NATIONAL ANIMAL GENOME RESEARCH PROGRAM

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
303	3710	1080	50%
304	3710	1040	50%

Progress 01/01/08 to 12/31/08

Outputs
OUTPUTS: On the basis of previously published framework genetic linkage maps, we have mapped over 1400 microsatellite markers. These include approximately 300 EST-derived microsatellites, 72 EST-derived SNP markers, and about 1100 BAC end anchored microsatellites derived from ESTs. A bacterial artificial chromosome (BAC) contig-based physical map of the channel catfish (Ictalurus punctatus) genome was generated using four color fluorescence-based fingerprints. A total of 40,416 BAC clones (6.5X genome coverage) was processed generating 34,580 fingerprints (5.6X genome coverage) for the FPC assembly of the BAC contigs. A total of 3,307 contigs was assembled. Each contig contains an average of 9.25 clones with an average size of 291 kb. The combined contig size for all contigs was 0.965 Gb, approximately the genome size of channel catfish. The reliability of the contig assembly was assessed by both hybridization of gene probes to BAC clones contained in the fingerprinted assembly, and by validation of randomly selected contigs using overgo probes designed from BAC end sequences. The presented physical map should greatly enhance genome research in catfish, particularly aiding in the identification of genomic regions containing genes underlying important performance traits. To date, a total of 63,387 BAC end sequences have been generated. From these BAC end sequences, a total of 17,640 microsatellites have been identified including 10,860 dinucleotide repeats, 4,007 trinucleotide repeats, 2,631 tetranucleotide repeats, and 135 pentanucleotide repeats. Of the total 17,640 BAC end-anchored microsatellites, 1,671 were located at the beginning of BAC end sequences and 4,392 were located at the end of BAC end sequences, making them not directly useful as markers, while 11,577 has sufficient flanking sequences for microsatellite primer design. Most of the contigs, especially the large ones with over 20 clones contain microsatellites. Mapping of these microsatellite makers will facilitate the integration of the physical map with the genetic linkage map. We have characterized a fraction of the large number of BAC-anchored microsatellites. This work has been published in Aquaculture (Somridhivej et al., 2008). One of the milestones for the past year was the completion of the EST sequencing project by JGI. Now over 300,000 ESTs have been deposited to GenBank for channel catfish, and over 139,000 ESTs have been deposited to GenBank from Blue catfish. Contig assembly and data analysis is under way, and a manuscript is under preparation. John Liu's lab continues their efforts on development of comparative genome tools such as chromosome-anchored ESTs of catfish. In this last year, Dr. Zhiliang Hu of Iowa State University trained our students on database construction. PARTICIPANTS: This national project has allowed the formation of the catfish genome consortium. Training students and postdocs are a major strength of this project. We have collaborated with various scientists from all over the country for catfish genome research. TARGET AUDIENCES: The aquaculture community, the animal genome community, and the aquaculture industry. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Several major achievements in this project will set as major milestones in catfish genome research. The first being the construction of the catfish physical map containing approximately 3307 contigs; the second is the completion of the large EST project that generated over 400,000 ESTs total. These resources will greatly enhance efficiency of catfish genome research that in turn will have a positive impact on genetic enhancement of catfish.

Publications

Wang S, Sha Z, Sonstegard TS, Liu H, Xu P, Somridhivej B, Peatman E, Kucuktas H, Liu ZJ. 2008. Quality assessment parameters for EST-derived SNPs from catfish. BMC Genomics 9:450.
Liu ZJ, Li RW, Waldbieser G. 2008. Utilization of microarray technology for functional genomics in ictalurid catfish. Journal of Fish Biology 72(9): 2377-2390,
Takano T, Sha Z, Peatman E, Terhune J, Liu H, Kucuktas H, Li P, Edholm E-S, Wilson M, Liu ZJ. 2008. The two channel catfish intelectin genes exhibit highly differential patterns of tissue expression and regulation after infection with Edwardsiella ictaluri. Developmental and Comparative Immunology 32: 693-705.
Sha Z, Xu P, Takano T, Liu H, Terhune J, Liu ZJ. 2008. The warm temperature acclimation protein Wap65 as an immune response gene: Its duplicates are differentially regulated by temperature and bacterial infections. Molecular Immunology 45: 1458-1469.
Somridhivej B, Wang S., Sha Z., Liu H., Quilang J., Xu P, Li P, Liu ZJ 2008. Characterization, polymorphism assessment, and database construction for microsatellites from BAC end sequences of catfish: a resource for integration of linkage and physical maps. Aquaculture 275: 76-80.
Peatman E, Terhune J, Baoprasertkul P, Xu P, Nandi S, Wang S, Somridhivej B, Kucuktas H, Li P, Dunham R, Liu ZJ. 2008. Microarray analysis of gene expression in the blue catfish liver reveals early activation of the MHC class I pathway after infection with Edwardsiella ictaluri. Molecular Immunology 45: 553-566.
Liu ZJ. 2008. Chapter 3, Catfish. Pp. 85-100. In: The Genome: A Series on Genome Mapping, Molecular Breeding & Genomics of Economic Species (C. Kole, Kocher eds.) Vol. 6, Oxford & IBH and Science Pub. Inc..
He C., Ge L, Zhou Z, X Mu Y, Liu W, Gao X, and Liu ZJ. 2008. Sequence and organization of the complete mitochondrial genome of spotted halibut (Verasper variegatus) and barfin flounder (Verasper moseri). DNA Sequence 19:246-255.

