title: QTL for white spot syndrome virus resistance and the sex-determining locus in the Indian black tiger shrimp (Penaeus monodon).
abstract: BACKGROUND
  Shrimp culture is a fast growing aquaculture sector, but in recent years there has been a shift away from tiger shrimp Penaeus monodon to other species. This is largely due to the susceptibility of P. monodon to white spot syndrome virus disease (Whispovirus sp.) which has impacted production around the world. As female penaeid shrimp grow more rapidly than males, mono-sex production would be advantageous, however little is known about genes controlling or markers associated with sex determination in shrimp. In this study, a mapped set of 3959 transcribed single nucleotide polymorphisms were used to scan the P. monodon genome for loci associated with resistance to white-spot syndrome virus and sex in seven full-sibling tiger shrimp families challenged with white spot syndrome virus.
  
  
  RESULTS
  Linkage groups 2, 3, 5, 6, 17, 18, 19, 22, 27 and 43 were found to contain quantitative trait loci significantly associated with hours of survival after white spot syndrome virus infection (P < 0.05 after Bonferroni correction). Nine QTL were significantly associated with hours of survival. Of the SNPs mapping to these and other regions with suggestive associations, many were found to occur in transcripts showing homology to genes with putative immune functions of interest, including genes affecting the action of the ubiquitin-proteasome pathway, lymphocyte-cell function, heat shock proteins, the TOLL pathway, protein kinase signal transduction pathways, mRNA binding proteins, lectins and genes affecting the development and differentiation of the immune system (eg. RUNT protein 1A). Several SNPs significantly associated with sex were mapped to linkage group 30, the strongest associations (P < 0.001 after Bonferroni correction) for 3 SNPs located in a 0.8 cM stretch between positions 43.5 and 44.3 cM where the feminisation gene (FEM-1, affecting sexual differentiation in Caenorhabditis elegans) mapped.
  
  
  CONCLUSIONS
  The markers for disease resistance and sexual differentiation identified by this study could be useful for marker assisted selection to improve resistance to WSSV and for identifying homogametic female individuals for mono-sex (all female) production. The genes with putative functions affecting immunity and sexual differentiation that were found to closely map to these loci provide leads about the mechanisms affecting these important economic traits in shrimp.
authors.affiliation: Nofima, PO Box 210, 1431 Ås, Norway. nick.robinson@nofima.no.
authors.forename: Nicholas A
authors.initials: NA
authors.lastname: Robinson
authors.forename: Gopalapillay
authors.initials: G
authors.lastname: Gopikrishna
authors.forename: Matthew
authors.initials: M
authors.lastname: Baranski
authors.forename: Vinaya Kumar
authors.initials: VK
authors.lastname: Katneni
authors.forename: Mudagandur S
authors.initials: MS
authors.lastname: Shekhar
authors.forename: Jayakani
authors.initials: J
authors.lastname: Shanmugakarthik
authors.forename: Sarangapani
authors.initials: S
authors.lastname: Jothivel
authors.forename: Chavali
authors.initials: C
authors.lastname: Gopal
authors.forename: Pitchaiyappan
authors.initials: P
authors.lastname: Ravichandran
authors.forename: Thomas
authors.initials: T
authors.lastname: Gitterle
authors.forename: Alphis G
authors.initials: AG
authors.lastname: Ponniah
mesh_terms: D000818:Animals; D060829:Arthropod Proteins / Q000235:genetics; D060467:Disease Resistance / Q000235:genetics*; D005260:Female; D056426:Genetic Loci; D054884:Host-Pathogen Interactions; D015810:Linkage Disequilibrium; D008297:Male; D008969:Molecular Sequence Data; D033561:Penaeidae / Q000235:genetics* / Q000276:immunology / Q000821:virology; D020641:Polymorphism, Single Nucleotide; D040641:Quantitative Trait Loci; D012732:Sex Determination Analysis; D019849:Sex Determination Processes; D046848:White spot syndrome virus 1 / Q000276:immunology*
chemical_list: D060829:Arthropod Proteins