Name: Alonso P

Biodeserts supervisors: Boratyński Z

Title: Genomic differences between desert specialist rodents

Institution: International University Menéndez Pelayo (UIMP), Spain

Status: Completed

 

Abstract

Rodents are among the best desert-adapted group of vertebrates. In North Africa, two species of the genus Jaculus (Rodentia: Dipodidae) occur throughout the Sahara and Sahel regions. Until recently they were both considered as conspecific under the name Jaculus jaculus (Linnaeus 1758), however, it is known that they are well differentiated and overlapping in their distributions. It is also known that they segregate their habitat at substrate level, with one species showing preference for the sandy and another for the rocky substrate. Despite being able to clearly separate the two species, previous studies failed to find any geographical structure on any of the two species. To study the system in more detail, one Genotyping-by-Sequencing (GBS) plate was sequenced. Single nucleotide polymorphisms (SNPs) were called from Illumina reads based on an available reference genome to finally produce a dataset of 9.791 sites. Different population genomics tools were applied, such as ADMIXTURE and PCA analysis to explore how genomic variation is distributed in both species. Our analyses confirm the separation among these two range-overlapping species. We also found that despite their great ecological and morphological similarities, there is not geneflow among them. Even with our extensive genomic sampling it was not possible to clarify the genetic structure of any of the two species in the area studied. Finally, FST outlier distribution was explored to find regions of the genome where they occur more frequently, as an indicator of selection, however, no clear pattern was revealed.