RESUMO
Understanding the molecular underpinnings involved in the reproduction of the salmon louse is critical for designing novel strategies of pest management for this ectoparasite. However, genomic information on sex-related genes is still limited. In the present work, sex-specific gene transcription was revealed in the salmon louse Caligus rogercresseyi using high-throughput Illumina sequencing. A total of 30,191,914 and 32,292,250 high quality reads were generated for females and males, and these were de novo assembled into 32,173 and 38,177 contigs, respectively. Gene ontology analysis showed a pattern of higher expression in the female as compared to the male transcriptome. Based on our sequence analysis and known sex-related proteins, several genes putatively involved in sex differentiation, including Dmrt3, FOXL2, VASA, and FEM1, and other potentially significant candidate genes in C. rogercresseyi, were identified for the first time. In addition, the occurrence of SNPs in several differentially expressed contigs annotating for sex-related genes was found. This transcriptome dataset provides a useful resource for future functional analyses, opening new opportunities for sea lice pest control.
Assuntos
Copépodes/genética , Salmonidae/parasitologia , Caracteres Sexuais , Transcriptoma/genética , Animais , Sequência de Bases , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Masculino , Dados de Sequência Molecular , Controle de Pragas/métodos , Polimorfismo de Nucleotídeo Único/genéticaRESUMO
The California red abalone, Haliotis rufescens that belongs to the Haliotidae family, is the largest species of abalone in the world that has sustained the major fishery and aquaculture production in the USA and Mexico. This native mollusk has not been evaluated or assigned a conservation category even though in the last few decades it was heavily exploited until it disappeared in some areas along the California coast. In Chile, the red abalone was introduced in the 1970s from California wild abalone stocks for the purposes of aquaculture. Considering the number of years that the red abalone has been cultivated in Chile crucial genetic information is scarce and critical issues remain unresolved. This study reports and validates novel single nucleotide polymorphisms (SNP) markers for the red abalone H. rufescens using cDNA pyrosequencing. A total of 622 high quality SNPs were identified in 146 sequences with an estimated frequency of 1 SNP each 1000bp. Forty-five SNPs markers with functional information for gene ontology were selected. Of these, 8 were polymorphic among the individuals screened: Heat shock protein 70 (HSP70), vitellogenin (VTG), lysin, alginate lyase enzyme (AL), Glucose-regulated protein 94 (GRP94), fructose-bisphosphate aldolase (FBA), sulfatase 1A precursor (S1AP) and ornithine decarboxylase antizyme (ODC). Two additional sequences were also identified with polymorphisms but no similarities with known proteins were achieved. To validate the putative SNP markers, High Resolution Melting Analysis (HRMA) was conducted in a wild and hatchery-bred population. Additionally, SNP cross-amplifications were tested in two further native abalone species, Haliotis fulgens and Haliotis corrugata. This study provides novel candidate genes that could be used to evaluate loss of genetic diversity due to hatchery selection or inbreeding effects.