2166, and UNH130, that could be used for comparison.…”

Genetic and developmental basis of cichlid trophic diversity

“…This offers a unique opportunity to study the genetic basis of characters that afford species an adaptive advantage. There are also a multitude of genomic resources available to cichlid researchers, including genetic linkage maps, physical maps, BAC libraries, and cDNA resources including microarrays (Kocher et al, 1998;Watanabe et al, 2003;Albertson et al, 2003a;Renn et al, 2004;Katagiri et al, 2005;Lang et al, 2005;Lee et al, 2005). Importantly, the close evolutionary relationship among African cichlids ensures that genomic resources developed in one species may be used for studies in thousands of related taxa.…”