Progress 10/01/03 to 09/30/08

Outputs
OUTPUTS: This project has been renewed under a different project number ALA016-2-08030. PARTICIPANTS: This project has been renewed under a different project number ALA016-2-08030. TARGET AUDIENCES: This project has been renewed under a different project number ALA016-2-08030. PROJECT MODIFICATIONS: This project has been renewed under a different project number ALA016-2-08030.

Impacts
This project has been renewed under a different project number ALA016-2-08030.

Publications

No publications reported this period

Progress 01/01/07 to 12/31/07

Outputs
Progress toward Objective 1: Enhance and integrate genetic and physical maps of agriculturally important animals for cross species comparisons and sequence annotation: On the basis of previously published framework genetic linkage maps, we have mapped over 300 microsatellite markers derived from ESTs. As ESTs represent known genes, mapping of EST-associated microsatellites allow comparative genome analysis. Manuscript on this work is under revision. We have also genotyped several hundreds of microsatellites derived from BAC-end sequences in effort to integrate the genetic linkage and physical maps (see below). Characterization of the channel catfish BAC library CHORI 212: The library has an average insert size of 161 kb, and provides 10.6-fold coverage of the channel catfish haploid genome. Screening of 32 genes using overgo or cDNA probes indicated that this library had a good representation of the genome as all tested genes existed in the library. A bacterial artificial chromosome (BAC) contig-based physical map of the channel catfish (Ictalurus punctatus) genome was generated with 5.6 genome coverage. A total of 3,307 contigs was assembled using a cutoff value of 1e-20. Each contig contains an average of 9.25 clones with an average size of 291 kb. The combined contig size for all contigs was 0.965 Gb, approximately the genome size of channel catfish. A total of 48,275 BAC end sequences have been generated. From these BAC end sequences, a total of 12,586 microsatellites were found, and after eliminating the microsatellites at the beginning and end of the sequence, a total of 5,875 distinct BAC-anchored microsatellites with sufficient flanking sequences for primer design was obtained. Progress toward Objective 2: Facilitate integration of genomic, transcriptional, proteomic and metabolomic approaches toward better understanding of biological mechanisms underlying economically important traits: A major achievement of the catfish genome community was their success in the approval of a EST project by the Joint Genome Institute under its Community Sequencing Program. This project will sequence 300,000 EST clones from catfish, of which 200,000 will be sequenced from channel catfish and 100,000 will be sequenced from blue catfish. John Liu (Auburn University), Geoff Waldbieser (USDA-ARS Catfish Genetics Unit), Melanie Wilson (University of Mississippi Medical Cenetr), Sylvie Quiniou (USDA-ARS Catfish Genetics Unit), and John Trant (University of Maryland) served as principal investigators for this project with 78 participants. This project is now coming close to its completion. Almost 300,000 EST sequences have been generated, and the remaining sequencing is well planned to completion in a couple of months. Progress Toward Objective 3: Facilitate and implement bioinformatic tools to extract, analyze, store and disseminate information. (See Attachment 1 for more details on objectives.): John Liu's lab continues their efforts on development of comparative genome tools such as chromosome-anchored ESTs of catfish. In this last year, Dr. Zhiliang Hu of Iowa State University trained our students on database construction.

