Abstract Detail

Comparative Genomics/Transcriptomics

Olson, Matt [1], Sanderson, Brian [2], Hu, Nan [3], Guo, Minghao [3], Feng, Guanqiao [3], DiFazio, Stephen [4].

Diverse Sex Chromosomes in the Salicaceae.

Dioecy (separate male and female sexes) occurs in only 6% of all plant species and has been estimated to have evolved as many as 5000 times independently from hermaphroditic ancestors. Because many dioecious lineages contain few species, patterns of the movement of sex chromosomes, which is common in some animal lineages, have rarely been studied in plants. The genus Salix(willows) includes ~400 dioecious species, with a single origin of dioecy and homomorphic sex chromosomes. Until recently, sex chromosomes have been mapped in only subgenus Vetrix,where it is located on chromosome 15 and has ZW heterogamety. Here we report on our efforts to map sex chromosomes in a wide diversity of Salix species using sequence capture marker methods. We discovered that both Salix nigra(subg. Protitea) and S. exigua (subg. Longifoliae)have novel sex chromosomes compared to species in subg. Vetrix. The S. nigrasex chromosome is likely located on a different chromosome than S. purpureaand is XY, whereas the S. exiguasex chromosome is in the same location as in subg.Vetrix but is XY instead of ZW. We also found that multiple species in subgenus Chamaetia have a similar genomic location of the sex determination region as is found in species in subgenus Vetrix. We interpret these results with reference to a newly-developed 300+ gene phylogeny of the willows and theory regarding predicted influences of switching between sex chromosomes and autosomes on regional nucleotide diversity.

1 - Texas Tech University, Biological Sciences, Lubbock, TX, 79409, USA
2 - Purdue University, Botany and Plant Pathology, West Lafayette, IN, 47907, USA
3 - Texas Tech University, Biological Sciences
4 - West Virginia University, Department of Biology, Morgantown, WV, 26506, USA

Keywords:
Sex Chromosomes
Salicaceae
Dioecy.

Presentation Type: Oral Paper
Session: CG2, Comparative Genetics/Genomics II
Location: Tucson I/Starr Pass
Date: Tuesday, July 30th, 2019
Time: 2:00 PM
Number: CG2002
Abstract ID:278
Candidate for Awards:Margaret Menzel Award