Abstract Detail

Hybrids and Hybridization

McAssey, Edward [1], Davidson, Toshiko [2], Tenorio, Mark [2], Heyduk, Karolina [3].

Cyto-nuclear interactions in the homoploid hybrid species Yucca gloriosa .

Genes in the nuclear genome can encode proteins that function in either the chloroplast or mitochondria. These nuclear encoded organellar proteins must interact with organellar encoded proteins to carry out complex biochemical processes, including photosynthesis, oxidative phosphorylation, transcription, translation, and DNA repair. Natural systems in which hybrids are routinely created set up a scenario to test whether these cyto-nuclear interactions are maintained or disrupted post-hybridization. Yucca gloriosa (Asparagaceae) is a homoploid hybrid species formed between Y. aloifolia and Y. filamentosa. The parental species vary for a number of traits including photosynthesis (Y. aloifolia is CAM; Y. gloriosa is C3). As Y. aloifolia is usually the maternal parent (and therefore the source of the organellar genomes) we used the Yucca hybrid system to test whether Y. gloriosa nuclear encoded organellar proteins show any bias in the retention of parental sequences. We used whole genome sequencing data from both parents and the hybrid to assess whether Y. gloriosa’s nuclear encoded organellar targeting genes tend to be from one, or both, parental species. We identified all fixed polymorphisms between the parents, and then subsequently characterized those sites in the hybrid. We found a surprising amount of fixed heterozygous positions in the hybrid species (24 hybrid individuals analyzed) both in the organellar targeting genes as well as genes having no role in the organelles. This suggests that either Y. gloriosa has a very recent origin, or that there may be some form of selection to retain parental haplotypes within the hybrid genome. To further uncover the functional relevance of this heterozygosity, we used RNA-seq to assess allele specific expression and whether it may play a role in Y. gloriosa’s unique hybrid genome and physiology.

1 - University of Hawai'i at Manoa, School of Life Sciences, LSB 212, Honolulu, HI, 96822, USA
2 - University of Hawai'i at Mānoa, School of Life Sciences, Honolulu, HI, 96822, USA
3 - University Of Hawai'i, School Of Life Sciences, 1800 East-West Road, Honolulu, HI, 96822, United States

Keywords:
hybridization
Yucca
genomics
organelle
genetic diversity.

Presentation Type: Oral Paper
Session: HH1, Hybrids and Hybridization I
Location: /
Date: Wednesday, July 21st, 2021
Time: 11:45 AM(EDT)
Number: HH1008
Abstract ID:644
Candidate for Awards:Margaret Menzel Award