The genomic structure of the highly-conserved dmrt1 gene in Solea senegalensis (Kaup, 1868) shows an unexpected intragenic duplication

• Published in: PloS one 2020-11, Vol.15 (11), p.e0241518
• Main Authors: Cross, Ismael, García, Emilio, Rodríguez, María E, Arias-Pérez, Alberto, Portela-Bens, Silvia, Merlo, Manuel A, Rebordinos, Laureana
• Format: Article
• Language: English
• Subjects: Alternative splicing; Alternative Splicing - genetics; Amino Acid Sequence; Animal species; Animals; Base Sequence; Biology and Life Sciences; Birds; Chromosomes; Conserved Sequence - genetics; Deoxyribonucleic acid; DNA; DNA, Complementary - genetics; Evolution; Exons; Exons - genetics; Fish; Flatfishes - genetics; Functional analysis; Gene Duplication; Gene expression; Gene Library; Gene Regulatory Networks; Genetic aspects; Genetic research; Genetic Variation; Genome; Genomes; Gonads; Identification and classification; Introns; Isoforms; miRNA; Nucleotide sequence; Nucleotides; Open reading frames; Ovaries; Phylogeny; Proteins; Repetitive Sequences, Nucleic Acid - genetics; Reproduction (copying); Research and Analysis Methods; Sex; Sex chromosomes; Sex determination; Sex determination (Genetics); Sex differentiation; Sexes; Solea senegalensis; Soleidae; Species; Transcription factors; Transcription Factors - chemistry; Transcription Factors - genetics; Y chromosomes
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0241518

Knowing the factors responsible for sex determination in a species has significant theoretical and practical implications; the dmrt1 gene (Doublesex and Mab-3 (DM)-related Transcription factor 1) plays this role in diverse animal species. Solea senegalensis is a commercially important flat fish in which females grow 30% faster than males. It has 2n = 42 chromosomes and an XX / XY chromosome system for sex determination, without heteromorph chromosomes but with sex proto-chromosome. In the present study, we are providing the genomic structure and nucleotide sequence of dmrt1 gene obtained from cDNA from male and female adult gonads. A cDNA of 2027 containing an open-reading frame (ORF) of 1206 bp and encoding a 402 aa protein it is described for dmrt1 gene of S. senegalensis. Multiple mRNA isoforms indicating a high variable system of alternative splicing in the expression of dmrt1 of the sole in gonads were studied. None isoforms could be related to sex of individuals. The genomic structure of the dmrt1 of S. senegalensis showed a gene of 31400 bp composed of 7 exons and 6 introns. It contains an unexpected duplication of more than 10399 bp, involving part of the exon I, exons II and III and a SINE element found in the sequence that it is proposed as responsible for the duplication. A mature miRNA of 21 bp in length was localized at 336 bp from exon V. Protein-protein interacting networks of the dmrt1 gene showed matches with dmrt1 protein from Cynoglossus semilaevis and a protein interaction network with 11 nodes (dmrt1 plus 10 other proteins). The phylogenetic relationship of the dmrt1 gene in S. senegalensis is consistent with the evolutionary position of its species. The molecular characterization of this gene will enhance its functional analysis and the understanding of sex differentiation in Solea senegalensis and other flatfish.