Impacts
Several major achievements in this project will set as major milestones in catfish genome research. The first being the construction of the catfish physical map containing approximately 3307 contigs; the second is the assessment of the repeat structure of the catfish genome. In addition to our previously reported tandem repeats of Xba elements that account for about 5% of the catfish genome, we have evaluated the Mermaid and Merman interspersed repeats. In this work, we have also assessed the status of Tc1/mariner transposons in the catfish genome. They accounted for 4.2% of the catfish genome in base pairs, and 0.6% of the catfish transcriptome. These milestones will advance catfish genome research, making the catfish genome ready to be completely sequenced. These studies of genome characterization set the foundation to fully sequence the catfish genome.

Publications

Peatman E, Terhune J, Baoprasertkul P, Xu P, Nandi S, Wang S, Somridhivej B, Kucuktas H, Li P, Dunham R, Liu ZJ. 2008. Microarray analysis of gene expression in the blue catfish liver reveals early activation of the MHC class I pathway after infection with Edwardsiella ictaluri. Molecular Immunology 45: 553-566.
Peatman E., and Liu ZJ. 2007. Evolution of CC chemokines in teleost fish: a case study in gene duplication and implications for immune diversity. Immunogenetics 59: 613-623.
Liu ZJ. 2006. Transcriptome characterization through the generation and analysis of expressed sequence tags: Factors to consider for a successful EST project. Israel Journal of Aquaculture-Bamidgeh 58:328-341.
Baoprasertkul P, Peatman E, Somridhivej B, Liu ZJ. 2006. Toll-like receptor 3 and TICAM genes in catfish: species-specific expression profiles following infection with Edwardsiella ictaluri. Immunogenetics 58:817-830.
Baoprasertkul, B, Peatman E, Abernathy J, Liu ZJ. 2007. Structural characterization and expression analysis of Toll-like receptor 2 gene from catfish. Fish and Shellfish Immunology 22:418-426.
Abernathy J, Xu P, Li P, Xu, D., Kucuktas H, Klesius, P., Arias, C., and Liu ZJ. 2007. Generation and analysis of expressed sequence tags from the ciliate protozoan parasite Ichthyophthirius multifiliis. BMC Genomics 8:176.
Peatman E, Baoprasertkul P, Terhune J, Xu P, Nandi S, Kucuktas H, Li P, Wang S, Somridhivej B, Dunham R, Liu, ZJ. 2007. Expression analysis of the acute phase response in channel catfish (Ictalurus punctatus) after infection with a Gram negative bacterium. Developmental and Comparative Immunology 31:1183-1196.
Baoprasertkul P, Xu P, Peatman E, Kucuktas H, Liu ZJ. 2007. Divergent Toll-like receptors in catfish (Ictalurus punctatus): TLR5S, TLR20, TLR21. Fish Shellfish Immunology 23:1218-1230.

Progress 01/01/06 to 12/31/06

Outputs
Progress toward Objective 1: Enhance and integrate genetic and physical maps of agriculturally important animals for cross species comparisons and sequence annotation: The physical mapping project has two major objectives: 1) to generate a large number of BAC end sequences and 2) to produce a BAC-contig-based catfish physical map using restriction fingerprints. To this end, we have completed objective 1. In John Liu's lab, 25,195 BAC ends were sequenced, generating 20,366 clean BAC end sequences (BES) with an average read length of 557 bp after trimming. A total of 11.4 million bp were generated representing approximately 1.2% of the catfish genome. Microsatellites were detected in 17.5% of BES, providing valuable resources for map integration. A total of 1,130 unique genes were identified from the BES at cut off value of 1 x 10-10. Additional 747 gene hits were identified with a p-value between 10-5 to 10-10. Catfish BACs were anchored to the zebrafish and Tetraodon genome sequences, revealing 16% and 8.2% significant hits (E < e-5), respectively. For objective 2 of the physical mapping project, we have prepared BAC DNA from more than 40,000 clones. We have used a four-restriction enzyme, four-fluorescence labeling system for fingerprinting. To date, we have completed restriction fingerprinting of all the 40,000 clones, generating over 34,000 good fingerprints for the construction of the contigs. We have assessed the repeat structure of the catfish genome. Through use of PCR amplification and sequencing, assessment of random BAC end sequences equivalent to 1.2% genome coverage, and screening of over 45,000 catfish ESTs, a significant proportion of Tc1-like elements and their associated transcripts were captured. Up to 4.2% of the catfish genome in base pairs appears to be composed of Tc1-like transposon-related sequences and a significant fraction of the catfish cellular mRNA, approximately 0.6%, was transcribed from transposon-related sequences in both sense and antisense orientations. Progress toward Objective 2: Facilitate integration of genomic, transcriptional, proteomic and metabolomic approaches toward better understanding of biological mechanisms underlying economically important traits: Work in John Liu's lab was focused on the development of genome resources including previously prepared 23 cDNA libraries from various tissues, and construction of four normalized cDNA libraries to support the JGI approved large-scale catfish EST project. Using existing EST as resources, comparative sets of chromosome-specific ESTs were identified by anchoring catfish ESTs to Tetraodon genome. Much effort was made to characterization of innate immune genes and analysis of their expression in the resistant blue catfish as compared to expression in the susceptible channel catfish after infection with the most serious bacterial disease enteric septicemia of catfish (ESC).

