Population Genomics

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     The Family Macrouridae, or the grenadiers, is a large and diverse family of fishes that inhabit the world's oceans from the continental slopes to the abyssal plains. As important members of bottom-dwelling fish communities, grenadiers are some of the most abundant demersal fishes in the North Atlantic Ocean. Some, such as Coryphaenoides rupestris, are targeted by commercial fisheries but don't reach sexual maturity until 14 years of age, making them particularly vulnerable to over exploitation.

     To investigate how genetic diversity is spatially divided, and what processes or factors impact gene flow we are conducting population genomic studies on two focal species: C. rupestris and C. brevibarbis. These species have overlapping ranges in the North Atlantic, but the former is found at shallower depths than the latter. Using restriction associated DNA sequencing (RADSeq) methods (Peterson et al. 2012) we are developing 1000s of loci in each species to detect population structure, to calculate migration rates and to identify regions of the genome under local selection. With these results we will test hypotheses concerning how depth and other physical characteristics such as ocean currents and geographic distance influence gene flow and drive evolution. 

References
Peterson BK, Weber JN, Kay EH et al. (2012) Double digest RADseq: an inexpensive method for de novo SNP discovery
and genotyping in model and non-model species. PloS ONE, 7, e37135.
White TA, Stamford J, Hoelzel AR (2010) Local selection and population structure in a deep-sea fish, the roundnose
grenadier (Coryphaenoides rupestris). Mol. Ecol. 19, 216-226.
White TA, Fotherby H, Hoelzel AR (2011) Comparative assessment of population genetics and demographic history of two
congeneric deep sea fish species living at different depths. Mar. Ecol. Prog. Series 434, 155-164.