AUTHOR=Pushkova Elena N. , Krasnov George S. , Lakunina Valentina A. , Novakovskiy Roman O. , Povkhova Liubov V. , Dvorianinova Ekaterina M. , Beniaminov Artemy D. , Fedorova Maria S. , Snezhkina Anastasiya V. , Kudryavtseva Anna V. , Dmitriev Alexey A. , Melnikova Nataliya V. 

TITLE=Genome and Transcriptome Sequencing of Populus × sibirica Identified Sex-Associated Allele-Specific Expression of the CLC Gene

JOURNAL=Frontiers in Genetics

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2021.676935

DOI=10.3389/fgene.2021.676935

ISSN=1664-8021

ABSTRACT=<p>Transcriptome sequencing of leaves, catkin axes, and flowers from male and female trees of <italic>Populus</italic> × <italic>sibirica</italic> and genome sequencing of the same plants were performed for the first time. The availability of both genome and transcriptome sequencing data enabled the identification of allele-specific expression. Such an analysis was performed for genes from the sex-determining region (SDR). <italic>P.</italic> × <italic>sibirica</italic> is an intersectional hybrid between species from sections <italic>Aigeiros</italic> (<italic>Populus nigra</italic>) and <italic>Tacamahaca</italic> (<italic>Populus laurifolia</italic>, <italic>Populus suaveolens</italic>, or <italic>Populus</italic> × <italic>moskoviensis</italic>); therefore, a significant number of heterozygous polymorphisms were identified in the SDR that allowed us to distinguish between alleles. In the SDR, both allelic variants of the <italic>TCP</italic> (T-complex protein 1 subunit gamma), <italic>CLC</italic> (Chloride channel protein CLC-c), and <italic>MET1</italic> (DNA-methyltransferase 1) genes were expressed in females, while in males, two allelic variants were expressed for <italic>TCP</italic> and <italic>MET1</italic> but only one allelic variant prevailed for <italic>CLC</italic>. Targeted sequencing of <italic>TCP</italic>, <italic>CLC</italic>, and <italic>MET1</italic> regions on a representative set of trees confirmed the sex-associated allele-specific expression of the <italic>CLC</italic> gene in generative and vegetative tissues of <italic>P.</italic> × <italic>sibirica</italic>. Our study brings new knowledge on sex-associated differences in <italic>Populus</italic> species.</p>