Impacts
Several major achievements in this project will set as major milestones in the history of catfish genome research. The first being the construction of the first catfish physical map containing approximately 3200 contigs; the second is the assessment of the repeat structure of the catfish genome. In addition to our previously reported tandem repeats of Xba elements that account for about 5% of the catfish genome, we have evaluated the Mermaid and Merman interspersed repeats. In this work, we have also assessed the status of Tc1/mariner transposons in the catfish genome. They accounted for 4.2% of the catfish genome in base pairs, and 0.6% of the catfish transcriptome. These milestones will advance catfish genome research, making the catfish genome ready to be completely sequenced.

Publications

Xu, P., Wang, S., Liu, L., Peatman, E., Somridhivej, B., Thimmapuram, J., Gong, G., Liu, Z.J. 2006. Channel catfish BAC end sequences for marker development and assessment of syntenic conservation with other fish species. Animal Genetics 37, 321-326.
Hou, L., Bi, X., Zou, X., He, C., Yang, L. Qu, R., Liu Z.J. 2006. Molecular systematics of bisexual Artemia populations. Aquaculture Research 37, 671-680.
Arias, C. R., Abernathy, and Liu, Z. J. 2006. Combined use of 16S ribosomal DNA and automated ribosomal intergenic spacer analysis (ARISA) to study the bacterial community in catfish ponds. Letters in Applied Microbiology 43:287-92.
Peatman, E., and Liu, Z.J. 2006. CC chemokines in zebrafish: evidence for extensive intrachromosomal gene duplications. Genomics 88, 381-385.
Liu, Z.J. 2006. Catfish genome mapping toward genetic enhancement of broodstocks. In The Genome: A Series on Genome Mapping, Molecular Breeding & Genomics of Economic Species (C. Kole ed.) Vol. 6, Oxford & IBH and Science Pub. Inc.
Simmons, M., Mickett K., Kucuktas H., Li P., Dunham R., Liu, Z.J. 2006. Comparison of domestic and wild catfish populations provide no evidence for genetic impact. Aquaculture 252,133-146.
Bao B., Peatman, E., Xu P., Baoprasertkul B., Wang G., Liu Z.J. 2006. Characterization of 23 CC chemokine genes and analysis of their expression in channel catfish (Ictalurus punctatus). Developmental and Comparative Immunology 30, 783-796.
Peatman E.,, Bao B., Xu P., Baoprasertkul P., Liu Z.J. 2006. Catfish CC chemokines: genomic clustering, duplications, and expression after bacterial infection with Edwardsiella ictaluri. Molecular Genetics and Genomics 275, 297-309.
Liu, Z.J., Peatman, E. 2006. Chemokines in fish: a rapidly expanding repertoire. pp. 121-144. In Focus on Immunology Research, (Editor, Barbara A. Veskler), Nova Science Publishers, Inc., New York.
Wang Q., Wang Y., Xu P., Liu Z.J. 2006. NK-lysin of channel catfish: gene triplication, sequence variation, and expression analysis. Molecular Immunology 43, 1676-1686.
Wang Y., Wang Q., Baoprasertkul P., Peatman E., Liu Z.J. 2006. Genomic organization, gene duplication, and expression analysis of interleukin-1beta in channel catfish (Ictalurus punctatus). Molecular Immunology 43: 1653-1664.

