It seems obvious to recall the found genomic results in Ophiocomina nigra and Antedon bifida (Echinodermata) from a point of view of genomic evolution: 2 MHC class I genes (HLA-E, HLA-B), 2 MHC class II genes (HLA-DRB1, HLA-DQB1) appear in them in the past, at the Cambrian period.

Keywords: HLA-E, HLA-B, HLA-DQB1, HLA-DRB1

INTRODUCTION

Recently, it was shown that, HLA-DRB1 gene existed in Ophiocomina nigra [1], so HLA-DQB1 gene [2]. In the same manner we demonstrated the existence of HLA-E, HLA-B genes in Ophiocomina nigra and Antedon bifida [2]. It was correlated to the presence of IPA (Invertebrate Primitive Antibody) in Echinodermata [3,4]. Genesis of these works were recalling in this paper.

MATERIALS AND METHODS

Animals

Ophiocomina nigra (Ophuirid) and Antedon bifida (Crinoïd) were obtained at the station « Of Biologie Marine of Roscoff » France.

Obtention of ophuirid and crinoïd mRNA

Digestive coeca were excised from their bodies and mRNA was obtained from Uptizol (Interchim) then quality controls were operated.

Sequencing

Sequencing was made on Illumina Next Seq 500 with paired-end: 2. 75 bp. Transcriptome was assembled from RNA-Seq fastq files using Trinity v2.1.1 with default parameters [5]. A BLAST database was created with the assembled transcripts using make blastdb application from ncbi-blast+ (v2.2.31+). The sequences of transcripts of interest were then blasted against this database using blastn application from ncbi-blast+ with parameter word_size 7 [6].

RESULTS

MHC gene Class II appears in the genome of Ophiocomina nigra and Antedon bifida one, in a significant manner. The transcriptomes are given with their sequences. Ophiocomina nigra results show the “HLA-DRB1” transcriptome which possesses a short sequence but a significative one:

>TRINITY_DN4807_c1_g1_i1

5'CATATAGTTTAGGGGGTTATAAAAAAATGACTCCGGTTACTGACATATTTGGGACCCCAA

CTGTCCAAAGAAAATTATAGCCCCTATAAATTATAATTTATTAATTTTTGTTTTCTCTTG

TATAGGGACCAGAGCCAATCCCACTGGAAGTTAGGGCACGAGCAGTCAAAGACCAATTTT

AAATGTAAAAAAAAAAAAAAAAAAAAATAAAAAATTAAAAAAAAAAAAAAAAAAATAAAA

AATTAAAAAAAAAAAAAAAAAAATAAA3'

Secondly, a HLA-DQB1 class II gene was found in O. nigra: The sequence of the transcriptome follows

>TRINITY_DN20883_c0_g1_i1 HLA-DQB1

5'GTAAAACAGCATTTCATCTGAAAAGAAATTCAATGTCCAAAGTTCAAAAACTCTGTGAAG

ACTTGAATGCAAAAAGTACTCAAGTCCATCACATATTTGGCATTTTTAGATATGATCTTC

CAAAGATTTTAAAATAAAACAAAAGAAAAACCAAAAGAAGAAAAAAATTTAACAAAAAAA

TAAAGGGCCAAAAAAAATTTTAAAAAAAAAAAAACCCCCATTTTTTTTGGGTCTAAAAAA

AAAAAAAAAAAAAAAATCGC3'

MHC class I genes appear in the Table 1 in Antedon bifida.

Class I, HLA-E, HLA-B, Transcriptomes are given in 5’-3’

First HLA-E:

>TRINITY_DN19334_c8_g2_i1 HLA-E

5'TGTAATCCCAGCACTTTGGGAGGCCGAGGCGGGCGGATCACGAGGTCAGGAGATCGAGAC

CATCCTGGCTAACACAGTGAAACCCCGTCTCTACTAAAAATACAAAAAATTAGCCGGGCG

TGGTGGCGGGCGCCTGTAGTCCCAGCTACTCGGGAGGCTGAGGCAGGAGAATGGCGTGAA

CCCGGGAGGCGGAGCTTGCAGTGAGCCGAGATCGCGCCACTGCACTCCAGCCTGGGCGAC

AGAGCGAGACTCTGTCTCAAAAAAAAAAAAAAAAAAAAAAA3'

Secondly HLA-B:

>TRINITY_DN15013_c0_g1_i1 HLA-B

5'GCCGAATATGATGCAGAGGTATCAGGGGGTGAAGCATCTGGAGGTGAGGTATCGGCAGGA

GAGGCATCTGGGGGAGAAGCTGAACAATCTGACAATGAAAGCGATTAGATAACATTTTTT

TAATTCTAGTTGCAGCCTAAATATTTCGATATTACTTTTTTTTACTAGTTGAATGATTAA

AAAAGAAAGCAACAACTGTGGTAATATTGCTAATTATGAAATGAAAAATGTTTAATGTG

GCCCTGACACTAAATTGTAAACTGTTTTTTAGTAATAAGAATTTCAATAGCTTCTCTGAA

AGAAGATGTCTCTGAGAGAGTAATATTTGACAGGTTCAGTGTATTTAAAGACTTATAATG

TAAAGCAGAGATGTAACTAGAGAAACCTAGATATTGATGTCAACAAACTAAGGGTGCATG

GAAAATGTGAAAGACTTTAAGAGTGGGTGACCCTGCCTACCAACACAATTCAATCCATGT

TTGAGGCTTTTTTTCATTAGCCTAATAGTGAAGTCAGTGGCGTAAGGCCCCCTTGTTTAG

CACTCCTAAGGGTCCCTAATGATGGATAATTGTATTGGGCTCTTCATGCTCTGGGGCCCT

GGGTTTAGCTAGTGAGTGCTCATAGCAGTTGGCTGGGCAAGGTTAGAAAGCAATGGTTCT

GTGCAGACATTTGCATTTAATTGACCAATATTTCAAATCGTGTGTTACACAGGAATCATA

ACCTAATCAGCAGTTGTTTTTAATAAACATTGCATCTTGGTCGACGTAATATTGTTATGG

ACTGTCTGTGAAACCATGTGAATCTAAACTCTTAAAAATGCCTGCCTCTCCTGTCCTTGC

TAAATATAAATTTGTTTTCTCAATTAGGCG

GCCCTGACACTAAATTGTAAACTGTTTTTTAGTAATAAGAATTTCAATAGCTTCTCTGAA

AGAAGATGTCTCTGAGAGAGTAATATTTGACAGGTTCAGTGTATTTAAAGACTTATAATG

TAAAGCAGAGATGTAACTAGAGAAACCTAGATATTGATGTCAACAAACTAAGGGTGCATG

GAAAATGTGAAAGACTTTAAGAGTGGGTGACCCTGCCTACCAACACAATTCAATCCATGT

TTGAGGCTTTTTTTCATTAGCCTAATAGTGAAGTCAGTGGCGTAAGGCCCCCTTGTTTAG

CACTCCTAAGGGTCCCTAATGATGGATAATTGTATTGGGCTCTTCATGCTCTGGGGCCCT

GGGTTTAGCTAGTGAGTGCTCATAGCAGTTGGCTGGGCAAGGTTAGAAAGCAATGGTTCT

GTGCAGACATTTGCATTTAATTGACCAATATTTCAAATCGTGTGTTACACAGGAATCATA

ACCTAATCAGCAGTTGTTTTTAATAAACATTGCATCTTGGTCGACGTAATATTGTTATGG

ACTGTCTGTGAAACCATGTGAATCTAAACTCTTAAAAATGCCTGCCTCTCCTGTCCTTGC

TAAATATAAATTTGTTTTCTCAATTAGGCG3’

CONCLUSION

From data to data it appears that Echinodermata possesses a sophisticated immune system. We recall the existence of B lymphocytes, T lymphocytes with the sea star as model of study, the IPA (Invertebrate Primitive Antibody) we meet in Asterids, Ophuirids, Crinoïds, the Igkappa genes, in these last ones such as Fag gene, Fc receptor gene, Cr gene, at last MHC class I, class II genes, all that is disturbing for classic scientifics, in 2019.

1.       Leclerc M (2019) Evidence of MHC class I and class II genes in Echinodermata. Cell Immunol (in press).

2.       Leclerc M (2019) CRP gene in an invertebrate: Ophiocomina nigra (Echinodermata). Gen Mol Med.

3.       Leclerc M, Letourneur F, Davoult D, Jolly A, de la Grange P (2018) Evidence of immune genes in the crinoid: Antedon bifida evidence of A. bifida Ig-kappa gene, Fc receptor gene. Int J Vaccine Res 3: 1-2.

4.       Leclerc M, Kresdorn N (2016) Evidence of Fab fragment gene in an invertebrate: The sea star Asterias Rubens. EC Microbiology 3: 539-541.

5.       Grabher MG, Haas BJ, Yassour M, Levin JZ, Thompson DA, et al. (2011) Full-length transcriptome assembly from RNA-Seq data without a reference genome. Nat Biotechnol 29: 644-652.

6.       Altschul SF, Gish W, Miller W, Myers EW, Lipman DJ (1990) Basic local alignment search tool. J Mol Biol 215: 403-410.