Primary hepatic pregnancy.

Abstract

<h3>Abstract</h3> Plant evolution has been a complex process involving hybridization and polyploidization making understanding the origin and evolution of a plant’s genome challenging even once a published genome is available. The oilseed crop, <i>Camelina sativa</i> (<i>Brassicaceae)</i>, has a fully sequenced allohexaploid genome with three unknown ancestors. To better understand which extant species best represent the ancestral genomes that contributed to <i>C. sativa</i>’s formation, we sequenced and assembled chromosome level draft genomes for four diploid members of <i>Camelina</i>: <i>C. neglecta C. hispida</i> var. <i>hispida</i>, <i>C. hispida</i> var. <i>grandiflora</i> and C. <i>laxa</i> using long and short read data scaffolded with proximity data. We then conducted phylogenetic analyses on regions of synteny and on genes described for <i>Arabidopsis thaliana,</i> from across each nuclear genome and the chloroplasts to examine evolutionary relationships within <i>Camelina</i> and <i>Camelineae</i>. We conclude that <i>C. neglecta</i> is closely related to <i>C. sativa</i>’s sub-genome 1 and that <i>C. hispida</i> var. <i>hispida</i> and <i>C. hispida</i> var. <i>grandiflora</i> are most closely related to <i>C. sativa</i>’s sub-genome 3. Further, the abundance and density of transposable elements, specifically <i>Helitrons</i>, suggest that the progenitor genome that contributed <i>C. sativa</i>’s sub-genome 3 maybe more similar to the genome of <i>C. hispida</i> var. <i>hispida</i> than that of <i>C. hispida</i> var. <i>grandiflora.</i> These diploid genomes show few structural differences when compared to <i>C. sativa</i>’s genome indicating little change to chromosome structure following allopolyploidization. This work also indicates that <i>C. neglecta</i> and <i>C. hispida</i> are important resources for understanding the genetics of <i>C. sativa</i> and potential resources for crop improvement.