Progress 01/01/05 to 12/31/05

Outputs
Progress toward Objective 1: The framework genetic linkage map was made with channel catfish x blue catfish interspecific families (Liu et al., 2003). Molecular markers of various kinds have been added in the past year to the linkage maps, especially the gene-associated type I markers.The physical mapping project involving BAC end sequencing and BAC fingerprinting was initiated a year ago. To date, 25,195 BAC ends were sequenced, generating 20,366 clean BAC end sequences (BES) with an average read length of 557 bp after trimming. A total of 11.4 million bp were generated representing approximately 1.2% of the catfish genome. A total of 1,130 unique genes were identified from the BES at cut off value of 1 x 10-10. Additional 747 gene hits were identified with a p-value between 10-5 to 10-10. Catfish BACs were anchored to the zebrafish and Tetraodon genome sequences, revealing 16% and 8.2% significant hits (E < e-5), respectively. A total of 1,074 and 773 significant hits were unique to the zebrafish and Tetraodon genomes, respectively. Fingerprinting of CHORI 212 BAC library is under way. Progress toward Objective 2: A major achievement of the catfish genome community was their success in the approval of a EST project by the Joint Genome Institute under its Community Sequencing Program. This project will sequence 300,000 EST clones from catfish, of which 210,000 will be sequenced from channel catfish and 90,000 will be sequenced from blue catfish. John Liu (Auburn University) served as principal investigator for this application with 4 co-P.I. and 78 participants. Work in John Liu lab was focused on the development of genome resources including previously prepared 23 cDNA libraries from various tissues, and construction of four normalized cDNA libraries to support the JGI approved large-scale catfish EST project. Using existing EST as resources, comparative sets of chromosome-specific ESTs were identified by anchoring catfish ESTs to Tetraodon genome. Much effort was made to characterization of innate immune genes and analysis of their expression in the resistant blue catfish as compared to expression in the susceptible channel catfish after infection with the most serious bacterial disease enteric septicemia of catfish (ESC). A total of 26 CC chemokine genes, 6 CXC genes, 4 antimicrobial peptide genes, interleukin-1 beta gene, 23 selenoprotein genes, 6 toll-like receptors, and a few dozens of other genes were completely sequenced, mapped to BACs, and expression was analyzed. Conserved syntenies were analyzed comparatively with zebrafish or Tetraodon genomes. Progress Toward Objective 3: We continue our efforts on development of comparative genome tools such as chromosome-anchored ESTs of catfish.

Impacts
The BAC end sequencing has led to the assessment of the catfish genome that will lead to the sequencing of the entire catfish genome. The comparative genome resources will make comparative mapping possible in catfish thereby making savings in millions for genome research of catfish.

Publications

Wang Q, Bao B, Wang Y, Peatman E, and Liu Z.J. 2006. Characterization of a NK-lysin antimicrobial peptide gene from channel catfish. Fish and Shellfish Immunology 20:419-426.
Bao B, Peatman E., Xu P, Li P, Zeng H, He C, and Liu Z.J. 2006. The catfish liver-expressed antimicrobial peptide 2 (LEAP-2) gene is expressed in a wide range of tissues and developmentally regulated. Molecular Immunology 43, 367-377.
Bao B., Yang G, Liu ZJ, Li s, Wang Z, Ren D. 2005. Isolation of Sfrs3 gene and its differential expression during metamorphosis involving eye migration of Japanese flounder Paralichthys olivaceus. Biochimica et Biophysica Acta 1725: 64-70.
Peatman, E., Bao, B., Baoprasertkul, P., and Liu, Z.J. 2005. In silico identification and expression analysis of 12 novel CC chemokines in catfish. Immunogenetics 57:409-419.
Bao B, Peatman E, Li P, He C, and Liu Z.J. 2005. Catfish hepcidin gene is expressed in a wide range of tissues and exhibits tissue-specific upregulation after bacterial infection. Developmental and Comparative Immunology 29:939-950.
Xu P, Bao B, He Q, Peatman E, He C, Liu Z.J. 2005. Characterization and expression analysis of bactericidal permeability-increasing protein (BPI) antimicrobial peptide gene from channel catfish Ictalurus punctatus. Developmental and Comparative Immunology 29:865-878.
Baoprasertkul P., He C., Peatman E., Zhang S., Li P., Liu Z.J. 2005. Constitutive expression of three novel catfish CXC chemokines: homeostatic chemokines in teleost fish. Molecular Immunology 42:1355-1366.
Liu, Z.J. 2005. Genetic Analysis-Amplified Fragment Length Polymorphism (AFLP), Chapter 19, In: Stock Identification Methods, Steve Cadrin, Keven D. Friedland, John Waldman, (eds.), Elsevier Press, New York, pp.389-411.

