Linkage Mapping Identifies the Sex Determining Region as a Single Locus in the Pennate Diatom Seminavis robusta

The pennate diatom Seminavis robusta, characterized by an archetypical diatom life cycle including a heterothallic mating system, is emerging as a model system for studying the molecular regulation of the diatom cell and life cycle. One of its main advantages compared with other diatom model systems is that sexual crosses can be made routinely, offering unprecedented possibilities for forward genetics. To date, nothing is known about the genetic basis of sex determination in diatoms. Here, we report on the construction of mating type-specific linkage maps for S. robusta, and use them to identify a single locus sex determination system in this diatom. We identified 13 mating type plus and 15 mating type minus linkage groups obtained from the analysis of 463 AFLP markers segregating in a full-sib family, covering 963.7 and 972.2 cM, respectively. Five linkage group pairs could be identified as putative homologues. The mating type phenotype mapped as a monogenic trait, disclosing the mating type plus as the heterogametic sex. This study provides the first evidence for a genetic sex determining mechanism in a diatom.

[1]  Ying Sun,et al.  CONSTRUCTION AND CHARACTERIZATION OF A TENTATIVE AMPLIFIED FRAGMENT LENGTH POLYMORPHISM–SIMPLE SEQUENCE REPEAT LINKAGE MAP OF LAMINARIA (LAMINARIALES, PHAEOPHYTA) 1 , 2009, Journal of phycology.

[2]  J. Ooijen,et al.  JoinMap® 4, Software for the calculation of genetic linkage maps in experimental populations , 2006 .

[3]  D. Balding,et al.  Genome-wide association mapping to candidate polymorphism resolution in the unsequenced barley genome , 2010, Proceedings of the National Academy of Sciences.

[4]  D. Mann,et al.  Auxosporulation of Licmophora communis (Bacillariophyta) and a review of mating systems and sexual reproduction in araphid pennate diatoms , 2004 .

[5]  David G. Mann,et al.  The species concept in diatoms , 1999 .

[6]  A. Falciatore,et al.  Gene silencing in the marine diatom Phaeodactylum tricornutum , 2009, Nucleic acids research.

[7]  M. Foulongne-Oriol.  Genetic linkage mapping in fungi: current state, applications, and future trends , 2012, Applied Microbiology and Biotechnology.

[8]  Alfonso,et al.  AFLP Linkage Map of the Oomycete Phytophthora infestans , 1997, Fungal genetics and biology : FG & B.

[9]  S. Whisson,et al.  Inheritance and mapping of 11 avirulence genes in Phytophthora sojae. , 2002, Fungal genetics and biology : FG & B.

[10]  D. Mann,et al.  Experimental studies on sexual reproduction in diatoms. , 2004, International review of cytology.

[11]  Leszek Rychlewski,et al.  The Phaeodactylum genome reveals the evolutionary history of diatom genomes , 2008, Nature.

[12]  D. Inzé,et al.  Physiological and Transcriptomic Evidence for a Close Coupling between Chloroplast Ontogeny and Cell Cycle Progression in the Pennate Diatom Seminavis robusta1[C][W][OA] , 2008, Plant Physiology.

[13]  John A. Raven,et al.  How do marine diatoms fix 10 billion tonnes of inorganic carbon per year , 2005 .

[14]  D. Inzé,et al.  Metabolomics enables the structure elucidation of a diatom sex pheromone. , 2013, Angewandte Chemie.

[15]  M. V. Eijk,et al.  AFLP technology for DNA fingerprinting , 2007, Nature Protocols.

[16]  Ulrich C. Klostermeier,et al.  Genome and low-iron response of an oceanic diatom adapted to chronic iron limitation , 2012, Genome Biology.

[17]  F. Govers,et al.  High-Density Genetic Linkage Maps of Phytophthora infestans Reveal Trisomic Progeny and Chromosomal Rearrangements , 2004, Genetics.

[18]  W. M. Lewis.  The Diatom Sex Clock and Its Evolutionary Significance , 1984, The American Naturalist.

[19]  J. Ehrman,et al.  Heterothallic and homothallic sexual reproduction in Tabularia fasciculata (Bacillariophyta). , 2010 .

[20]  Susana M. Coelho,et al.  A sequence-tagged genetic map for the brown alga Ectocarpus siliculosus provides large-scale assembly of the genome sequence. , 2010, The New phytologist.

[21]  K. Lamour,et al.  An Introduction to Reverse Genetic Tools for Investigating Gene Function. , 2005 .

[22]  Sarah K. Brown,et al.  A genetic map of the lettuce downy mildew pathogen, Bremia lactucae, constructed from molecular markers and avirulence genes. , 2003, Fungal genetics and biology : FG & B.

[23]  D. Mann,et al.  Genetic divergence and reproductive barriers among morphologically heterogeneous sympatric clones of Eunotia bilunaris sensu lato (Bacillariophyta). , 2008, Protist.

[24]  Koen Sabbe,et al.  SEXUAL REPRODUCTION, MATING SYSTEM, AND PROTOPLAST DYNAMICS OF SEMINAVIS (BACILLARIOPHYCEAE)1 , 2002 .

[25]  D. Mann,et al.  SEXUALITY, INCOMPATIBILITY, SIZE VARIATION, AND PREFERENTIAL POLYANDRY IN NATURAL POPULATIONS AND CLONES OF SELLAPHORA PUPULA (BACILLARIOPHYCEAE) , 1999 .

[26]  D. Charlesworth,et al.  The evolution of restricted recombination in sex chromosomes. , 2009, Trends in ecology & evolution.

[27]  David G. Mann,et al.  Evolution of the diatoms: insights from fossil, biological and molecular data , 2006 .

[28]  R. Voorrips.  MapChart: software for the graphical presentation of linkage maps and QTLs. , 2002, The Journal of heredity.

[29]  P. Vos,et al.  AFLP: a new technique for DNA fingerprinting. , 1995, Nucleic acids research.

[30]  Nicholas H. Putnam,et al.  The Genome of the Diatom Thalassiosira Pseudonana: Ecology, Evolution, and Metabolism , 2004, Science.

[31]  D. Inzé,et al.  In search of new tractable diatoms for experimental biology. , 2008, BioEssays : news and reviews in molecular, cellular and developmental biology.