Table 1 Functional roles of meiotic genes searched in the diatom genomes

 Mcm2-7

Mcm2-7 form hexamer and are involved in DNA replication [28]

 Mcm8

Mcm8 and Mcm9 are involved in meiotic recombination [81, 83, 84]

 Mcm9

Mcm8 and Mcm9 are involved in meiotic recombination [83, 84]

 Smc1-Smc3

Part of sister chromatids cohesin subunit, act as a heterodimer

 Smc2-Smc4

Heterodimer, essential for chromosome assembly and segregation, part of core condensing subunits

 Smc5-Smc6

Heterodimer, involved in DNA repair and checkpoint response, binds to single stranded DNA (ssDNA)

 Pds5

Involved in maintenance of sister chromatid cohesion in late prophase

 Scc3

Interacts with cohesin complex Smc1-Smc3 and Rad21/Rec8 and helps in holding cohesin ring together

 Rec8/Syn1^a

Meiotic homolog of Rad21, involved in holding sister chromatids together during meiotic recombination

 Rad21

Holds Smc1 and Smc3 together thus holding sister chromatids together during meiosis and mitosis

 Spo11-1^a

Creates double strand breaks (DSBs) in homologous chromosomes in meiotic recombination

 Spo11-2^a

Creates DSBs in homologous chromosomes in meiotic recombination in plants

 Spo11-3/Top VIA

Required for endoreduplication of DNA

 Rad50

DNA binding ATPase, holds broken DNA strands while Mre11 trims DSBs

 Mre11

3′–5′ dsDNA exonuclease and ssDNA endonuclease; trims 

broken DNA ends after DSBs and hairpins

 Xrs2/Nbs1

Component of Mre11-Rad50-Xrs2, involved in homologous recombination and non-homologous end joining [125]

 Mer3^a

DNA helicase that unwinds double stranded DNA during meiotic cross over formation [126]

 Hop1^a

Binds to DSBs, component of lateral and axial synaptonemal complex

 Red1/Asy3^a

Component of synaptonemal complex, interacts with Hop1 and facilitates meiosis I chromosome disjunction [48, 49]

 Zip1/Zyp1^a

Transverse filament protein involved in synaptonemal complex formation during meiosis [45, 47]

 Zip2^a,Zip3/Hei10^a,

Zip4^a

Components of synaptonemal complex required for morphogenesis of the synaptonemal complex [45, 64]

 Dmc1^a

Meiotic member of Rad51-RadA-RecA superfamily of proteins, binds to ssDNA end of DSBs and is involved in inter-homologous recombination

 Hop2^a

Homology search together with Mnd1, works in Dmc1 dependent homology search pathway downstream of Rad51

 Mnd1^a

Together with Hop2 works in homology searching and is also required in stable DNA heteroduplex

 Msh4^a-Msh5^a

Heterodimer, together with Mlh1/Mhl3 heterodimer directs Holliday junction resolution with crossover interference

 Rad51, Xrcc2, Xrcc3

Mediate homologous pairing and strand invasion, involved in DNA repair mechanisms in mitosis and meiosis. Part of Rad51-RadA-RecA superfamily, exhibit multiple paralogs

 Rad52

Binds to ssDNA and initiates homologous recombination, stimulates Rad51 mediated strand invasion

 Rad1

5′-3′ endonuclease, required in meiotic crossing over, functions during nucleotide excision repair

 Msh2

Forms heterodimer with Msh3 or Msh6, works in DNA mismatch repair

 Msh6

Forms heterodimer with Msh2, works in DNA mismatch repair

 Mlh1

DNA mismatch repair protein, forms heterodimers with Mlh2, Mlh3 and Pms1, interacts with Msh2/Msh6 and Msh4/Msh5

 Mlh2

DNA mismatch repair protein, forms heterodimer with Mlh1

 Mlh3

Forms heterodimer with Mlh1, interacts with Msh4/Msh5 to promote meiotic crossovers

 Pms1

Forms heterodimer with Mlh1, involved in DNA mismatch repair

 Mms4/Eme1

Interacts with Mus81 and is involved in interference insensitive, class II crossovers during meiotic recombination [104]

 Mus81

Interacts with Mms4 and is involved in interference insensitive, class II crossovers during meiotic recombination [104]

 Fancm

DNA helicase required for genome stability, involved in limiting meiotic crossovers [127]

 Fen1

Fen1 functions during homologous recombination mediated DNA repair by removing divergent sequences at DNA break ends [128]

 Exo1

A double-stranded DNA-specific 5′–3′ exonuclease [129]

 Dna2

A conserved DNA nuclease involved in DNA stability [130]

 Brca1

Regulates meiotic spindle assembly [131]

 Brca2

Involved in DNA damage-induced Rad51 foci formation during meiosis [132]