Progress 01/01/04 to 12/31/04

Outputs
Expressed sequence tags (ESTs) are valuable genome resources. We have generated 31,451 catfish ESTs including 21,147 from channel catfish and 10,304 from blue catfish. With the existing catfish ESTs, this project brings the total number of ESTs of catfish to over 43,000. For the purpose of cDNA microarrays, the channel and blue catfish ESTs were combined because they are extremely similar in sequence identities. Over 20,000 unique sequences have been identified from this project. Catfish ESTs are rich in microsatellites and single nucleotide polymorphisms (SNPs). While SNP analysis is still under way, searches of microsatellites resulted in identification of 4,855 ESTs containing microsatellites, which included 569 contigs and 3,534 singletons and together representing 4,103 unique sequences. These microsatellites should be useful for linkage mapping and for comparative mapping because they are associated with genes. We are currently conducting bioinformatic analysis for annotation, gene ontology, SNPs, and the unigene list. We have also initiated a physical mapping project in catfish using BAC-based fingerprints. However, additional funding is required for completion of the project.

Impacts
To date, we have developed large numbers of DNA markers, a genetic linkage map, and a collection of ESTs with over 25,000 unique genes sequences. These genomic resources will be very important toward genome enablement of catfish. Together with our efforts in QTL mapping and identification of important genes from catfish, these genomic studies will lead to the development of genome-based technologies that are needed for genetic improvement of catfish broodstocks.

Publications

Serapion, J., Kucuktas, H., Feng, J., Liu, Z.J. 2004. Bioinformatic Mining of Type I Microsatellites from Expressed Sequence Tags of Channel Catfish (Ictalurus punctatus). Marine Biotechnology 6, 364-377.
Peatman, E., Wei, X., Feng, J., Liu, L., Kucuktas, H., Li, L., He, C., Rouse, D., Wallace, R., Dunham, R., Liu, Z.J. 2005. Development of Expressed Sequence Tags (ESTs) from Eastern Oyster (Crassostrea virginica): Lessons Learned from Previous Efforts. Marine Biotechnology, in press.
Kocabas, A., Dunham, R., Liu, Z.J. 2005. Alterations in gene expression in the brain of white catfish (Ameirus catus) in response to cold acclimation. Marine Biotechnology, in press.
Liu, Z.J. 2004. Genetic Analysis-Amplified Fragment Length Polymorphism (AFLP), pp. 389-411, In: Stock Identification Methods, Steve Cadrin, Keven D. Friedland, John Waldman, (eds.), Elsevier Press, New York.
Baoprasertkul, P., Peatman, E., He, C., Kucuktas, H., Li, P., Chen, L., Simmons, M., and Liu, Z.J. 2004. Sequence analysis and expression of a CXC chemokine in resistant and susceptible catfish after infection of Edwardsiella ictaluri. Developmental and Comparative Immunology 28, 769-780.
Serapion, J., Waldbieser, G.C., Wolters, W., Liu, Z.J. 2004. Development of Type I markers in channel catfish through intron sequencing. Animal Genetics 35, 463-466.
Chen, L., He, C., Baoprasertkul, P., Xu, P., Li, P., Serapion, J., Waldbieser G., Wolters, W., Liu, Z.J. 2005. Analysis of a catfish gene resembling interleukin-8: cDNA cloning, gene structure, and expression after infection with Edwardsiella ictaluri. Developmental and Comparative Immunology 29, 135-142.
Liu, Z.J., Cordes, J. 2004. DNA marker technologies and their applications in aquaculture genetics. Aquaculture 238, 1-37.
He, C., Peatman, E., Baoprasertkul, P., Kucuktas, H., and Liu, Z.J. 2004. Multiple CC chemokines in channel catfish and blue catfish as revealed by analysis of expressed sequence tags. Immunogenetics 56, 379-387.
Pridgeon J.W., Liu, Z.J., and Liu, N. 2004. Identification of Mariner Elements from House Flies ( Musca domestica ) and German Cockroaches (Blattella germanica). Insect Molecular Biology 13, 443-447.
Chen, L., Jiang, H., Zhou, Z., Li, K., Li, K., Deng, G.Y. and Liu, Z.J. 2004. Purification of vitellin from the ovary of Chinese mitten-handed crab, Eriocheir sinensis, and development of an anti-vitellin ELISA. Comparative Biochemistry and Physiology B Biochemistry and Molecular Biology 138, 305-311.
Karsi, A., Waldbieser, G., Small, B., Liu, Z.J., and Wolters, W. 2004. Molecular cloning of proopiomelanocortin cDNA and multi-tissue mRNA expression in channel catfish. General and Comparative Endocrinology 137, 312-321.